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Sample records for inhibit microbial growth

  1. A novel process-based model of microbial growth: self-inhibition in Saccharomyces cerevisiae aerobic fed-batch cultures.

    Science.gov (United States)

    Mazzoleni, Stefano; Landi, Carmine; Cartenì, Fabrizio; de Alteriis, Elisabetta; Giannino, Francesco; Paciello, Lucia; Parascandola, Palma

    2015-07-30

    Microbial population dynamics in bioreactors depend on both nutrients availability and changes in the growth environment. Research is still ongoing on the optimization of bioreactor yields focusing on the increase of the maximum achievable cell density. A new process-based model is proposed to describe the aerobic growth of Saccharomyces cerevisiae cultured on glucose as carbon and energy source. The model considers the main metabolic routes of glucose assimilation (fermentation to ethanol and respiration) and the occurrence of inhibition due to the accumulation of both ethanol and other self-produced toxic compounds in the medium. Model simulations reproduced data from classic and new experiments of yeast growth in batch and fed-batch cultures. Model and experimental results showed that the growth decline observed in prolonged fed-batch cultures had to be ascribed to self-produced inhibitory compounds other than ethanol. The presented results clarify the dynamics of microbial growth under different feeding conditions and highlight the relevance of the negative feedback by self-produced inhibitory compounds on the maximum cell densities achieved in a bioreactor.

  2. Effect of dietary olive leaves and rosemary on microbial growth and ...

    African Journals Online (AJOL)

    Effect of dietary olive leaves and rosemary on microbial growth and lipid oxidation of turkey breast during refrigerated storage. ... During this period olive leaves were more effective in inhibiting bacterial growth than rosemary. Keywords: Antioxidant additives, α-tocopherol, turkey meat, herbs, spices, meat quality ...

  3. Inhibition of growth and mycotoxins formation in moulds by marine ...

    African Journals Online (AJOL)

    ... extracts (chloroform, hexane and methanol) had no activity on the microbial growth. Mycotoxins formation in Aspergillus flavus was inhibited by the ethanolic extracts at the concentration of 5%. Key Words: Algae, antimicrobial, minimal inhibitory concentration, moulds. African Journal of Biotechnology Vol.3(1) 2004: 71-75 ...

  4. Equol inhibits growth, induces atresia, and inhibits steroidogenesis of mouse antral follicles in vitro

    International Nuclear Information System (INIS)

    Mahalingam, Sharada; Gao, Liying; Gonnering, Marni; Helferich, William; Flaws, Jodi A.

    2016-01-01

    Equol is a non-steroidal estrogen metabolite produced by microbial conversion of daidzein, a major soy isoflavone, in the gut of some humans and many animal species. Isoflavones and their metabolites can affect endogenous estradiol production, action, and metabolism, potentially influencing ovarian follicle function. However, no studies have examined the effects of equol on intact ovarian antral follicles, which are responsible for sex steroid synthesis and further development into ovulatory follicles. Thus, the present study tested the hypothesis that equol inhibits antral follicle growth, increases follicle atresia, and inhibits steroidogenesis in the adult mouse ovary. To test this hypothesis, antral follicles isolated from adult CD-1 mice were cultured with vehicle control (dimethyl sulfoxide; DMSO) or equol (600 nM, 6 μM, 36 μM, and 100 μM) for 48 and 96 h. Every 24 h, follicle diameters were measured to monitor growth. At 48 and 96 h, the culture medium was subjected to measurement of hormone levels, and the cultured follicles were subjected to gene expression analysis. Additionally, follicles were histologically evaluated for signs of atresia after 96 h of culture. The results indicate that equol (100 μM) inhibited follicle growth, altered the mRNA levels of bcl2-associated X protein and B cell leukemia/lymphoma 2, and induced follicle atresia. Further, equol decreased the levels of estradiol, testosterone, androstenedione, and progesterone, and it decreased mRNA levels of cholesterol side-chain cleavage, steroid 17-α-hydroxalase, and aromatase. Collectively, these data indicate that equol inhibits growth, increases atresia, and inhibits steroidogenesis of cultured mouse antral follicles. - Highlights: • Equol exposure inhibits antral follicle growth. • Equol exposure increases follicle atresia. • Equol exposure inhibits sex steroid hormone levels. • Equol exposure inhibits mRNA levels of certain steroidogenic enzymes.

  5. Equol inhibits growth, induces atresia, and inhibits steroidogenesis of mouse antral follicles in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Mahalingam, Sharada, E-mail: mahalin2@illinois.edu [Department of Comparative Biosciences, College of Veterinary Medicine, University of Illinois, 2001 S. Lincoln Ave, Urbana, IL 61802 (United States); Gao, Liying, E-mail: lgao@uiuc.edu [Department of Comparative Biosciences, College of Veterinary Medicine, University of Illinois, 2001 S. Lincoln Ave, Urbana, IL 61802 (United States); Gonnering, Marni, E-mail: mgonne2@illinois.edu [Department of Comparative Biosciences, College of Veterinary Medicine, University of Illinois, 2001 S. Lincoln Ave, Urbana, IL 61802 (United States); Helferich, William, E-mail: helferic@illinois.edu [Department of Food Science and Human Nutrition, University of Illinois, 905 S. Goodwin, Urbana, IL 61801 (United States); Flaws, Jodi A., E-mail: jflaws@illinois.edu [Department of Comparative Biosciences, College of Veterinary Medicine, University of Illinois, 2001 S. Lincoln Ave, Urbana, IL 61802 (United States)

    2016-03-15

    Equol is a non-steroidal estrogen metabolite produced by microbial conversion of daidzein, a major soy isoflavone, in the gut of some humans and many animal species. Isoflavones and their metabolites can affect endogenous estradiol production, action, and metabolism, potentially influencing ovarian follicle function. However, no studies have examined the effects of equol on intact ovarian antral follicles, which are responsible for sex steroid synthesis and further development into ovulatory follicles. Thus, the present study tested the hypothesis that equol inhibits antral follicle growth, increases follicle atresia, and inhibits steroidogenesis in the adult mouse ovary. To test this hypothesis, antral follicles isolated from adult CD-1 mice were cultured with vehicle control (dimethyl sulfoxide; DMSO) or equol (600 nM, 6 μM, 36 μM, and 100 μM) for 48 and 96 h. Every 24 h, follicle diameters were measured to monitor growth. At 48 and 96 h, the culture medium was subjected to measurement of hormone levels, and the cultured follicles were subjected to gene expression analysis. Additionally, follicles were histologically evaluated for signs of atresia after 96 h of culture. The results indicate that equol (100 μM) inhibited follicle growth, altered the mRNA levels of bcl2-associated X protein and B cell leukemia/lymphoma 2, and induced follicle atresia. Further, equol decreased the levels of estradiol, testosterone, androstenedione, and progesterone, and it decreased mRNA levels of cholesterol side-chain cleavage, steroid 17-α-hydroxalase, and aromatase. Collectively, these data indicate that equol inhibits growth, increases atresia, and inhibits steroidogenesis of cultured mouse antral follicles. - Highlights: • Equol exposure inhibits antral follicle growth. • Equol exposure increases follicle atresia. • Equol exposure inhibits sex steroid hormone levels. • Equol exposure inhibits mRNA levels of certain steroidogenic enzymes.

  6. 21 CFR 866.2560 - Microbial growth monitor.

    Science.gov (United States)

    2010-04-01

    ...) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology Devices § 866.2560 Microbial growth monitor. (a) Identification. A microbial growth monitor is a device intended for medical purposes that...

  7. Understanding the performance of sulfate reducing bacteria based packed bed reactor by growth kinetics study and microbial profiling.

    Science.gov (United States)

    Dev, Subhabrata; Roy, Shantonu; Bhattacharya, Jayanta

    2016-07-15

    A novel marine waste extract (MWE) as alternative nitrogen source was explored for the growth of sulfate reducing bacteria (SRB). Variation of sulfate and nitrogen (MWE) showed that SRB growth follows an uncompetitive inhibition model. The maximum specific growth rates (μmax) of 0.085 and 0.124 h(-1) and inhibition constants (Ki) of 56 and 4.6 g/L were observed under optimized sulfate and MWE concentrations, respectively. The kinetic data shows that MWE improves the microbial growth by 27%. The packed bed bioreactor (PBR) under optimized sulfate and MWE regime showed sulfate removal efficiency of 62-66% and metals removal efficiency of 66-75% on using mine wastewater. The microbial community analysis using DGGE showed dominance of SRB (87-89%). The study indicated the optimum dosing of sulfate and cheap organic nitrogen to promote the growth of SRB over other bacteria. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Production of biosurfactant from Bacillus licheniformis for microbial enhanced oil recovery and inhibition the growth of sulfate reducing bacteria

    Directory of Open Access Journals (Sweden)

    H.S. El-Sheshtawy

    2015-06-01

    Full Text Available In this study, the bacterium Bacillus licheniformis has been isolated from oil reservoir; the ability of this bacterium to produce a biosurfactant was detected. Surface properties of the produced biosurfactant were confirmed by determining the emulsification power as well as surface and interfacial tension. The crude biosurfactant has been extracted from supernatant culture growth, and the yield of crude biosurfactant was about 1 g/l. Also, chemical structure of the produced biosurfactant was confirmed using FTIR analysis. Results revealed that, the emulsification power has been increased up to 96% and the surface tension decreased from 72 of distilled water to 36 mN/m after 72 h of incubation. The potential application of this bacterial species in microbial-enhanced oil recovery (MEOR was investigated. The percent of oil recovery was 16.6% upon application in a sand pack column designed to stimulate an oil recovery. It also showed antimicrobial activity against the growth of different strains of SRB (sulfate reducing bacteria. Results revealed that a complete inhibition of SRB growth using 1.0% crude biosurfactant is achieved after 3 h.

  9. Mathematical modeling of microbial growth in milk

    Directory of Open Access Journals (Sweden)

    Jhony Tiago Teleken

    2011-12-01

    Full Text Available A mathematical model to predict microbial growth in milk was developed and analyzed. The model consists of a system of two differential equations of first order. The equations are based on physical hypotheses of population growth. The model was applied to five different sets of data of microbial growth in dairy products selected from Combase, which is the most important database in the area with thousands of datasets from around the world, and the results showed a good fit. In addition, the model provides equations for the evaluation of the maximum specific growth rate and the duration of the lag phase which may provide useful information about microbial growth.

  10. The effect of antibrowning agents on inhibition of potato browning, volatile organic compound profile, and microbial inhibition.

    Science.gov (United States)

    Mosneaguta, Ruslan; Alvarez, Valente; Barringer, Sheryl A

    2012-11-01

    Burbank and Norkotah potato slices were dipped into 3% sodium acid sulfate (SAS), citric acid (CA), sodium erythorbate (SE), malic acid (MA), sodium acid pyrophosphate (SAPP), or a combination of SAS-CA-SE. Browning by polyphenol oxidase (PPO) obtained from potato extract with 0.04 to 0.016 g/mL of antibrowning solutions at pH 2.0 to 6.9 were measured by UV-Vis spectroscopy. The color of slices dipped in antibrowning solutions at pHs 2 to 7 and stored at 4 °C for 15 d was measured every 5 d by colorimeter. Headspace analysis of volatiles in raw and cooked potato samples was performed by selected ion flow tube mass spectrometer (SIFT-MS) and soft independent modelling by class analogy (SIMCA) analysis of the calculated odor activity values (OAV) determined interclass distances. Microbial growth was measured at 15 d. At unadjusted pHs (1.1 to 7.1), the PPO browning of the control and samples with SAPP was not significantly different, SAS, CA, and MA produced some inhibition and SE and SAS-CA-SE prevented browning. At pH 5 to 7, only SE and SAS-CA-SE were effective browning inhibitors. Based on the color of potato slices, SE was the most effective at pH 2 to 7, but SAS was most effective at unadjusted pH. Cooking increased volatile levels in the treated potatoes and decreased differences between volatile profiles. Differences between cooked samples may not be noticeable by the consumer because volatiles with high discriminating powers have low OAVs. SAS, CA, and SAS-CA-SE treatments inhibited microbial growth but SAPP, control, and SE did not, most likely due to pH. Antibrowning agents inhibit polyphenol oxidase, increasing shelf life and consumer acceptability of processed raw potato products by preserving the color. Their effectiveness was shown to be mainly due to a pH effect, except SE, which was not pH dependent. MA, CA, and SAS-CA-SE are better acidulants for inhibition of color change as well as growth of spoilage bacteria, yeast, and mold than SAPP, the

  11. Effect of Nisin's Controlled Release on Microbial Growth as Modeled for Micrococcus luteus.

    Science.gov (United States)

    Balasubramanian, Aishwarya; Lee, Dong Sun; Chikindas, Michael L; Yam, Kit L

    2011-06-01

    The need for safe food products has motivated food scientists and industry to find novel technologies for antimicrobial delivery for improving food safety and quality. Controlled release packaging is a novel technology that uses the package to deliver antimicrobials in a controlled manner and sustain antimicrobial stress on the targeted microorganism over the required shelf life. This work studied the effect of controlled release of nisin to inhibit growth of Micrococcus luteus (a model microorganism) using a computerized syringe pump system to mimic the release of nisin from packaging films which was characterized by an initially fast rate and a slower rate as time progressed. The results show that controlled release of nisin was strikingly more effective than instantly added ("formulated") nisin. While instant addition experiments achieved microbial inhibition only at the beginning, controlled release experiments achieved complete microbial inhibition for a longer time, even when as little as 15% of the amount of nisin was used as compared to instant addition.

  12. Quantum dots conjugated zinc oxide nanosheets: Impeder of microbial growth and biofilm

    Science.gov (United States)

    Patil, Rajendra; Gholap, Haribhau; Warule, Sambhaji; Banpurkar, Arun; Kulkarni, Gauri; Gade, Wasudeo

    2015-01-01

    The grieving problem of the 21st century has been the antimicrobial resistance in pathogenic microorganisms to conventional antibiotics. Therefore, developments of novel antibacterial materials which effectively inhibit or kill such resistant microorganisms have become the need of the hour. In the present study, we communicate the synthesis of quantum dots conjugated zinc oxide nanostructures (ZnO/CdTe) as an impeder of microbial growth and biofilm. The as-synthesized nanostructures were characterized by X-ray diffraction, ultraviolet-visible spectroscopy, photoluminescence spectroscopy, field emission scanning electron microscopy and high resolution transmission electron microscopy. The growth impedance property of ZnO and ZnO/CdTe on Gram positive organism, Bacillus subtilis NCIM 2063 and Gram negative, Escherichia coli NCIM 2931 and biofilm impedance activity in Pseudomonas aeruginosa O1 was found to occur due to photocatalytical action on the cell biofilm surfaces. The impedance in microbial growth and biofilm formation was further supported by ruptured appearances of cells and dettrered biofilm under field emission scanning electron and confocal laser scanning microscope. The ZnO/CdTe nanostructures array synthesized by hydrothermal method has an advantage of low growth temperature, and opportunity to fabricate inexpensive material for nano-biotechnological applications.

  13. Quantitative analysis of the modes of growth inhibition by weak organic acids in Saccharomyces cerevisiae

    NARCIS (Netherlands)

    Ullah, A.; Orij, R.; Brul, S.; Smits, G.J.

    2012-01-01

    Weak organic acids are naturally occurring compounds that are commercially used as preservatives in the food and beverage industries. They extend the shelf life of food products by inhibiting microbial growth. There are a number of theories that explain the antifungal properties of these weak acids,

  14. Microbial Metabolism and Inhibition Studies of Phenobarbital

    African Journals Online (AJOL)

    Erah

    techniques, high performance liquid chromatography (HPLC), mass spectrometry (MS) ... Keywords: Microbial metabolism, Phenobarbital, Inhibition studies, Rhizopus stolonifer, CYP 2C9, .... 24 h of incubation 0.5 ml of drug solution was ... mode, positive: spray voltage, 3.5 KV: ... Rhizopus stolonifer showed an extra peak at.

  15. Inhibition of Microbial Growth by Fatty Amine Catalysts from Polyurethane Foam Test Tube Plugs

    Science.gov (United States)

    Bach, John A.; Wnuk, Richard J.; Martin, Delano G.

    1975-01-01

    When polyurethane foam test tube plugs are autoclaved, they release volatile fatty amines that inhibit the growth of some microorganisms. The chemical structures of these amines were determined by the use of a gas chromatographmass spectrometer. They are catalysts used to produce the foam. The problem of contaminating growth media with toxic substances released from polymeric materials is discussed. PMID:1096816

  16. Radiation-induced sprout and growth inhibition in vegetables with special reference to the susceptibility to microbial attacks and the effect of calcium

    International Nuclear Information System (INIS)

    Skou, J.P.

    1979-03-01

    Experiments have shown ionizing irradiation to be an effective method for sprout and growth inhibition but it is necessary to keep the doses at the absolute minimum in order to avoid unwanted by-effects One of the by-effects is an increased susceptibility to storage rot in potatoes, onions and carrots. This effect is connected with the wounding and bruising caused by digging up and handling as the wound healing process is inhibited simultaneously with the sprout inhibition. Patogens increase tissue permeability during pathogenesis and, as irradiation has an analogous effect on tissues it might facilitate the growth of the pathogens. Irradiation softens the tissue and mobilizes the calcium in the tissue; this may thereby make the tissue more accessible to microbial attack. An external supply of calcium increases the firmness of tissue, reduces tissue permeability, and may compensate for the loss of calcium in irradiated tissue mainly as a result of a surplus of calcium in the wounds. Botrytis cinerea and Sclerotinia sclerotiorum were some of the most wide spread and serious pathogens in carrots, which vegetable were the main object of the studies. Culture filtrates of these fungi had a strong macerating activity on carrot tissues. The effect, which results from activity and interaction of pectolytic enzymes and oxalic acid, could be reduced or nullified by calcium. A diversity of the groups of pectolytic enzymes are widely distributed among organisms and not confined to plant pathogens. Because of this, because there exists pectolytic enzymes for every condition and pectic substances, and because calcium is not very inhibiting to all kinds of pectolytic enzymes it is not to be expected that the protective effect of calcium will always be expressed to the same extent on storage of the products. (author)

  17. Inhibition of microbial growth by spice extracts and their effect of irradiation

    International Nuclear Information System (INIS)

    Ito, Hitoshi; Meixu, G.

    1994-01-01

    The antimicrobial activity of black pepper, rosemary and red pepper has been tested against 12 microorganisms. Alcoholic extracts of these spices were not exhibited strong activity against gram-negative bacteria in laboratory media. The growth of Bacillus subtilis and Clostridium botulinum type A was inhibited by 1% of black pepper, 0.5% rosemary and 0.03% red pepper. A little reduction of antimicrobial activity to B. subtilis was observed on extracts of gamma-irradiated black pepper or rosemary at 10 and 50 kGy. In the case of red pepper, irradiation of 10 or 50 kGy enhanced a little of antimicrobial activity to B. subtilis. Similar effect of irradiation was also observed on the inhibition of aflatoxin production by Aspergillus parasiticus in SL broth. (author)

  18. A novel aromatic oil compound inhibits microbial overgrowth on feet: a case study

    Directory of Open Access Journals (Sweden)

    Misner Bill D

    2007-07-01

    Full Text Available Abstract Background Athlete's Foot (Tinea pedis is a form of ringworm associated with highly contagious yeast-fungi colonies, although they look like bacteria. Foot bacteria overgrowth produces a harmless pungent odor, however, uncontrolled proliferation of yeast-fungi produces small vesicles, fissures, scaling, and maceration with eroded areas between the toes and the plantar surface of the foot, resulting in intense itching, blisters, and cracking. Painful microbial foot infection may prevent athletic participation. Keeping the feet clean and dry with the toenails trimmed reduces the incidence of skin disease of the feet. Wearing sandals in locker and shower rooms prevents intimate contact with the infecting organisms and alleviates most foot-sensitive infections. Enclosing feet in socks and shoes generates a moisture-rich environment that stimulates overgrowth of pungent both aerobic bacteria and infectious yeast-fungi. Suppression of microbial growth may be accomplished by exposing the feet to air to enhance evaporation to reduce moistures' growth-stimulating effect and is often neglected. There is an association between yeast-fungi overgrowths and disabling foot infections. Potent agents virtually exterminate some microbial growth, but the inevitable presence of infection under the nails predicts future infection. Topical antibiotics present a potent approach with the ideal agent being one that removes moisture producing antibacterial-antifungal activity. Severe infection may require costly prescription drugs, salves, and repeated treatment. Methods A 63-y female volunteered to enclose feet in shoes and socks for 48 hours. Aerobic bacteria and yeast-fungi counts were determined by swab sample incubation technique (1 after 48-hours feet enclosure, (2 after washing feet, and (3 after 8-hours socks-shoes exposure to a aromatic oil powder-compound consisting of arrowroot, baking soda, basil oil, tea tree oil, sage oil, and clove oil. Conclusion

  19. Microbial background flora in small-scale cheese production facilities does not inhibit growth and surface attachment of Listeria monocytogenes.

    Science.gov (United States)

    Schirmer, B C T; Heir, E; Møretrø, T; Skaar, I; Langsrud, S

    2013-10-01

    The background microbiota of 5 Norwegian small-scale cheese production sites was examined and the effect of the isolated strains on the growth and survival of Listeria monocytogenes was investigated. Samples were taken from the air, food contact surfaces (storage surfaces, cheese molds, and brine) and noncontact surfaces (floor, drains, and doors) and all isolates were identified by sequencing and morphology (mold). A total of 1,314 isolates were identified and found to belong to 55 bacterial genera, 1 species of yeast, and 6 species of mold. Lactococcus spp. (all of which were Lactococcus lactis), Staphylococcus spp., Microbacterium spp., and Psychrobacter sp. were isolated from all 5 sites and Rhodococcus spp. and Chryseobacterium spp. from 4 sites. Thirty-two genera were only found in 1 out of 5 facilities each. Great variations were observed in the microbial background flora both between the 5 producers, and also within the various production sites. The greatest diversity of bacteria was found in drains and on rubber seals of doors. The flora on cheese storage shelves and in salt brines was less varied. A total of 62 bacterial isolates and 1 yeast isolate were tested for antilisterial activity in an overlay assay and a spot-on-lawn assay, but none showed significant inhibitory effects. Listeria monocytogenes was also co-cultured on ceramic tiles with bacteria dominating in the cheese production plants: Lactococcus lactis, Pseudomonas putida, Staphylococcus equorum, Rhodococcus spp., or Psychrobacter spp. None of the tested isolates altered the survival of L. monocytogenes on ceramic tiles. The conclusion of the study was that no common background flora exists in cheese production environments. None of the tested isolates inhibited the growth of L. monocytogenes. Hence, this study does not support the hypothesis that the natural background flora in cheese production environments inhibits the growth or survival of L. monocytogenes. Copyright © 2013 American

  20. Microbial growth and substrate utilization kinetics | Okpokwasili ...

    African Journals Online (AJOL)

    Microbial growth on and utilization of environmental contaminants as substrates have been studied by many researchers. Most times, substrate utilization results in removal of chemical contaminant, increase in microbial biomass and subsequent biodegradation of the contaminant. These are all aimed at detoxification of the ...

  1. Using growth-based methods to determine direct effects of salinity on soil microbial communities

    Science.gov (United States)

    Rath, Kristin; Rousk, Johannes

    2015-04-01

    measuring the bacterial growth response to added NaCl in a soil suspension. The bacterial community tolerance to salt increased along the salt gradients with higher in situ soil salinity. In samples from the low-saline end of the gradient, bacterial growth rates in the soil suspension showed a clear concentration-response relationship to NaCl resulting in inhibition curves. This relationship gradually changed toward higher salt concentrations. In soil samples from high salinity sites, bacterial growth was no longer inhibited by adding high concentrations of NaCl to the bacterial soil suspension. In fact, adding NaCl even promoted bacterial growth rates. These results show that salinity played an ecologically significant role in shaping communities at the highly saline end of the gradients and provide evidence for a direct salt effect on the microbial community

  2. The role of lactic acid bacteria (Lactobacillus sp yel133) from beef in inhibiting of microbial contaminants on various fillers of starter culture

    Science.gov (United States)

    Yunilas; Mirwandhono, E.

    2018-02-01

    The role of Lactic Acid Bacteria (LAB) on the starter culture can be seen from the ability to grow and suppress the growth of microbial contaminants (fungi). The research aimed to investigate the role of LAB (Lactobacillus sp YEL133) in inhibiting microbial contaminants (fungi) on starter cultures of various fillers. The materials used in this research was Lactobacillus sp YEL133 from beef and various fillers (rice flour, corn starch and wheat flour). The research methods used completely randomized design (CRD) with 3 treatments and 4 replications. The treatments of this research was P1(rice flour), P2 (corn starch) and P3 (wheat flour) that inoculated with Lactobacillus sp YEL133. Parameters which is observed such as: growth of lactic acid bacteria, total microbes and total fungi as microbial contaminants. The results showed that the starter culture with a filler material of rice flour produce lactic acid bacteria and microbes were highly significant (P wheat flour, as well as able to suppress the growth of microbial contaminants (fungi). The conclusion of the research is the use Lactobacillus sp YEL133 can suppress the growth of fungi on the starter culture using rice flour.

  3. Microbial biofilms: biosurfactants as antibiofilm agents.

    Science.gov (United States)

    Banat, Ibrahim M; De Rienzo, Mayri A Díaz; Quinn, Gerry A

    2014-12-01

    Current microbial inhibition strategies based on planktonic bacterial physiology have been known to have limited efficacy on the growth of biofilm communities. This problem can be exacerbated by the emergence of increasingly resistant clinical strains. All aspects of biofilm measurement, monitoring, dispersal, control, and inhibition are becoming issues of increasing importance. Biosurfactants have merited renewed interest in both clinical and hygienic sectors due to their potential to disperse microbial biofilms in addition to many other advantages. The dispersal properties of biosurfactants have been shown to rival those of conventional inhibitory agents against bacterial and yeast biofilms. This makes them suitable candidates for use in new generations of microbial dispersal agents and for use as adjuvants for existing microbial suppression or eradication strategies. In this review, we explore aspects of biofilm characteristics and examine the contribution of biologically derived surface-active agents (biosurfactants) to the disruption or inhibition of microbial biofilms.

  4. New microbial growth factor

    Science.gov (United States)

    Bok, S. H.; Casida, L. E., Jr.

    1977-01-01

    A screening procedure was used to isolate from soil a Penicillium sp., two bacterial isolates, and a Streptomyces sp. that produced a previously unknown microbial growth factor. This factor was an absolute growth requirement for three soil bacteria. The Penicillium sp. and one of the bacteria requiring the factor, an Arthrobacter sp., were selected for more extensive study concerning the production and characteristics of the growth factor. It did not seem to be related to the siderochromes. It was not present in soil extract, rumen fluid, or any other medium component tested. It appears to be a glycoprotein of high molecular weight and has high specific activity. When added to the diets for a meadow-vole mammalian test system, it caused an increased consumption of diet without a concurrent increase in rate of weight gain.

  5. Improved microbial growth inhibition activity of bio-surfactant induced Ag–TiO{sub 2} core shell nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Nithyadevi, D. [Department of Nanoscience and Technology, Bharathiar University, Coimbatore 641 046 (India); Kumar, P. Suresh [Thin Film and Nanomaterials Laboratory, Department of Physics, Bharathiar University, Coimbatore 641 046 (India); Mangalaraj, D., E-mail: dmraj800@yahoo.com [Department of Nanoscience and Technology, Bharathiar University, Coimbatore 641 046 (India); Ponpandian, N.; Viswanathan, C. [Department of Nanoscience and Technology, Bharathiar University, Coimbatore 641 046 (India); Meena, P. [Department of Physics, PSGR Krishnammal college for women, Coimbatore 641 004 (India)

    2015-02-01

    Graphical abstract: - Highlights: • TiO{sub 2} nanoparticles were synthesized by hydrolysis process and Ag nanoparticles were prepared by using hydrazine reduction method. • Ag–TiO{sub 2} core shell nanoparticles were synthesized by reverse micelle method. • Coatings of TiO{sub 2} shell leads to decrease the usage of silver particles and also it reduces the release of silver ions from the matrix. • Optimum ratio of TiO{sub 2} particles: Ag atoms are needed for better antibacterial activity. • Sodium alginate (Bio-copolymer) induced core shell nanoparticles results 100% cell growth inhibition toward Staphylococcus aureus. - Abstract: Surfactant induced silver–titanium dioxide core shell nanoparticles within the size range of 10–50 nm were applied in the antibacterial agent to inhibit the growth of bacterial cells. The single crystalline silver was located in the core part of the composite powder and the titanium dioxide components were uniformly distributed in the shell part. HRTEM and XRD results indicated that silver was completely covered by titanium dioxide and its crystal structure was not affected after being coated by titanium dioxide. The effect of silver–titanium dioxide nanoparticles in the inhibition of bacterial cell growth was studied by means of disk diffusion method. The inhibition zone results reveal that sodium alginate induced silver–titanium dioxide nanoparticles exhibit 100% more antibacterial activity than that with cetyltrimethylbromide or without surfactant. UV–vis spectroscopic analysis showed a large concentration of silver was rapidly released into phosphate buffer solution (PBS) within a period of 1 day, with a much smaller concentration being released after this 1-day period. It was concluded that sodium alginate induced silver–titanium dioxide core shell nanoparticles could enhance long term cell growth inhibition in comparison with cetyltrimethylbromide or without surfactant. The surfactant mediated core shell

  6. Growth Mechanism of Microbial Colonies

    Science.gov (United States)

    Zhu, Minhui; Martini, K. Michael; Kim, Neil H.; Sherer, Nicholas; Lee, Jia Gloria; Kuhlman, Thomas; Goldenfeld, Nigel

    Experiments on nutrient-limited E. coli colonies, growing on agar gel from single cells reveal a power-law distribution of sizes, both during the growth process and in the final stage when growth has ceased. We developed a Python simulation to study the growth mechanism of the bacterial population and thus understand the broad details of the experimental findings. The simulation takes into account nutrient uptake, metabolic function, growth and cell division. Bacteria are modeled in two dimensions as hard circle-capped cylinders with steric interactions and elastic stress dependent growth characteristics. Nutrient is able to diffuse within and between the colonies. The mechanism of microbial colony growth involves reproduction of cells within the colonies and the merging of different colonies. We report results on the dynamic scaling laws and final state size distribution, that capture in semi-quantitative detail the trends observed in experiment. Supported by NSF Grant 0822613.

  7. Impact of warm winters on microbial growth

    Science.gov (United States)

    Birgander, Johanna; Rousk, Johannes; Axel Olsson, Pål

    2014-05-01

    Growth of soil bacteria has an asymmetrical response to higher temperature with a gradual increase with increasing temperatures until an optimum after which a steep decline occurs. In laboratory studies it has been shown that by exposing a soil bacterial community to a temperature above the community's optimum temperature for two months, the bacterial community grows warm-adapted, and the optimum temperature of bacterial growth shifts towards higher temperatures. This result suggests a change in the intrinsic temperature dependence of bacterial growth, as temperature influenced the bacterial growth even though all other factors were kept constant. An intrinsic temperature dependence could be explained by either a change in the bacterial community composition, exchanging less tolerant bacteria towards more tolerant ones, or it could be due to adaptation within the bacteria present. No matter what the shift in temperature tolerance is due to, the shift could have ecosystem scale implications, as winters in northern Europe are getting warmer. To address the question of how microbes and plants are affected by warmer winters, a winter-warming experiment was established in a South Swedish grassland. Results suggest a positive response in microbial growth rate in plots where winter soil temperatures were around 6 °C above ambient. Both bacterial and fungal growth (leucine incorporation, and acetate into ergosterol incorporation, respectively) appeared stimulated, and there are two candidate explanations for these results. Either (i) warming directly influence microbial communities by modulating their temperature adaptation, or (ii) warming indirectly affected the microbial communities via temperature induced changes in bacterial growth conditions. The first explanation is in accordance with what has been shown in laboratory conditions (explained above), where the differences in the intrinsic temperature relationships were examined. To test this explanation the

  8. Effects of Spatial Localization on Microbial Consortia Growth.

    Directory of Open Access Journals (Sweden)

    Michael Venters

    Full Text Available Microbial consortia are commonly observed in natural and synthetic systems, and these consortia frequently result in higher biomass production relative to monocultures. The focus here is on the impact of initial spatial localization and substrate diffusivity on the growth of a model microbial consortium consisting of a producer strain that consumes glucose and produces acetate and a scavenger strain that consumes the acetate. The mathematical model is based on an individual cell model where growth is described by Monod kinetics, and substrate transport is described by a continuum-based, non-equilibrium reaction-diffusion model where convective transport is negligible (e.g., in a biofilm. The first set of results focus on a single producer cell at the center of the domain and surrounded by an initial population of scavenger cells. The impact of the initial population density and substrate diffusivity is examined. A transition is observed from the highest initial density resulting in the greatest cell growth to cell growth being independent of initial density. A high initial density minimizes diffusive transport time and is typically expected to result in the highest growth, but this expected behavior is not predicted in environments with lower diffusivity or larger length scales. When the producer cells are placed on the bottom of the domain with the scavenger cells above in a layered biofilm arrangement, a similar critical transition is observed. For the highest diffusivity values examined, a thin, dense initial scavenger layer is optimal for cell growth. However, for smaller diffusivity values, a thicker, less dense initial scavenger layer provides maximal growth. The overall conclusion is that high density clustering of members of a food chain is optimal under most common transport conditions, but under some slow transport conditions, high density clustering may not be optimal for microbial growth.

  9. Mechanistic model for microbial growth on hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Mallee, F M; Blanch, H W

    1977-12-01

    Based on available information describing the transport and consumption of insoluble alkanes, a mechanistic model is proposed for microbial growth on hydrocarbons. The model describes the atypical growth kinetics observed, and has implications in the design of large scale equipment for single cell protein (SCP) manufacture from hydrocarbons. The model presents a framework for comparison of the previously published experimental kinetic data.

  10. Susceptibility of green and conventional building materials to microbial growth.

    Science.gov (United States)

    Mensah-Attipoe, J; Reponen, T; Salmela, A; Veijalainen, A-M; Pasanen, P

    2015-06-01

    Green building materials are becoming more popular. However, little is known about their ability to support or limit microbial growth. The growth of fungi was evaluated on five building materials. Two green, two conventional building materials and wood as a positive control were selected. The materials were inoculated with Aspergillus versicolor, Cladosporium cladosporioides and Penicillium brevicompactum, in the absence and presence of house dust. Microbial growth was assessed at four different time points by cultivation and determining fungal biomass using the N-acetylhexosaminidase (NAHA) enzyme assay. No clear differences were seen between green and conventional building materials in their susceptibility to support microbial growth. The presence of dust, an external source of nutrients, promoted growth of all the fungal species similarly on green and conventional materials. The results also showed a correlation coefficient ranging from 0.81 to 0.88 between NAHA activity and culturable counts. The results suggest that the growth of microbes on a material surface depends on the availability of organic matter rather than the classification of the material as green or conventional. NAHA activity and culturability correlated well indicating that the two methods used in the experiments gave similar trends for the growth of fungi on material surfaces. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  11. Effect of Microbial inoculation in combating the aluminium toxicity effect on growth of Zea mays.

    Science.gov (United States)

    Arora, P; Singh, G; Tiwari, A

    2017-07-31

    The present study is aimed at improving the aluminium tolerance in maize crop employing the potential of microbial inoculants in conferring resistance to these toxicities via production of certain chelating compounds like siderophores, exopolysachharides and organic acids. Acid soils have now-a-days become one of the key factors for limiting growth of many agriculturally important crops. Aluminium  is one of the major elements present in acid soils and is mainly responsible for toxicity in the soil. This aluminium is rapidly soluble in soil water and hence absorbed by plant roots under conditions where soil pH is below 5. This toxicity leads to severe root growth inhibition, thereby limiting the production of maize crops. It was observed that use of microbial inoculums can be helpful in elimination of these toxic compounds and prevent the inhibition of root growth . It was found that the soils contaminated with aluminium toxicity decreased the root length of maize plant significantly by 65% but Bacillus and Burkholderia inoculation increased this root length significantly by 1.4- folds and 2- folds respectively thereby combating the effect of aluminium toxicity. Aluminium concentration was found maximum in roots of plants which were grown under aluminium stress condition. But this aluminium accumulation decreased ̴ 2-folds when Burkholderia was used as seed inoculants under aluminium stress conditions. Also, at 60mM aluminium accumulation, phosphorus solubilisation in roots was found to be increased upto 30% on Burkholderia inoculation. However, Bacillus inoculation didn't show any significant difference in either of the case. Thus, the inoculation of seeds with Burkholderia isolates could prove to be a boon in sequestering aluminium toxicity in Zea mays.

  12. Quantum dots conjugated zinc oxide nanosheets: Impeder of microbial growth and biofilm

    Energy Technology Data Exchange (ETDEWEB)

    Patil, Rajendra [Department of Biotechnology, Savitribai Phule Pune University, Pune 411007 (India); Gholap, Haribhau, E-mail: haribhau.gholap@fergusson.edu [Department of Physics, Fergusson College, Pune 411004 (India); Warule, Sambhaji [Department of Physics, Nowrosjee Wadia College, Pune 411001 (India); Banpurkar, Arun; Kulkarni, Gauri [Department of Physics, Savitribai Phule Pune University, Pune 411007 (India); Gade, Wasudeo, E-mail: wngade@unipune.ac.in [Department of Biotechnology, Savitribai Phule Pune University, Pune 411007 (India)

    2015-01-30

    Graphical abstract: The visible light upon incident on ZnO/CdTe initiate the phenomenon of photocatalytical impedance of biofilm. - Highlights: • Synthesis of efficient light photocatalyst ZnO/CdTe nanostructures by hydrothermal method. • ZnO/CdTe nanostructures show a good antibacterial activity by action on cell membrane. • ZnO/CdTe nanostructures show a good antibiofilm activity, and also act on the cells inside the biofilm. - Abstract: The grieving problem of the 21st century has been the antimicrobial resistance in pathogenic microorganisms to conventional antibiotics. Therefore, developments of novel antibacterial materials which effectively inhibit or kill such resistant microorganisms have become the need of the hour. In the present study, we communicate the synthesis of quantum dots conjugated zinc oxide nanostructures (ZnO/CdTe) as an impeder of microbial growth and biofilm. The as-synthesized nanostructures were characterized by X-ray diffraction, ultraviolet–visible spectroscopy, photoluminescence spectroscopy, field emission scanning electron microscopy and high resolution transmission electron microscopy. The growth impedance property of ZnO and ZnO/CdTe on Gram positive organism, Bacillus subtilis NCIM 2063 and Gram negative, Escherichia coli NCIM 2931 and biofilm impedance activity in Pseudomonas aeruginosa O1 was found to occur due to photocatalytical action on the cell biofilm surfaces. The impedance in microbial growth and biofilm formation was further supported by ruptured appearances of cells and dettrered biofilm under field emission scanning electron and confocal laser scanning microscope. The ZnO/CdTe nanostructures array synthesized by hydrothermal method has an advantage of low growth temperature, and opportunity to fabricate inexpensive material for nano-biotechnological applications.

  13. Quantum dots conjugated zinc oxide nanosheets: Impeder of microbial growth and biofilm

    International Nuclear Information System (INIS)

    Patil, Rajendra; Gholap, Haribhau; Warule, Sambhaji; Banpurkar, Arun; Kulkarni, Gauri; Gade, Wasudeo

    2015-01-01

    Graphical abstract: The visible light upon incident on ZnO/CdTe initiate the phenomenon of photocatalytical impedance of biofilm. - Highlights: • Synthesis of efficient light photocatalyst ZnO/CdTe nanostructures by hydrothermal method. • ZnO/CdTe nanostructures show a good antibacterial activity by action on cell membrane. • ZnO/CdTe nanostructures show a good antibiofilm activity, and also act on the cells inside the biofilm. - Abstract: The grieving problem of the 21st century has been the antimicrobial resistance in pathogenic microorganisms to conventional antibiotics. Therefore, developments of novel antibacterial materials which effectively inhibit or kill such resistant microorganisms have become the need of the hour. In the present study, we communicate the synthesis of quantum dots conjugated zinc oxide nanostructures (ZnO/CdTe) as an impeder of microbial growth and biofilm. The as-synthesized nanostructures were characterized by X-ray diffraction, ultraviolet–visible spectroscopy, photoluminescence spectroscopy, field emission scanning electron microscopy and high resolution transmission electron microscopy. The growth impedance property of ZnO and ZnO/CdTe on Gram positive organism, Bacillus subtilis NCIM 2063 and Gram negative, Escherichia coli NCIM 2931 and biofilm impedance activity in Pseudomonas aeruginosa O1 was found to occur due to photocatalytical action on the cell biofilm surfaces. The impedance in microbial growth and biofilm formation was further supported by ruptured appearances of cells and dettrered biofilm under field emission scanning electron and confocal laser scanning microscope. The ZnO/CdTe nanostructures array synthesized by hydrothermal method has an advantage of low growth temperature, and opportunity to fabricate inexpensive material for nano-biotechnological applications

  14. Growth and element flux at fine taxonomic resolution in natural microbial communities

    Science.gov (United States)

    Hungate, Bruce; Mau, Rebecca; Schwartz, Egbert; Caporaso, J. Gregory; Dijkstra, Paul; van Gestel, Natasja; Koch, Benjamin J.; Liu, Cindy M.; McHugh, Theresa; Marks, Jane C.; Morrissey, Ember; Price, Lance B.

    2015-04-01

    Microorganisms are the engines of global biogeochemical cycles, driving half of all photosynthesis and nearly all decomposition. Yet, quantifying the rates at which uncultured microbial taxa grow and transform elements in intact and highly diverse natural communities in the environment remains among the most pressing challenges in microbial ecology today. Here, we show how shifts in the density of DNA caused by stable isotope incorporation can be used to estimate the growth rates of individual bacterial taxa in intact soil communities. We found that the distribution of growth rates followed the familiar lognormal distribution observed for the abundances, biomasses, and traits of many organisms. Growth rates of most bacterial taxa increased in response to glucose amendment, though the increase in growth observed for many taxa was larger than could be explained by direct utilization of the added glucose for growth, illustrating that glucose addition indirectly stimulated the utilization of other substrates. Variation in growth rates and phylogenetic distances were quantitatively related, connecting evolutionary history and biogeochemical function in intact soil microbial communities. Our approach has the potential to identify biogeochemically significant taxa in the microbial community and quantify their contributions to element transformations and ecosystem processes.

  15. Microbial growth and quorum sensing antagonist activities of herbal plants extracts.

    Science.gov (United States)

    Al-Hussaini, Reema; Mahasneh, Adel M

    2009-09-03

    Antimicrobial and antiquorum sensing (AQS) activities of fourteen ethanolic extracts of different parts of eight plants were screened against four Gram-positive, five Gram-negative bacteria and four fungi. Depending on the plant part extract used and the test microorganism, variable activities were recorded at 3 mg per disc. Among the Grampositive bacteria tested, for example, activities of Laurus nobilis bark extract ranged between a 9.5 mm inhibition zone against Bacillus subtilis up to a 25 mm one against methicillin resistant Staphylococcus aureus. Staphylococcus aureus and Aspergillus fumigatus were the most susceptible among bacteria and fungi tested towards other plant parts. Of interest is the tangible antifungal activity of a Tecoma capensis flower extract, which is reported for the first time. However, minimum inhibitory concentrations (MIC's) for both bacteria and fungi were relatively high (0.5-3.0 mg). As for antiquorum sensing activity against Chromobacterium violaceum, superior activity (>17 mm QS inhibition) was associated with Sonchus oleraceus and Laurus nobilis extracts and weak to good activity (8-17 mm) was recorded for other plants. In conclusion, results indicate the potential of these plant extracts in treating microbial infections through cell growth inhibition or quorum sensing antagonism, which is reported for the first time, thus validating their medicinal use.

  16. Microbial Growth and Quorum Sensing Antagonist Activities of Herbal Plants Extracts

    Directory of Open Access Journals (Sweden)

    Reema Al-Hussaini

    2009-09-01

    Full Text Available Antimicrobial and antiquorum sensing (AQS activities of fourteen ethanolic extracts of different parts of eight plants were screened against four Gram-positive, five Gram-negative bacteria and four fungi. Depending on the plant part extract used and the test microorganism, variable activities were recorded at 3 mg per disc. Among the Grampositive bacteria tested, for example, activities of Laurus nobilis bark extract ranged between a 9.5 mm inhibition zone against Bacillus subtilis up to a 25 mm one against methicillin resistant Staphylococcus aureus. Staphylococcus aureus and Aspergillus fumigatus were the most susceptible among bacteria and fungi tested towards other plant parts. Of interest is the tangible antifungal activity of a Tecoma capensis flower extract, which is reported for the first time. However, minimum inhibitory concentrations (MIC's for both bacteria and fungi were relatively high (0.5-3.0 mg. As for antiquorum sensing activity against Chromobacterium violaceum, superior activity (>17 mm QS inhibition was associated with Sonchus oleraceus and Laurus nobilis extracts and weak to good activity (8-17 mm was recorded for other plants. In conclusion, results indicate the potential of these plant extracts in treating microbial infections through cell growth inhibition or quorum sensing antagonism, which is reported for the first time, thus validating their medicinal use.

  17. Microbial Growth and Carbon Use Efficiency in the Rhizosphere and Root-Free Soil

    Science.gov (United States)

    Blagodatskaya, Evgenia; Blagodatsky, Sergey; Anderson, Traute-Heidi; Kuzyakov, Yakov

    2014-01-01

    Plant-microbial interactions alter C and N balance in the rhizosphere and affect the microbial carbon use efficiency (CUE)–the fundamental characteristic of microbial metabolism. Estimation of CUE in microbial hotspots with high dynamics of activity and changes of microbial physiological state from dormancy to activity is a challenge in soil microbiology. We analyzed respiratory activity, microbial DNA content and CUE by manipulation the C and nutrients availability in the soil under Beta vulgaris. All measurements were done in root-free and rhizosphere soil under steady-state conditions and during microbial growth induced by addition of glucose. Microorganisms in the rhizosphere and root-free soil differed in their CUE dynamics due to varying time delays between respiration burst and DNA increase. Constant CUE in an exponentially-growing microbial community in rhizosphere demonstrated the balanced growth. In contrast, the CUE in the root-free soil increased more than three times at the end of exponential growth and was 1.5 times higher than in the rhizosphere. Plants alter the dynamics of microbial CUE by balancing the catabolic and anabolic processes, which were decoupled in the root-free soil. The effects of N and C availability on CUE in rhizosphere and root-free soil are discussed. PMID:24722409

  18. Pseudomonas aeruginosa inhibits the growth of Cryptococcus species.

    Science.gov (United States)

    Rella, Antonella; Yang, Mo Wei; Gruber, Jordon; Montagna, Maria Teresa; Luberto, Chiara; Zhang, Yong-Mei; Del Poeta, Maurizio

    2012-06-01

    Pseudomonas aeruginosa is a ubiquitous and opportunistic bacterium that inhibits the growth of different microorganisms, including Gram-positive bacteria and fungi such as Candida spp. and Aspergillus fumigatus. In this study, we investigated the interaction between P. aeruginosa and Cryptococcus spp. We found that P. aeruginosa PA14 and, to a lesser extent, PAO1 significantly inhibited the growth of Cryptococcus spp. The inhibition of growth was observed on solid medium by the visualization of a zone of inhibition of yeast growth and in liquid culture by viable cell counting. Interestingly, such inhibition was only observed when P. aeruginosa and Cryptococcus were co-cultured. Minimal inhibition was observed when cell-cell contact was prevented using a separation membrane, suggesting that cell contact is required for inhibition. Using mutant strains of Pseudomonas quinoline signaling, we showed that P. aeruginosa inhibited the growth of Cryptococcus spp. by producing antifungal molecules pyocyanin, a redox-active phenazine, and 2-heptyl-3,4-dihydroxyquinoline (PQS), an extracellular quorum-sensing signal. Because both P. aeruginosa and Cryptococcus neoformans are commonly found in lung infections of immunocompromised patients, this study may have important implication for the interaction of these microbes in both an ecological and a clinical point of view.

  19. Low concentration of copper inhibits colonization of soil by the arbuscular mycorrhizal fungus Glomus intraradices and radically changes the microbial community structure

    DEFF Research Database (Denmark)

    Hagerberg, David; Manique, Nina; Brandt, Kristian K.

    2011-01-01

    . To avoid indirect effects through the plant, copper was only added to root-free microcosm compartments. [Cu]bio was measured using a Pseudomonas fluorescens biosensor strain. In the range of 0–1.5 μg g−1 [Cu]bio, a log–log linear relationship between added copper and [Cu]bio was found. Microbial...... colonization of the root-free compartment was evaluated by whole-cell fatty acid analysis (WCFA) and amplified rDNA restriction analysis (ARDRA). The WCFA analysis showed that the AM fungus soil colonization was severely inhibited by Cu with a 50% reduction of mycorrhizal growth at 0.26 μg g−1 [Cu......]bio. The growth of other main microbial groups was not significantly affected by copper. However, ARDRA analysis showed a very strong effect of copper on the bacterial community composition probably caused by an increased proportion of Cu-resistant bacteria. Our results suggest that problems with plant yield may...

  20. Application of PCR-denaturing-gradient gel electrophoresis (DGGE) method to examine microbial community structure in asparagus fields with growth inhibition due to continuous cropping.

    Science.gov (United States)

    Urashima, Yasufumi; Sonoda, Takahiro; Fujita, Yuko; Uragami, Atsuko

    2012-01-01

    Growth inhibition due to continuous cropping of asparagus is a major problem; the yield of asparagus in replanted fields is low compared to that in new fields, and missing plants occur among young seedlings. Although soil-borne disease and allelochemicals are considered to be involved in this effect, this is still controversial. We aimed to develop a technique for the biological field diagnosis of growth inhibition due to continuous cropping. Therefore, in this study, fungal community structure and Fusarium community structure in continuously cropped fields of asparagus were analyzed by polymerase chain reaction/denaturing-gradient gel electrophoresis (PCR-DGGE). Soil samples were collected from the Aizu region of Fukushima Prefecture, Japan. Soil samples were taken from both continuously cropped fields of asparagus with growth inhibition and healthy neighboring fields of asparagus. The soil samples were collected from the fields of 5 sets in 2008 and 4 sets in 2009. We were able to distinguish between pathogenic and non-pathogenic Fusarium by using Alfie1 and Alfie2GC as the second PCR primers and PCR-DGGE. Fungal community structure was not greatly involved in the growth inhibition of asparagus due to continuous cropping. By contrast, the band ratios of Fusarium oxysporum f. sp. asparagi in growth-inhibited fields were higher than those in neighboring healthy fields. In addition, there was a positive correlation between the band ratios of Fusarium oxysporum f. sp. asparagi and the ratios of missing asparagus plants. We showed the potential of biological field diagnosis of growth inhibition due to continuous cropping of asparagus using PCR-DGGE.

  1. Microbial reprogramming inhibits Western diet-associated obesity.

    Directory of Open Access Journals (Sweden)

    Theofilos Poutahidis

    Full Text Available A recent epidemiological study showed that eating 'fast food' items such as potato chips increased likelihood of obesity, whereas eating yogurt prevented age-associated weight gain in humans. It was demonstrated previously in animal models of obesity that the immune system plays a critical role in this process. Here we examined human subjects and mouse models consuming Westernized 'fast food' diet, and found CD4(+ T helper (Th17-biased immunity and changes in microbial communities and abdominal fat with obesity after eating the Western chow. In striking contrast, eating probiotic yogurt together with Western chow inhibited age-associated weight gain. We went on to test whether a bacteria found in yogurt may serve to lessen fat pathology by using purified Lactobacillus reuteri ATCC 6475 in drinking water. Surprisingly, we discovered that oral L. reuteri therapy alone was sufficient to change the pro-inflammatory immune cell profile and prevent abdominal fat pathology and age-associated weight gain in mice regardless of their baseline diet. These beneficial microbe effects were transferable into naïve recipient animals by purified CD4(+ T cells alone. Specifically, bacterial effects depended upon active immune tolerance by induction of Foxp3(+ regulatory T cells (Treg and interleukin (Il-10, without significantly changing the gut microbial ecology or reducing ad libitum caloric intake. Our finding that microbial targeting restored CD4(+ T cell balance and yielded significantly leaner animals regardless of their dietary 'fast food' indiscretions suggests population-based approaches for weight management and enhancing public health in industrialized societies.

  2. Solar energy system reduces time taken to inhibit microbial growth in soil

    Energy Technology Data Exchange (ETDEWEB)

    Phitthayarachasak, Thanathep; Thepa, Sirichai; Kongkiattikajorn, Jirasak [Energy Technology Division, School of Energy Environment and Materials, King Mongkut' s University of Technology Thonburi, 126 Prachauthid Road, Tungkru, Bangkok 10140 (Thailand)

    2009-11-15

    This research studied how to reduce the time consumption and to increase and improve the efficiency of the solarization process. The asymmetry compound parabolic concentrator (ACPC) was developed to produce boiling water to be utilized while the solarization process was in operation. This could decrease the time consumed in the solarization process from 4 to 6 weeks to 4 h, with a temperature of approximately 41.25 C at the various depth levels, not exceeding 50 cm. The test to inhibit the growth of Ralstonia solanacearum, the causative agent of wilt in crops leaves, indicated that R. solanacearum was reduced from the total bacterial population of 10.9 x 10{sup 8} colony forming unit/g soil (cfu g{sup -1}) at soil surface to 9.0 x 10{sup 7}, 7.5 x 10{sup 4} and 4.1 x 10{sup 3} cfu g{sup -1} within 1, 2 and 4 h, respectively. (author)

  3. Jasmonic Acid Enhances Al-Induced Root Growth Inhibition.

    Science.gov (United States)

    Yang, Zhong-Bao; He, Chunmei; Ma, Yanqi; Herde, Marco; Ding, Zhaojun

    2017-02-01

    Phytohormones such as ethylene and auxin are involved in the regulation of the aluminum (Al)-induced root growth inhibition. Although jasmonate (JA) has been reported to play a crucial role in the regulation of root growth and development in response to environmental stresses through interplay with ethylene and auxin, its role in the regulation of root growth response to Al stress is not yet known. In an attempt to elucidate the role of JA, we found that exogenous application of JA enhanced the Al-induced root growth inhibition. Furthermore, phenotype analysis with mutants defective in either JA biosynthesis or signaling suggests that JA is involved in the regulation of Al-induced root growth inhibition. The expression of the JA receptor CORONATINE INSENSITIVE1 (COI1) and the key JA signaling regulator MYC2 was up-regulated in response to Al stress in the root tips. This process together with COI1-mediated Al-induced root growth inhibition under Al stress was controlled by ethylene but not auxin. Transcriptomic analysis revealed that many responsive genes under Al stress were regulated by JA signaling. The differential responsive of microtubule organization-related genes between the wild-type and coi1-2 mutant is consistent with the changed depolymerization of cortical microtubules in coi1 under Al stress. In addition, ALMT-mediated malate exudation and thus Al exclusion from roots in response to Al stress was also regulated by COI1-mediated JA signaling. Together, this study suggests that root growth inhibition is regulated by COI1-mediated JA signaling independent from auxin signaling and provides novel insights into the phytohormone-mediated root growth inhibition in response to Al stress. © 2017 American Society of Plant Biologists. All Rights Reserved.

  4. Microbial growth associated with granular activated carbon in a pilot water treatment facility.

    Science.gov (United States)

    Wilcox, D P; Chang, E; Dickson, K L; Johansson, K R

    1983-01-01

    The microbial dynamics associated with granular activated carbon (GAC) in a pilot water treatment plant were investigated over a period of 16 months. Microbial populations were monitored in the influent and effluent waters and on the GAC particles by means of total plate counts and ATP assays. Microbial populations between the influent and effluent waters of the GAC columns generally increased, indicating microbial growth. The dominant genera of microorganisms isolated from interstitial waters and GAC particles were Achromobacter, Acinetobacter, Aeromonas, Alcaligenes, Bacillus, Chromobacterium, Corynebacterium, Micrococcus, Microcyclus, Paracoccus, and Pseudomonas. Coliform bacteria were found in small numbers in the effluents from some of the GAC columns in the later months of the study. Oxidation of influent waters with ozone and maintenance of aerobic conditions on the GAC columns failed to appreciably enhance the microbial growth on GAC. PMID:6625567

  5. DEVELOPMENT OF AN ENVIRONMENTALLY BENIGN MICROBIAL INHIBITOR TO CONTROL INTERNAL PIPELINE CORROSION

    Energy Technology Data Exchange (ETDEWEB)

    Kristine L. Lowe; Bill W. Bogan; Wendy R. Sullivan; Kristine Mila H. Cruz; Brigid M. Lamb; John J. Kilbane II

    2004-07-30

    The overall program objective is to develop and evaluate environmentally benign agents or products that are effective in the prevention, inhibition, and mitigation of microbially influenced corrosion (MIC) in the internal surfaces of metallic natural gas pipelines. The goal is to develop one or more environmentally benign (a.k.a. ''green'') products that can be applied to maintain the structure and dependability of the natural gas infrastructure. Previous testing indicated that the growth, and the metal corrosion caused by pure cultures of sulfate reducing bacteria were inhibited by hexane extracts of some pepper plants. This quarter tests were performed with mixed bacterial cultures obtained from natural gas pipelines. Treatment with the pepper extracts affected the growth and metabolic activity of the microbial consortia. Specifically, the growth and metabolism of sulfate reducing bacteria was inhibited. The demonstration that pepper extracts can inhibit the growth and metabolism of sulfate reducing bacteria in mixed cultures is a significant observation validating a key hypothesis of the project. Future tests to determine the effects of pepper extracts on mature/established biofilms will be performed next.

  6. Conditions for microbial growth in the FILTRA steam absorption tower

    International Nuclear Information System (INIS)

    Nilsson, H.; Roffey, R.

    1983-08-01

    By the appointment of the Southern Sweden Power Supply an experimental study has been carried out in order to evaluate the risk for microbial growth in the planned FILTRA steam absorbtion tower at the nuclear power plant in Barsebaeck. Four modelsystems were supplied with nitrogen atmosphere and a relative humidity of 100, 75, 50 and 25 percent. The fifth system received air and 75 percent relative humidity. Samples were collected and analysed for microbial growth after 1, 2, 4 and 8 months. The amounts of microorganisms and the ATP content was monitored. No measureable growth of any significance could be observed after 8 months in any system. An elementary analyses showed that the level of nitrogen and carbon in the stones was below the limit of detection (<0.3 percent C, <0.2 percent N). (author)

  7. Hydrocarbon fermentation: kinetics of microbial cell growth

    Energy Technology Data Exchange (ETDEWEB)

    Goma, G [Institut National des Sciences Appliquees, Toulouse; Ribot, D

    1978-11-01

    Modeling of microbial growth using nonmiscible substrate is studied when kinetics of substrate dissolution is rate limiting. When the substrate concentration is low, the growth rate is described by an analytical relation that can be identified as a Contois relationship. If the substrate concentration is greater than a critical value S/sub crit/, the potentially useful hydrocarbon S* concentration is described by S* = S/sub crit//(1 + S/sub crit//S). A relationship was found between S/sub crit/ and the biomass concentration X. When X increased, S/sub crit/ decreased. The cell growth rate is related to a relation ..mu.. = ..mu../sub m/(A(X/S/sub crit/)(1 + S/sub crit//S) + 1)/sup -1/. This model describes the evolution of the growth rate when exponential or linear growth occurs, which is related to physico-chemical properties and hydrodynamic fermentation conditions. Experimental data to support the model are presented.

  8. Acoustic and Electrical Property Changes Due to Microbial Growth and Biofilm Formation in Porous Media

    Science.gov (United States)

    A laboratory study was conducted to investigate the effect of microbial growth and biofilm formation on compressional waves, and complex conductivity during stimulated microbial growth. Over the 29 day duration of the experiment, compressional wave amplitudes and arrival times f...

  9. Critical control points for the management of microbial growth in HVAC systems

    NARCIS (Netherlands)

    Gommers, S; Franchimon, F.; Bronswijk, van J.E.M.H.; Strøm-Tejsen, P; Olesen, BW; Wargocki, P; Zukowska, D; Toftum, J

    2008-01-01

    Office buildings with HVAC systems consistently report Sick Building Symptoms that are derived from microbial growth. We used the HACCP methodology to find the main critical control points (CCPs) for microbial management of HVAC systems in temperate climates. Desk research revealed relative humidity

  10. Inhibition of Klebsiella pneumoniae growth by selected Australian plants: natural approaches for the prevention and management of ankylosing spondylitis.

    Science.gov (United States)

    Winnett, V; Sirdaarta, J; White, A; Clarke, F M; Cock, I E

    2017-04-01

    A wide variety of herbal remedies are used in traditional Australian medicine to treat inflammatory disorders, including autoimmune inflammatory diseases. One hundred and six extracts from 40 native Australian plant species traditionally used for the treatment of inflammation and/or to inhibit bacterial growth were investigated for their ability to inhibit the growth of a microbial trigger for ankylosing spondylitis (K. pneumoniae). Eighty-six of the extracts (81.1%) inhibited the growth of K. pneumoniae. The D. leichardtii, Eucalyptus spp., K. flavescens, Leptospermum spp., M. quinquenervia, Petalostigma spp., P. angustifolium, S. spinescens, S. australe, S. forte and Tasmannia spp. extracts were effective K. pneumoniae growth inhibitors, with MIC values generally <1000 µg/mL. The T. lanceolata peppercorn extracts were the most potent growth inhibitors, with MIC values as low as 16 µg/mL. These extracts were examined by non-biased GC-MS headspace analysis and comparison with a compound database. A notable feature was the high relative abundance of the sesquiterpenoids polygodial, guaiol and caryophyllene oxide, and the monoterpenoids linalool, cineole and α-terpineol in the T. lanceolata peppercorn methanolic and aqueous extracts. The extracts with the most potent K. pneumoniae inhibitory activity (including the T. lanceolata peppercorn extracts) were nontoxic in the Artemia nauplii bioassay. The lack of toxicity and the growth inhibitory activity of these extracts against K. pneumoniae indicate their potential for both preventing the onset of ankylosing spondylitis and minimising its symptoms once the disease is established.

  11. Sulindac Sulfide, but Not Sulindac Sulfone, Inhibits Colorectal Cancer Growth

    Directory of Open Access Journals (Sweden)

    Christopher S. Williams

    1999-06-01

    Full Text Available Sulindac sulfide, a metabolite of the nonsteroidal antiinflammatory drug (NSAID sulindac sulfoxide, is effective at reducing tumor burden in both familial adenomatous polyposis patients and in animals with colorectal cancer. Another sulindac sulfoxide metabolite, sulindac sulfone, has been reported to have antitumor properties without inhibiting cyclooxygenase activity. Here we report the effect of sulindac sulfone treatment on the growth of colorectal carcinoma cells. We observed that sulindac sulfide or sulfone treatment of HCA-7 cells led to inhibition of prostaglandin E2 production. Both sulindac sulfide and sulfone inhibited HCA-7 and HCT-116 cell growth in vitro. Sulindac sulfone had no effect on the growth of either HCA-7 or HCT-116 xenografts, whereas the sulfide derivative inhibited HCA-7 growth in vivo. Both sulindac sulfide and sulfone inhibited colon carcinoma cell growth and prostaglandin production in vitro, but sulindac sulfone had no effect on the growth of colon cancer cell xenografts in nude mice.

  12. Counteracting ammonia inhibition during anaerobic digestion by recovery using submersible microbial desalination cell

    DEFF Research Database (Denmark)

    Zhang, Yifeng; Angelidaki, Irini

    2015-01-01

    Ammonia inhibition is one of the most frequent and serious problems in biogas plants. In this study, a novel hybrid system consisting of a submersible microbial desalination cell (SMDC) and a continuous stirred tank reactor (CSTR) was developed for counteracting ammonia inhibition during anaerobic...... digestion (AD) with simultaneous in situ ammonia recovery and electricity production. The SMDC was powered by acetate in a buffer solution, while synthetic ammonia-rich wastewater was used as the feeding of the CSTR. Under continuous operation, ammonia recovery rate of 86 g-N/m2 /day and current density...... of 4.33 A/m2 were achieved at steady-state condition. As a result, 112% extra biogas was produced due to ammonia recovery by the SMDC. High-throughput sequencing showed that ammonia recovery had an impact on the microbial community structures in the SMDC and CSTR. Considering the additional economic...

  13. Spectrum of microbial growth and antimicrobial usage in an ...

    African Journals Online (AJOL)

    white blood cell count, duration of first antibiotic used, length of ICU stay, length of ... the acute disease process, the presence of comorbidities, invasive devices, ... Against this background, this study aimed to look at the microbial growth.

  14. Microbial mineral illization of montmorillonite in low-permeability oil reservoirs for microbial enhanced oil recovery.

    Science.gov (United States)

    Cui, Kai; Sun, Shanshan; Xiao, Meng; Liu, Tongjing; Xu, Quanshu; Dong, Honghong; Wang, Di; Gong, Yejing; Sha, Te; Hou, Jirui; Zhang, Zhongzhi; Fu, Pengcheng

    2018-05-11

    Microbial mineral illization has been investigated for its role in the extraction and recovery of metals from ores. Here we report our application of mineral bioillization for the microbial enhanced oil recovery in low-permeability oil reservoirs. It aimed to reveal the etching mechanism of the four Fe (III)-reducing microbial strains under anaerobic growth conditions on the Ca-montmorillonite. The mineralogical characterization of the Ca-montmorillonite was performed by Fourier transform infrared spectroscopy, X-ray powder diffraction, scanning electron microscopy and energy dispersive spectrometer. Results showed that the microbial strains could efficiently reduce Fe (III) at an optimal rate of 71 %, and alter the crystal lattice structure of the lamella to promote the interlayer cation exchange, and to efficiently inhibit the Ca-montmorillonite swelling at an inhibitory rate of 48.9 %. Importance Microbial mineral illization is ubiquitous in the natural environment. Microbes in low-permeability reservoirs are able to enable the alteration of the structure and phase of the Fe-poor minerals by reducing Fe (III) and inhibiting clay swelling which is still poorly studied. This study aimed to reveal the interaction mechanism between Fe (III)-reducing bacterial strains and Ca-montmorillonite under anaerobic atmosphere, and to investigate the extent and rates of Fe (III) reduction and phase changes with their activities. Application of Fe (III)-reducing bacteria will provide a new way to inhibit clay swelling, to elevate reservoir permeability, and to reduce pore throat resistance after water flooding for enhanced oil recovery in low-permeability reservoirs. Copyright © 2018 American Society for Microbiology.

  15. DEVELOPMENT OF AN ENVIRONMENTALLY BENIGN MICROBIAL INHIBITOR TO CONTROL INTERNAL PIPELINE CORROSION

    Energy Technology Data Exchange (ETDEWEB)

    Bill W. Bogan; Brigid M. Lamb; John J. Kilbane II

    2004-10-30

    The overall program objective is to develop and evaluate environmentally benign agents or products that are effective in the prevention, inhibition, and mitigation of microbially influenced corrosion (MIC) in the internal surfaces of metallic natural gas pipelines. The goal is to develop one or more environmentally benign (a.k.a. ''green'') products that can be applied to maintain the structure and dependability of the natural gas infrastructure. Previous testing indicated that the growth, and the metal corrosion caused by pure cultures of sulfate reducing bacteria were inhibited by hexane extracts of some pepper plants. This quarter tests were performed to determine if chemical compounds other than pepper extracts could inhibit the growth of corrosion-associated microbes and to determine if pepper extracts and other compounds can inhibit corrosion when mature biofilms are present. Several chemical compounds were shown to be capable of inhibiting the growth of corrosion-associated microorganisms, and all of these compounds limited the amount of corrosion caused by mature biofilms to a similar extent. It is difficult to control corrosion caused by mature biofilms, but any compound that disrupts the metabolism of any of the major microbial groups present in corrosion-associated biofilms shows promise in limiting the amount/rate of corrosion.

  16. Carbon stabilization and microbial growth in acidic mine soils after addition of different amendments for soil reclamation

    Science.gov (United States)

    Zornoza, Raúl; Acosta, Jose; Ángeles Muñoz, María; Martínez-Martínez, Silvia; Faz, Ángel; Bååth, Erland

    2016-04-01

    The extreme soil conditions in metalliferous mine soils have a negative influence on soil biological activity and therefore on soil carbon estabilization. Therefore, amendments are used to increase organic carbon content and activate microbial communities. In order to elucidate some of the factors controlling soil organic carbon stabilization in reclaimed acidic mine soils and its interrelationship with microbial growth and community structure, we performed an incubation experiment with four amendments: pig slurry (PS), pig manure (PM) and biochar (BC), applied with and without marble waste (MW; CaCO3). Results showed that PM and BC (alone or together with MW) contributed to an important increment in recalcitrant organic C, C/N ratio and aggregate stability. Bacterial and fungal growths were highly dependent on pH and labile organic C. PS supported the highest microbial growth; applied alone it stimulated fungal growth, and applied with MW it stimulated bacterial growth. BC promoted the lowest microbial growth, especially for fungi, with no significant increase in fungal biomass. MW+BC increased bacterial growth up to values similar to PM and MW+PM, suggesting that part of the biochar was degraded, at least in short-term mainly by bacteria rather than fungi. PM, MW+PS and MW+PM supported the highest microbial biomass and a similar community structure, related with the presence of high organic C and high pH, with immobilization of metals and increased soil quality. BC contributed to improved soil structure, increased recalcitrant organic C, and decreased metal mobility, with low stimulation of microbial growth.

  17. Comparison of Two Mechanistic Microbial Growth Models to Estimate Shelf Life of Perishable Food Package under Dynamic Temperature Conditions

    Directory of Open Access Journals (Sweden)

    Dong Sun Lee

    2014-01-01

    Full Text Available Two mechanistic microbial growth models (Huang’s model and model of Baranyi and Roberts given in differential and integrated equation forms were compared in predicting the microbial growth and shelf life under dynamic temperature storage and distribution conditions. Literatures consistently reporting the microbial growth data under constant and changing temperature conditions were selected to obtain the primary model parameters, set up the secondary models, and apply them to predict the microbial growth and shelf life under fluctuating temperatures. When evaluated by general estimation behavior, bias factor, accuracy factor, and root-mean-square error, Huang’s model was comparable to Baranyi and Roberts’ model in the capability to estimate microbial growth under dynamic temperature conditions. Its simple form of single differential equation incorporating directly the growth rate and lag time may work as an advantage to be used in online shelf life estimation by using the electronic device.

  18. Autophagy contributes to gefitinib-induced glioma cell growth inhibition

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Cheng-Yi [Department of Surgery, Fong-Yuan Hospital, Taichung 420, Taiwan (China); Graduate Institute of Pharmaceutical Science and Technology, Central Taiwan University of Science and Technology, Taichung 406, Taiwan (China); Kuan, Yu-Hsiang [Department of Pharmacology, School of Medicine, Chung Shan Medical University, Taichung 402, Taiwan (China); Department of Pharmacy, Chung Shan Medical University Hospital, Taichung 402, Taiwan (China); Ou, Yen-Chuan; Li, Jian-Ri [Division of Urology, Taichung Veterans General Hospital, Taichung 407, Taiwan (China); Wu, Chih-Cheng [Department of Anesthesiology, Taichung Veterans General Hospital, Taichung 407, Taiwan (China); Department of Financial and Computational Mathematics, Providence University, Taichung 433, Taiwan (China); Pan, Pin-Ho [Department of Pediatrics, Tungs’ Taichung MetroHarbor Hospital, Taichung 435, Taiwan (China); Chen, Wen-Ying [Department of Veterinary Medicine, National Chung Hsing University, Taichung 402, Taiwan (China); Huang, Hsuan-Yi [Department of Surgery, Fong-Yuan Hospital, Taichung 420, Taiwan (China); Chen, Chun-Jung, E-mail: cjchen@vghtc.gov.tw [Department of Medical Research, Taichung Veterans General Hospital, Taichung 407, Taiwan (China); Institute of Biomedical Sciences, National Chung Hsing University, Taichung 402, Taiwan (China); Rong Hsing Research Center for Translational Medicine, National Chung Hsing University, Taichung 402, Taiwan (China); Center for General Education, Tunghai University, Taichung 407, Taiwan (China); Department of Nursing, HungKuang University, Taichung 433, Taiwan (China)

    2014-09-10

    Epidermal growth factor receptor tyrosine kinase inhibitors, including gefitinib, have been evaluated in patients with malignant gliomas. However, the molecular mechanisms involved in gefitinib-mediated anticancer effects against glioma are incompletely understood. In the present study, the cytostatic potential of gefitinib was demonstrated by the inhibition of glioma cell growth, long-term clonogenic survival, and xenograft tumor growth. The cytostatic consequences were accompanied by autophagy, as evidenced by monodansylcadaverine staining of acidic vesicle formation, conversion of microtubule-associated protein-1 light chain 3-II (LC3-II), degradation of p62, punctate pattern of GFP-LC3, and conversion of GFP-LC3 to cleaved-GFP. Autophagy inhibitor 3-methyladenosine and chloroquine and genetic silencing of LC3 or Beclin 1 attenuated gefitinib-induced growth inhibition. Gefitinib-induced autophagy was not accompanied by the disruption of the Akt/mammalian target of rapamycin signaling. Instead, the activation of liver kinase-B1/AMP-activated protein kinase (AMPK) signaling correlated well with the induction of autophagy and growth inhibition caused by gefitinib. Silencing of AMPK suppressed gefitinib-induced autophagy and growth inhibition. The crucial role of AMPK activation in inducing glioma autophagy and growth inhibition was further supported by the actions of AMP mimetic AICAR. Gefitinib was shown to be capable of reducing the proliferation of glioma cells, presumably by autophagic mechanisms involving AMPK activation. - Highlights: • Gefitinib causes cytotoxic and cytostatic effect on glioma. • Gefitinib induces autophagy. • Gefitinib causes cytostatic effect through autophagy. • Gefitinib induces autophagy involving AMPK.

  19. Autophagy contributes to gefitinib-induced glioma cell growth inhibition

    International Nuclear Information System (INIS)

    Chang, Cheng-Yi; Kuan, Yu-Hsiang; Ou, Yen-Chuan; Li, Jian-Ri; Wu, Chih-Cheng; Pan, Pin-Ho; Chen, Wen-Ying; Huang, Hsuan-Yi; Chen, Chun-Jung

    2014-01-01

    Epidermal growth factor receptor tyrosine kinase inhibitors, including gefitinib, have been evaluated in patients with malignant gliomas. However, the molecular mechanisms involved in gefitinib-mediated anticancer effects against glioma are incompletely understood. In the present study, the cytostatic potential of gefitinib was demonstrated by the inhibition of glioma cell growth, long-term clonogenic survival, and xenograft tumor growth. The cytostatic consequences were accompanied by autophagy, as evidenced by monodansylcadaverine staining of acidic vesicle formation, conversion of microtubule-associated protein-1 light chain 3-II (LC3-II), degradation of p62, punctate pattern of GFP-LC3, and conversion of GFP-LC3 to cleaved-GFP. Autophagy inhibitor 3-methyladenosine and chloroquine and genetic silencing of LC3 or Beclin 1 attenuated gefitinib-induced growth inhibition. Gefitinib-induced autophagy was not accompanied by the disruption of the Akt/mammalian target of rapamycin signaling. Instead, the activation of liver kinase-B1/AMP-activated protein kinase (AMPK) signaling correlated well with the induction of autophagy and growth inhibition caused by gefitinib. Silencing of AMPK suppressed gefitinib-induced autophagy and growth inhibition. The crucial role of AMPK activation in inducing glioma autophagy and growth inhibition was further supported by the actions of AMP mimetic AICAR. Gefitinib was shown to be capable of reducing the proliferation of glioma cells, presumably by autophagic mechanisms involving AMPK activation. - Highlights: • Gefitinib causes cytotoxic and cytostatic effect on glioma. • Gefitinib induces autophagy. • Gefitinib causes cytostatic effect through autophagy. • Gefitinib induces autophagy involving AMPK

  20. Prevention of 5-fluorouracil-caused growth inhibition in Sordaria fimicola.

    Science.gov (United States)

    Schoen, H F; Berech, J

    1977-02-01

    Growth (dry weight accumulation) of Sordaria fimicola in standing liquid culture (sucrose-nitrate-salts-vitamins) is inhibited by the presence of 5 muM 5-fluorouracil in the medium. This inhibition is completely prevented by uracil, deoxyuridine, and 5-bromouracil, partly prevented (40 to 90% of growth observed without 5-fluorouracil) by uridine, thymidine, and 5-bromodeoxyuridine, and slightly prevented by trifluorothymine, cytosine, cytidine, deoxycytidine, and 5-methylcytosine (all at 0.5 to 1 mM). Thymidine and thymine riboside were without any apparent effect. Growth is also inhibited by 0.2 mM 6-azauracil, and this inhibition was completely prevented by uracil and uridine, partly prevented by deoxyuridine, 5-bromouracil, cytidine, and 5-methylcytosine, and slightly prevented by thymine, thymidine, 5-bromodeoxyuridine, cytosine, and deoxycytidine. The data suggest that the observed inhibition of growth by 5-fluorouracil is due to inhibition of both ribonucleic acid and deoxyribonucleic acid synthesis. The data also allow inferences concerning pyrimidine interconversions in S. fimicola; i.e., thymine can be anabolized to thymidylic acid without first being demethylated, although demethylation appears to occur also.

  1. Micro-Food Web Structure Shapes Rhizosphere Microbial Communities and Growth in Oak

    Directory of Open Access Journals (Sweden)

    Hazel R. Maboreke

    2018-03-01

    Full Text Available The multitrophic interactions in the rhizosphere impose significant impacts on microbial community structure and function, affecting nutrient mineralisation and consequently plant performance. However, particularly for long-lived plants such as forest trees, the mechanisms by which trophic structure of the micro-food web governs rhizosphere microorganisms are still poorly understood. This study addresses the role of nematodes, as a major component of the soil micro-food web, in influencing the microbial abundance and community structure as well as tree growth. In a greenhouse experiment with Pedunculate Oak seedlings were grown in soil, where the nematode trophic structure was manipulated by altering the proportion of functional groups (i.e., bacterial, fungal, and plant feeders in a full factorial design. The influence on the rhizosphere microbial community, the ectomycorrhizal symbiont Piloderma croceum, and oak growth, was assessed. Soil phospholipid fatty acids were employed to determine changes in the microbial communities. Increased density of singular nematode functional groups showed minor impact by increasing the biomass of single microbial groups (e.g., plant feeders that of Gram-negative bacteria, except fungal feeders, which resulted in a decline of all microorganisms in the soil. In contrast, inoculation of two or three nematode groups promoted microbial biomass and altered the community structure in favour of bacteria, thereby counteracting negative impact of single groups. These findings highlight that the collective action of trophic groups in the soil micro-food web can result in microbial community changes promoting the fitness of the tree, thereby alleviating the negative effects of individual functional groups.

  2. Fluoxetine regulates cell growth inhibition of interferon-α.

    Science.gov (United States)

    Lin, Yu-Min; Yu, Bu-Chin; Chiu, Wen-Tai; Sun, Hung-Yu; Chien, Yu-Chieh; Su, Hui-Chen; Yen, Shu-Yang; Lai, Hsin-Wen; Bai, Chyi-Huey; Young, Kung-Chia; Tsao, Chiung-Wen

    2016-10-01

    Fluoxetine, a well-known anti-depression agent, may act as a chemosensitizer to assist and promote cancer therapy. However, how fluoxetine regulates cellular signaling to enhance cellular responses against tumor cell growth remains unclear. In the present study, addition of fluoxetine promoted growth inhibition of interferon-alpha (IFN-α) in human bladder carcinoma cells but not in normal uroepithelial cells through lessening the IFN-α-induced apoptosis but switching to cause G1 arrest, and maintaining the IFN-α-mediated reduction in G2/M phase. Activations and signal transducer and transactivator (STAT)-1 and peroxisome proliferator-activated receptor alpha (PPAR-α) were involved in this process. Chemical inhibitions of STAT-1 or PPAR-α partially rescued bladder carcinoma cells from IFN-α-mediated growth inhibition via blockades of G1 arrest, cyclin D1 reduction, p53 downregulation and p27 upregulation in the presence of fluoxetine. However, the functions of both proteins were not involved in the control of fluoxetine over apoptosis and maintained the declined G2/M phase of IFN-α. These results indicated that activation of PPAR-α and STAT-1 participated, at least in part, in growth inhibition of IFN-α in the presence of fluoxetine.

  3. Effects of six selected antibiotics on plant growth and soil microbial and enzymatic activities

    International Nuclear Information System (INIS)

    Liu Feng; Ying Guangguo; Tao Ran; Zhao Jianliang; Yang Jifeng; Zhao Lanfeng

    2009-01-01

    The potential impact of six antibiotics (chlortetracycline, tetracycline and tylosin; sulfamethoxazole, sulfamethazine and trimethoprim) on plant growth and soil quality was studied by using seed germination test on filter paper and plant growth test in soil, soil respiration and phosphatase activity tests. The phytotoxic effects varied between the antibiotics and between plant species (sweet oat, rice and cucumber). Rice was most sensitive to sulfamethoxazole with the EC10 value of 0.1 mg/L. The antibiotics tested inhibited soil phosphatase activity during the 22 days' incubation. Significant effects on soil respiration were found for the two sulfonamides (sulfamethoxazole and sulfamethazine) and trimethoprim, whereas little effects were observed for the two tetracyclines and tylosin. The effective concentrations (EC10 values) for soil respiration in the first 2 days were 7 mg/kg for sulfamethoxazole, 13 mg/kg for sulfamethazine and 20 mg/kg for trimethoprim. Antibiotic residues in manure and soils may affect soil microbial and enzyme activities. - Terrestrial ecotoxicological effects of antibiotics are related to their sorption and degradation behavior in soil.

  4. Effects of six selected antibiotics on plant growth and soil microbial and enzymatic activities

    Energy Technology Data Exchange (ETDEWEB)

    Liu Feng [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 511 Kehua Street, Tianhe District, Guangzhou 510640 (China); Ying Guangguo, E-mail: guangguo.ying@gmail.co [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 511 Kehua Street, Tianhe District, Guangzhou 510640 (China); Tao Ran; Zhao Jianliang; Yang Jifeng [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 511 Kehua Street, Tianhe District, Guangzhou 510640 (China); Zhao Lanfeng [College of Resource and Environmental Science, South China Agricultural University, Guangzhou 510642 (China)

    2009-05-15

    The potential impact of six antibiotics (chlortetracycline, tetracycline and tylosin; sulfamethoxazole, sulfamethazine and trimethoprim) on plant growth and soil quality was studied by using seed germination test on filter paper and plant growth test in soil, soil respiration and phosphatase activity tests. The phytotoxic effects varied between the antibiotics and between plant species (sweet oat, rice and cucumber). Rice was most sensitive to sulfamethoxazole with the EC10 value of 0.1 mg/L. The antibiotics tested inhibited soil phosphatase activity during the 22 days' incubation. Significant effects on soil respiration were found for the two sulfonamides (sulfamethoxazole and sulfamethazine) and trimethoprim, whereas little effects were observed for the two tetracyclines and tylosin. The effective concentrations (EC10 values) for soil respiration in the first 2 days were 7 mg/kg for sulfamethoxazole, 13 mg/kg for sulfamethazine and 20 mg/kg for trimethoprim. Antibiotic residues in manure and soils may affect soil microbial and enzyme activities. - Terrestrial ecotoxicological effects of antibiotics are related to their sorption and degradation behavior in soil.

  5. Trade-offs between microbial growth phases lead to frequency-dependent and non-transitive selection.

    Science.gov (United States)

    Manhart, Michael; Adkar, Bharat V; Shakhnovich, Eugene I

    2018-02-14

    Mutations in a microbial population can increase the frequency of a genotype not only by increasing its exponential growth rate, but also by decreasing its lag time or adjusting the yield (resource efficiency). The contribution of multiple life-history traits to selection is a critical question for evolutionary biology as we seek to predict the evolutionary fates of mutations. Here we use a model of microbial growth to show that there are two distinct components of selection corresponding to the growth and lag phases, while the yield modulates their relative importance. The model predicts rich population dynamics when there are trade-offs between phases: multiple strains can coexist or exhibit bistability due to frequency-dependent selection, and strains can engage in rock-paper-scissors interactions due to non-transitive selection. We characterize the environmental conditions and patterns of traits necessary to realize these phenomena, which we show to be readily accessible to experiments. Our results provide a theoretical framework for analysing high-throughput measurements of microbial growth traits, especially interpreting the pleiotropy and correlations between traits across mutants. This work also highlights the need for more comprehensive measurements of selection in simple microbial systems, where the concept of an ordinary fitness landscape breaks down. © 2018 The Author(s).

  6. Conditioning biomass for microbial growth

    Science.gov (United States)

    Bodie, Elizabeth A; England, George

    2015-03-31

    The present invention relates to methods for improving the yield of microbial processes that use lignocellulose biomass as a nutrient source. The methods comprise conditioning a composition comprising lignocellulose biomass with an enzyme composition that comprises a phenol oxidizing enzyme. The conditioned composition can support a higher rate of growth of microorganisms in a process. In one embodiment, a laccase composition is used to condition lignocellulose biomass derived from non-woody plants, such as corn and sugar cane. The invention also encompasses methods for culturing microorganisms that are sensitive to inhibitory compounds in lignocellulose biomass. The invention further provides methods of making a product by culturing the production microorganisms in conditioned lignocellulose biomass.

  7. Counteracting ammonia inhibition during anaerobic digestion by recovery using submersible microbial desalination cell.

    Science.gov (United States)

    Zhang, Yifeng; Angelidaki, Irini

    2015-07-01

    Ammonia inhibition is one of the most frequent and serious problems in biogas plants. In this study, a novel hybrid system consisting of a submersible microbial desalination cell (SMDC) and a continuous stirred tank reactor (CSTR) was developed for counteracting ammonia inhibition during anaerobic digestion (AD) with simultaneous in situ ammonia recovery and electricity production. The SMDC was powered by acetate in a buffer solution, while synthetic ammonia-rich wastewater was used as the feeding of the CSTR. Under continuous operation, ammonia recovery rate of 86 g-N/m(2) /day and current density of 4.33 A/m(2) were achieved at steady-state condition. As a result, 112% extra biogas was produced due to ammonia recovery by the SMDC. High-throughput sequencing showed that ammonia recovery had an impact on the microbial community structures in the SMDC and CSTR. Considering the additional economic benefits of biogas enhancement and possible wastewater treatment, the SMDC may represent a cost-effective and environmentally friendly method for waste resources recovery and biomethanation of ammonia-rich residues. © 2015 Wiley Periodicals, Inc.

  8. IAA Producing Enterobacter sp. I-3 as a Potent Bio-herbicide Candidate for Weed Control: A Special Reference with Lettuce Growth Inhibition

    OpenAIRE

    Park, Jae-Man; Radhakrishnan, Ramalingam; Kang, Sang-Mo; Lee, In-Jung

    2015-01-01

    Development of bio-herbicides is an emerging method to weed management in agricultural field. Very few studies were conducted on identification of microbial bio-herbicides to weed control. The present study was aimed to isolate and identify the effective bio-herbicide potential bacterium from soil and assess their role on plant growth inhibition. Three-hundred and one rhizobacteria were isolated from agriculture field soil samples collected from various parts of Republic of Korea. Two bacteri...

  9. Determination of rumen microbial growth in vitro form 32P-labelled phosphate incorporation

    International Nuclear Information System (INIS)

    Nevel, C.J. Van; Demeyer, D.I.

    1977-01-01

    The extracellular phosphate pool in incubations of rumen fluid or washed cell suspensions of mixed rumen bacteria (WCS) was labelled with 32 P. From the constant extracellular phosphate pool specific activity and the amount of radioactivity incorporated during incubation, the amount of P incorporated in the microbial fraction was calculated. From the value for nitrogen: P determined in microbial matter, the amount of N incorporated was calculated as a measure of microbial growth. Incorporation of soluble non-protein-N in incubations devoid of substrate protein was 50 and 80% of the values obtained using isotope method for rumen fluid and WCS respectively. Incorporation of 32 P in P-containing microbial components (mainly nucleic acids) was compared with net synthesis of these components in incubations of WCS. When N incorporation, calculated from results obtained using isotope method in incubations with rumen fluid, was compared with the amount of carbohydrate substrate fermented and the type of fermentation, values between 18.3 and 44.6 g N incorporated kg of organic matter fermented were obtained. The use of isotopes for determination of rumen microbial growth in vitro is critically discussed. (author)

  10. Rumen microbial growth estimation using in vitro radiophosphorous incorporation technique

    International Nuclear Information System (INIS)

    Bueno, Ives Claudio da Silva; Machado, Mariana de Carvalho; Cabral Filho, Sergio Lucio Salomon; Gobbo, Sarita Priscila; Vitti, Dorinha Miriam Silber Schmidt; Abdalla, Adibe Luiz

    2002-01-01

    Rumen microorganisms are able to transform low biological value nitrogen of feed stuff into high quality protein. To determine how much microbial protein that process forms, radiomarkers can be used. Radiophosphorous has been used to mark microbial protein, as element P is present in all rumen microorganisms (as phospholipids) and the P:N ratio of rumen biomass is quite constant. The aim of this work was to estimate microbial synthesis from feedstuff commonly used in ruminant nutrition in Brazil. Tested feeds were fresh alfalfa, raw sugarcane bagasse, rice hulls, rice meal, soybean meal, wheat meal, Tifton hay, leucaena, dehydrated citrus pulp, wet brewers' grains and cottonseed meal. 32 P-labelled phosphate solution was used as marker for microbial protein. Results showed the diversity of feeds by distinct quantities of nitrogen incorporated into microbial mass. Low nutrient availability feeds (sugarcane bagasse and rice hulls) promoted the lowest values of incorporated nitrogen. Nitrogen incorporation showed positive relationship (r=0.56; P=0.06) with the rate of degradation and negative relationship (r=-0.59; P<0.05) with fiber content of feeds. The results highlight that easier fermentable feeds (higher rates of degradation) and/or with lower fiber contents promote a more efficient microbial growth and better performance for the host animal. (author)

  11. Rumen microbial growth estimation using in vitro radiophosphorous incorporation technique

    Energy Technology Data Exchange (ETDEWEB)

    Bueno, Ives Claudio da Silva; Machado, Mariana de Carvalho; Cabral Filho, Sergio Lucio Salomon; Gobbo, Sarita Priscila; Vitti, Dorinha Miriam Silber Schmidt; Abdalla, Adibe Luiz [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil)

    2002-07-01

    Rumen microorganisms are able to transform low biological value nitrogen of feed stuff into high quality protein. To determine how much microbial protein that process forms, radiomarkers can be used. Radiophosphorous has been used to mark microbial protein, as element P is present in all rumen microorganisms (as phospholipids) and the P:N ratio of rumen biomass is quite constant. The aim of this work was to estimate microbial synthesis from feedstuff commonly used in ruminant nutrition in Brazil. Tested feeds were fresh alfalfa, raw sugarcane bagasse, rice hulls, rice meal, soybean meal, wheat meal, Tifton hay, leucaena, dehydrated citrus pulp, wet brewers' grains and cottonseed meal. {sup 32} P-labelled phosphate solution was used as marker for microbial protein. Results showed the diversity of feeds by distinct quantities of nitrogen incorporated into microbial mass. Low nutrient availability feeds (sugarcane bagasse and rice hulls) promoted the lowest values of incorporated nitrogen. Nitrogen incorporation showed positive relationship (r=0.56; P=0.06) with the rate of degradation and negative relationship (r=-0.59; P<0.05) with fiber content of feeds. The results highlight that easier fermentable feeds (higher rates of degradation) and/or with lower fiber contents promote a more efficient microbial growth and better performance for the host animal. (author)

  12. Linking genes to microbial growth kinetics: an integrated biochemical systems engineering approach

    NARCIS (Netherlands)

    Koutinas, M.; Kiparissides, A.; Silva-Rocha, R.; Lam, M.C.; Martins Dos Santos, V.A.P.; Lorenzo, de V.; Pistikopoulos, E.N.; Mantalaris, A.

    2011-01-01

    The majority of models describing the kinetic properties of a microorganism for a given substrate are unstructured and empirical. They are formulated in this manner so that the complex mechanism of cell growth is simplified. Herein, a novel approach for modelling microbial growth kinetics is

  13. E-cadherin homophilic ligation inhibits cell growth and epidermal growth factor receptor signaling independently of other cell interactions

    DEFF Research Database (Denmark)

    Perrais, Michaël; Chen, Xiao; Perez-Moreno, Mirna

    2007-01-01

    growth inhibitory signals. To address this question, we have selectively formed E-cadherin homophilic bonds at the cell surface of isolated epithelial cells by using functionally active recombinant E-cadherin protein attached to microspheres. We find that E-cadherin ligation alone reduces the frequency...... of cells entering the S phase, demonstrating that E-cadherin ligation directly transduces growth inhibitory signals. E-cadherin binding to beta-catenin is required for cell growth inhibition, but beta-catenin/T-cell factor transcriptional activity is not involved in growth inhibition resulting from...... homophilic binding. Neither E-cadherin binding to p120-catenin nor beta-catenin binding to alpha-catenin, and thereby the actin cytoskeleton, is required for growth inhibition. E-cadherin ligation also inhibits epidermal growth factor (EGF) receptor-mediated growth signaling by a beta...

  14. Spatial & Temporal Geophysical Monitoring of Microbial Growth and Biofilm Formation

    Science.gov (United States)

    Previous studies have examined the effect of biogenic gases and biomineralization on the acoustic properties of porous media. In this study, we investigated the spatiotemporal effect of microbial growth and biofilm formation on compressional waves and complex conductivity in sand...

  15. DSGOST inhibits tumor growth by blocking VEGF/VEGFR2-activated angiogenesis.

    Science.gov (United States)

    Choi, Hyeong Sim; Lee, Kangwook; Kim, Min Kyoung; Lee, Kang Min; Shin, Yong Cheol; Cho, Sung-Gook; Ko, Seong-Gyu

    2016-04-19

    Tumor growth requires a process called angiogenesis, a new blood vessel formation from pre-existing vessels, as newly formed vessels provide tumor cells with oxygen and nutrition. Danggui-Sayuk-Ga-Osuyu-Saenggang-Tang (DSGOST), one of traditional Chinese medicines, has been widely used in treatment of vessel diseases including Raynaud's syndrome in Northeast Asian countries including China, Japan and Korea. Therefore, we hypothesized that DSGOST might inhibit tumor growth by targeting newly formed vessels on the basis of its historical prescription. Here, we demonstrate that DSGOST inhibits tumor growth by inhibiting VEGF-induced angiogenesis. DSGOST inhibited VEGF-induced angiogenic abilities of endothelial cells in vitro and in vivo, which resulted from its inhibition of VEGF/VEGFR2 interaction. Furthermore, DSGOST attenuated pancreatic tumor growth in vivo by reducing angiogenic vessel numbers, while not affecting pancreatic tumor cell viability. Thus, our data conclude that DSGOST inhibits VEGF-induced tumor angiogenesis, suggesting a new indication for DSGOST in treatment of cancer.

  16. Gradient microfluidics enables rapid bacterial growth inhibition testing.

    Science.gov (United States)

    Li, Bing; Qiu, Yong; Glidle, Andrew; McIlvenna, David; Luo, Qian; Cooper, Jon; Shi, Han-Chang; Yin, Huabing

    2014-03-18

    Bacterial growth inhibition tests have become a standard measure of the adverse effects of inhibitors for a wide range of applications, such as toxicity testing in the medical and environmental sciences. However, conventional well-plate formats for these tests are laborious and provide limited information (often being restricted to an end-point assay). In this study, we have developed a microfluidic system that enables fast quantification of the effect of an inhibitor on bacteria growth and survival, within a single experiment. This format offers a unique combination of advantages, including long-term continuous flow culture, generation of concentration gradients, and single cell morphology tracking. Using Escherichia coli and the inhibitor amoxicillin as one model system, we show excellent agreement between an on-chip single cell-based assay and conventional methods to obtain quantitative measures of antibiotic inhibition (for example, minimum inhibition concentration). Furthermore, we show that our methods can provide additional information, over and above that of the standard well-plate assay, including kinetic information on growth inhibition and measurements of bacterial morphological dynamics over a wide range of inhibitor concentrations. Finally, using a second model system, we show that this chip-based systems does not require the bacteria to be labeled and is well suited for the study of naturally occurring species. We illustrate this using Nitrosomonas europaea, an environmentally important bacteria, and show that the chip system can lead to a significant reduction in the period required for growth and inhibition measurements (<4 days, compared to weeks in a culture flask).

  17. Preservatives and neutralizing substances in milk: analytical sensitivity of official specific and nonspecific tests, microbial inhibition effect, and residue persistence in milk

    Directory of Open Access Journals (Sweden)

    Livia Cavaletti Corrêa da Silva

    2015-09-01

    Full Text Available Milk fraud has been a recurring problem in Brazil; thus, it is important to know the effect of most frequently used preservatives and neutralizing substances as well as the detection capability of official tests. The objective of this study was to evaluate the analytical sensitivity of legislation-described tests and nonspecific microbial inhibition tests, and to investigate the effect of such substances on microbial growth inhibition and the persistence of detectable residues after 24/48h of refrigeration. Batches of raw milk, free from any contaminant, were divided into aliquots and mixed with different concentrations of formaldehyde, hydrogen peroxide, sodium hypochlorite, chlorine, chlorinated alkaline detergent, or sodium hydroxide. The analytical sensitivity of the official tests was 0.005%, 0.003%, and 0.013% for formaldehyde, hydrogen peroxide, and hypochlorite, respectively. Chlorine and chlorinated alkaline detergent were not detected by regulatory tests. In the tests for neutralizing substances, sodium hydroxide could not be detected when acidity was accurately neutralized. The yogurt culture test gave results similar to those obtained by official tests for the detection of specific substances. Concentrations of 0.05% of formaldehyde, 0.003% of hydrogen peroxide and 0.013% of sodium hypochlorite significantly reduced (P

  18. Canine tracheal epithelial cells are more sensitive than rat tracheal epithelial cells to transforming growth factor beta induced growth inhibition

    International Nuclear Information System (INIS)

    Hubbs, A.F.; Hahn, F.F.; Kelly, G.; Thomassen, D.G.

    1988-01-01

    Transforming growth factor beta (TGFβ) markedly inhibited growth of canine tracheal epithelial (CTE) cells. Reduced responsiveness to TGFβ-induced growth inhibition accompanied neoplastic progression of these cells from primary to transformed to neoplastic. This was similar to the relationship between neoplastic progression and increased resistance to TGFβ-induced growth inhibition seen for rat tracheal epithelial (RTE) cells. The canine cells were more sensitive than rat cells to TGFβ-induced growth inhibition at all stages in the neoplastic process. (author)

  19. The contribution of microbial biotechnology to economic growth and employment creation.

    Science.gov (United States)

    Timmis, Kenneth; de Lorenzo, Victor; Verstraete, Willy; Ramos, Juan Luis; Danchin, Antoine; Brüssow, Harald; Singh, Brajesh K; Timmis, James Kenneth

    2017-09-01

    Our communication discusses the profound impact of bio-based economies - in particular microbial biotechnologies - on SDG 8: Promote sustained, inclusive and sustainable economic growth, full and productive employment and decent work for all. A bio-based economy provides significant potential for improving labour supply, education and investment, and thereby for substantially increasing the demographic dividend. This, in turn, improves the sustainable development of economies. © 2017 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

  20. Factors limiting microbial growth and activity at a proposed high-level nuclear repository, Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    Kieft, T.L.; Kovacik, W.P. Jr.; Ringelberg, D.B.; White, D.C.; Haldeman, D.L.; Amy, P.S.; Hersman, L.E.

    1997-01-01

    As part of the characterization of Yucca Mountain, Nev., as a potential repository for high-level nuclear waste, volcanic tuff was analyzed for microbial abundance and activity. Tuff was collected aseptically from nine sites along a tunnel in Yucca Mountain. Microbial abundance was generally low: direct microscopic cell counts were near detection limits at all sites (3.2 X 10(1) to 2.0 X 10(5) cells g-1 [dry weight]); plate counts of aerobic heterotrophs ranged from 1.0 X 10(1) to 3.2 X 10(3) CFU g-1 (dry weight). Phospholipid fatty acid concentrations (0.1 to 3.7 pmol g-1) also indicated low microbial biomasses: diglyceride fatty acid concentrations, indicative of dead cells, were in a similar range (0.2 to 2.3 pmol g-1). Potential microbial activity was quantified as 14CO2 production in microcosms containing radiolabeled substrates (glucose, acetate, and glutamic acid); amendments with water and nutrient solutions (N and P) were used to test factors potentially limiting this activity. Similarly, the potential for microbial growth and the factors limiting growth were determined by performing plate counts before and after incubating volcanic tuff samples for 24 h under various conditions: ambient moisture, water-amended, and amended with various nutrient solutions (N, P, and organic C). A high potential for microbial activity was demonstrated by high rates of substrate mineralization (as much as 70% of added organic C in 3 weeks). Water was the major limiting factor to growth and microbial activity, while amendments with N and P resulted in little further stimulation. Organic C amendments stimulated growth more than water alone

  1. Understanding Mechanism of Photocatalytic Microbial Decontamination of Environmental Wastewater

    Directory of Open Access Journals (Sweden)

    Chhabilal Regmi

    2018-02-01

    Full Text Available Several photocatalytic nanoparticles are synthesized and studied for potential application for the degradation of organic and biological wastes. Although these materials degrade organic compounds by advance oxidation process, the exact mechanisms of microbial decontamination remains partially known. Understanding the real mechanisms of these materials for microbial cell death and growth inhibition helps to fabricate more efficient semiconductor photocatalyst for large-scale decontamination of environmental wastewater or industries and hospitals/biomedical labs generating highly pathogenic bacteria and toxic molecules containing liquid waste by designing a reactor. Recent studies on microbial decontamination by photocatalytic nanoparticles and their possible mechanisms of action is highlighted with examples in this mini review.

  2. PLANT GROWTH-PROMOTING MICROBIAL INOCULANT FOR Schizolobium parahyba pv. parahyba

    Directory of Open Access Journals (Sweden)

    Priscila Jane Romano de Oliveira Gonçalves

    2015-08-01

    Full Text Available ABSTRACTSchizolobium parahyba pv. amazonicum (Huber ex Ducke Barneby (paricá occurs naturally in the Amazon and is significant commercial importance due to its rapid growth and excellent performance on cropping systems. The aim of this paper was to evaluate a microbial inoculants such as arbuscular mycorrhiza fungi (AMF and Rhizobium sp. that promote plant growth. The inocula was 10 g of root colonized and spores of Glomus clarum and/or 1 mL of cell suspension (107 CFU/mL of Rhizobium sp. and/or 100 g of chemical fertilizer NPK 20-05-20 per planting hole. The experimental design was complete randomized blocks with five replications and eight treatments (n = 800. Plant height, stem diameter and plant survival were measured. The results were tested for normality and homogeneity of variances and analyzed by ANOVA and Tukey test (p < 0.05. Rhizobium sp and AM fungi showed no effect on plant growth. Environmental factors probably influenced the effectiveness of symbiosis of both microorganisms and plant growth. The chemical fertilizer increased S. parahyba growth. During the first 120 days plants suffered with drought and frost, and at 180 days plants inoculated with microorganism plus chemical fertilizer showed higher survival when compared with control. The results showed that the microbial inoculants used showed an important role on plant survival after high stress conditions, but not in plant growth. Also was concluded that the planting time should be between November to December to avoid the presence of young plants during winter time that is dry and cold.

  3. Elevated atmospheric CO2 increases microbial growth rates and enzymes activity in soil

    Science.gov (United States)

    Blagodatskaya, Evgenia; Blagodatsky, Sergey; Dorodnikov, Maxim; Kuzyakov, Yakov

    2010-05-01

    Increasing the belowground translocation of assimilated carbon by plants grown under elevated CO2 can cause a shift in the structure and activity of the microbial community responsible for the turnover of organic matter in soil. We investigated the long-term effect of elevated CO2 in the atmosphere on microbial biomass and specific growth rates in root-free and rhizosphere soil. The experiments were conducted under two free air carbon dioxide enrichment (FACE) systems: in Hohenheim and Braunschweig, as well as in the intensively managed forest mesocosm of the Biosphere 2 Laboratory (B2L) in Oracle, AZ. Specific microbial growth rates (μ) were determined using the substrate-induced respiration response after glucose and/or yeast extract addition to the soil. We evaluated the effect of elevated CO2 on b-glucosidase, chitinase, phosphatase, and sulfatase to estimate the potential enzyme activity after soil amendment with glucose and nutrients. For B2L and both FACE systems, up to 58% higher μ were observed under elevated vs. ambient CO2, depending on site, plant species and N fertilization. The μ-values increased linearly with atmospheric CO2 concentration at all three sites. The effect of elevated CO2 on rhizosphere microorganisms was plant dependent and increased for: Brassica napus=Triticum aestivumyeast extract then for those growing on glucose, i.e. the effect of elevated CO2 was smoothed on rich vs. simple substrate. So, the r/K strategies ratio can be better revealed by studying growth on simple (glucose) than on rich substrate mixtures (yeast extract). After adding glucose, enzyme activities under elevated CO2 were 1.2-1.9-fold higher than under ambient CO2. This indicates the increased activity of microorganisms, which leads to accelerated C turnover in soil under elevated CO2. Our results clearly showed that the functional characteristics of the soil microbial community (i.e. specific growth rates and enzymes activity) rather than total microbial biomass

  4. Microbial growth on C1 compounds: proceedings

    International Nuclear Information System (INIS)

    Crawford, R.L.; Hanson, R.S.

    1984-01-01

    This book contains individual papers prepared for the 4th International Symposium on Microbial Growth on One Carbon Compounds. Individual reports were abstracted and indexed for EDB. Topics presented were in the areas of the physiology and biochemistry of autotraps, physiology and biochemistry of methylotrophs and methanotrops, physiology and biochemistry of methanogens, genetics of microbes that use C 1 compounds, taxonomy and ecology of microbes tht grow on C 1 compounds, applied aspects of microbes that grow on C 1 compounds, and new directions in C 1 metabolism. (DT)

  5. EVELOPMENT OF AN ENVIRONMENTALLY BENIGN MICROBIAL INHIBITOR TO CONTROL INTERNAL PIPELINE CORROSION

    Energy Technology Data Exchange (ETDEWEB)

    Bill W. Bogan; Wendy R. Sullivan; Kristine M. H. Cruz; Kristine L. Lowe; John J. Kilbane II

    2004-04-30

    The overall program objective is to develop and evaluate environmentally benign agents or products that are effective in the prevention, inhibition, and mitigation of microbially influenced corrosion (MIC) in the internal surfaces of metallic natural gas pipelines. The goal is to develop one or more environmentally benign (a.k.a. ''green'') products that can be applied to maintain the structure and dependability of the natural gas infrastructure. Previous testing of pepper extracts resulted in preliminary data indicating that some pepper extracts inhibit the growth of some corrosion-associated microorganisms. This quarter additional tests were performed to more specifically investigate the ability of three pepper extracts to inhibit the growth, and to influence the metal corrosion caused by two microbial species: Desulfovibrio vulgaris, and Comomonas denitrificans. All three pepper extracts rapidly killed Desulfovibrio vulgaris, but did not appear to inhibit Comomonas denitrificans. While corrosion rates were at control levels in experiments with Desulfovibrio vulgaris that received pepper extract, corrosion rates were increased in the presence of Comomonas denitrificans plus pepper extract. Further testing with a wider range of pure bacterial cultures, and more importantly, with mixed bacterial cultures should be performed to determine the potential effectiveness of pepper extracts to inhibit MIC.

  6. Spatial & Temporal Geophysical Monitoring of Microbial Growth and Biofilm Formation

    Science.gov (United States)

    Davis, C. A.; Pyrak-Nolte, L. J.; Atekwana, E. A.; Werkema, D. D.; Haugen, M. E.

    2009-12-01

    Previous studies have examined the effect of biogenic gases and biomineralization on the acoustic properties of porous media. In this study, we investigated the spatiotemporal effect of microbial growth and biofilm formation on compressional waves and complex conductivity in sand columns. A control column (non-biostimulated) and a biostimulated column were studied in a 2D acoustic scanning apparatus, and a second set of columns were constructed with Ag-AgCl electrodes for complex conductivity measurements. At the completion of the 29-day experiment, compressional wave amplitudes and arrival times for the control column were observed to be relatively uniform over the scanned 2D region. However, the biostimulated sample exhibited a high degree of spatial variability within the column for both the amplitude and arrival times. Furthermore, portions of the sample exhibited increased attenuation (~ 80%) concurrent with an increase in the arrival times, while other portions exhibited decreased attenuation (~ 45%) and decreased arrival time. The acoustic amplitude and arrival times changed significantly in the biostimulated column between Days 5 and 7 of the experiment and are consistent with a peak in the imaginary conductivity (σ”) values. The σ” response corresponds to different stages of biofilm development. That is, we interpret the peak σ” with the maximum biofilm thickness and decreasing σ” due to cell death or detachment. Environmental scanning electron microscope (ESEM) imaging confirmed microbial cell attachment to sand surfaces in the biostimulated columns, showed apparent differences in the morphology of attached biomass between regions of increased and decreased attenuation, and indicated no mineral precipitation or biomineralization. The heterogeneity in the elastic properties arises from the differences in the morphology and structure of attached biofilms. These results suggest that combining acoustic imaging and complex conductivity techniques

  7. Dicumarol inhibition of NADPH:quinone oxidoreductase induces growth inhibition of pancreatic cancer via a superoxide-mediated mechanism.

    Science.gov (United States)

    Cullen, Joseph J; Hinkhouse, Marilyn M; Grady, Matthew; Gaut, Andrew W; Liu, Jingru; Zhang, Yu Ping; Weydert, Christine J Darby; Domann, Frederick E; Oberley, Larry W

    2003-09-01

    NADPH:quinone oxidoreductase (NQO(1)), a homodimeric, ubiquitous, flavoprotein, catalyzes the two-electron reduction of quinones to hydroquinones. This reaction prevents the one-electron reduction of quinones by cytochrome P450 reductase and other flavoproteins that would result in oxidative cycling with generation of superoxide (O(2)(.-)). NQO(1) gene regulation may be up-regulated in some tumors to accommodate the needs of rapidly metabolizing cells to regenerate NAD(+). We hypothesized that pancreatic cancer cells would exhibit high levels of this enzyme, and inhibiting it would suppress the malignant phenotype. Reverse transcription-PCR, Western blots, and activity assays demonstrated that NQO(1) was up-regulated in the pancreatic cancer cell lines tested but present in very low amounts in the normal human pancreas. To determine whether inhibition of NQO(1) would alter the malignant phenotype, MIA PaCa-2 pancreatic cancer cells were treated with a selective inhibitor of NQO(1), dicumarol. Dicumarol increased intracellular production of O(2)(.-), as measured by hydroethidine staining, and inhibited cell growth. Both of these effects were blunted with infection of an adenoviral vector containing the cDNA for manganese superoxide dismutase. Dicumarol also inhibited cell growth, plating efficiency, and growth in soft agar. We conclude that inhibition of NQO(1) increases intracellular O(2)(.-) production and inhibits the in vitro malignant phenotype of pancreatic cancer. These mechanisms suggest that altering the intracellular redox environment of pancreatic cancer cells may inhibit growth and delineate a potential strategy directed against pancreatic cancer.

  8. Prevention of Acid Mine Drainage Through Complexation of Ferric Iron by Soluble Microbial Growth Products

    Science.gov (United States)

    Pandey, S.; Yacob, T. W.; Silverstein, J.; Rajaram, H.; Minchow, K.; Basta, J.

    2011-12-01

    Acid mine drainage (AMD) is a widespread environmental problem with deleterious impacts on water quality in streams and watersheds. AMD is generated largely by the oxidation of metal sulfides (i.e. pyrite) by ferric iron. This abiotic reaction is catalyzed by conversion of ferrous to ferric iron by iron and sulfur oxidizing microorganisms. Biostimulation is currently being investigated as an attempt to inhibit the oxidation of pyrite and growth of iron oxidizing bacteria through addition of organic carbon. This may stimulate growth of indigenous communities of acidophilic heterotrophic bacteria to compete for oxygen. The goal of this research is to investigate a secondary mechanism associated with carbon addition: complexation of free Fe(III) by soluble microbial growth products (SMPs) produced by microorganisms growing in waste rock. Exploratory research at the laboratory scale examined the effect of soluble microbial products (SMPs) on the kinetics of oxidation of pure pyrite during shaker flask experiments. The results confirmed a decrease in the rate of pyrite oxidation that was dependent upon the concentration of SMPs in solution. We are using these data to verify results from a pyrite oxidation model that accounts for SMPs. This reactor model involves differential-algebraic equations incorporating total component mass balances and mass action laws for equilibrium reactions. Species concentrations determined in each time step are applied to abiotic pyrite oxidation rate expressions from the literature to determine the evolution of total component concentrations. The model was embedded in a parameter estimation algorithm to determine the reactive surface area of pyrite in an abiotic control experiment, yielding an optimized value of 0.0037 m2. The optimized model exhibited similar behavior to the experiment for this case; the root mean squared of residuals for Fe(III) was calculated to be 7.58 x 10-4 M, which is several orders of magnitude less than the actual

  9. Phosphate solubilization as a microbial strategy for promoting plant growth

    Directory of Open Access Journals (Sweden)

    Mayra Eleonora Beltrán Pineda

    2014-01-01

    Full Text Available Because of the constant application of chemical inputs in Agroecosystem, the cost of crop production and environmental quality of soil and water have been affected. Microorganisms carry out most biogeochemical cycles; therefore, their role is essential for agro ecosystem balance. One such functional group is the phosphate solubilizing microorganisms, which are recognized plant growth promoters. These microbial populations perform an important activity, since in many soils there are large reserves of insoluble phosphorus, as a result of fixing much of the phosphorus fertilizer applied, which cannot be assimilated by the plant. The phosphate solubilizing microorganisms use different solubilization mechanisms such as the production of organic acids, which solubilize theses insoluble phosphates in the rhizosphere region. Soluble phosphates are absorbed by the plant, which enhances their growth and productivity. By using these phosphate reserves in soils, application of chemical fertilizers is decreased, on the one hand, can again be fixed by ions Ca, Al or Fe making them insoluble and, by the other hand, increase the costs of crop production. Microbial populations have been widely studied in different types of ecosystems, both natural and Agroecosystem. Thanks to its effectiveness, in laboratory and field studies, the phosphate solubilizing phenotype is of great interest to microbial ecologists who have begun to establish the molecular basis of the traitr.

  10. Predicting the dynamics of bacterial growth inhibition by ribosome-targeting antibiotics

    Science.gov (United States)

    Greulich, Philip; Doležal, Jakub; Scott, Matthew; Evans, Martin R.; Allen, Rosalind J.

    2017-12-01

    Understanding how antibiotics inhibit bacteria can help to reduce antibiotic use and hence avoid antimicrobial resistance—yet few theoretical models exist for bacterial growth inhibition by a clinically relevant antibiotic treatment regimen. In particular, in the clinic, antibiotic treatment is time-dependent. Here, we use a theoretical model, previously applied to steady-state bacterial growth, to predict the dynamical response of a bacterial cell to a time-dependent dose of ribosome-targeting antibiotic. Our results depend strongly on whether the antibiotic shows reversible transport and/or low-affinity ribosome binding (‘low-affinity antibiotic’) or, in contrast, irreversible transport and/or high affinity ribosome binding (‘high-affinity antibiotic’). For low-affinity antibiotics, our model predicts that growth inhibition depends on the duration of the antibiotic pulse, and can show a transient period of very fast growth following removal of the antibiotic. For high-affinity antibiotics, growth inhibition depends on peak dosage rather than dose duration, and the model predicts a pronounced post-antibiotic effect, due to hysteresis, in which growth can be suppressed for long times after the antibiotic dose has ended. These predictions are experimentally testable and may be of clinical significance.

  11. Growth of antarctic cyanobacteria under ultraviolet radiation: UVA counteracts UVB inhibition

    International Nuclear Information System (INIS)

    Quesada, A.; Mouget, J.L.; Vincent, W.F.

    1995-01-01

    A mat-forming cyanobacterium (Phormidium murayi West and West) isolated from an ice-shelf pond in Antarctica was grown under white light combined with a range of UVA and UVB irradiance. The 4-day growth rate decreased under increasing ultraviolet (UV) radiation, with a ninefold greater response to UVB relative to UVA. In vivo absorbance spectra showed that UVA and to a greater extent UVB caused a decrease in phycocyanin/chlorophyll a and an increase in carotenoids/chlorophyll a. The phycocyanin/chlorophyll a ratio was closely and positively correlated to the UVB-inhibited growth rate. Under fixed spectral gradients of UV radiation, the growth inhibition effect was dominated by UVB. However, at specific UVB irradiances the inhibition of growth depended on the ratio of UVB to UVA, and growth rates increased linearly with increasing UVA. These results are consistent with the view that UVB inhibition represents the balance between damage and repair processes that are each controlled by separate wavebands. They also underscore the need to consider UV spectral balance in laboratory and field assays of UVB toxicity. 49 refs., 6 figs

  12. Growth Inhibition of Breast Cancer in Rat by AAV Mediated Angiostatin Gene

    Institute of Scientific and Technical Information of China (English)

    LI Ran; CHEN Hong; REN Chang-shan

    2007-01-01

    Objective: To observe growth inhibition effect of adeno-associated viral vectors (AAV) mediated angiostatin (ANG) gene on implanted breast cancer in rat and its mechanism. Methods: Gene transfer technique was used to transfer AAV-ANG to the tumor. Growth curves were drawn to observe the growth of breast cancer implanted in rat, and immunohistochemical method was used to detect the effects of angiostatin on microvesel density (MVD) of breast cancer implanted in rat. Results: Angiostatin inhibited the growth of breast cancer implanted in rat and decreased the microvessel density of tumor. Conclusion: Expression of an angiostatin transgene can suppress the growth of breast cancer implanted in rat through the inhibition of the growth of microvessels, surggesting that angiostatin gene transfer technique may be effective against breast cancer.

  13. The effect of denture adhesives on Candida albicans growth in vitro.

    Science.gov (United States)

    Sampaio-Maia, Benedita; Figueiral, Maria Helena; Sousa-Rodrigues, Patricia; Fernandes, Maria Helena; Scully, Crispian

    2012-06-01

    Denture-wearing favours the growth of Candida. In view of the fact that many denture wearers regularly use adhesives to enhance denture retention, stability and function, the aim of this work was to study the effect of denture adhesives on Candida albicans growth in vitro. The denture adhesives tested were Corega(®) cream, Kukident(®) cream, Novafix(®) cream, Polident(®) cream, Protefix(®) cream, Steradent(®) cream, Aderyn(®) powder, Corega(®) ultra powder, Protefix(®) powder and Corega(®) strip. C. albicans growth curves were obtained in the presence or absence of a 1% solution of the denture adhesive diluted in Sabouraud broth. Macro- and microscopic morphological changes in C. albicans were analysed, as was microbial contamination of the denture adhesive. Most of the denture adhesives studied induced morphological changes in C. albicans cells and colonies, but only two had any significant inhibitory effect on yeast growth. Kukident(®) cream markedly inhibited C. albicans growth in a concentration-dependent way, reducing the growth rate by 95%, whereas Corega(®) cream also inhibited C. albicans growth but in a non-concentration-dependent way, reducing the growth rate by 37%. In addition, denture adhesives available as powders had detectable microbial contamination. Some commercially available denture adhesives showed microbial contamination and some had significant inhibitory effect on C. albicans growth. © 2011 The Gerodontology Society and John Wiley & Sons A/S.

  14. Prolyl oligopeptidase inhibition-induced growth arrest of human gastric cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Kanayo [Laboratory of Cell Biology, Osaka University of Pharmaceutical Sciences, 4-20-1 Nasahara, Takatsuki, Osaka 569-1094 (Japan); Sakaguchi, Minoru, E-mail: sakaguti@gly.oups.ac.jp [Laboratory of Cell Biology, Osaka University of Pharmaceutical Sciences, 4-20-1 Nasahara, Takatsuki, Osaka 569-1094 (Japan); Tanaka, Satoshi [Laboratory of Cell Biology, Osaka University of Pharmaceutical Sciences, 4-20-1 Nasahara, Takatsuki, Osaka 569-1094 (Japan); Yoshimoto, Tadashi [Department of Life Science, Setsunan University, 17-8 Ikeda-Nakamachi, Neyagawa, Osaka 572-8508 (Japan); Takaoka, Masanori [Laboratory of Cell Biology, Osaka University of Pharmaceutical Sciences, 4-20-1 Nasahara, Takatsuki, Osaka 569-1094 (Japan)

    2014-01-03

    Highlights: •We examined the effects of prolyl oligopeptidase (POP) inhibition on p53 null gastric cancer cell growth. •POP inhibition-induced cell growth suppression was associated with an increase in a quiescent G{sub 0} state. •POP might regulate the exit from and/or reentry into the cell cycle. -- Abstract: Prolyl oligopeptidase (POP) is a serine endopeptidase that hydrolyzes post-proline peptide bonds in peptides that are <30 amino acids in length. We recently reported that POP inhibition suppressed the growth of human neuroblastoma cells. The growth suppression was associated with pronounced G{sub 0}/G{sub 1} cell cycle arrest and increased levels of the CDK inhibitor p27{sup kip1} and the tumor suppressor p53. In this study, we investigated the mechanism of POP inhibition-induced cell growth arrest using a human gastric cancer cell line, KATO III cells, which had a p53 gene deletion. POP specific inhibitors, 3-((4-[2-(E)-styrylphenoxy]butanoyl)-L-4-hydroxyprolyl)-thiazolidine (SUAM-14746) and benzyloxycarbonyl-thioprolyl-thioprolinal, or RNAi-mediated POP knockdown inhibited the growth of KATO III cells irrespective of their p53 status. SUAM-14746-induced growth inhibition was associated with G{sub 0}/G{sub 1} cell cycle phase arrest and increased levels of p27{sup kip1} in the nuclei and the pRb2/p130 protein expression. Moreover, SUAM-14746-mediated cell cycle arrest of KATO III cells was associated with an increase in the quiescent G{sub 0} state, defined by low level staining for the proliferation marker, Ki-67. These results indicate that POP may be a positive regulator of cell cycle progression by regulating the exit from and/or reentry into the cell cycle by KATO III cells.

  15. Monitoring microbial growth and activity using spectral induced polarization and low-field nuclear magnetic resonance

    Science.gov (United States)

    Zhang, Chi; Keating, Kristina; Revil, Andre

    2015-04-01

    Microbes and microbial activities in the Earth's subsurface play a significant role in shaping subsurface environments and are involved in environmental applications such as remediation of contaminants in groundwater and oil fields biodegradation. Stimulated microbial growth in such applications could cause wide variety of changes of physical/chemical properties in the subsurface. It is critical to monitor and determine the fate and transportation of microorganisms in the subsurface during such applications. Recent geophysical studies demonstrate the potential of two innovative techniques, spectral induced polarization (SIP) and low-field nuclear magnetic resonance (NMR), for monitoring microbial growth and activities in porous media. The SIP measures complex dielectric properties of porous media at low frequencies of exciting electric field, and NMR studies the porous structure of geologic media and characterizes fluids subsurface. In this laboratory study, we examined both SIP and NMR responses from bacterial growth suspension as well as suspension mixed with silica sands. We focus on the direct contribution of microbes to the SIP and NMR signals in the absence of biofilm formation or biomineralization. We used Zymomonas mobilis and Shewanella oneidensis (MR-1) for SIP and NMR measurements, respectively. The SIP measurements were collected over the frequency range of 0.1 - 1 kHz on Z. mobilis growth suspension and suspension saturated sands at different cell densities. SIP data show two distinct peaks in imaginary conductivity spectra, and both imaginary and real conductivities increased as microbial density increased. NMR data were collected using both CPMG pulse sequence and D-T2 mapping to determine the T2-distribution and diffusion properties on S. oneidensis suspension, pellets (live and dead), and suspension mixed with silica sands. NMR data show a decrease in the T2-distribution in S. oneidensis suspension saturated sands as microbial density increase. A

  16. [Isolation of endophytic fungi from medicinal plant Brucea javanica and their microbial inhibition activity].

    Science.gov (United States)

    Liang, Zi-Ning; Zhu, Hua; Lai, Kai-Ping; Chen, Long

    2014-04-01

    To isolate and identify endophytic fungi from Brucea javanica, and to detect the antimicrobial activity of these strains. Endophytic fungi were isolated by tissue inoculation culture and identified by conventional morphological characteristic method. Seven kinds of pathogenic fungi and three kinds of bacteria were used as targeting microbes to test microbial inhibition activities by agar plate antagonistic action and modified agar gel diffusion methods, respectively. A total of 83 endophytic fungi strains were isolated from the root, stem, leaf and fruit of Brucea javanica. 34 strains were obtained from the stem, 32 strains were obtained from the leaf, 15 strains were isolated from the root and 2 strains came from the fruit. These 73 strains which had been identified attribute to 5 orders, 6 families and 12 genera. For the isolated strains, 14 strains had antifungal activities against at least one pathogenic fungi, 9 strains showed antibacterial activities against one or more bacteria. Especially, the strain YJ-17 which belonged to Phomopsis genus showed the best inhibitory effect on the targeting microbes. The endophytic fungi from Brucea javanica show diversity and microbial inhibition activity, and are worthy for further study on plant disease controlling.

  17. ITE inhibits growth of human pulmonary artery endothelial cells.

    Science.gov (United States)

    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.

  18. Phytotoxicity of nanoparticles: Inhibition of seed germination and root growth

    Energy Technology Data Exchange (ETDEWEB)

    Lin Daohui [Department of Environmental Science, Zhejiang University, Hangzhou 310028 (China); Department of Plant, Soil and Insect Sciences, University of Massachusetts, Stockbridge Hall, Amherst, MA 01003 (United States); Xing Baoshan [Department of Plant, Soil and Insect Sciences, University of Massachusetts, Stockbridge Hall, Amherst, MA 01003 (United States)], E-mail: bx@pssci.umass.edu

    2007-11-15

    Plants need to be included to develop a comprehensive toxicity profile for nanoparticles. Effects of five types of nanoparticles (multi-walled carbon nanotube, aluminum, alumina, zinc, and zinc oxide) on seed germination and root growth of six higher plant species (radish, rape, ryegrass, lettuce, corn, and cucumber) were investigated. Seed germination was not affected except for the inhibition of nanoscale zinc (nano-Zn) on ryegrass and zinc oxide (nano-ZnO) on corn at 2000 mg/L. Inhibition on root growth varied greatly among nanoparticles and plants. Suspensions of 2000 mg/L nano-Zn or nano-ZnO practically terminated root elongation of the tested plant species. Fifty percent inhibitory concentrations (IC{sub 50}) of nano-Zn and nano-ZnO were estimated to be near 50 mg/L for radish, and about 20 mg/L for rape and ryegrass. The inhibition occurred during the seed incubation process rather than seed soaking stage. These results are significant in terms of use and disposal of engineered nanoparticles. - Engineered nanoparticles can inhibit the seed germination and root growth.

  19. Phytotoxicity of nanoparticles: Inhibition of seed germination and root growth

    International Nuclear Information System (INIS)

    Lin Daohui; Xing Baoshan

    2007-01-01

    Plants need to be included to develop a comprehensive toxicity profile for nanoparticles. Effects of five types of nanoparticles (multi-walled carbon nanotube, aluminum, alumina, zinc, and zinc oxide) on seed germination and root growth of six higher plant species (radish, rape, ryegrass, lettuce, corn, and cucumber) were investigated. Seed germination was not affected except for the inhibition of nanoscale zinc (nano-Zn) on ryegrass and zinc oxide (nano-ZnO) on corn at 2000 mg/L. Inhibition on root growth varied greatly among nanoparticles and plants. Suspensions of 2000 mg/L nano-Zn or nano-ZnO practically terminated root elongation of the tested plant species. Fifty percent inhibitory concentrations (IC 50 ) of nano-Zn and nano-ZnO were estimated to be near 50 mg/L for radish, and about 20 mg/L for rape and ryegrass. The inhibition occurred during the seed incubation process rather than seed soaking stage. These results are significant in terms of use and disposal of engineered nanoparticles. - Engineered nanoparticles can inhibit the seed germination and root growth

  20. Accelerated microbial turnover but constant growth efficiency with warming in soil

    Science.gov (United States)

    Shannon B. Hagerty; Kees Jan van Groenigen; Steven D. Allison; Bruce A. Hungate; Egbert Schwartz; George W. Koch; Randall K. Kolka; Paul. Dijkstra

    2014-01-01

    Rising temperatures are expected to reduce global soil carbon (C) stocks, driving a positive feedback to climate change1-3. However, the mechanisms underlying this prediction are not well understood, including how temperature affects microbial enzyme kinetics, growth effiency (MGE), and turnover4,5. Here, in a laboratory...

  1. Platelet-derived growth factor inhibits platelet activation in heparinized whole blood.

    Science.gov (United States)

    Selheim, F; Holmsen, H; Vassbotn, F S

    1999-08-15

    We previously have demonstrated that human platelets have functionally active platelet-derived growth factor alpha-receptors. Studies with gel-filtered platelets showed that an autocrine inhibition pathway is transduced through this tyrosine kinase receptor during platelet activation. The physiological significance of this inhibitory effect of platelet-derived growth factor on gel-filtered platelets activation is, however, not known. In the present study, we investigated whether platelet-derived growth factor inhibits platelet activation under more physiological conditions in heparinized whole blood, which represents a more physiological condition than gel-filtered platelets. Using flow cytometric assays, we demonstrate here that platelet-derived growth factor inhibits thrombin-, thrombin receptor agonist peptide SFLLRN-, and collagen-induced platelet aggregation and shedding of platelet-derived microparticles from the platelet plasma membrane during platelet aggregation in stirred heparinized whole blood. The inhibitory effect of platelet-derived growth factor was dose dependent. However, under nonaggregating conditions (no stirring), we could not demonstrate any significant effect of platelet-derived growth factor on thrombin- and thrombin receptor agonist peptide-induced platelet surface expression of P-selectin. Our results demonstrate that platelet-derived growth factor appears to be a true antithrombotic agent only under aggregating conditions in heparinized whole blood.

  2. Biohydrogen production in the suspended and attached microbial growth systems from waste pastry hydrolysate.

    Science.gov (United States)

    Han, Wei; Hu, Yunyi; Li, Shiyi; Li, Feifei; Tang, Junhong

    2016-10-01

    Waste pastry was hydrolyzed by glucoamylase and protease which were obtained from solid state fermentation of Aspergillus awamori and Aspergillus oryzae to produce waste pastry hydrolysate. Then, the effects of hydraulic retention times (HRTs) (4-12h) on hydrogen production rate (HPR) in the suspended microbial growth system (continuous stirred tank reactor, CSTR) and attached microbial growth system (continuous mixed immobilized sludge reactor, CMISR) from waste pastry hydrolysate were investigated. The maximum HPRs of CSTR (201.8mL/(h·L)) and CMISR (255.3mL/(h·L)) were obtained at HRT of 6h and 4h, respectively. The first-order reaction could be used to describe the enzymatic hydrolysis of waste pastry. The carbon content of the waste pastry remained 22.8% in the undigested waste pastry and consumed 77.2% for carbon dioxide and soluble microbial products. To our knowledge, this is the first study which reports biohydrogen production from waste pastry. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Biochar increases plant growth and alters microbial communities via regulating the moisture and temperature of green roof substrates.

    Science.gov (United States)

    Chen, Haoming; Ma, Jinyi; Wei, Jiaxing; Gong, Xin; Yu, Xichen; Guo, Hui; Zhao, Yanwen

    2018-09-01

    Green roofs have increasingly been designed and applied to relieve environmental problems, such as water loss, air pollution as well as heat island effect. Substrate and vegetation are important components of green roofs providing ecosystem services and benefiting the urban development. Biochar made from sewage sludge could be potentially used as the substrate amendment for green roofs, however, the effects of biochar on substrate quality and plant performance in green roofs are still unclear. We evaluated the effects of adding sludge biochar (0, 5, 10, 15 and 20%, v/v) to natural soil planted with three types of plant species (ryegrass, Sedum lineare and cucumber) on soil properties, plant growth and microbial communities in both green roof and ground ecosystems. Our results showed that sludge biochar addition significantly increased substrate moisture, adjusted substrate temperature, altered microbial community structure and increased plant growth. The application rate of 10-15% sludge biochar on the green roof exerted the most significant effects on both microbial and plant biomass by 63.9-89.6% and 54.0-54.2% respectively. Path analysis showed that biochar addition had a strong effect on microbial biomass via changing the soil air-filled porosity, soil moisture and temperature, and promoted plant growth through the positive effects on microbial biomass. These results suggest that the applications of biochar at an appropriate rate can significantly alter plant growth and microbial community structure, and increase the ecological benefits of green roofs via exerting effects on the moisture, temperature and nutrients of roof substrates. Copyright © 2018 Elsevier B.V. All rights reserved.

  4. An approach to mitigating soil CO2 emission by biochemically inhibiting cellulolytic microbial populations through mediation via the medicinal herb Isatis indigotica

    Science.gov (United States)

    Wu, Hong-Sheng; Chen, Su-Yun; Li, Ji; Liu, Dong-Yang; Zhou, Ji; Xu, Ya; Shang, Xiao-Xia; Wei, Dong-yang; Yu, Lu-ji; Fang, Xiao-hang; Li, Shun-yi; Wang, Ke-ke

    2017-06-01

    Greenhouse gases (GHGs, particularly carbon dioxide (CO2)) emissions from soil under wheat production are a significant source of agricultural carbon emissions that have not been mitigated effectively. A field experiment and a static incubation study in a lab were conducted to stimulate wheat growth and investigate its potential to reduce CO2 emissions from soil through intercropping with a traditional Chinese medicinal herb called Isatis indigotica. This work was conducted by adding I. indigotica root exudates based on the quantitative real-time PCR (qPCR) analysis of the DNA copy number of the rhizosphere or bulk soil microbial populations. This addition was performed in relation to the CO2 formation by cellulolytic microorganisms (Penicillium oxalicum, fungi and Ruminococcus albus) to elucidate the microbial ecological basis for the molecular mechanism that decreases CO2 emissions from wheat fields using I. indigotica. The results showed that the panicle weight and full grains per panicle measured through intercropping with I. indigotica (NPKWR) increased by 39% and 28.6%, respectively, compared to that of the CK (NPKW). Intercropping with I. indigotica significantly decreased the CO2 emissions from soil under wheat cultivation. Compared with CK, the total CO2 emission flux during the wheat growth period in the I. indigotica (NPKWR) intercropping treatment decreased by 29.26%. The intensity of CO2 emissions per kg of harvested wheat grain declined from 7.53 kg CO2/kg grain in the NPKW (CK) treatment to 5.55 kg CO2/kg grain in the NPKWR treatment. The qPCR analysis showed that the DNA copy number of the microbial populations of cellulolytic microorganisms (P. oxalicum, fungi and R. albus) in the field rhizosphere around I. indigotica or in the bulk soil under laboratory incubation was significantly lower than that of CK. This finding indicated that root exudates from I. indigotica inhibited the activity and number of cellulolytic microbial populations, which led

  5. 3-Bromopyruvate inhibits human gastric cancer tumor growth in nude mice via the inhibition of glycolysis.

    Science.gov (United States)

    Xian, Shu-Lin; Cao, Wei; Zhang, Xiao-Dong; Lu, Yun-Fei

    2015-02-01

    Tumor cells primarily depend upon glycolysis in order to gain energy. Therefore, the inhibition of glycolysis may inhibit tumor growth. Our previous study demonstrated that 3-bromopyruvate (3-BrPA) inhibited gastric cancer cell proliferation in vitro . However, the ability of 3-BrPA to suppress tumor growth in vivo, and its underlying mechanism, have yet to be elucidated. The aim of the present study was to investigate the inhibitory effect of 3-BrPA in an animal model of gastric cancer. It was identified that 3-BrPA exhibited strong inhibitory effects upon xenograft tumor growth in nude mice. In addition, the antitumor function of 3-BrPA exhibited a dose-effect association, which was similar to that of the chemotherapeutic agent, 5-fluorouracil. Furthermore, 3-BrPA exhibited low toxicity in the blood, liver and kidneys of the nude mice. The present study hypothesized that the inhibitory effect of 3-BrPA is achieved through the inhibition of hexokinase activity, which leads to the downregulation of B-cell lymphoma 2 (Bcl-2) expression, the upregulation of Bcl-2-associated X protein expression and the subsequent activation of caspase-3. These data suggest that 3-BrPA may be a novel therapy for the treatment of gastric cancer.

  6. Inhibition of ice crystal growth in ice cream mix by gelatin hydrolysate.

    Science.gov (United States)

    Damodaran, Srinivasan

    2007-12-26

    The inhibition of ice crystal growth in ice cream mix by gelatin hydrolysate produced by papain action was studied. The ice crystal growth was monitored by thermal cycling between -14 and -12 degrees C at a rate of one cycle per 3 min. It is shown that the hydrolysate fraction containing peptides in the molecular weight range of about 2000-5000 Da exhibited the highest inhibitory activity on ice crystal growth in ice cream mix, whereas fractions containing peptides greater than 7000 Da did not inhibit ice crystal growth. The size distribution of gelatin peptides formed in the hydrolysate was influenced by the pH of hydrolysis. The optimum hydrolysis conditions for producing peptides with maximum ice crystal growth inhibitory activity was pH 7 at 37 degrees C for 10 min at a papain to gelatin ratio of 1:100. However, this may depend on the type and source of gelatin. The possible mechanism of ice crystal growth inhibition by peptides from gelatin is discussed. Molecular modeling of model gelatin peptides revealed that they form an oxygen triad plane at the C-terminus with oxygen-oxygen distances similar to those found in ice nuclei. Binding of this oxygen triad plane to the prism face of ice nuclei via hydrogen bonding appears to be the mechanism by which gelatin hydrolysate might be inhibiting ice crystal growth in ice cream mix.

  7. Mullerian Inhibiting Substance (MIS) Augments IFN-gamma Mediated Inhibition of Breast Cancer Cell Growth

    National Research Council Canada - National Science Library

    Gupta, Vandana

    2004-01-01

    Mullerian Inhibiting Substance (MIS), a member of the TGFB family regulates growth, differentiation, and apoptosis in many cell types In the male embryo, MIS causes regression of the Mullerian duct...

  8. The utilization of microbial inoculants based on irradiated compost in dryland remediation to increase the growth of king grass and maize

    International Nuclear Information System (INIS)

    TRD Larasati; N Mulyana; D Sudradjat

    2016-01-01

    This research was conducted to evaluate the capability of functional microbial inoculants to remediate drylands. The microbial inoculants used consist of hydrocarbon-degrading microbial inoculants and plant-growth-promoting microbial inoculants. Compost-based carrier was sterilized by a gamma irradiation dose of 25 kGy to prepare seed inoculants. The irradiated-compost-based hydrocarbon-degrading microbial inoculants and king grass (Pennisetum purpureum Schumach.) were used to remediate oil-sludge-contaminated soil using in-situ composting for 60 days. The results showed that they could reduce THP (total petroleum hydrocarbons) by up to 82.23%. Plant-growth-promoting microbial inoculants were able to increase the dry weight of king grass from 47.39 to 100.66 g/plant, N uptake from 415.53 to 913.67 mg/plant, and P uptake from 76.52 to 178.33 mg/plant. Cow dung and irradiated-compost-based plant-growth-promoting microbial inoculants were able to increase the dry weight of maize (Zea mays L.) from 5.75 to 6.63 ton/ha (12.54%) and dry weight of grain potential from 5.30 to 7.15 ton/ha (35.03%). The results indicate that irradiated-compost-based microbial inoculants are suitable for remediating a dryland and therefore increase potential resources and improve the quality of the environment. (author)

  9. Effect of Chitosan Coating Containing Active Agents on Microbial Growth, Rancidity and Moisture Loss of Meatball During Storage

    OpenAIRE

    Pranoto, Yudi; Rakshit, Sudip Kumar

    2008-01-01

    Edible coatings based on chitosan were applied on meatball product in order to preserve quality during storages atambient and refrigeration temperatures. To improve its efficacy, chitosan coatings were incorporated with garlic oil0.2%, potassium sorbate 0.1 % and nisin 51,000 IU. The qualities of meatball assessed were total microbial growth, TBA value and percentage of moisture loss. All chitosan coatings suppressed microbial growth in meatball and strong- ly revealed when stored at refriger...

  10. Targeting fibroblast growth factor receptor signaling inhibits prostate cancer progression.

    Science.gov (United States)

    Feng, Shu; Shao, Longjiang; Yu, Wendong; Gavine, Paul; Ittmann, Michael

    2012-07-15

    Extensive correlative studies in human prostate cancer as well as studies in vitro and in mouse models indicate that fibroblast growth factor receptor (FGFR) signaling plays an important role in prostate cancer progression. In this study, we used a probe compound for an FGFR inhibitor, which potently inhibits FGFR-1-3 and significantly inhibits FGFR-4. The purpose of this study is to determine whether targeting FGFR signaling from all four FGFRs will have in vitro activities consistent with inhibition of tumor progression and will inhibit tumor progression in vivo. Effects of AZ8010 on FGFR signaling and invasion were analyzed using immortalized normal prostate epithelial (PNT1a) cells and PNT1a overexpressing FGFR-1 or FGFR-4. The effect of AZ8010 on invasion and proliferation in vitro was also evaluated in prostate cancer cell lines. Finally, the impact of AZ8010 on tumor progression in vivo was evaluated using a VCaP xenograft model. AZ8010 completely inhibits FGFR-1 and significantly inhibits FGFR-4 signaling at 100 nmol/L, which is an achievable in vivo concentration. This results in marked inhibition of extracellular signal-regulated kinase (ERK) phosphorylation and invasion in PNT1a cells expressing FGFR-1 and FGFR-4 and all prostate cancer cell lines tested. Treatment in vivo completely inhibited VCaP tumor growth and significantly inhibited angiogenesis and proliferation and increased cell death in treated tumors. This was associated with marked inhibition of ERK phosphorylation in treated tumors. Targeting FGFR signaling is a promising new approach to treating aggressive prostate cancer.

  11. Furfural Inhibits Growth by Limiting Sulfur Assimilation in Ethanologenic Escherichia coli Strain LY180▿

    Science.gov (United States)

    Miller, Elliot N.; Jarboe, Laura R.; Turner, Peter C.; Pharkya, Priti; Yomano, Lorraine P.; York, Sean W.; Nunn, David; Shanmugam, K. T.; Ingram, Lonnie O.

    2009-01-01

    A wide variety of commercial products can be potentially made from monomeric sugars produced by the dilute acid hydrolysis of lignocellulosic biomass. However, this process is accompanied by side products such as furfural that hinder microbial growth and fermentation. To investigate the mechanism of furfural inhibition, mRNA microarrays of an ethanologenic strain of Escherichia coli (LY180) were compared immediately prior to and 15 min after a moderate furfural challenge. Expression of genes and regulators associated with the biosynthesis of cysteine and methionine was increased by furfural, consistent with a limitation of these critical metabolites. This was in contrast to a general stringent response and decreased expression of many other biosynthetic genes. Of the 20 amino acids individually tested as supplements (100 μM each), cysteine and methionine were the most effective in increasing furfural tolerance with serine (precursor of cysteine), histidine, and arginine of lesser benefit. Supplementation with other reduced sulfur sources such as d-cysteine and thiosulfate also increased furfural tolerance. In contrast, supplementation with taurine, a sulfur source that requires 3 molecules of NADPH for sulfur assimilation, was of no benefit. Furfural tolerance was also increased by inserting a plasmid encoding pntAB, a cytoplasmic NADH/NADPH transhydrogenase. Based on these results, a model is proposed for the inhibition of growth in which the reduction of furfural by YqhD, an enzyme with a low Km for NADPH, depletes NADPH sufficiently to limit the assimilation of sulfur into amino acids (cysteine and methionine) by CysIJ (sulfite reductase). PMID:19684179

  12. Differential chlorate inhibition of Chaetomium globosum germination, hyphal growth, and perithecia synthesis.

    Science.gov (United States)

    Biles, Charles L; Wright, Desiree; Fuego, Marianni; Guinn, Angela; Cluck, Terry; Young, Jennifer; Martin, Markie; Biles, Josiah; Poudyal, Shubhra

    2012-12-01

    Chaetomium globosum Kunze:Fr is a dermatophytic, dematiaceous fungus that is ubiquitous in soils, grows readily on cellulolytic materials, and is commonly found on water-damaged building materials. Chlorate affects nitrogen metabolism in fungi and is used to study compatibility among anamorphic fungi by inducing nit mutants. The effect of chlorate toxicity on C. globosum was investigated by amending a modified malt extract agar (MEA), oat agar, and carboxymethyl cellulose agar (CMC) with various levels of potassium chlorate (KClO(3)). C. globosum perithecia production was almost completely inhibited (90-100 %) at low levels of KClO(3) (0.1 mM) in amended MEA. Inhibition of perithecia production was also observed on oat agar and CMC at 1 and 10 mM, respectively. However, hyphal growth in MEA was only inhibited 20 % by 0.1-100 mM KClO(3) concentrations. Hyphal growth was never completely inhibited at the highest levels tested (200 mM). Higher levels of KClO(3) were needed on gypsum board to inhibit perithecia synthesis. In additional experiments, KClO(3) did not inhibit C. globosum, Fusarium oxysporum, Aspergillus niger, Penicillum expansum, and airborne fungal spore germination. The various fungal spores were not inhibited by KClO(3) at 1-100 mM levels. These results suggest that C. globosum perithecia synthesis is more sensitive to chlorate toxicity than are hyphal growth and spore germination. This research provides basic information that furthers our understanding about perithecia formation and may help in developing control methods for fungal growth on building materials.

  13. The Growth Rate and Efficiency of Rumen Microbial Protein Digestion of Red Clover Silage (Trifolium pratense cv. Sabatron)

    International Nuclear Information System (INIS)

    Asih Kurniawati

    2004-01-01

    (Trifolium pratense cv. Sabatron). Red clover silage supplemented with different level of carbohydrates has been examined using the in-vitro gas production technique. Cumulative gas production, hydro.gen sulfite production, and ammonia was followed and used as indicators of microbial growth rate and extent of protein degradation. Microbial nitrogen production, VFA, and efficiency microbial production was used as indicator of nitrogen use efficiency. 15 N was used as a microbial marker to estimate the amount of nitrogen incorporation into microbial protein. Supplementation of Red clover with increasing 5 levels; 0 g; 0.625 g; 0.15 g; 0.225 g and 0.3 g of maize starch led to graded increase in microbial growth and protein degradation. This was reflected in the increasing gas production and the accumulation of hydrogen sulfite. Diurnal change in ammonia production reflected the microbial utilization of ammonia for protein synthesis. Protein microbe (P<0.001) as VFA (P<0.001) increased due to carbohydrate addition as well as utilization of nitrogen (P<0.001). There was also the efficiency of nitrogen utilization which increased significantly. This result suggested that energy supply can increased efficiency of nitrogen use in the rumen and may reduce nitrogen losses into the environment. (author)

  14. A comparative study of ethylene growth response kinetics in eudicots and monocots reveals a role for gibberellin in growth inhibition and recovery.

    Science.gov (United States)

    Kim, Joonyup; Wilson, Rebecca L; Case, J Brett; Binder, Brad M

    2012-11-01

    Time-lapse imaging of dark-grown Arabidopsis (Arabidopsis thaliana) hypocotyls has revealed new aspects about ethylene signaling. This study expands upon these results by examining ethylene growth response kinetics of seedlings of several plant species. Although the response kinetics varied between the eudicots studied, all had prolonged growth inhibition for as long as ethylene was present. In contrast, with continued application of ethylene, white millet (Panicum miliaceum) seedlings had a rapid and transient growth inhibition response, rice (Oryza sativa 'Nipponbare') seedlings had a slow onset of growth stimulation, and barley (Hordeum vulgare) had a transient growth inhibition response followed, after a delay, by a prolonged inhibition response. Growth stimulation in rice correlated with a decrease in the levels of rice ETHYLENE INSENSTIVE3-LIKE2 (OsEIL2) and an increase in rice F-BOX DOMAIN AND LRR CONTAINING PROTEIN7 transcripts. The gibberellin (GA) biosynthesis inhibitor paclobutrazol caused millet seedlings to have a prolonged growth inhibition response when ethylene was applied. A transient ethylene growth inhibition response has previously been reported for Arabidopsis ethylene insensitive3-1 (ein3-1) eil1-1 double mutants. Paclobutrazol caused these mutants to have a prolonged response to ethylene, whereas constitutive GA signaling in this background eliminated ethylene responses. Sensitivity to paclobutrazol inversely correlated with the levels of EIN3 in Arabidopsis. Wild-type Arabidopsis seedlings treated with paclobutrazol and mutants deficient in GA levels or signaling had a delayed growth recovery after ethylene removal. It is interesting to note that ethylene caused alterations in gene expression that are predicted to increase GA levels in the ein3-1 eil1-1 seedlings. These results indicate that ethylene affects GA levels leading to modulation of ethylene growth inhibition kinetics.

  15. PANC-1 pancreatic cancer cell growth inhibited by cucurmosin alone and in combination with an epidermal growth factor receptor-targeted drug.

    Science.gov (United States)

    Wang, Congfei; Yang, Aiqin; Zhang, Baoming; Yin, Qiang; Huang, Heguang; Chen, Minghuang; Xie, Jieming

    2014-03-01

    To investigate the inhibition of PANC-1 pancreatic cancer cell growth by cucurmosin (CUS) and its possible mechanism. We observed the inhibition of PANC-1 cell growth by sulforhodamine B and colony-forming experiments in vitro and established nonobese diabetic/severe combined immunodeficiency mouse subcutaneous tumor models in vivo. We used Western blot to analyze protein levels related to apoptosis and epidermal growth factor receptor (EGFR) signaling pathways after drug intervention, whereas the messenger RNA expression of EGFR was analyzed by quantitative real-time polymerase chain reaction. Sulforhodamine B and colony-forming experiments indicated that CUS inhibited PANC-1 cell proliferation in a dose- and time-dependent manner. A stronger inhibitory effect was observed when CUS was combined with gefitinib. The subcutaneous tumor growth was also inhibited. Western blot showed that all the examined proteins decreased, except for 4E-BP1 and the active fragments of caspase 3 and caspase 9 increased. Epidermal growth factor receptor expression did not change significantly in quantitative real-time polymerase chain reaction. Cucurmosin can strongly inhibit the growth of PANC-1 cells in vitro and in vivo. Cucurmosin can down-regulate EGFR protein expression, but not at the messenger RNA level. Cucurmosin can also inhibit the ras/raf and phosphatidylinositol 3-kinase/Akt downstream signaling pathways and enhance the sensitivity of the EGFR-targeted drug gefitinib.

  16. Performance evaluation of nanoclay enriched anti-microbial hydrogels for biomedical applications

    Directory of Open Access Journals (Sweden)

    Sonali Karnik

    2016-02-01

    Full Text Available A major factor contributing to the failure of orthopedic and orthodontic implants is post-surgical infection. Coating metallic implant surfaces with anti-microbial agents has shown promise but does not always prevent the formation of bacterial biofilms. Furthermore, breakdown of these coatings within the human body can cause release of the anti-microbial drugs in an uncontrolled or unpredictable fashion. In this study, we used a calcium alginate and calcium phosphate cement (CPC hydrogel composite as the base material and enriched these hydrogels with the anti-microbial drug, gentamicin sulfate, loaded within a halloysite nanotubes (HNTs. Our results demonstrate a sustained and extended release of gentamicin from hydrogels enriched with the gentamicin-loaded HNTs. When tested against the gram-negative bacteria, the hydrogel/nanoclay composites showed a pronounced zone of inhibition suggesting that anti-microbial doped nanoclay enriched hydrogels can prevent the growth of bacteria. The release of gentamicin sulfate for a period of five days from the nanoclay-enriched hydrogels would supply anti-microbial agents in a sustained and controlled manner and assist in preventing microbial growth and biofilm formation on the titanium implant surface. A pilot study, using mouse osteoblasts, confirmed that the nanoclay enriched surfaces are also cell supportive as osteoblasts readily, proliferated and produced a type I collagen and proteoglycan matrix.

  17. Life-history trait of the Mediterranean keystone species Patella rustica: growth and microbial bioerosion

    Directory of Open Access Journals (Sweden)

    I. PRUSINA

    2015-05-01

    Full Text Available The age and shell growth patterns in populations of Patella rustica of the Adriatic Sea were determined by analyzing the inner growth lines visible in shell sections. Marginal increment analysis showed annual periodicity with annual growth line being deposited in May. The growth analysis of 120 individual shells showed that 90.8 % of collected individuals were less than 4 years of age and only two individuals (1.6 % were older than 6 years. Population structure was described and the generalized von Bertalanffy growth parameters were calculated: asymptotic length (L∞ was 38.22 mm and the growth constant (K was 0.30 year-1. Growth performance index value of P. rustica (Ø’ was 2.64 and is among the lowest ranges reported for limpet species. Patella rustica shells were degraded to different degrees by microbial bioerosion. Microboring organisms identified were pseudofilamentous and filamentous cyanobacteria Hormathonema paulocellulare, Hyella caespitosa, Mastigocoleus testarum and Leptolyngbya sp. The overall intensity of infestation was relatively low, but increased in severity with shell length. The damage was most often restricted to the oldest parts of the shell, i.e. apex of the shell, posing difficulties in determining the exact position of the first growth line. The present study is first to introduce the use of inner growth lines in Patella rustica shell sections as a reliable method for age determination and it provides the first insight into the growth patterns of this keystone species while taking the interference of microbial shell bioerosion in consideration.

  18. Inhibition of placenta growth factor with TB-403

    DEFF Research Database (Denmark)

    Nielsen, Dorte Lisbet; Sengeløv, Lisa

    2012-01-01

    INTRODUCTION: There is clinical evidence that therapies targeting the vascular endothelial growth factor pathway are effective in delaying cancer progression. However, tumors may be either intrinsically resistant or evolve resistance to such therapies. Hence, there is a need for new therapies...... targeting angiogenesis. AREAS COVERED: The data are obtained by searching in the PubMed database. The search terms used included antiangiogenic therapy, TB-403 (RO5323441), placenta growth factor (PlGF) and VEGFR-1 (Flt-1). We review preclinical data concerning the function and inhibition of Pl......GF and summarize data on expression of PlGF in cancer patients. Data from early-phase clinical trials of TB-403 (RO5323441), a monoclonal antibody inhibiting PlGF, are discussed. Future development strategies, therapeutic potentials and limitations of TB-403 are further evaluated. EXPERT OPINION: There are some...

  19. Accounting for inherent variability of growth in microbial risk assessment.

    Science.gov (United States)

    Marks, H M; Coleman, M E

    2005-04-15

    Risk assessments of pathogens need to account for the growth of small number of cells under varying conditions. In order to determine the possible risks that occur when there are small numbers of cells, stochastic models of growth are needed that would capture the distribution of the number of cells over replicate trials of the same scenario or environmental conditions. This paper provides a simple stochastic growth model, accounting only for inherent cell-growth variability, assuming constant growth kinetic parameters, for an initial, small, numbers of cells assumed to be transforming from a stationary to an exponential phase. Two, basic, microbial sets of assumptions are considered: serial, where it is assume that cells transform through a lag phase before entering the exponential phase of growth; and parallel, where it is assumed that lag and exponential phases develop in parallel. The model is based on, first determining the distribution of the time when growth commences, and then modelling the conditional distribution of the number of cells. For the latter distribution, it is found that a Weibull distribution provides a simple approximation to the conditional distribution of the relative growth, so that the model developed in this paper can be easily implemented in risk assessments using commercial software packages.

  20. Flavonoids apigenin and quercetin inhibit melanoma growth and metastatic potential.

    Science.gov (United States)

    Caltagirone, S; Rossi, C; Poggi, A; Ranelletti, F O; Natali, P G; Brunetti, M; Aiello, F B; Piantelli, M

    2000-08-15

    Flavonoids are a class of polyphenolic compounds widely distributed in the plant kingdom, which display a variety of biological activities, including chemoprevention and tumor growth inhibition. Our aim was to investigate the effects of several polyphenols on the growth and metastatic potential of B16-BL6 melanoma cells in vivo. Intraperitoneal administration of quercetin, apigenin, (-)-epigallocathechin-3-gallate (EGCG), resveratrol, and the anti-estrogen tamoxifen, at the time of i.m. injection of B16-BL6 cells into syngeneic mice, resulted in a significant, dose-dependent delay of tumor growth, without toxicity. The relative descending order of potency was EGCG > apigenin = quercetin = tamoxifen > resveratrol > control. Furthermore, polyphenols significantly potentiated the inhibitory effect of a non-toxic dose of cisplatin. When tested for the ability to inhibit lung colonization, quercetin, apigenin, and tamoxifen (but not EGCG or resveratrol) significantly decreased the number of B16-BL6 colonies in the lungs in a dose-dependent manner, with quercetin and apigenin being more effective than tamoxifen. Interestingly, quercetin, apigenin, and tamoxifen (but not EGCG or resveratrol) significantly decreased the invasion of B16-BL6 cells in vitro, with quercetin and apigenin being more effective than tamoxifen. This suggests that anti-invasive activity is one of the mechanisms underlying inhibition of lung colonization by quercetin and apigenin. In conclusion, quercetin and apigenin inhibit melanoma growth and invasive and metastatic potential; therefore, they may constitute a valuable tool in the combination therapy of metastatic melanoma. Copyright 2000 Wiley-Liss, Inc.

  1. D-Tagatose inhibits the growth and biofilm formation of Streptococcus mutans

    Science.gov (United States)

    Hasibul, Khaleque; Nakayama-Imaohji, Haruyuki; Hashimoto, Masahito; Yamasaki, Hisashi; Ogawa, Takaaki; Waki, Junpei; Tada, Ayano; Yoneda, Saori; Tokuda, Masaaki; Miyake, Minoru; Kuwahara, Tomomi

    2018-01-01

    Dental caries is an important global health concern and Streptococcus mutans has been established as a major cariogenic bacterial species. Reports indicate that a rare sugar, D-tagatose, is not easily catabolized by pathogenic bacteria. In the present study, the inhibitory effects of D-tagatose on the growth and biofilm formation of S. mutans GS-5 were examined. Monitoring S. mutans growth over a 24 h period revealed that D-tagatose prolonged the lag phase without interfering with the final cell yield. This growth retardation was also observed in the presence of 1% sucrose, although it was abolished by the addition of D-fructose. S. mutans biofilm formation was significantly inhibited by growth in sucrose media supplemented with 1 and 4% D-tagatose compared with that in a culture containing sucrose alone, while S. mutans formed granular biofilms in the presence of this rare sugar. The inhibitory effect of D-tagatose on S. mutans biofilm formation was significantly more evident than that of xylitol. Growth in sucrose media supplemented with D-tagatose significantly decreased the expression of glucosyltransferase, exo-β-fructosidase and D-fructose-specific phosphotransferase genes but not the expression of fructosyltransferase compared with the culture containing sucrose only. The activity of cell-associated glucosyltransferase in S. mutans was inhibited by 4% D-tagatose. These results indicate that D-tagatose reduces water-insoluble glucan production from sucrose by inhibiting glucosyltransferase activities, which limits access to the free D-fructose released during this process and retards the growth of S. mutans. Therefore, foods and oral care products containing D-tagatose are anticipated to reduce the risk of caries by inhibiting S. mutans biofilm formation. PMID:29115611

  2. Microbial uptake of radiolabeled substrates: estimates of growth rates from time course measurements

    International Nuclear Information System (INIS)

    Li, W.K.W.

    1984-01-01

    The uptake of [ 3 H]glucose and a mixture of 3 H-labeled amino acids was measured, in time course fashion, in planktonic microbial assemblages of the eastern tropical Pacific Ocean. The average generation times of those portions of the assemblages able to utilize these substrates were estimated from a simple exponential growth model. Other workers have independently used this model in its integrated or differential form. A mathematical verification and an experimental demonstration of the equivalence of the two approaches are presented. A study was made of the size distribution of heterotrophic activity, using time course measurements. It was found that the size distribution and the effect of sample filtration before radiolabeling were dependent on time of incubation. In principle, it was possible to ascribe these time dependences to differences in th specific growth rate and initial standing stock of the microbial assemblages. 33 references

  3. p8 inhibits the growth of human pancreatic cancer cells and its expression is induced through pathways involved in growth inhibition and repressed by factors promoting cell growth

    Directory of Open Access Journals (Sweden)

    Vasseur Sophie

    2003-11-01

    Full Text Available Abstract Background p8 is a stress-induced protein with multiple functions and biochemically related to the architectural factor HMG-I/Y. We analyzed the expression and function of p8 in pancreatic cancer-derived cells. Methods Expression of p8 was silenced in the human pancreatic cancer cell lines Panc-1 and BxPc-3 by infection with a retrovirus expressing p8 RNA in the antisense orientation. Cell growth was measured in control and p8-silenced cells. Influence on p8 expression of the induction of intracellular pathways promoting cellular growth or growth arrest was monitored. Results p8-silenced cells grew more rapidly than control cells transfected with the empty retrovirus. Activation of the Ras→Raf→MEK→ERK and JNK intracellular pathways down-regulated p8 expression. In addition, the MEK1/2 inhibitor U0126 and the JNK inhibitor SP600125 up-regulates expression of p8. Conversely, p38 or TGFβ-1 induced p8 expression whereas the specific p38 inhibitor SB203580 down-regulated p8 expression. Finally, TGFβ-1 induction was in part mediated through p38. Conclusions p8 inhibits the growth of human pancreatic cancer cells. p8 expression is induced through pathways involved in growth inhibition and repressed by factors that promote cell growth. These results suggest that p8 belongs to a pathway regulating the growth of pancreatic cancer cells.

  4. A new diatom growth inhibition assay using the XTT colorimetric method.

    Science.gov (United States)

    Jiang, Weina; Akagi, Takuya; Suzuki, Hidekazu; Takimoto, Ayaka; Nagai, Hiroshi

    2016-01-01

    Marine biofouling, which leads to significant operational stress and economic damage on marine infrastructures, is a major problem in marine related industries. Currently, the most common way to avoid marine biofouling involves the use of biocidal products in surface coatings. However, the need for environmentally friendly antibiofouling compounds has increased rapidly with the recent global prohibition of harmful antifoulants, such as tributyltin (TBT). In particular, periphytic diatoms have been shown to contribute significantly to biofilms, which play an important role in biofouling. Therefore, inhibiting the proliferation of fouling diatoms is a very important step in the prevention of marine biofouling. In this study, we developed a new, rapid, accurate, and convenient growth inhibition assay using the XTT colorimetric method to prevent the growth of the fouling periphytic diatom, Nitzschia amabilis Hidek. Suzuki (replaced synonym, Nitzschia laevis Hustedt). The feasibility of this method was verified by determining the growth inhibition activities of two standard photosynthetic inhibitors, DCMU and CuSO4. However, neither inhibitor had any cytotoxic activities at the range of concentrations tested. Moreover, this method was applied by screening and purification of herbicidic but non-cytotoxic compounds from cyanobacteria extracts. Our results demonstrate the utility of this newly established growth inhibition assay for the identification of marine anti-biofouling compounds. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Mixed metal oxide nanoparticles inhibit growth of Mycobacterium tuberculosis into THP-1 cells

    Directory of Open Access Journals (Sweden)

    A R Jafari

    2016-01-01

    Conclusion: Although Ag NPs exhibited low cytotoxicity, they were unable to inhibit Mtb growth in vitro. ZnO NPs exhibited strong anti-Mtb activity and inhibited bacterial growth, but exhibited high cytotoxicity to human macrophage cells. By mixing Ag and ZnO NPs at a ratio of 8ZnO/2Ag, we acquired a mixture that exhibited potent antibacterial activity against Mtb and no cytotoxic effects on THP-1 cells, resulting in inhibition of both in vitro and ex vivo Mtb growth [Figure 1],[Figure 2],[Figure 3], [Table 1],[Table 2],[Table 3].{Figure 1}{Figure 2}{Figure 3} {Table 1}{Table 2}{Table 3}

  6. Platelet-Derived Growth Factor-Receptor α Strongly Inhibits Melanoma Growth In Vitro and In Vivo

    Directory of Open Access Journals (Sweden)

    Debora Faraone

    2009-08-01

    Full Text Available Cutaneous melanoma is the most aggressive skin cancer; it is highly metastatic and responds poorly to current therapies. The expression of platelet-derived growth factor receptors (PDGF-Rs is reported to be reduced in metastatic melanoma compared with benign nevi or normal skin; we then hypothesized that PDGF-Rα may control growth of melanoma cells. We show here that melanoma cells overexpressing PDGF-Rα respond to serum with a significantly lower proliferation compared with that of controls. Apoptosis, cell cycle arrest, pRb dephosphorylation, and DNA synthesis inhibition were also observed in cells overexpressing PDGF-Rα. Proliferation was rescued by PDGF-Rα inhibitors, allowing to exclude nonspecific toxic effects and indicating that PDGF-Rα mediates autocrine antiproliferation signals in melanoma cells. Accordingly, PDGF-Rα was found to mediate staurosporine cytotoxicity. A protein array-based analysis of the mitogen-activated protein kinase pathway revealed that melanoma cells overexpressing PDGF-Rα show a strong reduction of c-Jun phosphorylated in serine 63 and of protein phosphatase 2A/Bα and a marked increase of p38γ, mitogen-activated protein kinase kinase 3, and signal regulatory protein α1 protein expression. In a mouse model of primary melanoma growth, infection with the Ad-vector overexpressing PDGF-Rα reached a significant 70% inhibition of primary melanoma growth (P < .001 and a similar inhibition of tumor angiogenesis. All together, these data demonstrate that PDGF-Rα strongly impairs melanoma growth likely through autocrine mechanisms and indicate a novel endogenous mechanism involved in melanoma control.

  7. Mullerian Inhibiting Substances (MIS) Augments IFN-gamma Mediated Inhibition of Breast Cancer Cell Growth

    National Research Council Canada - National Science Library

    Gupta, Vandana

    2006-01-01

    MIS is a member of the TGF family. The purpose of this study is to test the hypothesis that MIS and IFN-gamma might be more effective in the inhibition of breast cancer cell growth than either agent alone...

  8. The effect of concentrating of whitewater to the microbial growth in papermachine; Paperikoneen kiertovesien konsentroitumisen vaikutus mikrobien kasvuun - MPKT 03

    Energy Technology Data Exchange (ETDEWEB)

    Yloestalo, T. [Helsinki Univ. of Technology, Otaniemi (Finland)

    1998-12-31

    The closing of the whitewater cycle increases the amount of nutrients available for the micro-organisms living in a papermachine. The microbial flora in papermachines can vary significantly. The type and concentration of nutrients and the operating conditions of the papermachine (for example pH and temperature) affect the type of microbes that may live there. Strong microbial contamination has negative impact to the quality of the products and the operation of the papermachine. In this project microbes isolated from papermachines are cultivated in different concentrations of whitewater and with different pH and temperature values. The cultivations of microbes and modeling of the microbial growth are used for finding out how the closing of the whitewater cycle affects the microbial growth in papermachines. (orig.)

  9. The effect of concentrating of whitewater to the microbial growth in papermachine; Paperikoneen kiertovesien konsentroitumisen vaikutus mikrobien kasvuun - MPKT 03

    Energy Technology Data Exchange (ETDEWEB)

    Yloestalo, T [Helsinki Univ. of Technology, Otaniemi (Finland)

    1999-12-31

    The closing of the whitewater cycle increases the amount of nutrients available for the micro-organisms living in a papermachine. The microbial flora in papermachines can vary significantly. The type and concentration of nutrients and the operating conditions of the papermachine (for example pH and temperature) affect the type of microbes that may live there. Strong microbial contamination has negative impact to the quality of the products and the operation of the papermachine. In this project microbes isolated from papermachines are cultivated in different concentrations of whitewater and with different pH and temperature values. The cultivations of microbes and modeling of the microbial growth are used for finding out how the closing of the whitewater cycle affects the microbial growth in papermachines. (orig.)

  10. Effect of gamma irradiation and storage time on microbial growth and physicochemical characteristics of pumpkin (Cucurbita Moschata Duchesne ex Poiret) puree.

    Science.gov (United States)

    Gliemmo, María F; Latorre, María E; Narvaiz, Patricia; Campos, Carmen A; Gerschenson, Lía N

    2014-01-01

    The effect of gamma irradiation (0-2 kGy) and storage time (0-28 days) on microbial growth and physicochemical characteristics of a packed pumpkin puree was studied. For that purpose, a factorial design was applied. The puree contained potassium sorbate, glucose and vanillin was stored at 25°C . Gamma irradiation diminished and storage time increased microbial growth. A synergistic effect between both variables on microbial growth was observed. Storage time decreased pH and color of purees. Sorbate content decreased with storage time and gamma irradiation. Mathematical models of microbial growth generated by the factorial design allowed estimating that a puree absorbing 1.63 kGy would have a shelf-life of 4 days. In order to improve this time, some changes in the applied hurdles were assayed. These included a thermal treatment before irradiation, a reduction of irradiation dose to 0.75 kGy and a decrease in storage temperature at 20°C . As a result, the shelf-life of purees increased to 28 days.

  11. Ultrasound-mediated interferon β gene transfection inhibits growth of malignant melanoma

    International Nuclear Information System (INIS)

    Yamaguchi, Kazuki; Feril, Loreto B.; Tachibana, Katsuro; Takahashi, Akira; Matsuo, Miki; Endo, Hitomi; Harada, Yoshimi; Nakayama, Juichiro

    2011-01-01

    Highlights: → Successful ultrasound-mediated transfection of melanoma (C32) cells with IFN-β genes both in vitro and in vivo. → Ultrasound-mediated IFN-β transfection inhibited proliferation of melanoma cells in vitro. → Ultrasound-mediated IFN-β transfection inhibited melanoma tumor growth in vivo. -- Abstract: We investigated the effects of ultrasound-mediated transfection (sonotransfection) of interferon β (IFN-β) gene on melanoma (C32) both in vitro and in vivo. C32 cells were sonotransfected with IFN-β in vitro. Subcutaneous C32 tumors in mice were sonicated weekly immediately after intra-tumor injection with IFN-β genes mixed with microbubbles. Successful sonotransfection with IFN-β gene in vitro was confirmed by ELISA, which resulted in C32 growth inhibition. In vivo, the growth ratio of tumors transfected with IFN-β gene was significantly lower than the other experimental groups. These results may lead to a new method of treatment against melanoma and other hard-to-treat cancers.

  12. Application of Sodium Silicate Enhances Cucumber Resistance to Fusarium Wilt and Alters Soil Microbial Communities

    Directory of Open Access Journals (Sweden)

    Xingang Zhou

    2018-05-01

    Full Text Available Exogenous silicates can enhance plant resistance to pathogens and change soil microbial communities. However, the relationship between changes in soil microbial communities and enhanced plant resistance remains unclear. Here, effects of exogenous sodium silicate on cucumber (Cucumis sativus L. seedling resistance to Fusarium wilt caused by the soil-borne pathogen Fusarium oxysporum f.sp. cucumerinum Owen (FOC were investigated by drenching soil with 2 mM sodium silicate. Soil bacterial and fungal community abundances and compositions were estimated by real-time PCR and high-throughput amplicon sequencing; then, feedback effects of changes in soil biota on cucumber seedling resistance to FOC were assessed. Moreover, effects of sodium silicate on the growth of FOC and Streptomyces DHV3-2, an antagonistic bacterium to FOC, were investigated both in vitro and in the soil environment. Results showed that exogenous sodium silicate enhanced cucumber seedling growth and resistance to FOC. In bare soil, sodium silicate increased bacterial and fungal community abundances and diversities. In cucumber-cultivated soil, sodium silicate increased bacterial community abundances, but decreased fungal community abundances and diversities. Sodium silicate also changed soil bacterial and fungal communality compositions, and especially, decreased the relative abundances of microbial taxa containing plant pathogens but increased these with plant-beneficial potentials. Moreover, sodium silicate increased the abundance of Streptomyces DHV3-2 in soil. Soil biota from cucumber-cultivated soil treated with sodium silicate decreased cucumber seedling Fusarium wilt disease index, and enhanced cucumber seedling growth and defense-related enzyme activities in roots. Sodium silicate at pH 9.85 inhibited FOC abundance in vitro, but did not affect FOC abundance in soil. Overall, our results suggested that, in cucumber-cultivated soil, sodium silicate increased cucumber seedling

  13. A theoretical reassessment of microbial maintenance and implications for microbial ecology modeling.

    Science.gov (United States)

    Wang, Gangsheng; Post, Wilfred M

    2012-09-01

    We attempted to reconcile three microbial maintenance models (Herbert, Pirt, and Compromise) through a theoretical reassessment. We provided a rigorous proof that the true growth yield coefficient (Y(G)) is the ratio of the specific maintenance rate (a in Herbert) to the maintenance coefficient (m in Pirt). Other findings from this study include: (1) the Compromise model is identical to the Herbert for computing microbial growth and substrate consumption, but it expresses the dependence of maintenance on both microbial biomass and substrate; (2) the maximum specific growth rate in the Herbert (μ(max,H)) is higher than those in the other two models (μ(max,P) and μ(max,C)), and the difference is the physiological maintenance factor (m(q) = a); and (3) the overall maintenance coefficient (m(T)) is more sensitive to m(q) than to the specific growth rate (μ(G)) and Y(G). Our critical reassessment of microbial maintenance provides a new approach for quantifying some important components in soil microbial ecology models. © This article is a US government work and is in the public domain in the USA.

  14. Osteoclast inhibition impairs chondrosarcoma growth and bone destruction.

    Science.gov (United States)

    Otero, Jesse E; Stevens, Jeff W; Malandra, Allison E; Fredericks, Douglas C; Odgren, Paul R; Buckwalter, Joseph A; Morcuende, Jose

    2014-12-01

    Because Chondrosarcoma is resistant to available chemotherapy and radiation regimens, wide resection is the mainstay in treatment, which frequently results in high morbidity and which may not prevent local recurrence. There is a clear need for improved adjuvant treatment of this malignancy. We have observed the presence of osteoclasts in the microenvironment of chondrosarcoma in human pathological specimens. We utilized the Swarm rat chondrosarcoma (SRC) model to test the hypothesis that osteoclasts affect chondrosarcoma pathogenesis. We implanted SRC tumors in tibia of Sprague-Dawley rats and analyzed bone histologically and radiographically for bone destruction and tumor growth. At three weeks, tumors invaded local bone causing cortical disruption and trabecular resorption. Bone destruction was accompanied by increased osteoclast number and resorbed bone surface. Treatment of rats with the zoledronic acid prevented cortical destruction, inhibited trabecular resorption, and resulted in decreased tumor volume in bone. To confirm that inhibition of osteoclasts per se, and not off-target effects of drug, was responsible for the prevention of tumor growth and bone destruction, we implanted SRC into osteopetrotic rat tibia. SRC-induced bone destruction and tumor growth were impaired in osteopetrotic bone compared with control bone. The results from our animal model demonstrate that osteoclasts contribute to chondrosarcoma-mediated bone destruction and tumor growth and may represent a therapeutic target in particular chondrosarcoma patients. © 2014 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  15. Genistein exposure inhibits growth and alters steroidogenesis in adult mouse antral follicles

    International Nuclear Information System (INIS)

    Patel, Shreya; Peretz, Jackye; Pan, Yuan-Xiang; Helferich, William G.; Flaws, Jodi A.

    2016-01-01

    Genistein is a naturally occurring isoflavone phytoestrogen commonly found in plant products such as soybeans, lentils, and chickpeas. Genistein, like other phytoestrogens, has the potential to mimic, enhance, or impair the estradiol biosynthesis pathway, thereby potentially altering ovarian follicle growth. Previous studies have inconsistently indicated that genistein exposure may alter granulosa cell proliferation and hormone production, but no studies have examined the effects of genistein on intact antral follicles. Thus, this study was designed to test the hypothesis that genistein exposure inhibits follicle growth and steroidogenesis in intact antral follicles. To test this hypothesis, antral follicles isolated from CD-1 mice were cultured with vehicle (dimethyl sulfoxide; DMSO) or genistein (6.0 and 36 μM) for 18–96 h. Every 24 h, follicle diameters were measured to assess growth. At the end of each culture period, the media were pooled to measure hormone levels, and the cultured follicles were collected to measure expression of cell cycle regulators and steroidogenic enzymes. The results indicate that genistein (36 μM) inhibits growth of mouse antral follicles. Additionally, genistein (6.0 and 36 μM) increases progesterone, testosterone, and dehydroepiandrosterone (DHEA) levels, but decreases estrone and estradiol levels. The results also indicate that genistein alters the expression of steroidogenic enzymes at 24, 72 and 96 h, and the expression of cell cycle regulators at 18 h. These data indicate that genistein exposure inhibits antral follicle growth by inhibiting the cell cycle, alters sex steroid hormone levels, and dysregulates steroidogenic enzymes in cultured mouse antral follicles. - Highlights: • Genistein exposure inhibits antral follicle growth. • Genistein exposure alters expression of cell cycle regulators. • Genistein exposure alters sex steroid hormones. • Genistein exposure alters expression of steroidogenic enzymes.

  16. Genistein exposure inhibits growth and alters steroidogenesis in adult mouse antral follicles

    Energy Technology Data Exchange (ETDEWEB)

    Patel, Shreya, E-mail: Shreya.patel214@gmail.com [Department of Comparative Biosciences, University of Illinois, 2001 S. Lincoln Ave, Urbana, IL 61802 (United States); Peretz, Jackye, E-mail: Jackye.peretz@gmail.com [Department of Comparative Biosciences, University of Illinois, 2001 S. Lincoln Ave, Urbana, IL 61802 (United States); Pan, Yuan-Xiang, E-mail: yxpan@illinois.edu [Department of Food Science and Human Nutrition, University of Illinois, 905 S. Goodwin, Urbana, IL 61801 (United States); Helferich, William G., E-mail: helferic@illinois.edu [Department of Food Science and Human Nutrition, University of Illinois, 905 S. Goodwin, Urbana, IL 61801 (United States); Flaws, Jodi A., E-mail: jflaws@illinois.edu [Department of Comparative Biosciences, University of Illinois, 2001 S. Lincoln Ave, Urbana, IL 61802 (United States)

    2016-02-15

    Genistein is a naturally occurring isoflavone phytoestrogen commonly found in plant products such as soybeans, lentils, and chickpeas. Genistein, like other phytoestrogens, has the potential to mimic, enhance, or impair the estradiol biosynthesis pathway, thereby potentially altering ovarian follicle growth. Previous studies have inconsistently indicated that genistein exposure may alter granulosa cell proliferation and hormone production, but no studies have examined the effects of genistein on intact antral follicles. Thus, this study was designed to test the hypothesis that genistein exposure inhibits follicle growth and steroidogenesis in intact antral follicles. To test this hypothesis, antral follicles isolated from CD-1 mice were cultured with vehicle (dimethyl sulfoxide; DMSO) or genistein (6.0 and 36 μM) for 18–96 h. Every 24 h, follicle diameters were measured to assess growth. At the end of each culture period, the media were pooled to measure hormone levels, and the cultured follicles were collected to measure expression of cell cycle regulators and steroidogenic enzymes. The results indicate that genistein (36 μM) inhibits growth of mouse antral follicles. Additionally, genistein (6.0 and 36 μM) increases progesterone, testosterone, and dehydroepiandrosterone (DHEA) levels, but decreases estrone and estradiol levels. The results also indicate that genistein alters the expression of steroidogenic enzymes at 24, 72 and 96 h, and the expression of cell cycle regulators at 18 h. These data indicate that genistein exposure inhibits antral follicle growth by inhibiting the cell cycle, alters sex steroid hormone levels, and dysregulates steroidogenic enzymes in cultured mouse antral follicles. - Highlights: • Genistein exposure inhibits antral follicle growth. • Genistein exposure alters expression of cell cycle regulators. • Genistein exposure alters sex steroid hormones. • Genistein exposure alters expression of steroidogenic enzymes.

  17. Structural, spectroscopic and anti-microbial inspection of PEG capped ZnO nanoparticles for biomedical applications

    Science.gov (United States)

    Meshram, J. V.; Koli, V. B.; Kumbhar, S. G.; Borde, L. C.; Phadatare, M. R.; Pawar, S. H.

    2018-04-01

    Zinc oxide (ZnO) nanoparticles (NPs) have a wide range of biomedical applications. Present study demonstrates the new methodology in sol-gel technology for synthesizing Polyethylene glycol (PEG) capped ZnO NPs and its size effect on anti-microbial activity. The reaction time was increased from 1 h to 5 h for the synthesis of ZnO NPs at 130 °C. The size of PEG capped ZnO NPs is increased from 10 to 84 nm by increasing the reaction upto 5 h. The x-ray diffraction studies and transmission electron microscopy analysis reveals the phase purity and hexagonal wurtzite crystal structure with uniform PEG capping on the surface of ZnO NPs. UV–visible spectroscopy exhibits the peak at 366 nm which is attributed to ZnO NPs. No adverse effect is observed in case of absorbance spectroscopy. Further, Fourier transforms infrared spectroscopy and thermo gravimetric analysis depicts the adsorption of PEG molecules on the ZnO NPs surface. The anti-microbial activities for both Gram-positive (S. aureus) and Gram-negative (E. coli) bacteria were studied by optical density (OD) mesurement. The remarkable anti-microbial activity was observed for PEG capped ZnO NPs synthesized at 1 h reaction time showing higher activity in comparison with that synthesized from 2 h to 5 h reaction time. The microbial growth was found to be inhibited after 10 h OD measurement for both the bacteria. The anti-microbial activity may be attributed to the generation of ROS and H2O2. However, these generated species plays a vital role in inhibition of microbial growth. Hence, PEG capped ZnO NPs has promising biomedical applications.

  18. Drug Repurposing Screening Identifies Novel Compounds That Effectively Inhibit Toxoplasma gondii Growth

    Science.gov (United States)

    Dittmar, Ashley J.; Drozda, Allison A.

    2016-01-01

    ABSTRACT The urgent need to develop new antimicrobial therapies has spawned the development of repurposing screens in which well-studied drugs and other types of compounds are tested for potential off-label uses. As a proof-of-principle screen to identify compounds effective against Toxoplasma gondii, we screened a collection of 1,120 compounds for the ability to significantly reduce Toxoplasma replication. A total of 94 compounds blocked parasite replication with 50% inhibitory concentrations of parasite invasion and replication but did so independently of inhibition of dopamine or other neurotransmitter receptor signaling. Tamoxifen, which is an established inhibitor of the estrogen receptor, also reduced parasite invasion and replication. Even though Toxoplasma can activate the estrogen receptor, tamoxifen inhibits parasite growth independently of this transcription factor. Tamoxifen is also a potent inducer of autophagy, and we find that the drug stimulates recruitment of the autophagy marker light chain 3-green fluorescent protein onto the membrane of the vacuolar compartment in which the parasite resides and replicates. In contrast to other antiparasitic drugs, including pimozide, tamoxifen treatment of infected cells leads to a time-dependent elimination of intracellular parasites. Taken together, these data suggest that tamoxifen restricts Toxoplasma growth by inducing xenophagy or autophagic destruction of this obligate intracellular parasite. IMPORTANCE There is an urgent need to develop new therapies to treat microbial infections, and the repurposing of well-characterized compounds is emerging as one approach to achieving this goal. Using the protozoan parasite Toxoplasma gondii, we screened a library of 1,120 compounds and identified several compounds with significant antiparasitic activities. Among these were pimozide and tamoxifen, which are well-characterized drugs prescribed to treat patients with psychiatric disorders and breast cancer

  19. Impact of Microbial Growth on Subsurface Perfluoroalkyl Acid Transport

    Science.gov (United States)

    Weathers, T. S.; Higgins, C. P.; Sharp, J.

    2014-12-01

    The fate and transport of poly and perfluoroalkyl substances (PFASs) in the presence of active microbial communities has not been widely investigated. These emerging contaminants are commonly utilized in aqueous film-forming foams (AFFF) and have often been detected in groundwater. This study explores the transport of a suite of perfluorocarboxylic acids and perfluoroalkylsulfonates, including perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS), in microbially active settings. Single point organic carbon normalized sorption coefficients derived by exposing inactive cellular material to PFASs result in more than an order of magnitude increase in sorption compared to soil organic carbon sorption coefficients found in literature. For example, the sorption coefficients for PFOS are 4.05±0.07 L/kg and 2.80±0.08 L/kg for cellular organic carbon and soil organic carbon respectively. This increase in sorption, coupled with enhanced extracellular polymeric substance production observed during growth of a common hydrocarbon degrading soil microbe exposed to source-level concentrations of PFASs (10 mg/L of 11 analytes, 110 mg/L total) may result in PFAS retardation in situ. To address the upscaling of this phenomenon, flow-through columns packed with low-organic carbon sediment and biostimulated with 10 mg/L glucose were exposed to PFAS concentrations from 15 μg/L to 10 mg/L of each 11 analytes. Breakthrough and tailing of each analyte was measured and modeled with Hydrus-1D to explore sorption coefficients over time for microbially active columns.

  20. Common Cutaneous Bacteria Isolated from Snakes Inhibit Growth of Ophidiomyces ophiodiicola.

    Science.gov (United States)

    Hill, Aubree J; Leys, Jacob E; Bryan, Danny; Erdman, Fantasia M; Malone, Katherine S; Russell, Gabrielle N; Applegate, Roger D; Fenton, Heather; Niedringhaus, Kevin; Miller, Andrew N; Allender, Matthew C; Walker, Donald M

    2018-03-01

    There is increasing concern regarding potential impacts of snake fungal disease (SFD), caused by Ophidiomyces ophiodiicola (Oo), on free-ranging snake populations in the eastern USA. The snake cutaneous microbiome likely serves as the first line of defense against Oo and other pathogens; however, little is known about microbial associations in snakes. The objective of this study was to better define the composition and immune function of the snake cutaneous microbiome. Eight timber rattlesnakes (Crotalus horridus) and four black racers (Coluber constrictor) were captured in Arkansas and Tennessee, with some snakes exhibiting signs of SFD. Oo was detected through real-time qPCR in five snakes. Additional histopathological techniques confirmed a diagnosis of SFD in one racer, the species' first confirmed case of SFD in Tennessee. Fifty-eight bacterial and five fungal strains were isolated from skin swabs and identified with Sanger sequencing. Non-metric multidimensional scaling and PERMANOVA analyses indicated that the culturable microbiome does not differ between snake species. Fifteen bacterial strains isolated from rattlesnakes and a single strain isolated from a racer inhibited growth of Oo in vitro. Results shed light on the culturable cutaneous microbiome of snakes and probiotic members that may play a role in fighting an emergent disease.

  1. Microbial corrosion resistance of galvanized coatings with 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one as a biocidal ingredient in electrolytes

    International Nuclear Information System (INIS)

    Zhai, Xiaofan; Myamina, Maria; Duan, Jizhou; Hou, Baorong

    2013-01-01

    Highlights: •Addition of DCOIT to zinc electrolyte increases current efficiency. •Zn deposited from electrolytes with DCOIT inhibits growth and metabolism of SRB. •DCOIT on coating surfaces influences the coating structure and morphology. •EIS and polarization results show good microbial-corrosion resistance in SRB. -- Abstract: Electrodeposition of galvanized coatings from electrolyte containing 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one (DCOIT) can increase microbial corrosion resistance. Coatings were found to inhibit the growth and metabolism of sulphate-reducing bacteria (SRB). Open circuit potentials and corrosion rates of coupons revealed DCOIT effectively influences the coating property. Energy diffraction spectrum and infrared absorption spectra were used to detect DCOIT on the coating surface. Scanning electron microscopy and X-ray diffraction revealed morphological and structural modifications. Electrochemical impedance spectroscopy and polarization techniques determined the corrosion behaviour of coatings in SRB. Results showed coatings formed from electrolytes with DCOIT have improved microbial corrosion resistance and bactericidal action

  2. Glyphosate and AMPA inhibit cancer cell growth through inhibiting intracellular glycine synthesis.

    Science.gov (United States)

    Li, Qingli; Lambrechts, Mark J; Zhang, Qiuyang; Liu, Sen; Ge, Dongxia; Yin, Rutie; Xi, Mingrong; You, Zongbing

    2013-01-01

    Glycine is a nonessential amino acid that is reversibly converted from serine intracellularly by serine hydroxymethyltransferase. Glyphosate and its degradation product, aminomethylphosphonic acid (AMPA), are analogs to glycine, thus they may inhibit serine hydroxymethyltransferase to decrease intracellular glycine synthesis. In this study, we found that glyphosate and AMPA inhibited cell growth in eight human cancer cell lines but not in two immortalized human normal prostatic epithelial cell lines. AMPA arrested C4-2B and PC-3 cancer cells in the G1/G0 phase and inhibited entry into the S phase of the cell cycle. AMPA also promoted apoptosis in C4-2B and PC-3 cancer cell lines. AMPA upregulated p53 and p21 protein levels as well as procaspase 9 protein levels in C4-2B cells, whereas it downregulated cyclin D3 protein levels. AMPA also activated caspase 3 and induced cleavage of poly (adenosine diphosphate [ADP]-ribose) polymerase. This study provides the first evidence that glyphosate and AMPA can inhibit proliferation and promote apoptosis of cancer cells but not normal cells, suggesting that they have potentials to be developed into a new anticancer therapy.

  3. Di(2-ethylhexyl) phthalate inhibits antral follicle growth, induces atresia, and inhibits steroid hormone production in cultured mouse antral follicles

    Energy Technology Data Exchange (ETDEWEB)

    Hannon, Patrick R., E-mail: phannon2@illinois.edu; Brannick, Katherine E., E-mail: kbran@illinois.edu; Wang, Wei, E-mail: Wei.Wang2@covance.com; Gupta, Rupesh K., E-mail: drrupesh@yahoo.com; Flaws, Jodi A., E-mail: jflaws@illinois.edu

    2015-04-01

    Di(2-ethylhexyl) phthalate (DEHP) is a ubiquitous environmental toxicant found in consumer products that causes ovarian toxicity. Antral follicles are the functional ovarian units and must undergo growth, survival from atresia, and proper regulation of steroidogenesis to ovulate and produce hormones. Previous studies have determined that DEHP inhibits antral follicle growth and decreases estradiol levels in vitro; however, the mechanism by which DEHP elicits these effects is unknown. The present study tested the hypothesis that DEHP directly alters regulators of the cell cycle, apoptosis, and steroidogenesis to inhibit antral follicle functionality. Antral follicles from adult CD-1 mice were cultured with vehicle control or DEHP (1–100 μg/ml) for 24–96 h to establish the temporal effects of DEHP on the follicle. Following 24–96 h of culture, antral follicles were subjected to gene expression analysis, and media were subjected to measurements of hormone levels. DEHP increased the mRNA levels of cyclin D2, cyclin dependent kinase 4, cyclin E1, cyclin A2, and cyclin B1 and decreased the levels of cyclin-dependent kinase inhibitor 1A prior to growth inhibition. Additionally, DEHP increased the mRNA levels of BCL2-associated agonist of cell death, BCL2-associated X protein, BCL2-related ovarian killer protein, B-cell leukemia/lymphoma 2, and Bcl2-like 10, leading to an increase in atresia. Further, DEHP decreased the levels of progesterone, androstenedione, and testosterone prior to the decrease in estradiol levels, with decreased mRNA levels of side-chain cleavage, 17α-hydroxylase-17,20-desmolase, 17β-hydroxysteroid dehydrogenase, and aromatase. Collectively, DEHP directly alters antral follicle functionality by inhibiting growth, inducing atresia, and inhibiting steroidogenesis. - Highlights: • DEHP inhibits antral follicle growth by dysregulating cell cycle regulators. • DEHP induces antral follicle atresia by dysregulating apoptosis regulators. • DEHP

  4. Di(2-ethylhexyl) phthalate inhibits antral follicle growth, induces atresia, and inhibits steroid hormone production in cultured mouse antral follicles

    International Nuclear Information System (INIS)

    Hannon, Patrick R.; Brannick, Katherine E.; Wang, Wei; Gupta, Rupesh K.; Flaws, Jodi A.

    2015-01-01

    Di(2-ethylhexyl) phthalate (DEHP) is a ubiquitous environmental toxicant found in consumer products that causes ovarian toxicity. Antral follicles are the functional ovarian units and must undergo growth, survival from atresia, and proper regulation of steroidogenesis to ovulate and produce hormones. Previous studies have determined that DEHP inhibits antral follicle growth and decreases estradiol levels in vitro; however, the mechanism by which DEHP elicits these effects is unknown. The present study tested the hypothesis that DEHP directly alters regulators of the cell cycle, apoptosis, and steroidogenesis to inhibit antral follicle functionality. Antral follicles from adult CD-1 mice were cultured with vehicle control or DEHP (1–100 μg/ml) for 24–96 h to establish the temporal effects of DEHP on the follicle. Following 24–96 h of culture, antral follicles were subjected to gene expression analysis, and media were subjected to measurements of hormone levels. DEHP increased the mRNA levels of cyclin D2, cyclin dependent kinase 4, cyclin E1, cyclin A2, and cyclin B1 and decreased the levels of cyclin-dependent kinase inhibitor 1A prior to growth inhibition. Additionally, DEHP increased the mRNA levels of BCL2-associated agonist of cell death, BCL2-associated X protein, BCL2-related ovarian killer protein, B-cell leukemia/lymphoma 2, and Bcl2-like 10, leading to an increase in atresia. Further, DEHP decreased the levels of progesterone, androstenedione, and testosterone prior to the decrease in estradiol levels, with decreased mRNA levels of side-chain cleavage, 17α-hydroxylase-17,20-desmolase, 17β-hydroxysteroid dehydrogenase, and aromatase. Collectively, DEHP directly alters antral follicle functionality by inhibiting growth, inducing atresia, and inhibiting steroidogenesis. - Highlights: • DEHP inhibits antral follicle growth by dysregulating cell cycle regulators. • DEHP induces antral follicle atresia by dysregulating apoptosis regulators. • DEHP

  5. Interactions between selected PAHs and the microbial community in rhizosphere of a paddy soil.

    Science.gov (United States)

    Su, Yu H; Yang, Xue Y

    2009-01-15

    This study investigated the interaction of three polycyclic aromatic hydrocarbons (PAHs), i.e., naphthalene (NAP), phenanthrene (PHN), and pyrene (PYR), with the microbial community in the rhizosphere of a paddy soil and the influence of the rice (Oryza sativa) rhizosphere on the microbial community structure. A range of initial NAP, PHN and PYR levels in soil (50-200, 18-72, and 6.6-26.6 mg kg(-1), respectively) were prepared and the soil samples were then aged for 4 months (to yield PAH concentrations at 1.02-1.42, 1.32-4.77, and 2.98-18.5 mg kg(-)(1), respectively) before the soil samples were planted with rice seedlings. The microbial phospholipid-fatty-acid (PLFA) patterns in PAH-contaminated soils were analyzed to elucidate the changes of the microbial biomass and community composition. Results indicated that at the applied concentrations the PAHs were not toxic to rice seedlings, as evidenced by no growth inhibition during the 8-week planting period. However, the microbial biomass, as revealed by PLFAs, decreased significantly with increasing PAH concentration in both rhizospheric and non-rhizospheric soils. The PAHs in soils were obviously toxic to microorganisms, and the toxicity of PHN was greater than PYR due likely to the higher PHN bioavailability. Total PLFAs in rhizospheric soils were profoundly higher than those in non-rhizospheric soils, suggesting that the inhibitive effect of PAHs on microbial activities was alleviated by the rice roots. The principal component analysis (PCA) of the PLFA signatures revealed pronounced changes in PLFA pattern in rhizospheric and non-rhizospheric soils with or without spiked PAHs. Using the PLFA patterns as a biomarker, it was found that Gram-positive bacteria were more sensitive to PAHs than Gram-negative bacteria, and the rhizosphere of rice roots stimulated the growth of aerobic bacteria.

  6. Lactam inhibiting Streptococcus mutans growth on titanium

    International Nuclear Information System (INIS)

    Xavier, J.G.; Geremias, T.C.; Montero, J.F.D.; Vahey, B.R.; Benfatti, C.A.M.; Souza, J.C.M.; Magini, R.S.; Pimenta, A.L.

    2016-01-01

    The aim of this work was to analyze the activity of novel synthetic lactams on preventing biofilm formation on titanium surfaces. Titanium (Ti6Al4V) samples were exposed to Streptococcus mutans cultures in the presence or absence of a synthetic lactam. After 48 h incubation, planktonic growth was determined by spectrophotometry. Biofilm was evaluated by crystal violet staining and colony forming units (CFU·ml −1 ), followed by scanning electron microscopy (SEM). Results showed that the average of adhered viable cells was approximately 1.5 × 10 2 CFU/ml in the presence of lactam and 4 × 10 2 CFU/ml in its absence. This novel compound was considerable active in reducing biofilm formation over titanium surfaces, indicating its potential for the development of antimicrobial drugs targeting the inhibition of the initial stages of bacterial biofilms on dental implants abutments. - Highlights: • A novel synthetic compound is tested on preventing biofilm formation on titanium surfaces • Biofilm inhibition has been achieved on titanium surfaces containing the novel compound. • Planktonic growth of S. mutans was not affected by the presence of lactams on titanium.

  7. Lactam inhibiting Streptococcus mutans growth on titanium

    Energy Technology Data Exchange (ETDEWEB)

    Xavier, J.G.; Geremias, T.C.; Montero, J.F.D. [Center for Research on Dental Implants (CEPID), School of Dentistry (ODT), Federal University of Santa Catarina - UFSC, Florianópolis/SC, 88040-900 (Brazil); Vahey, B.R. [Herman Ostrow School of Dentistry of USC, 925 W 34 St, Los Angeles, CA 90089 (United States); Benfatti, C.A.M.; Souza, J.C.M.; Magini, R.S. [Center for Research on Dental Implants (CEPID), School of Dentistry (ODT), Federal University of Santa Catarina - UFSC, Florianópolis/SC, 88040-900 (Brazil); Pimenta, A.L., E-mail: andrea@intelab.ufsc.br [Department of Biologia, ERRMECe, Université de Cergy Pontoise, 2, Av. Adolphe Chauvin 95302 Cergy, Pontoise (France); Integrated Laboratories Technologies (InteLab), Dept. Chemical and Food Engineering (EQA), Federal University of Santa Catarina - UFSC, Florianópolis/SC, 88040-970 (Brazil)

    2016-11-01

    The aim of this work was to analyze the activity of novel synthetic lactams on preventing biofilm formation on titanium surfaces. Titanium (Ti6Al4V) samples were exposed to Streptococcus mutans cultures in the presence or absence of a synthetic lactam. After 48 h incubation, planktonic growth was determined by spectrophotometry. Biofilm was evaluated by crystal violet staining and colony forming units (CFU·ml{sup −1}), followed by scanning electron microscopy (SEM). Results showed that the average of adhered viable cells was approximately 1.5 × 10{sup 2} CFU/ml in the presence of lactam and 4 × 10{sup 2} CFU/ml in its absence. This novel compound was considerable active in reducing biofilm formation over titanium surfaces, indicating its potential for the development of antimicrobial drugs targeting the inhibition of the initial stages of bacterial biofilms on dental implants abutments. - Highlights: • A novel synthetic compound is tested on preventing biofilm formation on titanium surfaces • Biofilm inhibition has been achieved on titanium surfaces containing the novel compound. • Planktonic growth of S. mutans was not affected by the presence of lactams on titanium.

  8. Growth inhibition of shrimp pathogens by isolated gastrointestinal microflora of Macrobrachium rosenbergii de Man

    Directory of Open Access Journals (Sweden)

    Seehanat, S.

    2005-02-01

    Full Text Available The useful bacteria which were isolated from the gastrointestinal tract of freshwater prawn (Macrobrachium rosenbergii de Man, cultivated in earthen pond at Maha Sarakham province, Thailand, consisted of 14 isolates of Bacillus (B1 – B14 and 18 isolates of Lactic acid bacteria (LA1 – LA18. The abilities of all isolated bacteria on growth inhibition of pathogenic bacteria (Escherichia coli, Bacillus cereus, Aeromonas hydrophila and Pseudomonas aeruginosa were studied by paperdisc plate method. The results showed that the Bacillus B2 and B5 were unable to inhibit the growth of all of the tested pathogens. Bacillus B1, B10 and B12 were capable of inhibiting the growth of 3 of 4 tested pathogen strains. Although all of the isolated lactic acid bacteria (LA1 –LA18 could not inhibit the E. coli growth, all of them could inhibit the growth of B. cereus. The isolated lactic acid bacteria which were capable of inhibiting the growth of 3 tested pathogen strains (excluded E. coli were LA12 , LA13 , LA14 , LA15 , LA16 , LA17 and LA18. In order to select the high potential strain of bacteria for using as probiotics, Bacillus B1 , B3 , B4 , B10 and B12 and lactic acid bacteria LA12 , LA13 , LA14 , LA15 , LA16 , LA17 and LA18 were tested for their growth abilities in various growth conditions. The tested growth conditions included various concentrations of the bile salt and salt (NaCl and various pH and temperatures. The results revealed that Bacillus B1 and B10 and lactic acid bacteria LA13 , LA16 and LA18 exhibited high potential for using as probiotics. The results of biochemical test for identification of these high potential strains showed that Bacillus B1 and B10 were possibly B. licheniformis and B. thuringiensis respectively. The lactic acid bacteria LA13 , LA16 and LA18 were possibly the same strain and belonged to the genus Pediococcus.

  9. The effect of dosages of microbial consortia formulation and synthetic fertilizer on the growth and yield of field-grown chili

    Science.gov (United States)

    Istifadah, N.; Sapta, D.; Krestini, H.; Natalie, B.; Suryatmana, P.; Nurbaity, A.; Hidersah, R.

    2018-03-01

    Chili (Capsicum annuum, L) is one of important horticultural crop in Indonesia. Formulation of microbial consortia containing Bacillus subtilis, Pseudomonas sp., Azotobacter chroococcum and Trichoderma harzianum has been developed. This study evaluated the effects of dosage of the microbial formulation combined with NPK fertilizer on growth and yield of chili plants in the field experiment. The experiment was arranged in completely randomized design of factorial, in which the first factor was dosage of formulation (0, 2.5, 5.0, 7.5, 10 g per plant) and the second factor was NPK fertilizer dosage (0, 25, 50 and 75% of the standard dosage). The treatments were replicated three times. For application, the formulation was mixed with chicken manure 1:10 (w/v). The results showed that application of microbial formulation solely improved the chili growth. There was interaction between dosages of the microbial formulation and NPK fertilizer in improving plant height, nitrogen availability and the chili yield, while there was no interaction between those dosages in improving the root length. Combination between microbial formulation at the dosage of 5.0-7.5 g per plant combined with NPK fertilizer with the dosage 50 or 75% of the standard dosage support relatively better growth and the chili yield.

  10. Shifts in microbial populations in Rusitec fermenters as affected by the type of diet and impact of the method for estimating microbial growth (15N v. microbial DNA).

    Science.gov (United States)

    Mateos, I; Ranilla, M J; Saro, C; Carro, M D

    2017-11-01

    offered similar results for diets comparison, but both methods presented contrasting results for microbial growth in SOL and LIQ phases. The study showed that fermentation parameters remained fairly stable over the commonly used sampling period (days 8 to 14), but shifts in microbial populations were detected. Moreover, microbial populations differed markedly from those in the inocula, which indicates the difficulty of directly transposing results on microbial populations developed in Rusitec fermenters to in vivo conditions.

  11. Use of an uncertainty analysis for genome-scale models as a prediction tool for microbial growth processes in subsurface environments.

    Science.gov (United States)

    Klier, Christine

    2012-03-06

    The integration of genome-scale, constraint-based models of microbial cell function into simulations of contaminant transport and fate in complex groundwater systems is a promising approach to help characterize the metabolic activities of microorganisms in natural environments. In constraint-based modeling, the specific uptake flux rates of external metabolites are usually determined by Michaelis-Menten kinetic theory. However, extensive data sets based on experimentally measured values are not always available. In this study, a genome-scale model of Pseudomonas putida was used to study the key issue of uncertainty arising from the parametrization of the influx of two growth-limiting substrates: oxygen and toluene. The results showed that simulated growth rates are highly sensitive to substrate affinity constants and that uncertainties in specific substrate uptake rates have a significant influence on the variability of simulated microbial growth. Michaelis-Menten kinetic theory does not, therefore, seem to be appropriate for descriptions of substrate uptake processes in the genome-scale model of P. putida. Microbial growth rates of P. putida in subsurface environments can only be accurately predicted if the processes of complex substrate transport and microbial uptake regulation are sufficiently understood in natural environments and if data-driven uptake flux constraints can be applied.

  12. Exogenous ethylene inhibits sprout growth in onion bulbs.

    Science.gov (United States)

    Bufler, Gebhard

    2009-01-01

    Exogenous ethylene has recently gained commercial interest as a sprouting inhibitor of onion bulbs. The role of ethylene in dormancy and sprouting of onions, however, is not known. A cultivar (Allium cepa 'Copra') with a true period of dormancy was used. Dormant and sprouting states of onion bulbs were treated with supposedly saturating doses of ethylene or with the ethylene-action inhibitor 1-methylcyclopropene (1-MCP). Initial sprouting was determined during storage at 18 degrees C by monitoring leaf blade elongation in a specific size class of leaf sheaths. Changes in ATP content and sucrose synthase activity in the sprout leaves, indicators of the sprouting state, were determined. CO(2) and ethylene production of onion bulbs during storage were recorded. Exogenous ethylene suppressed sprout growth of both dormant and already sprouting onion bulbs by inhibiting leaf blade elongation. In contrast to this growth-inhibiting effect, ethylene stimulated CO(2) production by the bulbs about 2-fold. The duration of dormancy was not significantly affected by exogenous ethylene. However, treatment of dormant bulbs with 1-MCP caused premature sprouting. Exogenous ethylene proved to be a powerful inhibitor of sprout growth in onion bulbs. The dormancy breaking effect of 1-MCP indicates a regulatory role of endogenous ethylene in onion bulb dormancy.

  13. Metagenomic analysis of the rumen microbial community following inhibition of methane formation by a halogenated methane analogue

    Directory of Open Access Journals (Sweden)

    Stuart E Denman

    2015-10-01

    Full Text Available Japanese goats fed a diet of 50% Timothy grass and 50% concentrate with increasing levels of the anti-methanogenic compound, bromochloromethane (BCM were investigated with respect to the microbial shifts in the rumen. Microbial ecology methods identified many species that exhibited positive and negative responses to the increasing levels of BCM. The methane-inhibited rumen appeared to adapt to the higher H2 levels by shifting fermentation to propionate which was mediated by an increase in the population of hydrogen-consuming Prevotella and Selenomonas spp. Metagenomic analysis of propionate production pathways was dominated by genomic content from these species. Reductive acetogenic marker gene libraries and metagenomics analysis indicate that reductive acetogenic species do not play a major role in the BCM treated rumen.

  14. 1-o-acetylbritannilactone (ABL) inhibits angiogenesis and lung cancer cell growth through regulating VEGF-Src-FAK signaling

    Energy Technology Data Exchange (ETDEWEB)

    Zhengfu, He; Hu, Zhang; Huiwen, Miao; Zhijun, Li [Department of Thoracic Surgery, Sir Run Run Shaw Hospital of Zhejiang University School of Medicine, Hangzhou (China); Jiaojie, Zhou [Zhejiang University School of Medicine, Hangzhou (China); Xiaoyi, Yan, E-mail: xiaoyiyan163@163.com [Zhejiang University School of Medicine, Hangzhou (China); Xiujun, Cai, E-mail: xiujuncaomaj@163.com [Sir Run Run Shaw Hospital of Zhejiang University School of Medicine, Hangzhou (China)

    2015-08-21

    The search for safe, effective and affordable therapeutics against non-small cell lung cancer (NSCLC) and other lung cancers is important. Here we explored the potential effect of 1-o-acetylbritannilactone (ABL), a novel extract from Inula britannica-F, on angiogenesis and lung cancer cell growth. We demonstrated that ABL dose-dependently inhibited vascular endothelial growth factor (VEGF)-induced proliferation, migration, and capillary structure formation of cultured human umbilical vascular endothelial cells (HUVECs). In vivo, ABL administration suppressed VEGF-induced new vasculature formation in Matrigel plugs. For the mechanism investigations, we found that ABL largely inhibited VEGF-mediated activation of Src kinase and focal adhesion kinase (FAK) in HUVECs. Furthermore, treatment of A549 NSCLC cells with ABL resulted in cell growth inhibition and Src-FAK in-activation. Significantly, administration of a single dose of ABL (12 mg/kg/day) remarkably suppressed growth of A549 xenografts in nude mice. In vivo microvessels formation and Src activation were also significantly inhibited in ABL-treated xenograft tumors. Taken together, our findings suggest that ABL suppresses angiogenesis and lung cancer cell growth possibly via regulating the VEGFR-Src-FAK signaling. - Highlights: • 1-o-acetylbritannilactone (ABL) inhibits VEGF-induced angiogenesis in vivo. • ABL inhibits VEGF-induced HUVEC migration, proliferation, capillary tube formation. • ABL inhibits VEGF-mediated activation of Src and FAK in HUVECs. • ABL inhibits growth and Src-FAK activation in A549 cells. • ABL administration inhibits A549 tumor angiogenesis and growth in nude mice.

  15. Development of fluorescent Plasmodium falciparum for in vitro growth inhibition assays

    Directory of Open Access Journals (Sweden)

    Crabb Brendan S

    2010-06-01

    Full Text Available Abstract Background Plasmodium falciparum in vitro growth inhibition assays are widely used to evaluate and quantify the functional activity of acquired and vaccine-induced antibodies and the anti-malarial activity of known drugs and novel compounds. However, several constraints have limited the use of these assays in large-scale population studies, vaccine trials and compound screening for drug discovery and development. Methods The D10 P. falciparum line was transfected to express green fluorescent protein (GFP. In vitro growth inhibition assays were performed over one or two cycles of P. falciparum asexual replication using inhibitory polyclonal antibodies raised in rabbits, an inhibitory monoclonal antibody, human serum samples, and anti-malarials. Parasitaemia was evaluated by microscopy and flow cytometry. Results Transfected parasites expressed GFP throughout all asexual stages and were clearly detectable by flow cytometry and fluorescence microscopy. Measurement of parasite growth inhibition was the same when determined by detection of GFP fluorescence or staining with ethidium bromide. There was no difference in the inhibitory activity of samples when tested against the transfected parasites compared to the parental line. The level of fluorescence of GFP-expressing parasites increased throughout the course of asexual development. Among ring-stages, GFP-fluorescent parasites were readily separated from uninfected erythrocytes by flow cytometry, whereas this was less clear using ethidium bromide staining. Inhibition by serum and antibody samples was consistently higher when tested over two cycles of growth compared to one, and when using a 1 in 10 sample dilution compared to 1 in 20, but there was no difference detected when using a different starting parasitaemia to set-up growth assays. Flow cytometry based measurements of parasitaemia proved more reproducible than microscopy counts. Conclusions Flow cytometry based assays using GFP

  16. Inhibition of Lung Cancer Growth in Mice by Dietary Mixed Tocopherols

    Science.gov (United States)

    Lambert, Joshua D.; Lu, Gang; Lee, Mao-Jung; Hu, Jennifer; Ju, Jihyeung; Yang, Chung S.

    2009-01-01

    Tocopherols are lipophilic antioxidants found in vegetable oils. Here, we examined the growth inhibitory effect of a γ-tocopherol-enriched tocopherol mixture (γTmT) against CL13 murine lung cancer cells grown in culture and as subcutaneous tumors in A/J mice. We found γTmT had no effect after 2 d and weakly inhibited the growth of CL13 in culture after 5 d (28% growth inhibition at 80 µM). Dietary treatment with 0.1% and 0.3% γTmT for 50 d inhibited the growth of CL13 tumors in A/J mice by 53.9 and 80.5%, respectively. Histopathological analysis revealed an increase in tumor necrosis compared to control tumors (80% and 240% increase by 0.1% and 0.3% γTmT, respectively). Dietary treatment with γTmT dose-dependently increased γ- (10.0 – 37.6-fold) and δ-tocopherol (8.9 – 26.7-fold) in the tumors of treated mice compared to controls. Dietary treatment with γTmT also increased plasma γ- (5.4 – 6.7-fold) and δ-tocopherol (5.5 – 7-fold). Whereas others have demonstrated the cancer preventive activity of γTmT against mammary and colon cancer, this is the first report of growth inhibitory activity against lung cancer. Further studies are needed to determine the underlying mechanisms for this anticancer activity, and to determine if such activity occurs in other models of cancer. PMID:19557822

  17. Nitrification inhibition by hexavalent chromium Cr(VI)--Microbial ecology, gene expression and off-gas emissions.

    Science.gov (United States)

    Kim, Young Mo; Park, Hongkeun; Chandran, Kartik

    2016-04-01

    The goal of this study was to investigate the responses in the physiology, microbial ecology and gene expression of nitrifying bacteria to imposition of and recovery from Cr(VI) loading in a lab-scale nitrification bioreactor. Exposure to Cr(VI) in the reactor strongly inhibited nitrification performance resulting in a parallel decrease in nitrate production and ammonia consumption. Cr(VI) exposure also led to an overall decrease in total bacterial concentrations in the reactor. However, the fraction of ammonia oxidizing bacteria (AOB) decreased to a greater extent than the fraction of nitrite oxidizing bacteria (NOB). In terms of functional gene expression, a rapid decrease in the transcript concentrations of amoA gene coding for ammonia oxidation in AOB was observed in response to the Cr(VI) shock. In contrast, transcript concentrations of the nxrA gene coding for nitrite oxidation in NOB were relatively unchanged compared to Cr(VI) pre-exposure levels. Therefore, Cr(VI) exposure selectively and directly inhibited activity of AOB, which indirectly resulted in substrate (nitrite) limitation to NOB. Significantly, trends in amoA expression preceded performance trends both during imposition of and recovery from inhibition. During recovery from the Cr(VI) shock, the high ammonia concentrations in the bioreactor resulted in an irreversible shift towards AOB populations, which are expected to be more competitive in high ammonia environments. An inadvertent impact during recovery was increased emission of nitrous oxide (N2O) and nitric oxide (NO), consistent with recent findings linking AOB activity and the production of these gases. Therefore, Cr(VI) exposure elicited multiple responses on the microbial ecology, gene expression and both aqueous and gaseous nitrogenous conversion in a nitrification process. A complementary interrogation of these multiple responses facilitated an understanding of both direct and indirect inhibitory impacts on nitrification. Copyright

  18. Secreted pitfall-trap fluid of carnivorous Nepenthes plants is unsuitable for microbial growth.

    Science.gov (United States)

    Buch, Franziska; Rott, Matthias; Rottloff, Sandy; Paetz, Christian; Hilke, Ines; Raessler, Michael; Mithöfer, Axel

    2013-03-01

    Carnivorous plants of the genus Nepenthes possess modified leaves that form pitfall traps in order to capture prey, mainly arthropods, to make additional nutrients available for the plant. These pitchers contain a digestive fluid due to the presence of hydrolytic enzymes. In this study, the composition of the digestive fluid was further analysed with regard to mineral nutrients and low molecular-weight compounds. A potential contribution of microbes to the composition of pitcher fluid was investigated. Fluids from closed pitchers were harvested and analysed for mineral nutrients using analytical techniques based on ion-chromatography and inductively coupled plasma-optical emission spectroscopy. Secondary metabolites were identified by a combination of LC-MS and NMR. The presence of bacteria in the pitcher fluid was investigated by PCR of 16S-rRNA genes. Growth analyses of bacteria and yeast were performed in vitro with harvested pitcher fluid and in vivo within pitchers with injected microbes. The pitcher fluid from closed pitchers was found to be primarily an approx. 25-mm KCl solution, which is free of bacteria and unsuitable for microbial growth probably due to the lack of essential mineral nutrients such as phosphate and inorganic nitrogen. The fluid also contained antimicrobial naphthoquinones, plumbagin and 7-methyl-juglone, and defensive proteins such as the thaumatin-like protein. Challenging with bacteria or yeast caused bactericide as well as fungistatic properties in the fluid. Our results reveal that Nepenthes pitcher fluids represent a dynamic system that is able to react to the presence of microbes. The secreted liquid of closed and freshly opened Nepenthes pitchers is exclusively plant-derived. It is unsuitable to serve as an environment for microbial growth. Thus, Nepenthes plants can avoid and control, at least to some extent, the microbial colonization of their pitfall traps and, thereby, reduce the need to vie with microbes for the prey

  19. Macroalgae Decrease Growth and Alter Microbial Community Structure of the Reef-Building Coral, Porites astreoides

    Science.gov (United States)

    Vega Thurber, Rebecca; Burkepile, Deron E.; Correa, Adrienne M. S.; Thurber, Andrew R.; Shantz, Andrew A.; Welsh, Rory; Pritchard, Catharine; Rosales, Stephanie

    2012-01-01

    With the continued and unprecedented decline of coral reefs worldwide, evaluating the factors that contribute to coral demise is of critical importance. As coral cover declines, macroalgae are becoming more common on tropical reefs. Interactions between these macroalgae and corals may alter the coral microbiome, which is thought to play an important role in colony health and survival. Together, such changes in benthic macroalgae and in the coral microbiome may result in a feedback mechanism that contributes to additional coral cover loss. To determine if macroalgae alter the coral microbiome, we conducted a field-based experiment in which the coral Porites astreoides was placed in competition with five species of macroalgae. Macroalgal contact increased variance in the coral-associated microbial community, and two algal species significantly altered microbial community composition. All macroalgae caused the disappearance of a γ-proteobacterium previously hypothesized to be an important mutualist of P. astreoides. Macroalgal contact also triggered: 1) increases or 2) decreases in microbial taxa already present in corals, 3) establishment of new taxa to the coral microbiome, and 4) vectoring and growth of microbial taxa from the macroalgae to the coral. Furthermore, macroalgal competition decreased coral growth rates by an average of 36.8%. Overall, this study found that competition between corals and certain species of macroalgae leads to an altered coral microbiome, providing a potential mechanism by which macroalgae-coral interactions reduce coral health and lead to coral loss on impacted reefs. PMID:22957055

  20. Macroalgae decrease growth and alter microbial community structure of the reef-building coral, Porites astreoides.

    Directory of Open Access Journals (Sweden)

    Rebecca Vega Thurber

    Full Text Available With the continued and unprecedented decline of coral reefs worldwide, evaluating the factors that contribute to coral demise is of critical importance. As coral cover declines, macroalgae are becoming more common on tropical reefs. Interactions between these macroalgae and corals may alter the coral microbiome, which is thought to play an important role in colony health and survival. Together, such changes in benthic macroalgae and in the coral microbiome may result in a feedback mechanism that contributes to additional coral cover loss. To determine if macroalgae alter the coral microbiome, we conducted a field-based experiment in which the coral Porites astreoides was placed in competition with five species of macroalgae. Macroalgal contact increased variance in the coral-associated microbial community, and two algal species significantly altered microbial community composition. All macroalgae caused the disappearance of a γ-proteobacterium previously hypothesized to be an important mutualist of P. astreoides. Macroalgal contact also triggered: 1 increases or 2 decreases in microbial taxa already present in corals, 3 establishment of new taxa to the coral microbiome, and 4 vectoring and growth of microbial taxa from the macroalgae to the coral. Furthermore, macroalgal competition decreased coral growth rates by an average of 36.8%. Overall, this study found that competition between corals and certain species of macroalgae leads to an altered coral microbiome, providing a potential mechanism by which macroalgae-coral interactions reduce coral health and lead to coral loss on impacted reefs.

  1. A Comparative Study of Ethylene Growth Response Kinetics in Eudicots and Monocots Reveals a Role for Gibberellin in Growth Inhibition and Recovery1[W][OA

    Science.gov (United States)

    Kim, Joonyup; Wilson, Rebecca L.; Case, J. Brett; Binder, Brad M.

    2012-01-01

    Time-lapse imaging of dark-grown Arabidopsis (Arabidopsis thaliana) hypocotyls has revealed new aspects about ethylene signaling. This study expands upon these results by examining ethylene growth response kinetics of seedlings of several plant species. Although the response kinetics varied between the eudicots studied, all had prolonged growth inhibition for as long as ethylene was present. In contrast, with continued application of ethylene, white millet (Panicum miliaceum) seedlings had a rapid and transient growth inhibition response, rice (Oryza sativa ‘Nipponbare’) seedlings had a slow onset of growth stimulation, and barley (Hordeum vulgare) had a transient growth inhibition response followed, after a delay, by a prolonged inhibition response. Growth stimulation in rice correlated with a decrease in the levels of rice ETHYLENE INSENSTIVE3-LIKE2 (OsEIL2) and an increase in rice F-BOX DOMAIN AND LRR CONTAINING PROTEIN7 transcripts. The gibberellin (GA) biosynthesis inhibitor paclobutrazol caused millet seedlings to have a prolonged growth inhibition response when ethylene was applied. A transient ethylene growth inhibition response has previously been reported for Arabidopsis ethylene insensitive3-1 (ein3-1) eil1-1 double mutants. Paclobutrazol caused these mutants to have a prolonged response to ethylene, whereas constitutive GA signaling in this background eliminated ethylene responses. Sensitivity to paclobutrazol inversely correlated with the levels of EIN3 in Arabidopsis. Wild-type Arabidopsis seedlings treated with paclobutrazol and mutants deficient in GA levels or signaling had a delayed growth recovery after ethylene removal. It is interesting to note that ethylene caused alterations in gene expression that are predicted to increase GA levels in the ein3-1 eil1-1 seedlings. These results indicate that ethylene affects GA levels leading to modulation of ethylene growth inhibition kinetics. PMID:22977279

  2. Inhibition of B16-BL6 melanoma growth in mice by methionine-enkephalin.

    Science.gov (United States)

    Murgo, A J

    1985-08-01

    The antitumor effect of methionine-enkephalin [( Met]enkephalin) was demonstrated in C57BL/6J mice inoculated with B16-BL6 melanoma cells. Local subcutaneous tumor growth was inhibited with a 50-micrograms dose daily for 7 or 14 days. The antitumor effect of [Met]enkephalin was inhibited by the administration of the opioid receptor antagonist naloxone. Naloxone alone had no significant effect on tumor growth.

  3. Smad7 induces tumorigenicity by blocking TGF-beta-induced growth inhibition and apoptosis.

    Science.gov (United States)

    Halder, Sunil K; Beauchamp, R Daniel; Datta, Pran K

    2005-07-01

    Smad proteins play a key role in the intracellular signaling of the transforming growth factor beta (TGF-beta) superfamily of extracellular polypeptides that initiate signaling to regulate a wide variety of biological processes. The inhibitory Smad, Smad7, has been shown to function as intracellular antagonists of TGF-beta family signaling and is upregulated in several cancers. To determine the effect of Smad7-mediated blockade of TGF-beta signaling, we have stably expressed Smad7 in a TGF-beta-sensitive, well-differentiated, and non-tumorigenic cell line, FET, that was derived from human colon adenocarcinoma. Smad7 inhibits TGF-beta-induced transcriptional responses by blocking complex formation between Smad 2/3 and Smad4. While Smad7 has no effect on TGF-beta-induced activation of p38 MAPK and ERK, it blocks the phosphorylation of Akt by TGF-beta and enhances TGF-beta-induced phosphorylation of c-Jun. FET cells expressing Smad7 show anchorage-independent growth and enhance tumorigenicity in athymic nude mice. Smad7 blocks TGF-beta-induced growth inhibition by preventing TGF-beta-induced G1 arrest. Smad7 inhibits TGF-beta-mediated downregulation of c-Myc, CDK4, and Cyclin D1, and suppresses the expression of p21(Cip1). As a result, Smad7 inhibits TGF-beta-mediated downregulation of Rb phosphorylation. Furthermore, Smad7 inhibits the apoptosis of these cells. Together, Smad7 may increase the tumorigenicity of FET cells by blocking TGF-beta-induced growth inhibition and by inhibiting apoptosis. Thus, this study provides a mechanism by which a portion of human colorectal tumors may become refractory to tumor-suppressive actions of TGF-beta that might result in increased tumorigenicity.

  4. STAT6 Mediates Interleukin-4 Growth Inhibition in Human Breast Cancer Cells

    Directory of Open Access Journals (Sweden)

    Jennifer L. Gooch

    2002-01-01

    Full Text Available In addition to acting as a hematopoietic growth factor, interleukin-4 (IL-4 inhibits growth of some transformed cells in vitro and in vivo. In this study, we show that insulin receptor substrate (IRS-1, IRS-2, and signal transducer and activator of transcription 6 (STAT6 are phosphorylated following IL-4 treatment in MCF-7 breast cancer cells. STAT6 DNA binding is enhanced by IL-4 treatment. STAT6 activation occurs even after IRS-1 depletion, suggesting the two pathways are independent. To examine the role of STAT6 in IL-4-mediated growth inhibition and apoptosis, a fulllength STAT6 cDNA was transfected into MCF-7 cells. Transient overexpression of STAT6 resulted in both cytoplasmic and nuclear expression of the protein, increased DNA binding in response to IL-4, and increased transactivation of an IL-4 responsive promoter. In STAT6-transfected cells, basal proliferation was reduced whereas apoptosis was increased. Finally, stable expression of STAT6 resulted in reduced foci formation compared to vector-transfected cells alone. These results suggest STAT6 is required for IL-4mediated growth inhibition and induction of apoptosis in human breast cancer cells.

  5. Simultaneous Assessment of Acidogenesis-Mitigation and Specific Bacterial Growth-Inhibition by Dentifrices.

    Directory of Open Access Journals (Sweden)

    Sarah Forbes

    Full Text Available Dentifrices can augment oral hygiene by inactivating bacteria and at sub-lethal concentrations may affect bacterial metabolism, potentially inhibiting acidogenesis, the main cause of caries. Reported herein is the development of a rapid method to simultaneously measure group-specific bactericidal and acidogenesis-mitigation effects of dentifrices on oral bacteria. Saliva was incubated aerobically and anaerobically in Tryptone Soya Broth, Wilkins-Chalgren Broth with mucin, or artificial saliva and was exposed to dentifrices containing triclosan/copolymer (TD; sodium fluoride (FD; stannous fluoride and zinc lactate (SFD1; or stannous fluoride, zinc lactate and stannous chloride (SFD2. Minimum inhibitory concentrations (MIC were determined turbidometrically whilst group-specific minimum bactericidal concentrations (MBC were assessed using growth media and conditions selective for total aerobes, total anaerobes, streptococci and Gram-negative anaerobes. Minimum acid neutralization concentration (MNC was defined as the lowest concentration of dentifrice at which acidification was inhibited. Differences between MIC and MNC were calculated and normalized with respect to MIC to derive the combined inhibitory and neutralizing capacity (CINC, a cumulative measure of acidogenesis-mitigation and growth inhibition. The overall rank order for growth inhibition potency (MIC under aerobic and anaerobic conditions was: TD> SFD2> SFD1> FD. Acidogenesis-mitigation (MNC was ordered; TD> FD> SFD2> SFD1. CINC was ordered TD> FD> SFD2> SFD1 aerobically and TD> FD> SFD1> SFD2 anaerobically. With respect to group-specific bactericidal activity, TD generally exhibited the greatest potency, particularly against total aerobes, total anaerobes and streptococci. This approach enables the rapid simultaneous evaluation of acidity mitigation, growth inhibition and specific antimicrobial activity by dentifrices.

  6. Microbial community composition affects soil fungistasis.

    Science.gov (United States)

    de Boer, Wietse; Verheggen, Patrick; Klein Gunnewiek, Paulien J A; Kowalchuk, George A; van Veen, Johannes A

    2003-02-01

    Most soils inhibit fungal germination and growth to a certain extent, a phenomenon known as soil fungistasis. Previous observations have implicated microorganisms as the causal agents of fungistasis, with their action mediated either by available carbon limitation (nutrient deprivation hypothesis) or production of antifungal compounds (antibiosis hypothesis). To obtain evidence for either of these hypotheses, we measured soil respiration and microbial numbers (as indicators of nutrient stress) and bacterial community composition (as an indicator of potential differences in the composition of antifungal components) during the development of fungistasis. This was done for two fungistatic dune soils in which fungistasis was initially fully or partly relieved by partial sterilization treatment or nutrient addition. Fungistasis development was measured as restriction of the ability of the fungi Chaetomium globosum, Fusarium culmorum, Fusarium oxysporum, and Trichoderma harzianum to colonize soils. Fungistasis did not always reappear after soil treatments despite intense competition for carbon, suggesting that microbial community composition is important in the development of fungistasis. Both microbial community analysis and in vitro antagonism tests indicated that the presence of pseudomonads might be essential for the development of fungistasis. Overall, the results lend support to the antibiosis hypothesis.

  7. Preliminary screening of some traditional zulu medicinal plants for anti-inflammatory and anti-microbial activities.

    Science.gov (United States)

    Lin, J; Opoku, A R; Geheeb-Keller, M; Hutchings, A D; Terblanche, S E; Jäger, A K; van Staden, J

    1999-12-15

    Aqueous and methanolic extracts from different parts of nine traditional Zulu medicinal plants, of the Vitaceae from KwaZulu-Natal, South Africa were evaluated for therapeutic potential as anti-inflammatory and anti-microbial agents. Of the twenty-nine crude extracts assayed for prostaglandin synthesis inhibitors, only five methanolic extracts of Cyphostemma natalitium-root, Rhoicissus digitata-leaf, R. rhomboidea-root, R. tomentosa-leaf/stem and R. tridentata-root showed significant inhibition of cyclo-oxygenase (COX-1). The extracts of R. digitata-leaf and of R. rhomboidea-root exhibited the highest inhibition of prostaglandin synthesis with 53 and 56%, respectively. The results suggest that Rhoicissus digitata leaves and of Rhoicissus rhomboidea roots may have the potential to be used as anti-inflammatory agents. All the screened plant extracts showed some degrees of anti-microbial activity against gram-positive and gram-negative microorganisms. The methanolic extracts of C. natalitium-stem and root, R. rhomboidea-root, and R. tomentosa-leaf/stem, showed different anti-microbial activities against almost all micro-organisms tested. Generally, these plant extracts inhibited the gram-positive micro-organisms more than the gram-negative ones. Several plant extracts inhibited the growth of Candida albicans while only one plant extract showed inhibitory activity against Saccharomyces cerevisiae. All the plant extracts which demonstrated good anti-inflammatory activities also showed better inhibitory activity against Candida albicans.

  8. Genome-scale biological models for industrial microbial systems.

    Science.gov (United States)

    Xu, Nan; Ye, Chao; Liu, Liming

    2018-04-01

    The primary aims and challenges associated with microbial fermentation include achieving faster cell growth, higher productivity, and more robust production processes. Genome-scale biological models, predicting the formation of an interaction among genetic materials, enzymes, and metabolites, constitute a systematic and comprehensive platform to analyze and optimize the microbial growth and production of biological products. Genome-scale biological models can help optimize microbial growth-associated traits by simulating biomass formation, predicting growth rates, and identifying the requirements for cell growth. With regard to microbial product biosynthesis, genome-scale biological models can be used to design product biosynthetic pathways, accelerate production efficiency, and reduce metabolic side effects, leading to improved production performance. The present review discusses the development of microbial genome-scale biological models since their emergence and emphasizes their pertinent application in improving industrial microbial fermentation of biological products.

  9. Metformin enhances tamoxifen-mediated tumor growth inhibition in ER-positive breast carcinoma

    International Nuclear Information System (INIS)

    Ma, Ji; Zhang, Jian; Liu, Wenchao; Guo, Yan; Chen, Suning; Zhong, Cuiping; Xue, Yan; Zhang, Yuan; Lai, Xiaofeng; Wei, Yifang; Yu, Shentong

    2014-01-01

    Tamoxifen, an endocrine therapy drug used to treat breast cancer, is designed to interrupt estrogen signaling by blocking the estrogen receptor (ER). However, many ER-positive patients are low reactive or resistant to tamoxifen. Metformin is a widely used anti-diabetic drug with noteworthy anti-cancer effects. We investigated whether metformin has the additive effects with tamoxifen in ER-positive breast cancer therapy. The efficacy of metformin alone and in combination with tamoxifen against ER-positive breast cancer was analyzed by cell survival, DNA replication activity, plate colony formation, soft-agar, flow cytometry, immunohistochemistry, and nude mice model assays. The involved signaling pathways were detected by western blot assay. When metformin was combined with tamoxifen, the concentration of tamoxifen required for growth inhibition was substantially reduced. Moreover, metformin enhanced tamoxifen-mediated inhibition of proliferation, DNA replication activity, colony formation, soft-agar colony formation, and induction of apoptosis in ER-positive breast cancer cells. In addition, these tamoxifen-induced effects that were enhanced by metformin may be involved in the bax/bcl-2 apoptotic pathway and the AMPK/mTOR/p70S6 growth pathway. Finally, two-drug combination therapy significantly inhibited tumor growth in vivo. The present work shows that metformin and tamoxifen additively inhibited the growth and augmented the apoptosis of ER-positive breast cancer cells. It provides leads for future research on this drug combination for the treatment of ER-positive breast cancer

  10. Biochar and microbial signaling: production conditions determine effects on microbial communication

    Science.gov (United States)

    Masiello, Caroline A.; Chen, Ye; Gao, Xiaodong; Liu, Shirley; Cheng, Hsiao-Ying; Bennett, Matthew R.; Rudgers, Jennifer A.; Wagner, Daniel S.; Zygourakis, Kyriacos; Silberg, Jonathan J.

    2013-01-01

    Charcoal has a long soil residence time, which has resulted in its production and use as a carbon sequestration technique (biochar). A range of biological effects can be triggered by soil biochar that can positively and negatively influence carbon storage, such as changing the decomposition rate of organic matter and altering plant biomass production. Sorption of cellular signals has been hypothesized to underlie some of these effects, but it remains unknown whether the binding of biochemical signals occurs, and if so, on time scales relevant to microbial growth and communication. We examined biochar sorption of N-3-oxo-dodecanoyl-L-homoserine lactone, an acyl-homoserine lactone (AHL) intercellular signaling molecule used by many gram-negative soil microbes to regulate gene expression. We show that wood biochars disrupt communication within a growing multicellular system that is made up of sender cells that synthesize AHL and receiver cells that express green fluorescent protein in response to an AHL signal. However, biochar inhibition of AHL-mediated cell-cell communication varied, with the biochar prepared at 700°C (surface area of 301 m2/g) inhibiting cellular communication 10-fold more than an equivalent mass of biochar prepared at 300°C (surface area of 3 m2/g). These findings provide the first direct evidence that biochars elicit a range of effects on gene expression dependent on intercellular signaling, implicating the method of biochar preparation as a parameter that could be tuned to regulate microbial-dependent soil processes, like nitrogen fixation and pest attack of root crops. PMID:24066613

  11. Biochar and microbial signaling: production conditions determine effects on microbial communication.

    Science.gov (United States)

    Masiello, Caroline A; Chen, Ye; Gao, Xiaodong; Liu, Shirley; Cheng, Hsiao-Ying; Bennett, Matthew R; Rudgers, Jennifer A; Wagner, Daniel S; Zygourakis, Kyriacos; Silberg, Jonathan J

    2013-10-15

    Charcoal has a long soil residence time, which has resulted in its production and use as a carbon sequestration technique (biochar). A range of biological effects can be triggered by soil biochar that can positively and negatively influence carbon storage, such as changing the decomposition rate of organic matter and altering plant biomass production. Sorption of cellular signals has been hypothesized to underlie some of these effects, but it remains unknown whether the binding of biochemical signals occurs, and if so, on time scales relevant to microbial growth and communication. We examined biochar sorption of N-3-oxo-dodecanoyl-L-homoserine lactone, an acyl-homoserine lactone (AHL) intercellular signaling molecule used by many gram-negative soil microbes to regulate gene expression. We show that wood biochars disrupt communication within a growing multicellular system that is made up of sender cells that synthesize AHL and receiver cells that express green fluorescent protein in response to an AHL signal. However, biochar inhibition of AHL-mediated cell-cell communication varied, with the biochar prepared at 700 °C (surface area of 301 m(2)/g) inhibiting cellular communication 10-fold more than an equivalent mass of biochar prepared at 300 °C (surface area of 3 m(2)/g). These findings provide the first direct evidence that biochars elicit a range of effects on gene expression dependent on intercellular signaling, implicating the method of biochar preparation as a parameter that could be tuned to regulate microbial-dependent soil processes, like nitrogen fixation and pest attack of root crops.

  12. Herbicide glufosinate inhibits yeast growth and extends longevity during wine fermentation.

    Science.gov (United States)

    Vallejo, Beatriz; Picazo, Cecilia; Orozco, Helena; Matallana, Emilia; Aranda, Agustín

    2017-09-29

    Glufosinate ammonium (GA) is a widely used herbicide that inhibits glutamine synthetase. This inhibition leads to internal amino acid starvation which, in turn, causes the activation of different nutrient sensing pathways. GA also inhibits the enzyme of the yeast Saccharomyces cerevisiae in such a way that, although it is not used as a fungicide, it may alter yeast performance in industrial processes like winemaking. We describe herein how GA indeed inhibits the yeast growth of a wine strain during the fermentation of grape juice. In turn, GA extends longevity in a variety of growth media. The biochemical analysis indicates that GA partially inhibits the nutrient sensing TORC1 pathway, which may explain these phenotypes. The GCN2 kinase mutant is hypersensitive to GA. Hence the control of translation and amino acid biosynthesis is required to also deal with the damaging effects of this pesticide. A global metabolomics analysis under winemaking conditions indicated that an increase in amino acid and in polyamines occurred. In conclusion, GA affects many different biochemical processes during winemaking, which provides us with some insights into both the effect of this herbicide on yeast physiology and into the relevance of the metabolic step for connecting nitrogen and carbon metabolism.

  13. MicroRNA-375 inhibits colorectal cancer growth by targeting PIK3CA

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yihui [Department of Colorectal Surgery, The Third Affiliated Hospital of Harbin Medical University, 150 Haping Road, 150081 Harbin (China); Tang, Qingchao [Cancer Center, The Second Affiliated Hospital of Harbin Medical University, 246 Xuefu Road, 150086 Harbin (China); Li, Mingqi; Jiang, Shixiong [Department of Colorectal Surgery, The Third Affiliated Hospital of Harbin Medical University, 150 Haping Road, 150081 Harbin (China); Wang, Xishan, E-mail: wxshan12081@163.com [Cancer Center, The Second Affiliated Hospital of Harbin Medical University, 246 Xuefu Road, 150086 Harbin (China)

    2014-02-07

    Highlights: • miR-375 is downregulated in colorectal cancer cell lines and tissues. • miR-375 inhibits colorectal cancer cell growth by targeting PIK3CA. • miR-375 inhibits colorectal cancer cell growth in xenograft nude mice model. - Abstract: Colorectal cancer (CRC) is the second most common cause of death from cancer. MicroRNAs (miRNAs) represent a class of small non-coding RNAs that control gene expression by triggering RNA degradation or interfering with translation. Aberrant miRNA expression is involved in human disease including cancer. Herein, we showed that miR-375 was frequently down-regulated in human colorectal cancer cell lines and tissues when compared to normal human colon tissues. PIK3CA was identified as a potential miR-375 target by bioinformatics. Overexpression of miR-375 in SW480 and HCT15 cells reduced PIK3CA protein expression. Subsequently, using reporter constructs, we showed that the PIK3CA untranslated region (3′-UTR) carries the directly binding site of miR-375. Additionally, miR-375 suppressed CRC cell proliferation and colony formation and led to cell cycle arrest. Furthermore, miR-375 overexpression resulted in inhibition of phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway. SiRNA-mediated silencing of PIK3CA blocked the inhibitory effect of miR-375 on CRC cell growth. Lastly, we found overexpressed miR-375 effectively repressed tumor growth in xenograft animal experiments. Taken together, we propose that overexpression of miR-375 may provide a selective growth inhibition for CRC cells by targeting PI3K/Akt signaling pathway.

  14. Microbial community shifts and biogas conversion computation during steady, inhibited and recovered stages of thermophilic methane fermentation on chicken manure with a wide variation of ammonia.

    Science.gov (United States)

    Niu, Qigui; Qiao, Wei; Qiang, Hong; Li, Yu-You

    2013-10-01

    The thermophilic methane fermentation of chicken manure (10% TS) was investigated within a wide range of ammonia. Microbiological analysis showed significant shifts in Archaeal and Bacterial proportions with VFA accmulation and CH4 formation before and after inhibition. VFA accumulated sharply with lower methane production, 0.29 L/g VS, than during the steady stage, 0.32 L/g VS. Biogas production almost ceased with the synergy inhibition of TAN (8000 mg/L) and VFA (25,000 mg/L). Hydrogenotrophic Methanothermobacter thermautotrophicus str. was the dominate archaea with 95% in the inhibition stage and 100% after 40 days recovery compared to 9.3% in the steady stage. Aceticlastic Methanosarcina was not encountered with coincided phenomenal of high VFA in the inhibition stage as well as recovery stage. Evaluation of the microbial diversity and functional bacteria indicated the dominate phylum of Firmicutes were 94.74% and 84.4% with and without inhibition. The microbial community shifted significantly with elevated ammonia concentration affecting the performance. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. Microbial growth yield estimates from thermodynamics and its importance for degradation of pesticides and formation of biogenic non-extractable residues

    DEFF Research Database (Denmark)

    Brock, Andreas Libonati; Kästner, M.; Trapp, Stefan

    2017-01-01

    NER. Formation of microbial mass can be estimated from the microbial growth yield, but experimental data is rare. Instead, we suggest using prediction methods for the theoretical yield based on thermodynamics. Recently, we presented the Microbial Turnover to Biomass (MTB) method that needs a minimum...... and using the released CO2 as a measure for microbial activity, we predicted a range for the formation of biogenic NER. For the majority of the pesticides, a considerable fraction of the NER was estimated to be biogenic. This novel approach provides a theoretical foundation applicable to the evaluation...

  16. Targeting Insulin-Like Growth Factor 1 Receptor Inhibits Pancreatic Cancer Growth and Metastasis

    Science.gov (United States)

    Subramani, Ramadevi; Lopez-Valdez, Rebecca; Arumugam, Arunkumar; Nandy, Sushmita; Boopalan, Thiyagarajan; Lakshmanaswamy, Rajkumar

    2014-01-01

    Pancreatic cancer is one of the most lethal cancers. Increasing incidence and mortality indicates that there is still much lacking in detection and management of the disease. This is partly due to a lack of specific symptoms during early stages of the disease. Several growth factor receptors have been associated with pancreatic cancer. Here, we have investigated if an RNA interference approach targeted to IGF-IR could be effective and efficient against pancreatic cancer growth and metastasis. For that, we evaluated the effects of IGF-1R inhibition using small interfering RNA (siRNAs) on tumor growth and metastasis in HPAC and PANC-1 pancreatic cancer cell lines. We found that silencing IGF-1R inhibits pancreatic cancer growth and metastasis by blocking key signaling pathways such AKT/PI3K, MAPK, JAK/STAT and EMT. Silencing IGF-1R resulted in an anti-proliferative effect in PANC-1 and HPAC pancreatic cancer cell lines. Matrigel invasion, transwell migration and wound healing assays also revealed a role for IGF-1R in metastatic properties of pancreatic cancer. These results were further confirmed using Western blotting analysis of key intermediates involved in proliferation, epithelial mesenchymal transition, migration, and invasion. In addition, soft agar assays showed that silencing IGF-1R also blocks the colony forming capabilities of pancreatic cancer cells in vitro. Western blots, as well as, flow cytometric analysis revealed the induction of apoptosis in IGF-1R silenced cells. Interestingly, silencing IGF-1R also suppressed the expression of insulin receptor β. All these effects together significantly control pancreatic cancer cell growth and metastasis. To conclude, our results demonstrate the significance of IGF-1R in pancreatic cancer. PMID:24809702

  17. The effect of substrate modification on microbial growth on surfaces

    International Nuclear Information System (INIS)

    Brown, Angela Ann

    1998-01-01

    The principle aim of the program was to produce a novel, non-leaching antimicrobial surface for commercial development and future use in the liquid food packaging industry. Antimicrobial surfaces which exist presently have been produced to combat the growth of prokaryotic organisms and usually function as slow release systems. A system which could inhibit eukaryotic growth without contaminating the surrounding 'environment' with the inhibitor was considered of great commercial importance. The remit of this study was concerned with creating a surface which could control the growth of eukaryotic organisms found in fruit juice with particular interest in the yeast, Saccharomyces cerevisiae. Putative antimicrobial surfaces were created by the chemical modification of the test substrate polymers; nylon and ethylvinyl alcohol (EVOH). Surfaces were chemically modified by the covalent coupling of antimicrobial agents known to be active against the yeast Saccharomyces cerevisiae as ascertained by the screening process determining the minimum inhibitory concentration (MIC) values of agents in the desired test medium. During the study it was found that a number of surfaces did appear to inhibit yeast growth in fruit juice, however on further investigation the apparent inhibitory effect was discovered to be the result of un-bound material free in the test medium. On removing the possibility of any un-bound material present on the test surface, by a series of surface washings, the inhibitory effect on yeast growth was eliminated. Of the agents tested only one appeared to have an inhibitory effect which could be attributed to a true antimicrobial surface effect, Amical 48. As there is little known about this agent in the literature, its affect on yeast growth was examined and in particular a proposal for the mode of action on yeast is discussed, providing a plausible explanation for the inhibitory effect observed when this agent is covalently immobilised onto nylon. (author)

  18. Growth inhibition of fouling bacteria and diatoms by extract of terrestrial plant, Derris scandens (Dicotyledonae:Leguminocae)

    Digital Repository Service at National Institute of Oceanography (India)

    Sawant, S.S.; Sonak, S.; Garg, A.

    Methanol extract of terrestrial plant, Derris scandens Benth, was found to inhibit growth of four diatoms and 7 bacterial species of fouling community. The concentrations required to bring about 100% inhibition of growth of the diatoms ranged...

  19. Electrochemical and Chemical Complications Resulting from Yeast Extract Addition to Stimulate Microbial Growth

    Science.gov (United States)

    2016-09-22

    including strains of Saccharomyces cerevisiae grown on molasses-based media, debittered brewers yeasts (strains of Saccharo- myces cerevisiae or...RESPONSIBLE PERSON 19b. TELEPHONE NUMBER (Include area code) Technical Note: Electrochemical and Chemical Complications Resulting from Yeast Extract...Addition to Stimulate Microbial Growth Jason S. Lee‡,* and Brenda J. Little* ABSTRACT Addition of 1 g/L yeast extract (YE) to sterile, aerobic

  20. Limonene inhibits Candida albicans growth by inducing apoptosis.

    Science.gov (United States)

    Thakre, Archana; Zore, Gajanan; Kodgire, Santosh; Kazi, Rubina; Mulange, Shradha; Patil, Rajendra; Shelar, Amruta; Santhakumari, Bayitigeri; Kulkarni, Mahesh; Kharat, Kiran; Karuppayil, Sankunny Mohan

    2018-07-01

    Anti-Candida potential of limonene was evaluated against planktonic growth, biofilm (adhesion, development and maturation) and morphogenesis of Candida albicans in this study. Limonene is a major constituent of citrus oil and most frequently used terpene in food and beverage industry due to its pleasant fragrance, nontoxic, and is generally recognized as safe (GRAS) flavoring agent as well as treatment option in many gastrointestinal diseases.Limonene exhibited excellent anti-Candida activity and was equally effective against planktonic growth of C. albicans isolates differentially susceptible to FLC (N = 35). Limonene inhibited morphogenesis significantly at low concentration. However, it showed stage dependent activity against biofilm formation, that is, it was more effective against adhesion followed by development and maturation. Limonene also exhibited excellent synergy with FLC against planktonic and biofilm growth. SWATH-MS analysis led to identification of limonene responsive proteins that provided molecular insight of its anti-Candida activity. Proteomic analysis revealed upregulation of proteins involved in cell wall glucan synthesis (Kre6); oxidative stress (Rhr2, Adh7 and Ebp1); DNA damage stress (Mbf1 and Npl3); nucleolar stress (Rpl11, Rpl7, Rpl29, Rpl15) and down regulation of cytoskeleton organization (Crn1, Pin3, Cct8, Rbl2), and so forth, in response to limonene. Limonene mediated down regulation of Tps3 indicates activation of caspase (CaMca1) and induction of apoptosis in C. albicans. These results suggest that limonene inhibits C. albicans growth by cell wall/membrane damage induced oxidative stress that leads to DNA damage resulting into modulation of cell cycle and induction of apoptosis through nucleolar stress and metacaspase dependent pathway.

  1. Effects of rhizobacteria on the respiration and growth of Cerasus sachalinensis Kom. seedlings

    Energy Technology Data Exchange (ETDEWEB)

    Qin, S.; Zhou, W.; Li, Z.; Lyu, D.

    2016-11-01

    In this study, we investigated the influence of rhizosphere microorganisms on seed germination and root metabolism in Cerasus sachalinensis Kom. We inoculated C. sachalinensis plants with suspensions of dominant bacterial strains isolated from their rhizosphere. Four bacterial strains each with significant growth-promoting or growth-inhibiting effects were screened from the efficient root-colonizing microorganisms. The number of actinomycetes increased and that of fungi decreased significantly in the seedling rhizospheres after rhizobacteria treatment. The growth-promoting bacteria slightly affected the respiration rates and respiratory pathway enzymes, but significantly improved root viability, root carbohydrate concentration and seedling growth. Bacillus cereus, Staphylococcus sp. and Pseudomonas fluorescens were identified as the growth-promoting rhizobacteria; one strain could not be identified. After inoculation with the growth-inhibiting bacteria, the number of fungal colonies in the seedling rhizospheres increased and root viability and respiration rate as well as starch and sucrose accumulation in the roots significantly decreased. The glycolysis, pentose phosphate and alternative oxidase pathways became the major pathways of respiratory metabolism after inoculation with the growth-inhibiting bacteria. The height, leaf number, growth and dry weight of the seedlings decreased significantly in plants inoculated with the growth-inhibiting bacteria. Inoculation of C. sachalinensis rhizosphere with growth-promoting and growth-inhibiting bacteria affected the soil environmental factors such as microbial group composition, nutrient concentration and seedling biomass. (Author)

  2. Components in aqueous Hibiscus rosa-sinensis flower extract inhibit in vitro melanoma cell growth

    Directory of Open Access Journals (Sweden)

    Karina H. Goldberg

    2017-01-01

    Full Text Available Skin cancer is extremely common, and melanoma causes about 80% of skin cancer deaths. In fact, melanoma kills over 50 thousand people around the world each year, and these numbers are rising. Clearly, standard treatments are not effectively treating melanoma, and alternative therapies are needed to address this problem. Hibiscus tea has been noted to have medicinal properties, including anticancer effects. Extracts from Hibiscus have been shown to inhibit the growth of a variety of cancer cells. In particular, recent studies found that polyphenols extracted from Hibiscus sabdariffa by organic solvents can inhibit melanoma cell growth. However, effects of aqueous extracts from Hibiscus rosa-sinesis flowers, which are commonly used to make traditional medicinal beverages, have not been examined on melanoma cells. Here, we report that aqueous H. rosa-sinesis flower extract contains compounds that inhibit melanoma cell growth in a dose dependent manner at concentrations that did not affect the growth of nontransformed cells. In addition, these extracts contain low molecular weight growth inhibitory compounds below 3 kD in size that combine with larger compounds to more effectively inhibit melanoma cell growth. Future work should identify these compounds, and evaluate their potential to prevent and treat melanoma and other cancers.

  3. Inhibition of platelet-derived growth factor signaling prevents muscle fiber growth during skeletal muscle hypertrophy.

    Science.gov (United States)

    Sugg, Kristoffer B; Korn, Michael A; Sarver, Dylan C; Markworth, James F; Mendias, Christopher L

    2017-03-01

    The platelet-derived growth factor receptors alpha and beta (PDGFRα and PDGFRβ) mark fibroadipogenic progenitor cells/fibroblasts and pericytes in skeletal muscle, respectively. While the role that these cells play in muscle growth and development has been evaluated, it was not known whether the PDGF receptors activate signaling pathways that control transcriptional and functional changes during skeletal muscle hypertrophy. To evaluate this, we inhibited PDGFR signaling in mice subjected to a synergist ablation muscle growth procedure, and performed analyses 3 and 10 days after induction of hypertrophy. The results from this study indicate that PDGF signaling is required for fiber hypertrophy, extracellular matrix production, and angiogenesis that occur during muscle growth. © 2017 Federation of European Biochemical Societies.

  4. Does iron inhibit cryptoendolithic microbial communities?

    Science.gov (United States)

    Johnston, C. G.; Vestal, J. R.; Friedmann, E. I. (Principal Investigator)

    1988-01-01

    Photosynthetic activity of three cryptoendolithic microbial communities was studied under controlled conditions in the laboratory. In two of these communities, the dominant organisms were lichens, collected from Linnaeus Terrace and from Battleship Promontory. The third community, dominated by cyanobacteria, was collected from Battleship Promontory. Both sites are in the ice-free valleys of southern Victoria Land. Previous efforts have shown how physical conditions can influence metabolic activity in endolithic communities (Kappen and Friedmann 1983; Kappen, Friedmann, and Garty 1981; Vestal, Federle, and Friedmann 1984). Biological activity can also be strongly influenced by the chemical environment. Inorganic nutrients such as nitrate, ammonia, and phosphate are often limiting factors, so their effects on photosynthetic carbon-14 bicarbonate incorporation were investigated. Iron and manganese are two metals present in Linnaeus Terrace and Battleship Promontory sandstones, and their effects on photosynthesis were also studied. The results may add to our understanding of biogeochemical interactions within this unique microbial community.

  5. Biological activity of the non-microbial fraction of kefir: antagonism against intestinal pathogens.

    Science.gov (United States)

    Iraporda, Carolina; Abatemarco Júnior, Mário; Neumann, Elisabeth; Nunes, Álvaro Cantini; Nicoli, Jacques R; Abraham, Analía G; Garrote, Graciela L

    2017-08-01

    Kefir is a fermented milk obtained by the activity of kefir grains which are composed of lactic and acetic acid bacteria, and yeasts. Many beneficial health effects have been associated with kefir consumption such as stimulation of the immune system and inhibition of pathogenic microorganisms. The biological activity of kefir may be attributed to the presence of a complex microbiota as well as the microbial metabolites that are released during fermentation. The aim of this work was to characterise the non-microbial fraction of kefir and to study its antagonism against Escherichia coli, Salmonella spp. and Bacillus cereus. During milk fermentation there was a production of organic acids, mainly lactic and acetic acid, with a consequent decrease in pH and lactose content. The non-microbial fraction of kefir added to nutrient broth at concentrations above 75% v/v induced a complete inhibition of pathogenic growth that could be ascribed to the presence of un-dissociated lactic acid. In vitro assays using an intestinal epithelial cell model indicated that pre-incubation of cells with the non-microbial fraction of kefir did not modify the association/invasion of Salmonella whereas pre-incubation of Salmonella with this fraction under conditions that did not affect their viability significantly decreased the pathogen's ability to invade epithelial cells. Lactate exerted a protective effect against Salmonella in a mouse model, demonstrating the relevance of metabolites present in the non-microbial fraction of kefir produced during milk fermentation.

  6. Di (2-ethylhexyl) phthalate inhibits growth of mouse ovarian antral follicles through an oxidative stress pathway

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Wei, E-mail: weiwang2@illinois.edu; Craig, Zelieann R., E-mail: zelieann@illinois.edu; Basavarajappa, Mallikarjuna S., E-mail: mbasava2@illinois.edu; Gupta, Rupesh K., E-mail: drrupesh@yahoo.com; Flaws, Jodi A., E-mail: jflaws@illinois.edu

    2012-01-15

    Di (2-ethylhexyl) phthalate (DEHP) is a plasticizer that has been shown to inhibit growth of mouse antral follicles, however, little is known about the mechanisms by which DEHP does so. Oxidative stress has been linked to follicle growth inhibition as well as phthalate-induced toxicity in non-ovarian tissues. Thus, we hypothesized that DEHP causes oxidative stress and that this leads to inhibition of the growth of antral follicles. To test this hypothesis, antral follicles isolated from CD-1 mice (age 31–35 days) were cultured with vehicle control (dimethylsulfoxide [DMSO]) or DEHP (1–100 μg/ml) ± N-acetyl cysteine (NAC, an antioxidant at 0.25–1 mM). During culture, follicles were measured daily. At the end of culture, follicles were collected and processed for in vitro reactive oxygen species (ROS) assays to measure the presence of free radicals or for measurement of the expression and activity of various key antioxidant enzymes: Cu/Zn superoxide dismutase (SOD1), glutathione peroxidase (GPX) and catalase (CAT). The results indicate that DEHP inhibits the growth of follicles compared to DMSO control and that NAC (0.25–1 mM) blocks the ability of DEHP to inhibit follicle growth. Furthermore, DEHP (10 μg/ml) significantly increases ROS levels and reduces the expression and activity of SOD1 compared to DMSO controls, whereas NAC (0.5 mM) rescues the effects of DEHP on ROS levels and SOD1. However, the expression and activity of GPX and CAT were not affected by DEHP treatment. Collectively, these data suggest that DEHP inhibits follicle growth by inducing production of ROS and by decreasing the expression and activity of SOD1. -- Highlights: ► DEHP inhibits growth and increases reactive oxygen species in ovarian antral follicles in vitro. ► NAC rescues the effects of DEHP on the growth and reactive oxygen species levels in follicles. ► DEHP decreases the expression and activity of Cu/Zn superoxide dismutase, which can be rescued by NAC, in antral

  7. Ionic liquid-tolerant microorganisms and microbial communities for lignocellulose conversion to bioproducts.

    Science.gov (United States)

    Yu, Chaowei; Simmons, Blake A; Singer, Steven W; Thelen, Michael P; VanderGheynst, Jean S

    2016-12-01

    Chemical and physical pretreatment of biomass is a critical step in the conversion of lignocellulose to biofuels and bioproducts. Ionic liquid (IL) pretreatment has attracted significant attention due to the unique ability of certain ILs to solubilize some or all components of the plant cell wall. However, these ILs inhibit not only the enzyme activities but also the growth and productivity of microorganisms used in downstream hydrolysis and fermentation processes. While pretreated biomass can be washed to remove residual IL and reduce inhibition, extensive washing is costly and not feasible in large-scale processes. IL-tolerant microorganisms and microbial communities have been discovered from environmental samples and studies begun to elucidate mechanisms of IL tolerance. The discovery of IL tolerance in environmental microbial communities and individual microbes has lead to the proposal of molecular mechanisms of resistance. In this article, we review recent progress on discovering IL-tolerant microorganisms, identifying metabolic pathways and mechanisms of tolerance, and engineering microorganisms for IL tolerance. Research in these areas will yield new approaches to overcome inhibition in lignocellulosic biomass bioconversion processes and increase opportunities for the use of ILs in biomass pretreatment.

  8. Effect of temperature on microbial growth rate - thermodynamic analysis, the arrhenius and eyring-polanyi connection

    Science.gov (United States)

    The objective of this work is to develop a new thermodynamic mathematical model for evaluating the effect of temperature on the rate of microbial growth. The new mathematical model is derived by combining the Arrhenius equation and the Eyring-Polanyi transition theory. The new model, suitable for ...

  9. Involvement of allelopathy in inhibition of understory growth in red pine forests.

    Science.gov (United States)

    Kato-Noguchi, Hisashi; Kimura, Fukiko; Ohno, Osamu; Suenaga, Kiyotake

    2017-11-01

    Japanese red pine (Pinus densiflora Sieb. et Zucc.) forests are characterized by sparse understory vegetation although sunlight intensity on the forest floor is sufficient for undergrowth. The possible involvement of pine allelopathy in the establishment of the sparse understory vegetation was investigated. The soil of the red pine forest floor had growth inhibitory activity on six test plant species including Lolium multiflorum, which was observed at the edge of the forest but not in the forest. Two growth inhibitory substances were isolated from the soil and characterized to be 15-hydroxy-7-oxodehydroabietate and 7-oxodehydroabietic acid. Those compounds are probably formed by degradation process of resin acids. Resin acids are produced by pine and delivered into the soil under the pine trees through balsam and defoliation. Threshold concentrations of 15-hydroxy-7-oxodehydroabietate and 7-oxodehydroabietic acid for the growth inhibition of L. multiflorum were 30 and 10μM, respectively. The concentrations of 15-hydroxy-7-oxodehydroabietate and 7-oxodehydroabietic acid in the soil were 312 and 397μM, respectively, which are sufficient concentrations to cause the growth inhibition because of the threshold. These results suggest that those compounds are able to work as allelopathic agents and may prevent from the invasion of herbaceous plants into the forests by inhibiting their growth. Therefore, allelopathy of red pine may be involved in the formation of the sparse understory vegetation. Copyright © 2017 Elsevier GmbH. All rights reserved.

  10. Effect of silver nanoparticles on growth performance, metabolism and microbial profile of broiler chickens

    DEFF Research Database (Denmark)

    Pineda, Lane Manalili; Chwalibog, André; Sawosz, Ewa

    2012-01-01

    and intestinal content were collected to evaluate the effects of AgNano on plasma concentration of immunoglobulins and the intestinal microflora, respectively. The provision of water solutions containing different concentrations of AgNano had no effect on postnatal growth performance and the energy metabolism...... (IgG) in the blood plasma of broilers supplemented with AgNano decreased at day 36 (p = 0.012). The results demonstrated that AgNano affects N utilisation and plasma IgG concentration; however, it does not influence the microbial populations in the digestive tract, the energy metabolism and growth...

  11. Fluoro-sorafenib (Regorafenib) effects on hepatoma cells: growth inhibition, quiescence and recovery

    Science.gov (United States)

    Carr, Brian I.; Cavallini, Aldo; Lippolis, Catia; D’Alessandro, Rosalba; Messa, Caterina; Refolo, Maria Grazia; Tafaro, Angela

    2015-01-01

    To evaluate the growth-inhibitory properties of the potent multi-kinase antagonist Regorafenib (Fluoro-Sorafenib), which was synthesized as a more potent Sorafenib, a Raf inhibitor and to determine whether similar mechanisms were involved, human hepatoma cell lines were grown in the presence or absence of Regorafanib and examined for growth inhibition. Western blots were performed for Raf targets, for apoptosis and autophagy. Regorafenib inhibited growth of human Hep3B, PLC/PRF/5 and HepG2 cells in a concentration- and time-dependent manner. Multiple signaling pathways were altered, including MAP kinases phospho-ERK and phospho-JNK and its target phospho-c-Jun. There was evidence for apoptosis by FACS, cleavage of caspases and increased Bax levels; as well as induction of autophagy, as judged by increased Beclin-1 and LC3 (II) levels. Prolonged drug exposure resulted in cell quiescence. Full growth recovery occurred after drug removal, unlike with doxorubicin chemotherapy. Regorafenib is a potent inhibitor of cell growth. Cells surviving Regorafenib treatment remain viable, but quiescent and capable of regrowth following drug removal. The reversibility of tumor cell growth suppression after drug removal may have clinical implications. PMID:22777740

  12. Plant growth inhibition by soluble salts in sewage sludge-amended mine spoils

    Energy Technology Data Exchange (ETDEWEB)

    Rodgers, C.S.; Anderson, R.C. [Illinois State University, Normal, IL (United States). Dept. of Biological Sciences

    1995-07-01

    The growth response of prairie switchgrass {ital Panicum virgatum}L was compared in strip mine spoil amended with various levels of anaerobically digested waste-activated sewage sludge (0, 56, 111, 222, or 333 dry Mg ha{sup -1}) and commercial fertilizer, pure sludge, and glasshouse soil. Plants were grown in a growth chamber and substrates were maintained at field capacity during the study. Soluble salt concentrations of the substrates increased linearly as a function of sludge amendment and were within the range known to inhibit the growth of many plant species at the high levels of sludge application. There was, however, a linear response of biomass production to increasing levels of sludge amendment. Maintaining substrates at field capacity apparently prevented the high concentration of soluble salts from inhibiting plant growth. The increased biomass yield associated with sludge application was likely due to the increased availability of inorganic nutrients associated with sludge amendment. 22 refs., 2 figs., 2 tabs.

  13. Algal growth inhibition test in filled, closed bottles for volatile and sorptive materials

    DEFF Research Database (Denmark)

    Mayer, Philipp; Nyholm, Niels; Verbruggen, Eric M. J.

    2000-01-01

    Exposure concentrations of many hydrophobic substances are difficult to maintain in algal growth inhibition tests performed in open agitated flasks. This is partly because such compounds tend to volatilize from aqueous solution and partly because of sorption to the algal biomass as well as to the......Exposure concentrations of many hydrophobic substances are difficult to maintain in algal growth inhibition tests performed in open agitated flasks. This is partly because such compounds tend to volatilize from aqueous solution and partly because of sorption to the algal biomass as well......, and the resulting dissolved CO2 concentration supported maximum algal growth rates without pH drift for algal densities up to 4 mg dry weight/L. Two-day toxicity tests with kerosene were performed with this new test design and compared with an open bottle test and with a closed bottle test with headspace. Exposure...... concentrations of the volatile fraction of kerosene decreased by 99% in the open test, by 77% in the closed flask test with headspace, and by 16% in the filled closed bottle test. Algal growth inhibition was observed at much lower additions of kerosene in the new test design because of the improved maintenance...

  14. BH3 mimetics inhibit growth of chondrosarcoma--a novel targeted-therapy for candidate models.

    Science.gov (United States)

    Morii, Takeshi; Ohtsuka, Kouki; Ohnishi, Hiroaki; Mochizuki, Kazuo; Yoshiyama, Akira; Aoyagi, Takayuki; Hornicek, Francis J; Ichimura, Shoichi

    2014-11-01

    Chondrosarcoma is refractory to conventional chemotherapy. BH-3 mimetics ABT-737 and ABT-263 are synthetic small-molecule inhibitors of anti-apoptotic proteins B-cell lymphoma-2 (Bcl2) and Bcl-xL, which play a critical role in survival of chondrosarcoma cells. Chondrosarcoma cell lines SW-1353 and CS-1 were used as the disease model. We used immunoblotting to assess the expression of target molecules Bcl2 and Bcl-xL, and the apoptotic inducers Bcl2-associated X (Bax) and Bcl2-antagonist/killer (Bak). In vitro growth inhibition by BH-3 mimetics was confirmed by photomicroscopic cell counting and 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt (MTS) assay. Apoptotic induction was confirmed by Enzyme-Linked ImmunoSorbent Assay (ELISA). In vivo growth inhibition was assessed in a non-obese diabetic/severe combined immunodeficient (NOD/SCID) mouse model. Expression of the target and effector molecules was confirmed in chondrosarcoma cell lines. BH3 mimetics significantly inhibited cell growth and induced apoptosis in vitro. Administration of ABT-263 inhibited chondrosarcoma growth and improved survival in a mouse model. BH3 mimetics represent a novel treatment modality for chondrosarcoma. Copyright© 2014 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

  15. The effect of essential oils on microbial composition and quality of grass carp (Ctenopharyngodon idellus) fillets during chilled storage.

    Science.gov (United States)

    Huang, Zhan; Liu, Xiaochang; Jia, Shiliang; Zhang, Longteng; Luo, Yongkang

    2018-02-02

    Antimicrobial and antioxidant effects of essential oils (oregano, thyme, and star anise) on microbial composition and quality of grass carp fillets were investigated. Essential oils treatment was found to be effective in inhibiting microbial growth, delaying lipid oxidation, and retarding the increase of TVB-N, putrescine, hypoxanthine, and K-value. Based on sensory analysis, shelf-life of grass carp fillets was 6days for control and 8days for treatment groups. Among the essential oils, oregano essential oil exhibited the highest antimicrobial and antioxidant activities. GC-MS analysis of essential oils components revealed that carvacrol (88.64%) was the major component of oregano essential oil. According to the results of high-throughput sequencing, Aeromonas, Glutamicibacter, and Aequorivita were the predominant microbiota in fresh control samples. However, oregano essential oil decreased the relative abundance of Aeromonas, while thyme and star anise essential oils decreased the relative abundance of Glutamicibacter and Aequorivita in fresh treated samples. The microbial composition of both control and treatment groups became less diverse as storage time increased. Aeromonas and Pseudomonas were dominant in spoiled samples and contributed to fish spoilage. Compared to the control, essential oils effectively inhibited the growth of Aeromonas and Shewanella in grass carp fillets during chilled storage. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Influence of heterotrophic microbial growth on biological oxidation of pyrite

    Energy Technology Data Exchange (ETDEWEB)

    Marchand, E.A.; Silverstein, J. [University of Nevada, Reno, NV (United States). Dept. of Civil Engineering

    2002-12-15

    Experiments were carried out to examine the possibility that enhanced growth of heterotrophic (non-iron-oxidising) bacteria would inhibit pyrite oxidation by Acidithiobacillus ferroxidans by out-competing the more slowly growing autotrophs for oxygen, nutrients or even attachment sites on the mineral surface. Glucose was added to microcosms containing pyrite, acidic mineral solution and cultures of A-ferrooxidans and Acidiphilium acidophilus under various experimental conditions. Results suggest that encouraging the growth of heterotrophic microorganisms under acid mine drainage conditions may be a feasible strategy for decreasing both the rate and the extent of sulfide mineral oxidation. 43 refs., 8 figs., 3 tabs.

  17. Molecular characterization of microbial population dynamics during sildenafil citrate degradation.

    Science.gov (United States)

    De Felice, Bruna; Argenziano, Carolina; Guida, Marco; Trifuoggi, Marco; Russo, Francesca; Condorelli, Valerio; Inglese, Mafalda

    2009-02-01

    Little is known about pharmaceutical and personal care products pollutants (PPCPs), but there is a growing interest in how they might impact the environment and microbial communities. The widespread use of Viagra (sildenafil citrate) has attracted great attention because of the high usage rate, the unpredictable disposal and the unknown potential effects on wildlife and the environment. Until now information regarding the impact of Viagra on microbial community in water environment has not been reported. In this research, for the first time, the genetic profile of the microbial community, developing in a Viagra polluted water environment, was evaluated by means of the 16S and 18S rRNA genes, for bacteria and fungi, respectively, amplified by polymerase chain reaction (PCR) and separated using the denaturing gradient gel electrophoresis (DGGE) technique. The DGGE results revealed a complex microbial community structure with most of the population persisting throughout the experimental period. DNA sequences from bands observed in the different denaturing gradient gel electrophoresis profiles exhibited the highest degree of identity to uncultured bacteria and fungi found previously mainly in polluted environmental and treating bioreactors. Biotransformation ability of sildenafil citrate by the microbial pool was studied and the capability of these microorganisms to detoxify a polluted water ecosystem was assessed. The bacterial and fungal population was able to degrade sildenafil citrate entirely. Additionally, assays conducted on Daphnia magna, algal growth inhibition assay and cell viability determination on HepG2 human cells showed that biotransformation products obtained from the bacterial growth was not toxic. The higher removal efficiency for sildenafil citrate and the lack of toxicity by the biotransformation products obtained showed that the microbial community identified here represented a composite population that might have biotechnological relevance to

  18. Changes in Microbial Energy Metabolism Measured by Nanocalorimetry during Growth Phase Transitions

    Science.gov (United States)

    Robador, Alberto; LaRowe, Douglas E.; Finkel, Steven E.; Amend, Jan P.; Nealson, Kenneth H.

    2018-01-01

    Calorimetric measurements of the change in heat due to microbial metabolic activity convey information about the kinetics, as well as the thermodynamics, of all chemical reactions taking place in a cell. Calorimetric measurements of heat production made on bacterial cultures have recorded the energy yields of all co-occurring microbial metabolic reactions, but this is a complex, composite signal that is difficult to interpret. Here we show that nanocalorimetry can be used in combination with enumeration of viable cell counts, oxygen consumption rates, cellular protein content, and thermodynamic calculations to assess catabolic rates of an isolate of Shewanella oneidensis MR-1 and infer what fraction of the chemical energy is assimilated by the culture into biomass and what fraction is dissipated in the form of heat under different limiting conditions. In particular, our results demonstrate that catabolic rates are not necessarily coupled to rates of cell division, but rather, to physiological rearrangements of S. oneidensis MR-1 upon growth phase transitions. In addition, we conclude that the heat released by growing microorganisms can be measured in order to understand the physiochemical nature of the energy transformation and dissipation associated with microbial metabolic activity in conditions approaching those found in natural systems. PMID:29449836

  19. Inhibition of phospholipase C disrupts cytoskeletal organization and gravitropic growth in Arabidopsis roots.

    Science.gov (United States)

    Andreeva, Zornitza; Barton, Deborah; Armour, William J; Li, Min Y; Liao, Li-Fen; McKellar, Heather L; Pethybridge, Kylie A; Marc, Jan

    2010-10-01

    The phospholipase protein superfamily plays an important role in hormonal signalling and cellular responses to environmental stimuli. There is also growing evidence for interactions between phospholipases and the cytoskeleton. In this report we used a pharmacological approach to investigate whether inhibiting a member of the phospholipase superfamily, phospholipase C (PLC), affects microtubules and actin microfilaments as well as root growth and morphology of Arabidopsis thaliana seedlings. Inhibiting PLC activity using the aminosteroid U73122 significantly inhibited root elongation and disrupted root morphology in a concentration-dependent manner, with the response being saturated at 5 μM, whereas the inactive analogue U73343 was ineffective. The primary root appeared to lose growth directionality accompanied by root waving and formation of curls. Immunolabelling of roots exposed to increasingly higher U73122 concentrations revealed that the normal transverse arrays of cortical microtubules in the elongation zone became progressively more disorganized or depolymerized, with the disorganization appearing within 1 h of incubation. Likewise, actin microfilament arrays also were disrupted. Inhibiting PLC using an alternative inhibitor, neomycin, caused similar disruptions to both cytoskeletal organization and root morphology. In seedlings gravistimulated by rotating the culture plates by 90°, both U73122 and neomycin disrupted the normal gravitropic growth of roots and etiolated hypocotyls. The effects of PLC inhibitors are therefore consistent with the notion that, as with phospholipases A and D, PLC likewise interacts with the cytoskeleton, alters growth morphology, and is involved in gravitropism.

  20. Air, surfaces and copper halos, interstitial microbial zones. Has it been measured; can it be predicted?

    CSIR Research Space (South Africa)

    Nice, Jaco A

    2014-07-01

    Full Text Available microbial modelling, inhibition of microbial contamination and microbial ‘fall out’. However the literature implicitly addresses mechanism of inhibition by ionisation and contact, methods for model development and for airborne and surface microbial ‘fall out...

  1. Microbial stratification in low pH oxic and suboxic macroscopic growths along an acid mine drainage

    DEFF Research Database (Denmark)

    Méndez-García, Celia; Mesa, Victoria; Sprenger, Richard Remko

    2014-01-01

    Macroscopic growths at geographically separated acid mine drainages (AMDs) exhibit distinct populations. Yet, local heterogeneities are poorly understood. To gain novel mechanistic insights into this, we used OMICs tools to profile microbial populations coexisting in a single pyrite gallery AMD (pH...

  2. Microbial stratification in low pH oxic and suboxic macroscopic growths along an acid mine drainage

    NARCIS (Netherlands)

    Méndez-Garcia, C.; Mesa, V.; Sprenger, R.R.; Richter, M.; Suarez Diez, M.; Solano, J.; Bargiela, R.; Golyshina, O.V.; Manteca, A.; Ramos, J.L.; Gallego, J.R.; Llorente, I.; Martins Dos Santos, V.A.P.; Jensen, O.N.; Paláez, A.I.; Sánchez, J.; Ferrer, M.

    2014-01-01

    Macroscopic growths at geographically separated acid mine drainages (AMDs) exhibit distinct populations. Yet, local heterogeneities are poorly understood. To gain novel mechanistic insights into this, we used OMICs tools to profile microbial populations coexisting in a single pyrite gallery AMD (pH

  3. Earthworms (Amynthas spp. increase common bean growth, microbial biomass, and soil respiration

    Directory of Open Access Journals (Sweden)

    Julierme Zimmer Barbosa

    2017-10-01

    Full Text Available Few studies have evaluated the effect of earthworms on plants and biological soil attributes, especially among legumes. The objective of this study was to evaluate the influence of earthworms (Amynthas spp. on growth in the common bean (Phaseolus vulgaris L. and on soil biological attributes. The experiment was conducted in a greenhouse using a completely randomized design with five treatments and eight repetitions. The treatments consisted of inoculation with five different quantities of earthworms of the genus Amynthas (0, 2, 4, 6, and 8 worms per pot. Each experimental unit consisted of a plastic pot containing 4 kg of soil and two common bean plants. The experiment was harvested 38 days after seedling emergence. Dry matter and plant height, soil respiration, microbial respiration, microbial biomass, and metabolic quotient were determined. Earthworm recovery in our study was high in number and mass, with all values above 91.6% and 89.1%, respectively. In addition, earthworm fresh biomass decreased only in the treatment that included eight earthworms per pot. The presence of earthworms increased the plant growth and improved soil biological properties, suggesting that agricultural practices that favor the presence of these organisms can be used to increase the production of common bean, and the increased soil CO2 emission caused by the earthworms can be partially offset by the addition of common bean crop residues to the soil.

  4. Growth inhibition of Listeria monocytogenes by a nonbacteriocinogenic Carnobacterium piscicola

    DEFF Research Database (Denmark)

    Nilsson, Lilian; Bech Hansen, T.; Garrido, P.

    2005-01-01

    Aims: This study elucidates the mechanisms by which a nonbacteriocinogenic Carnobacterium piscicola inhibits growth of Listeria monocytogenes. Methods and Results: Listeria monocytogenes was exposed to live cultures of a bacteriocin-negative variant of C. piscicola A9b in co-culture, in a diffusion...... chamber system, and to a cell-free supernatant. Suppression of maximum cell density (0-3.5 log units) of L. monocytogenes was proportional to initial levels of C. pisciola (10(3)-10(7) CFU ml(-1)). Cell-to-cell contact was not required to cause inhibition. The cell-free C. piscicola supernatant caused...... a decrease in L. monocytogenes maximum cell density, which was abolished by glucose addition but not by amino acid, vitamin or mineral addition. The fermentate also gave rise to a longer lag phase and a reduction in growth rate. These effects were independent of glucose and may have been caused by acetate...

  5. Growth inhibition of fouling bacteria and diatoms by extract of terrestrial plant, @iDerris scandens@@ (Dicotyledonae:Leguminocae)

    Digital Repository Service at National Institute of Oceanography (India)

    Sawant, S.S.; Sonak, S.; Garg, A.

    Methanol extract of terrestrial plant, @iDerris scandens@@ Benth, was found to inhibit growth of four diatoms and 7 bacterial species of fouling community. The concentrations required to bring about 100% inhibition of growth of the diatoms ranged...

  6. Adenoviral gene transfer of angiostatic ATF-BPTI inhibits tumour growth

    International Nuclear Information System (INIS)

    Lefesvre, Pierre; Attema, Joline; Bekkum, Dirk van

    2002-01-01

    The outgrowth of new vessels – angiogenesis – in the tumour mass is considered to be a limiting factor of tumour growth. To inhibit the matrix lysis that is part of the tumour angiogenesis, we employed the chimeric protein mhATF-BPTI, composed of the receptor binding part of the urokinase (ATF) linked to an inhibitor of plasmin (BPTI). For delivery, recombinant adenovirus encoding the transgene of interest was injected intravenously or locally into the tumour. The anti tumour effect of this compound was compared to that of human endostatin and of mhATF alone in two different rat bronchial carcinomas growing either as subcutaneous implants or as metastases. Significant inhibition of the tumour growth and decrease of the number of lung metastasis was achieved when the concentration of mhATF-BPTI at the tumour site was above 400 of ng / g tissue. This concentration could be achieved via production by the liver, only if permissive to the recombinant adenovirus. When the tumour cells could be transduced, local delivery of the vector was enough to obtain a response. In the case of metastasis, the capacity of the lung tissue to concentrate the encoded protein was essential to reach the required therapeutic levels. Further, endostatin or mhATF could not reproduce the effects of mhATF-BPTI, at similar concentrations (mhATF) and even at 10-fold higher concentration (endostatin). The ATF-BPTI was shown to inhibit tumour growth of different rat lung tumours when critical concentration was reached. In these tumour models, endostatin or ATF induce almost no tumour response

  7. Luteolin inhibits the Nrf2 signaling pathway and tumor growth in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Chian, Song; Thapa, Ruby; Chi, Zhexu [Department of Biochemistry and Genetics, School of Medicine, Zhejiang University, Hangzhou 310058 (China); Wang, Xiu Jun [Department of Pharmacology, School of Medicine, Zhejiang University, Hangzhou 310058 (China); Tang, Xiuwen, E-mail: xiuwentang@zju.edu.cn [Department of Biochemistry and Genetics, School of Medicine, Zhejiang University, Hangzhou 310058 (China)

    2014-05-16

    Highlights: • Luteolin inhibits the Nrf2 pathway in mouse liver and in xenografted tumors. • Luteolin markedly inhibits the growth of xenograft tumors. • Luteolin enhances the anti-cancer effect of cisplatin in mice in vivo. • Luteolin could serve as an adjuvant in the chemotherapy of NSCLC. - Abstract: Nuclear factor erythroid 2-related factor 2 (Nrf2) is over-expressed in many types of tumor, promotes tumor growth, and confers resistance to anticancer therapy. Hence, Nrf2 is regarded as a novel therapeutic target in cancer. Previously, we reported that luteolin is a strong inhibitor of Nrf2 in vitro. Here, we showed that luteolin reduced the constitutive expression of NAD(P)H quinone oxidoreductase 1 in mouse liver in a time- and dose-dependent manner. Further, luteolin inhibited the expression of antioxidant enzymes and glutathione transferases, decreasing the reduced glutathione in the liver of wild-type mice under both constitutive and butylated hydroxyanisole-induced conditions. In contrast, such distinct responses were not detected in Nrf2{sup −/−} mice. In addition, oral administration of luteolin, either alone or combined with intraperitoneal injection of the cytotoxic drug cisplatin, greatly inhibited the growth of xenograft tumors from non-small-cell lung cancer (NSCLC) cell line A549 cells grown subcutaneously in athymic nude mice. Cell proliferation, the expression of Nrf2, and antioxidant enzymes were all reduced in tumor xenograft tissues. Furthermore, luteolin enhanced the anti-cancer effect of cisplatin. Together, our findings demonstrated that luteolin inhibits the Nrf2 pathway in vivo and can serve as an adjuvant in the chemotherapy of NSCLC.

  8. Effusanin E suppresses nasopharyngeal carcinoma cell growth by inhibiting NF-κB and COX-2 signaling.

    Directory of Open Access Journals (Sweden)

    Mingzhu Zhuang

    Full Text Available Rabdosia serra is well known for its antibacterial, anti-inflammatory and antitumor activities, but no information has been available for the active compounds derived from this plant in inhibiting human nasopharyngeal carcinoma (NPC cell growth. In this study, we isolated and purified a natural diterpenoid from Rabdosia serra and identified its chemical structure as effusanin E and elucidated its underlying mechanism of action in inhibiting NPC cell growth. Effusanin E significantly inhibited cell proliferation and induced apoptosis in NPC cells. Effusanin E also induced the cleavage of PARP, caspase-3 and -9 proteins and inhibited the nuclear translocation of p65 NF-κB proteins. Moreover, effusanin E abrogated the binding of NF-κB to the COX-2 promoter, thereby inhibiting the expression and promoter activity of COX-2. Pretreatment with a COX-2 or NF-κB-selective inhibitor (celecoxib or ammonium pyrrolidinedithiocarbamate had an additive effect on the effusanin E-mediated inhibition of proliferation, while pretreatment with an activator of NF-κB/COX-2 (lipopolysaccharides abrogated the effusanin E-mediated inhibition of proliferation. Effusanin E also significantly suppressed tumor growth in a xenograft mouse model without obvious toxicity, furthermore, the expression of p50 NF-κB and COX-2 were down-regulated in the tumors of nude mice. These data suggest that effusanin E suppresses p50/p65 proteins to down-regulate COX-2 expression, thereby inhibiting NPC cell growth. Our findings provide new insights into exploring effusanin E as a potential therapeutic compound for the treatment of human nasopharyngeal carcinoma.

  9. Picropodophyllin inhibits the growth of Ewing's sarcoma cells through the insulin‑like growth factor‑1 receptor/Akt signaling pathway.

    Science.gov (United States)

    Wu, Yong-Tao; Wang, Bao-Jun; Miao, Sheng-Wu; Gao, Jian-Jun

    2015-11-01

    Ewing's sarcoma (ES) is the second most common type of pediatric bone tumor, and is associated with a poor prognosis. Picropodophyllin (PPP), a novel selective inhibitor of insulin‑like growth factor‑1 receptor (IGF‑1R), is able to strongly inhibit various types of cancers. However, the effect of IGF‑1R on ES remains unclear. Following treatment with various concentrations of PPP for various times, cell viability was determined using an MTT assay. In addition, cell proliferation and apoptosis was investigated separately by bromodeoxyuridine staining and flow cytometry, respectively. The PPP‑associated signaling pathway was also investigated. The results of the present study suggested that PPP inhibited cell proliferation and viability of A673 and SK‑ES‑1 human Ewing's sarcoma cells in a dose- and time‑dependent manner. In addition, cell apoptosis rates were increased following treatment with PPP. Further investigation of the underlying mechanism revealed that PPP inhibited Akt phosphorylation. Fumonisin B1, an Akt‑specific activator, reversed the inhibitory effects of PPP on cell growth. Furthermore, the results suggested that PPP decreased the expression levels of IGF‑1R, a common activator of Akt signaling. PPP inhibited the growth of human Ewing's sarcoma cells by targeting the IGF‑1R/Akt signaling pathway. Therefore, PPP may prove useful in the development of an effective strategy for the treatment of Ewing's sarcoma.

  10. Water Deficit and Abscisic Acid Cause Differential Inhibition of Shoot versus Root Growth in Soybean Seedlings : Analysis of Growth, Sugar Accumulation, and Gene Expression.

    Science.gov (United States)

    Creelman, R A; Mason, H S; Bensen, R J; Boyer, J S; Mullet, J E

    1990-01-01

    Roots often continue to elongate while shoot growth is inhibited in plants subjected to low-water potentials. The cause of this differential response to water deficit was investigated. We examined hypocotyl and root growth, polysome status and mRNA populations, and abscisic acid (ABA) content in etiolated soybean (Glycine max [L.] Merr. cv Williams) seedlings whose growth was inhibited by transfer to low-water potential vermiculite or exogenous ABA. Both treatments affected growth and dry weight in a similar fashion. Maximum inhibition of hypocotyl growth occurred when internal ABA levels (modulated by ABA application) reached the endogenous level found in the elongating zone of seedlings grown in water-deficient vermiculite. Conversely, root growth was affected to only a slight extent in low-water potential seedlings and by most ABA treatments (in some, growth was promoted). In every seedling section examined, transfer of seedlings into low-water potential vermiculite caused ABA levels to increase approximately 5- to 10-fold over that found in well-watered seedlings. Changes in soluble sugar content, polysome status, and polysome mRNA translation products seen in low-water potential seedlings did not occur with ABA treatments sufficient to cause significant inhibition of hypocotyl elongation. These data suggest that both variation in endogenous ABA levels, and differing sensitivity to ABA in hypocotyls and roots can modulate root/shoot growth ratios. However, exogenous ABA did not induce changes in sugar accumulation, polysome status, and mRNA populations seen after transfer into low-water potential vermiculite.

  11. A molecular framework for the inhibition of Arabidopsis root growth in response to boron toxicity.

    Science.gov (United States)

    Aquea, Felipe; Federici, Fernan; Moscoso, Cristian; Vega, Andrea; Jullian, Pastor; Haseloff, Jim; Arce-Johnson, Patricio

    2012-04-01

    Boron is an essential micronutrient for plants and is taken up in the form of boric acid (BA). Despite this, a high BA concentration is toxic for the plants, inhibiting root growth and is thus a significant problem in semi-arid areas in the world. In this work, we report the molecular basis for the inhibition of root growth caused by boron. We show that application of BA reduces the size of root meristems, correlating with the inhibition of root growth. The decrease in meristem size is caused by a reduction of cell division. Mitotic cell number significantly decreases and the expression level of key core cell cycle regulators is modulated. The modulation of the cell cycle does not appear to act through cytokinin and auxin signalling. A global expression analysis reveals that boron toxicity induces the expression of genes related with abscisic acid (ABA) signalling, ABA response and cell wall modifications, and represses genes that code for water transporters. These results suggest that boron toxicity produces a reduction of water and BA uptake, triggering a hydric stress response that produces root growth inhibition. © 2011 Blackwell Publishing Ltd.

  12. Growth inhibition and differences in protein profiles in azadirachtin-treated Drosophila melanogaster larvae.

    Science.gov (United States)

    Wang, Hao; Lai, Duo; Yuan, Mei; Xu, Hanhong

    2014-04-01

    Azadirachtin A is a very effective biopesticide widely used in insect pest control. It has strong antifeeding and growth inhibitory activity against most insects, however, its mode of action is still unclear. Proteomic experiments using 2DE indicate significant effects of Azadirachtin A on the amount of proteins related to growth inhibition in Drosophila melanogaster larvae. Twenty-one spots with different intensity in azadirachtin-treated larvae were identified. These proteins are involved in cytoskeletal organization, transcription and translation, hormonal regulation, and energy metabolism. Protein network analysis reveals heat shock protein 23 to be a potential target of azadirachtin. These results provide new insights into understanding the mechanism of growth inhibition in insects in response to azadirachtin. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Phytochemical analysis of Binahong (Anredera Cordifolia) leaves extract to inhibit In Vitro growth of Aeromonas Hydrophila

    Science.gov (United States)

    Basyuni, Mohammad; Ginting, Prita Yulianti Anasta Br; Lesmana, Indra

    2017-11-01

    Binahong (Anredera cordifolia) is one of the medicinal plants commonly used to treat the disease of living organisms. The secondary metabolite of A. cordifolia leaves has been shown antibacterial activity. This study aimed to investigate the secondary metabolite of A. cordifolia leaves showing antibacterial and analysis the effectiveness of antibacterial to inhibit the growth of bacteria Aeromonas hydrophila. A paper disc soaked in a solution of A. cordifolia leaves extract was used to test in vitro at a concentration of 0% (w/v), 0.2%, 0.4%, 0.6%, 0.8%, and positive control of antibiotic (oxytetracycline), respectively. The extracts then placed on a tryptone soy agar (TSA) medium containing bacteria A. hydrophila and incubated at 37 °C for 24 hours. In vitro test showed that A. cordifolia leaves extract inhibited the growth of bacteria A. hydrophila with an inhibition area around the paper disc. The inhibition growth of A. hydrophila increased with the increasing of extract concentration. Bacterial growth was inhibited in the diameter zone of A. hydrophila under different levels of the extracts were 0 mm (0 % negative control), 8.4 mm (0.2 %), 9.4 mm (0.4 %), 10.5 mm (0.6 %), 11.9 mm (0.8 %), 27.5 mm (positive control), respectively. Phytochemical screening of A. cordifolia leaves extract indicated that the extracts contained flavonoid, phenol, saponin, alkaloid, triterpenoid, and β-sitosterol. Our in vitro study demonstrated the inhibition growth of A. hydrophila that caused the disease of motile Aeromonas septicemia (MAS).

  14. By passing microbial resistance: xylitol controls microorganisms growth by means of its anti-adherence property.

    Science.gov (United States)

    Ferreira, Aline S; Silva-Paes-Leme, Annelisa F; Raposo, Nádia R B; da Silva, Sílvio S

    2015-01-01

    Xylitol is an important polyalcohol suitable for use in odontological, medical and pharmaceutical products and as an additive in food. The first studies on the efficacy of xylitol in the control and treatment of infections started in the late 1970s and it is still applied for this purpose, with safety and very little contribution to resistance. Xylitol seems to act against microorganisms exerting an anti-adherence effect. Some research studies have demonstrated its action against Gram-positive and Gram-negative bacteria and yeasts. However, a clear explanation of how xylitol is effective has not been completely established yet. Some evidence shows that xylitol acts on gene expression, down-regulating the ones which are involved in the microorganisms' virulence, such as capsule formation. Another possible clarification is that xylitol blocks lectin-like receptors. The most important aspect is that, over time, xylitol bypasses microbial resistance and succeeds in controlling infection, either alone or combined with another compound. In this review, the effect of xylitol in inhibiting the growth of a different microorganism is described, focusing on studies in which such an anti-adherent property was highlighted. This is the first mini-review to describe xylitol as an anti-adherent compound and take into consideration how it exerts such action.

  15. Microbial Inoculantes Effects on Growth Promotion of Mangrove and Citrullus vulgaris San Andrés Isla, Colombia

    Directory of Open Access Journals (Sweden)

    Tania Galindo

    2006-01-01

    Full Text Available In order to test the effect of two microbial inoculants (obtained from red and black mangrove roots on the growth and stability of mangrove and watermelon plants, four treatments were carried out in San Andres Island, Colombia. The treatments consisted in the application of the inoculants in: A. germinans propagules collected in a mangrove area, and then individually planted in gavels with sun-pasteurized soil (in order to decrease the microbial load, A. germinans and R. mangle plants collected in the proximity of nursery trees, A. germinans and R. mangle planted and maintained in nursery, and in Citrullus vulgaris seeds planted in a traditional cultivar without chemical fertilizers. The growth and vegetative development variables were: number of nodes, number of leaves and steam length. The inoculants (phosphate solubilizing microorganisms -PSM- and nitrogen fixing bacteria -NFB- were applied in the mentioned vegetable material, doing measures during three months. The results show a positive effect on growth measured by steam length in plants treated specifically with the inoculants in C. vulgaris and A. germinans seedlings maintained in nursery.

  16. Iodine from bacterial iodide oxidization by Roseovarius spp. inhibits the growth of other bacteria.

    Science.gov (United States)

    Zhao, Dan; Lim, Choon-Ping; Miyanaga, Kazuhiko; Tanji, Yasunori

    2013-03-01

    Microbial activities in brine, seawater, or estuarine mud are involved in iodine cycle. To investigate the effects of the microbiologically induced iodine on other bacteria in the environment, a total of 13 bacteria that potentially participated in the iodide-oxidizing process were isolated from water or biofilm at a location containing 131 μg ml(-1) iodide. Three distinct strains were further identified as Roseovarius spp. based on 16 S rRNA gene sequences after being distinguished by restriction fragment length polymorphism analysis. Morphological characteristics of these three Roseovarius spp. varied considerably across and within strains. Iodine production increased with Roseovarius spp. growth when cultured in Marine Broth with 200 μg ml(-1) iodide (I(-)). When 10(6) CFU/ml Escherichia coli, Pseudomonas aeruginosa, and Bacillus pumilus were exposed to various concentrations of molecular iodine (I(2)), the minimum inhibitory concentrations (MICs) were 0.5, 1.0, and 1.0 μg ml(-1), respectively. However, fivefold increases in the MICs for Roseovarius spp. were obtained. In co-cultured Roseovarius sp. IOB-7 and E. coli in Marine Broth containing iodide (I(-)), the molecular iodine concentration was estimated to be 0.76 μg ml(-1) after 24 h and less than 50 % of E. coli was viable compared to that co-cultured without iodide. The growth inhibition of E. coli was also observed in co-cultures with the two other Roseovarius spp. strains when the molecular iodine concentration was assumed to be 0.52 μg ml(-1).

  17. Survivin inhibits anti-growth effect of p53 activated by aurora B

    International Nuclear Information System (INIS)

    Jung, Ji-Eun; Kim, Tae-Kyung; Lee, Joong-Seob; Oh, Se-Yeong; Kwak, Sungwook; Jin, Xun; Sohn, Jin-Young; Song, Min-Keun; Sohn, Young-Woo; Lee, Soo-Yeon; Pian, Xumin; Lee, Jang-Bo; Chung, Yong Gu; Choi, Young Ki; You, Seungkwon; Kim, Hyunggee

    2005-01-01

    Genomic instability and apoptosis evasion are hallmarks of cancer, but the molecular mechanisms governing these processes remain elusive. Here, we found that survivin, a member of the apoptosis-inhibiting gene family, and aurora B kinase, a chromosomal passenger protein, were co-overexpressed in the various glioblastoma cell lines and tumors. Notably, exogenous introduction of the aurora B in human BJ cells was shown to decrease cell growth and increase the senescence-associated β-galactosidase activity by activation of p53 tumor suppressor. However, aurora B overexpression failed to inhibit cell proliferation in BJ and U87MG cells transduced with dominant-negative p53 as well as in p53 -/- mouse astrocytes. Aurora B was shown to increase centrosome amplification in the p53 -/- astrocytes. Survivin was shown to induce anchorage-independent growth and inhibit anti-proliferation and drug-sensitive apoptosis caused by aurora B. Overexpression of both survivin and aurora B further accelerated the proliferation of BJ cells. Taken together, the present study indicates that survivin should accelerate tumorigenesis by inhibiting the anti-proliferative effect of p53 tumor suppressor that is activated by aurora B in normal and glioblastoma cells containing intact p53

  18. Inhibition of the growth of Alexandrium tamarense by algicidal substances in Chinese fir (Cunninghamia lanceolata).

    Science.gov (United States)

    Yang, Wei-Dong; Liu, Jie-Sheng; Li, Hong-Ye; Zhang, Xin-Lian; Qi, Yu-Zao

    2009-10-01

    The wood sawdust from Chinese fir (Cunninghamia lanceolata) exhibited stronger inhibition on the growth of Alexandrium tamarense than those from alder (Alnus cremastogyne), pine (Pinus massoniana), birch (Betula alnoides) and sapele (Entandrophragma cylindricum). The water extract, acetone-water extract and essential oil from fir sawdust were all shown to inhibit the growth of A. tamarense. The inhibition of fir essential oil was the strongest among all the above wood sources while the half effective concentration was only 0.65 mg/L. These results suggested that the fir essential oil may play an important role in the algicidal effect of Chinese fir.

  19. Alternative natural seasoning to improve the microbial stability of low-salt beef patties.

    Science.gov (United States)

    García-Lomillo, Javier; González-SanJosé, M A Luisa; Del Pino-García, Raquel; Rivero-Pérez, M A Dolores; Muñiz-Rodríguez, Pilar

    2017-07-15

    The meat industry is seeking new strategies to reduce the sodium content of meat products without shortening their shelf-life. Natural seasonings as salt alternatives are more appreciated than chemical preservatives and also enable the incorporation of interesting nutrients. The present work studies the potential of a new red wine pomace seasoning (RWPS), derived from wine pomace, to inhibit spoilage growth in beef patties with different salt levels (2%, 1.5% and 1%) held in storage at 4°C. The use of RWPS (2% w/w) improved the microbial stability of the patties, delaying total aerobic mesophilic, and lactic acid bacteria growth, especially in samples with low salt levels. Satisfactory results were obtained in modified-atmosphere and air-packaged patties. RWPS also enabled the incorporation of fiber and phenolic compounds, and increased potassium and calcium levels. In summary, RWPS presented an interesting potential as a seasoning in meat products, enabling salt reduction without compromising their microbial stability. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. H32, a non-quinone sulfone analog of vitamin K3, inhibits human hepatoma cell growth by inhibiting Cdc25 and activating ERK.

    Science.gov (United States)

    Kar, Siddhartha; Wang, Meifang; Ham, Seung Wook; Carr, Brian I

    2006-10-01

    We previously synthesized a K-vitamin derivative, Cpd 5, which was a potent growth inhibitor of human tumor cells, including Hep3B hepatoma cells. However, being a quinone compound, Cpd 5 has the potential for generating toxic reactive oxygen species (ROS). We therefore synthesized a nonquinone sulfone derivative, H32, which has a sufone group substituting the quinone. The IC50 of H32 for Hep3B cells was found to be 2.5 microM, which was 2.5 and 3.2 times more potent than Cpd 5 and vitamin K3 respectively. It induced apoptosis in Hep3B cells but did not generate ROS when compared to Cpd 5. Interestingly, under similar culture conditions, normal rat hepatocytes were 14-fold more and 7-fold more resistant to the growth inhibitory effects of H32 than Hep3B and PLC/PRF5 cells respectively. H32 preferentially inhibited the activities of the cell cycle controlling Cdc25A phosphatase likely by binding to its catalytic cysteine. As a consequence, it induced inhibitory tyrosine phosphorylation of the Cdc25 substrate kinases Cdk2 and Cdk4 in Hep3B cells and the cells undergo an arrest in the G1 phase of the cell cycle. H32 also induced persistent phosphorylation of the MAPK protein ERK1/2, but marginal JNK1/2 and p38 phosphorylation. The ERK inhibitor U0126, added at least 30 min prior to H32, antagonized the growth inhibition induced by H32. However, the JNK and p38 inhibitors, JNKI-II and SB203580, were not able to antagonize H32 induced growth inhibition. Thus, H32 differentially inhibited growth of normal and liver tumor cells by preferentially inhibiting the actions of Cdc25 phosphatases and inducing persistent ERK phosphorylation.

  1. The relative importance of exogenous and substrate-derived nitrogen for microbial growth during leaf decomposition

    Science.gov (United States)

    B.M. Cheever; J. R. Webster; E. E. Bilger; S. A. Thomas

    2013-01-01

    Heterotrophic microbes colonizing detritus obtain nitrogen (N) for growth by assimilating N from their substrate or immobilizing exogenous inorganic N. Microbial use of these two pools has different implications for N cycling and organic matter decomposition in the face of the global increase in biologically available N. We used sugar maple leaves labeled with

  2. Inhibition of Listeria monocytogenes by Lactobacillus bavaricus MN in beef systems at refrigeration temperatures.

    OpenAIRE

    Winkowski, K; Crandall, A D; Montville, T J

    1993-01-01

    The ability of Lactobacillus bavaricus, a meat isolate, to inhibit the growth of three Listeria monocytogenes strains was examined in three beef systems: beef cubes, beef cubes in gravy, and beef cubes in gravy containing glucose. The beef was minimally heat treated, inoculated with L. bavaricus at 10(5) or 10(3) CFU/g and L. monocytogenes at 10(2) CFU/g, vacuum sealed, and stored at 4 or 10 degrees C. The meat samples were monitored for microbial growth, pH, and bacteriocin production. The p...

  3. Increase the Visibility of Microbial Growth in a Winogradsky Column by Substituting Diatomaceous Earth for Sediment

    Directory of Open Access Journals (Sweden)

    Thomas G. Benoit

    2015-02-01

    Full Text Available The difficulty students have seeing the color associated with microbial growth in a traditional Winogradsky column can be overcome by substituting diatomaceous earth (DE for sediment. Microbial growth in a DE column is visible from the early stages of ecological succession and the colors produced appear more vibrant. A flat-sided tissue culture flask can be used as a column container to provide a large surface area for observation. The enhanced visual experience provided by a DE column increases student engagement and learning. Editor's Note:The ASM advocates that students must successfully demonstrate the ability to explain and practice safe laboratory techniques. For more information, read the laboratory safety section of the ASM Curriculum Recommendations: Introductory Course in Microbiology and the Guidelines for Biosafety in Teaching Laboratories, available at www.asm.org. The Editors of JMBE recommend that adopters of the protocols included in this article follow a minimum of Biosafety Level 1 practices.

  4. Calcite growth-rate inhibition by fulvic acid and magnesium ion—Possible influence on biogenic calcite formation

    Science.gov (United States)

    Reddy, Michael M.

    2012-01-01

    Increases in ocean surface water dissolved carbon dioxide (CO2) concentrations retard biocalcification by reducing calcite supersaturation (Ωc). Reduced calcification rates may influence growth-rate dependent magnesium ion (Mg) incorporation into biogenic calcite modifying the use of calcifying organisms as paleoclimate proxies. Fulvic acid (FA) at biocalcification sites may further reduce calcification rates. Calcite growth-rate inhibition by FA and Mg, two common constituents of seawater and soil water involved in the formation of biogenic calcite, was measured separately and in combination under identical, highly reproducible experimental conditions. Calcite growth rates (pH=8.5 and Ωc=4.5) are reduced by FA (0.5 mg/L) to 47% and by Mg (10−4 M) to 38%, compared to control experiments containing no added growth-rate inhibitor. Humic acid (HA) is twice as effective a calcite growth-rate inhibitor as FA. Calcite growth rate in the presence of both FA (0.5 mg/L) and Mg (10−4 M) is reduced to 5% of the control rate. Mg inhibits calcite growth rates by substitution for calcium ion at the growth site. In contrast, FA inhibits calcite growth rates by binding multiple carboxylate groups on the calcite surface. FA and Mg together have an increased affinity for the calcite growth sites reducing calcite growth rates.

  5. Gallic acid inhibits gastric cancer cells metastasis and invasive growth via increased expression of RhoB, downregulation of AKT/small GTPase signals and inhibition of NF-κB activity

    Energy Technology Data Exchange (ETDEWEB)

    Ho, Hsieh-Hsun [Institute of Biochemistry and Biotechnology, Chung Shan Medical University, Taichung 402, Taiwan (China); Chang, Chi-Sen [Department of Medicine, Chung Shan Medical University, Taichung 402, Taiwan (China); Division of Gastroenterology, Taichung Veterans General Hospital, Taichung 402, Taiwan (China); Ho, Wei-Chi [Division of Gastroenterology, Jen-Ai Hospital, Taichung 402, Taiwan (China); Liao, Sheng-You [Institute of Biochemistry and Biotechnology, Chung Shan Medical University, Taichung 402, Taiwan (China); Lin, Wea-Lung [Department of Pathology, School of Medicine, Chung Shan Medical University, Taichung 402, Taiwan (China); Department of Pathology, Chung Shan Medical University Hospital, Taichung 402, Taiwan (China); Wang, Chau-Jong, E-mail: wcj@csmu.edu.tw [Institute of Biochemistry and Biotechnology, Chung Shan Medical University, Taichung 402, Taiwan (China); Department of Medical Research, Chung Shan Medical University Hospital, Taichung 402, Taiwan (China)

    2013-01-01

    Our previous study demonstrated the therapeutic potential of gallic acid (GA) for controlling tumor metastasis through its inhibitory effect on the motility of AGS cells. A noteworthy finding in our previous experiment was increased RhoB expression in GA-treated cells. The aim of this study was to evaluate the role of RhoB expression on the inhibitory effects of GA on AGS cells. By applying the transfection of RhoB siRNA into AGS cells and an animal model, we tested the effect of GA on inhibition of tumor growth and RhoB expression. The results confirmed that RhoB-siRNA transfection induced GA to inhibit AGS cells’ invasive growth involving blocking the AKT/small GTPase signals pathway and inhibition of NF-κB activity. Finally, we evaluated the effect of GA on AGS cell metastasis by colonization of tumor cells in nude mice. It showed GA inhibited tumor cells growth via the expression of RhoB. These data support the inhibitory effect of GA which was shown to inhibit gastric cancer cell metastasis and invasive growth via increased expression of RhoB, downregulation of AKT/small GTPase signals and inhibition of NF-κB activity. Thus, GA might be a potential agent in treating gastric cancer. Highlights: ► GA could downregulate AKT signal via increased expression of RhoB. ► GA inhibits metastasis in vitro in gastric carcinoma. ► GA inhibits tumor growth in nude mice model.

  6. Rhizospheric microbial communities are driven by Panax ginseng at different growth stages and biocontrol bacteria alleviates replanting mortality

    Directory of Open Access Journals (Sweden)

    Linlin Dong

    2018-03-01

    Full Text Available The cultivation of Panax plants is hindered by replanting problems, which may be caused by plant-driven changes in the soil microbial community. Inoculation with microbial antagonists may efficiently alleviate replanting issues. Through high-throughput sequencing, this study revealed that bacterial diversity decreased, whereas fungal diversity increased, in the rhizosphere soils of adult ginseng plants at the root growth stage under different ages. Few microbial community, such as Luteolibacter, Cytophagaceae, Luteibacter, Sphingomonas, Sphingomonadaceae, and Zygomycota, were observed; the relative abundance of microorganisms, namely, Brevundimonas, Enterobacteriaceae, Pandoraea, Cantharellales, Dendryphion, Fusarium, and Chytridiomycota, increased in the soils of adult ginseng plants compared with those in the soils of 2-year-old seedlings. Bacillus subtilis 50-1, a microbial antagonist against the pathogenic Fusarium oxysporum, was isolated through a dual culture technique. These bacteria acted with a biocontrol efficacy of 67.8%. The ginseng death rate and Fusarium abundance decreased by 63.3% and 46.1%, respectively, after inoculation with B. subtilis 50-1. Data revealed that microecological degradation could result from ginseng-driven changes in rhizospheric microbial communities; these changes are associated with the different ages and developmental stages of ginseng plants. Biocontrol using microbial antagonists alleviated the replanting problem. KEY WORDS: Panax ginseng, Microbial communities, Replanting problem, High-throughput sequencing, Different ages, Bioremediation

  7. Combination of α-Tomatine and Curcumin Inhibits Growth and Induces Apoptosis in Human Prostate Cancer Cells.

    Directory of Open Access Journals (Sweden)

    Huarong Huang

    Full Text Available α-Tomatine is a glycoalkaloid found in tomatoes and curcumin is a major yellow pigment of turmeric. In the present study, the combined effect of these two compounds on prostate cancer cells was studied. Treatment of different prostate cancer cells with curcumin or α-tomatine alone resulted in growth inhibition and apoptosis in a concentration-dependent manner. Combinations of α-tomatine and curcumin synergistically inhibited the growth and induced apoptosis in prostate cancer PC-3 cells. Effects of the α-tomatine and curcumin combination were associated with synergistic inhibition of NF-κB activity and a potent decrease in the expression of its downstream gene Bcl-2 in the cells. Moreover, strong decreases in the levels of phospho-Akt and phosphor-ERK1/2 were found in PC-3 cells treated with α-tomatine and curcumin in combination. In animal experiment, SCID mice with PC-3 xenograft tumors were treated with α-tomatine and curcumin. Combination of α-tomatine and curcumin more potently inhibited the growth of PC-3 tumors than either agent alone. Results from the present study indicate that α-tomatine in combination with curcumin may be an effective strategy for inhibiting the growth of prostate cancer.

  8. Large plasma-membrane depolarization precedes rapid blue-light-induced growth inhibition in cucumber

    Science.gov (United States)

    Spalding, E. P.; Cosgrove, D. J.

    1989-01-01

    Blue-light (BL)-induced suppression of elongation of etiolated Cucumis sativus L. hypocotyls began after a 30-s lag time, which was halved by increasing the fluence rate from 10 to 100 micromoles m-2 s-1. Prior to the growth suppression, the plasma-membrane of the irradiated cells depolarized by as much as 100 mV, then returned within 2-3 min to near its initial value. The potential difference measured with surface electrodes changed with an identical time course but opposite polarity. The lag time for the change in surface potential showed an inverse dependence on fluence rate, similar to the lag for the growth inhibition. Green light and red light caused neither the electrical response nor the rapid inhibition of growth. The depolarization by BL did not propagate to nonirradiated regions and exhibited a refractory period of about 10 min following a BL pulse. Fluence-response relationships for the electrical and growth responses provide correlational evidence that the plasma-membrane depolarization reflects an event in the transduction chain of this light-growth response.

  9. Potential mechanisms for the inhibition of tumor cell growth by manganese superoxide dismutase.

    Science.gov (United States)

    Kim, K H; Rodriguez, A M; Carrico, P M; Melendez, J A

    2001-06-01

    Studies from many laboratories have shown that overexpression of manganese superoxide dismutase (MnSOD) inhibits the growth of numerous tumor cell types. The inhibition of tumor cell growth can be attributed to the increase in the steady-state levels of H2O2 as a result of the increased dismuting activity of MnSOD. Here we demonstrate that overexpression of MnSOD enhances the activity of the superoxide (O2*-)-sensitive enzyme aconitase, decreases the intracellular GSH/GSSG ratio, and dose-dependently inhibits pyruvate carboxylase activity. Thus, alterations in the steady-state concentrations of mitochondrial O2*- and H2O2 as a result of MnSOD overexpression can alter the metabolic capacity of the cell leading to inhibition of cell growth. Furthermore, we propose that MnSOD overexpression can modulate the activity of nitric oxide (*NO) by preventing its reaction with O2*-. This hypothesis suggests that the redox environment of the mitochondria can be altered to favor the activity of *NO rather than peroxynitrite (ONOO-) and may explain the enhanced toxicity of *NO-generating compounds toward MnSOD-overexpressing cell lines. These findings indicate that therapeutic strategies targeted at overexpressing MnSOD in tumor tissue may be more effective when used in combination with agents that deplete the oxidant-buffering and enhance the *NO-generating capacity of the tumor and host, respectively.

  10. Inhibition of hydroxyapatite growth by casein, a potential salivary phosphoprotein homologue.

    Science.gov (United States)

    Romero, Maria J R H; Nakashima, Syozi; Nikaido, Toru; Ichinose, Shizuko; Sadr, Alireza; Tagami, Junji

    2015-08-01

    Salivary phosphoproteins are essential in tooth mineral regulation but are often overlooked in vitro. This study aimed to evaluate the effect of casein, as a salivary phosphoprotein homologue, on the deposition and growth of hydroxyapatite (HA) on tooth surfaces. Hydroxyapatite growth was quantified using seeded crystal systems. Artificial saliva (AS) containing HA powder and 0, 10, 20, 50, or 100 μg ml(-1) of casein, or 100 μg ml(-1) of dephosphorylated casein (Dcasein), was incubated for 0-8 h at 37°C, pH 7.2. Calcium concentrations were measured using atomic absorption spectroscopy (AAS). Surface precipitation of HA on bovine enamel and dentine blocks, incubated in similar conditions for 7 d, was examined using field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM) with selected area electron diffraction (SAED). Casein adsorption was assessed using modified Lowry assays and zeta-potential measurements. The AAS results revealed a concentration-dependent inhibition of calcium consumption. Hydroxyapatite precipitation occurred when no casein was present, whereas precipitation of HA was apparently completely inhibited in casein-containing groups. Adsorption data demonstrated increasingly negative zeta-potential with increased casein concentration and an affinity constant similar to proline-rich proteins with Langmuir modelling. Casein inhibited the deposition and growth of HA primarily through the binding of esterized phosphate to HA active sites, indicating its potential as a mineral-regulating salivary phosphoprotein homologue in vitro. © 2015 Eur J Oral Sci.

  11. Fungi & Health: can polysaccharides from the fungus inonotus obliquus (CHAGA) inhibit tumor growth?

    DEFF Research Database (Denmark)

    Wold, C. W.; Corthay, A.; Kjeldsen, Christian

    Inonotus obliquus (Chaga) – a white rot fungus found on birch trees in the northern hemisphere –has been used in traditional medicine in Europe and Asia for centuries. Native peoples have made use of Chaga by brewing it as a tea to treat gastro-intestinal problems, to heal wounds and even to treat...... cancer. The last few decades, studies have found Chaga to contain biologically active substances such as polysaccharides, triterpenoids, polyphenols and melanin. In vivo effects such as tumor growth inhibition have been observed in mice receiving various Chaga extracts. The main hypothesis behind...... the tumor inhibiting effect is two-fold: i) fungal polysaccharides may inhibit tumor growth indirectly by activating certain immune cells such as macrophages and ii) triterpenoids and other steroids from Chaga may give a direct cytotoxic effect against cancer cells. While triterpenoids from Chaga have been...

  12. Nitrogen-fixing trees inhibit growth of regenerating Costa Rican rainforests.

    Science.gov (United States)

    Taylor, Benton N; Chazdon, Robin L; Bachelot, Benedicte; Menge, Duncan N L

    2017-08-15

    More than half of the world's tropical forests are currently recovering from human land use, and this regenerating biomass now represents the largest carbon (C)-capturing potential on Earth. How quickly these forests regenerate is now a central concern for both conservation and global climate-modeling efforts. Symbiotic nitrogen-fixing trees are thought to provide much of the nitrogen (N) required to fuel tropical secondary regrowth and therefore to drive the rate of forest regeneration, yet we have a poor understanding of how these N fixers influence the trees around them. Do they promote forest growth, as expected if the new N they fix facilitates neighboring trees? Or do they suppress growth, as expected if competitive inhibition of their neighbors is strong? Using 17 consecutive years of data from tropical rainforest plots in Costa Rica that range from 10 y since abandonment to old-growth forest, we assessed how N fixers influenced the growth of forest stands and the demographic rates of neighboring trees. Surprisingly, we found no evidence that N fixers facilitate biomass regeneration in these forests. At the hectare scale, plots with more N-fixing trees grew slower. At the individual scale, N fixers inhibited their neighbors even more strongly than did nonfixing trees. These results provide strong evidence that N-fixing trees do not always serve the facilitative role to neighboring trees during tropical forest regeneration that is expected given their N inputs into these systems.

  13. Comparison of fermentation of diets of variable composition and microbial populations in the rumen of sheep and Rusitec fermenters. I. Digestibility, fermentation parameters, and microbial growth.

    Science.gov (United States)

    Martínez, M E; Ranilla, M J; Tejido, M L; Ramos, S; Carro, M D

    2010-08-01

    Four ruminally and duodenally cannulated sheep and 8 Rusitec fermenters were used to determine the effects of forage to concentrate (F:C) ratio and type of forage in the diet on ruminal fermentation and microbial protein synthesis. The purpose of the study was to assess how closely fermenters can mimic the dietary differences found in vivo. The 4 experimental diets contained F:C ratios of 70:30 or 30:70 with either alfalfa hay or grass hay as the forage. Microbial growth was determined in both systems using (15)N as a microbial marker. Rusitec fermenters detected differences between diets similar to those observed in sheep by changing F:C ratio on pH; neutral detergent fiber digestibility; total volatile fatty acid concentrations; molar proportions of acetate, propionate, butyrate, isovalerate, and caproate; and amylase activity. In contrast, Rusitec fermenters did not reproduce the dietary differences found in sheep for NH(3)-N and lactate concentrations, dry matter (DM) digestibility, proportions of isobutyrate and valerate, carboxymethylcellulase and xylanase activities, and microbial growth and its efficiency. Regarding the effect of the type of forage in the diet, Rusitec fermenters detected differences between diets similar to those found in sheep for most determined parameters, with the exception of pH, DM digestibility, butyrate proportion, and carboxymethylcellulase activity. Minimum pH and maximal volatile fatty acid concentrations were reached at 2h and at 6 to 8h postfeeding in sheep and fermenters, respectively, indicating that feed fermentation was slower in fermenters compared with that in sheep. There were differences between systems in the magnitude of most determined parameters. In general, fermenters showed lower lactate concentrations, neutral detergent fiber digestibility, acetate:propionate ratios, and enzymatic activities. On the contrary, fermenters showed greater NH(3)-N concentrations, DM digestibility, and proportions of propionate

  14. Better to light a candle than curse the darkness: illuminating spatial localization and temporal dynamics of rapid microbial growth in the rhizosphere

    Directory of Open Access Journals (Sweden)

    Patrick M Herron

    2013-09-01

    Full Text Available The rhizosphere is a hotbed of microbial activity in ecosystems, fueled by carbon compounds from plant roots. Basic questions about the location and dynamics of plant-spurred microbial growth in the rhizosphere are difficult to answer with standard, destructive soil assays mixing a multitude of microbe-scale microenvironments in a single, often sieved, sample. Soil microbial biosensors designed with the luxCDABE reporter genes fused to a promoter of interest enable continuous imaging of the microbial perception of (and response to environmental conditions in soil. We used the common soil bacterium Pseudomonas putida KT2440 as host to plasmid pZKH2 containing a fusion between the strong constituitive promoter nptII and luxCDABE (coding for light-emitting proteins from Vibrio fischeri. Experiments in liquid media demonstrated that high light production by KT2440/pZKH2 was associated with rapid microbial growth supported by high carbon availability. We applied the biosensors in microcosms filled with non-sterile soil in which corn (Zea mays L., black poplar (Populus nigra L. or tomato (Solanum lycopersicum L. was growing. We detected minimal light production from microbiosensors in the bulk soil, but biosensors reported continuously from around roots for as long as six days. For corn, peaks of luminescence were detected 1-4 and 20-35 mm along the root axis behind growing root tips, with the location of maximum light production moving farther back from the tip as root growth rate increased. For poplar, luminescence around mature roots increased and decreased on a coordinated diel rhythm, but was not bright near root tips. For tomato, luminescence was dynamic, but did not exhibit a diel rhythm, appearing in acropetal waves along roots. KT2440/pZKH2 revealed that root tips are not always the only, or even the dominant, hotspots for rhizosphere microbial growth, and carbon availability is highly variable in space and time around roots.

  15. Silencing VDAC1 Expression by siRNA Inhibits Cancer Cell Proliferation and Tumor Growth In Vivo

    Directory of Open Access Journals (Sweden)

    Tasleem Arif

    2014-01-01

    Full Text Available Alterations in cellular metabolism and bioenergetics are vital for cancer cell growth and motility. Here, the role of the mitochondrial protein voltage-dependent anion channel (VDAC1, a master gatekeeper regulating the flux of metabolites and ions between mitochondria and the cytoplasm, in regulating the growth of several cancer cell lines was investigated by silencing VDAC1 expression using small interfering RNA (siRNA. A single siRNA specific to the human VDAC1 sequence at nanomolar concentrations led to some 90% decrease in VDAC1 levels in the lung A549 and H358, prostate PC-3, colon HCT116, glioblastoma U87, liver HepG2, and pancreas Panc-1 cancer cell lines. VDAC1 silencing persisted 144 hours post-transfection and resulted in profound inhibition of cell growth in cancer but not in noncancerous cells, with up to 90% inhibition being observed over 5 days that was prolonged by a second transfection. Cells expressing low VDAC1 levels showed decreased mitochondrial membrane potential and adenoside triphosphate (ATP levels, suggesting limited metabolite exchange between mitochondria and cytosol. Moreover, cells silenced for VDAC1 expression showed decreased migration, even in the presence of the wound healing accelerator basic fibroblast growth factor (bFGF. VDAC1-siRNA inhibited cancer cell growth in a Matrigel-based assay in host nude mice. Finally, in a xenograft lung cancer mouse model, chemically modified VDAC1-siRNA not only inhibited tumor growth but also resulted in tumor regression. This study thus shows that VDAC1 silencing by means of RNA interference (RNAi dramatically inhibits cancer cell growth and tumor development by disabling the abnormal metabolic behavior of cancer cells, potentially paving the way for a more effective pipeline of anticancer drugs.

  16. Suppression of polymorphonuclear (PMN) and monocyte-mediated inhibition of Candida albicans growth by delta-9-tetrahydrocannabinol

    International Nuclear Information System (INIS)

    Djeu, J.Y.; Parapanios, A.; Halkias, D.; Friedman, H.

    1986-01-01

    This study was an in vitro attempt to identify the effector cells responsible for growth inhibition of the opportunistic fungus, candida albicans, and to determine if THC or another marijuana derivatives, 11-hydroxyTHC, would adversely affect their function. Using a 24h radiolabel assay, the authors found that growth inhibition of C. albicans was primarily mediated by PMN and monocytes that could be isolated normal human peripheral blood. Both effector cell types caused almost complete inhibition of Candida growth at effector/target ratio of 300/1 and inhibition was often still seen at 30/1-. Incubation of PMN, PBL, or monocytes for 1 hr at 37C with THC or 11-hydroxyTHC caused a marked suppression of function in all 3 cell populations. Maximal suppression was obtained with 7.5-10μg/ml of the drugs in medium containing 10% fetal bovine serum (FBS) or with 2-4μg/ml in 1% FBS. These drug concentrations did not affect lymphoid cell viability or candida growth in the absence of lymphoid effector cells. Marijuana derivatives, therefore, are doubly dangerous in that opportunistic fungi such as C. albicans can grow in their presence while the effector cells that control fungal growth are readily inactivated

  17. Berberine suppresses tumorigenicity and growth of nasopharyngeal carcinoma cells by inhibiting STAT3 activation induced by tumor associated fibroblasts

    International Nuclear Information System (INIS)

    Tsang, Chi Man; Cheung, Yuk Chun; Lui, Vivian Wai-Yan; Yip, Yim Ling; Zhang, Guitao; Lin, Victor Weitao; Cheung, Kenneth Chat-Pan; Feng, Yibin; Tsao, Sai Wah

    2013-01-01

    Cortidis rhizoma (Huanglian) and its major therapeutic component, berberine, have drawn extensive attention in recent years for their anti-cancer properties. Growth inhibitory effects of berberine on multiple types of human cancer cells have been reported. Berberine inhibits invasion, induces cell cycle arrest and apoptosis in human cancer cells. The anti-inflammatory property of berberine, involving inhibition of Signal Transducer and Activator of Transcription 3 (STAT3) activation, has also been documented. In this study, we have examined the effects of berberine on tumorigenicity and growth of nasopharyngeal carcinoma (NPC) cells and their relationship to STAT3 signaling using both in vivo and in vitro models. Berberine effectively inhibited the tumorigenicity and growth of an EBV-positive NPC cell line (C666-1) in athymic nude mice. Inhibition of tumorigenic growth of NPC cells in vivo was correlated with effective inhibition of STAT3 activation in NPC cells inside the tumor xenografts grown in nude mice. In vitro, berberine inhibited both constitutive and IL-6-induced STAT3 activation in NPC cells. Inhibition of STAT3 activation by berberine induced growth inhibition and apoptotic response in NPC cells. Tumor-associated fibroblasts were found to secret IL-6 and the conditioned medium harvested from the fibroblasts also induced STAT3 activation in NPC cells. Furthermore, STAT3 activation by conditioned medium of tumor-associated fibroblasts could be blocked by berberine or antibodies against IL-6 and IL-6R. Our observation that berberine effectively inhibited activation of STAT3 induced by tumor-associated fibroblasts suggests a role of berberine in modulating the effects of tumor stroma on the growth of NPC cells. The effective inhibition of STAT3 activation in NPC cells by berberine supports its potential use in the treatment of NPC

  18. Effect of growth conditions on microbial activity and iron-sulfide production by Desulfovibrio vulgaris

    International Nuclear Information System (INIS)

    Zhou, Chen; Vannela, Raveender; Hayes, Kim F.; Rittmann, Bruce E.

    2014-01-01

    Highlights: • Extended incubation time to 16 days allowed significant FeS crystallization. • A weakly acidic pH greatly enhanced particle growth of mackinawite. • Microbial metabolism of different donors systematically altered the ambient pH. • Greater sulfide accumulation stimulated mackinawite transformation to greigite. - Abstract: Sulfate-reducing bacteria (SRB) can produce iron sulfide (FeS) solids with mineralogical characteristics that may be beneficial for a variety of biogeochemical applications, such as long-term immobilization of uranium. In this study, the growth and metabolism of Desulfovibrio vulgaris, one of the best-studied SRB species, were comprehensively monitored in batch studies, and the biogenic FeS solids were characterized by X-ray diffraction. Controlling the pH by varying the initial pH, the iron-to-sulfate ratio, or the electron donor – affected the growth of D. vulgaris and strongly influenced the formation and growth of FeS solids. In particular, lower pH (from initial conditions or a decrease caused by less sulfate reduction, FeS precipitation, or using pyruvate as the electron donor) produced larger-sized mackinawite (Fe 1+x S). Greater accumulation of free sulfide, from more sulfate reduction by D. vulgaris, also led to larger-sized mackinawite and particularly stimulated mackinawite transformation to greigite (Fe 3 S 4 ) when the free sulfide concentration was 29.3 mM. Furthermore, sufficient free Fe 2+ led to the additional formation of vivianite [Fe 3 (PO 4 ) 2 ·8(H 2 O)]. Thus, microbially relevant conditions (initial pH, choice of electron donor, and excess or deficiency of sulfide) are tools to generate biogenic FeS solids of different characteristics

  19. [Influence of Mirabilis jalapa Linn. Growth on the Microbial Community and Petroleum Hydrocarbon Degradation in Petroleum Contaminated Saline-alkali Soil].

    Science.gov (United States)

    Jiao, Hai-hua; Cui, Bing-jian; Wu, Shang-hua; Bai, Zhi-hui; Huang, Zhan-bin

    2015-09-01

    In order to explore the effect of Mirabilis jalapa Linn. growth on the structure characteristics of the microbial community and the degradation of petroleum hydrocarbon (TPH) in the petroleum-contaminated saline-alkali soil, Microbial biomass and species in the rhizosphere soils of Mirabilis jalapa Linn. in the contaminated saline soil were studied with the technology of phospholipid fatty acids (PLFAs) analysis. The results showed that comparing to CK soils without Mirabilis jalapa Linn., the ratio of PLFAs species varied were 71. 4%, 69. 2% and 33. 3% in the spring, summer and autumn season, respectively. In addition, there was distinct difference of the biomasses of the microbial community between the CK and rhizosphere soils and among the difference seasons of growth of Mirabilis jalapa Linn.. Compare to CK soil, the degradation rates of total petroleum hydrocarbon (TPH) was increased by 47. 6%, 28. 3%, and 18. 9% in spring, summer, and autumn rhizosphere soils, respectively. Correlation analysis was used to determine the correlation between TPH degradation and the soil microbial community. 77. 8% of the total soil microbial PLFAs species showed positive correlation to the TPH degradation (the correlation coefficient r > 0), among which, 55. 6% of PLFAs species showed high positive correlation(the correlation coefficient was r≥0. 8). In addition, the relative content of SAT and MONO had high correlation with TPH degradation in the CK sample soils, the corelation coefficient were 0. 92 and 0. 60 respectively; However, the percent of positive correlation was 42. 1% in the rhizosphere soils with 21. 1% of them had high positive correlation. The relative content of TBSAT, MONO and CYCLO had moderate or low correlation in rhizosphere soils, and the correlation coefficient were 0. 56, 0. 50, and 0. 07 respectively. Our study showed that the growth of mirabilis Mirabilis jalapa Linn. had a higher influence on the species and biomass of microbial community in the

  20. Inhibition of growth of Trichophyton tonsurans by Lactobacillus reuteri.

    Science.gov (United States)

    Guo, J; Mauch, A; Galle, S; Murphy, P; Arendt, E K; Coffey, A

    2011-08-01

    The aims of this study were to identify antifungal lactic acid bacteria (LAB) and characterize their activity against the dermatophyte Trichophyton tonsurans. A total of 165 different LAB were isolated and initially screened for anti-Penicillium expansum activity. Five strains, which exhibited strong inhibitory activity, were then tested against the dermatophyte T. tonsurans DSM12285, where they also caused inhibition as observed by large fungal clearing on agar surface. The strongest inhibition was seen with Lactobacillus reuteri R2. When freeze-dried cell-free supernatant powder from this strain was incorporated in culture medium at concentrations >1%, growth of fungal colony was inhibited. Conidia germination was also inhibited under these conditions as determined by microscopy. The anti-T. tonsurans activity of Lact. reuteri R2 was not affected neither by heat treatment nor by proteolytic treatment using pronase E and proteinase K, indicating that the responsible agent(s) were nonproteinaceous in nature. Lactobacillus reuteri R2 was identified as having strong inhibitory activity against the dermatophyte T. tonsurans DSMZ12285. LAB are naturally associated with many foods and are well recognized for their biopreservative properties. The use of these and/or their products may well provide alternative safe approaches for the inhibition of dermatophytic fungi. © 2011 The Authors. Journal of Applied Microbiology © 2011 The Society for Applied Microbiology.

  1. Exogenous nitrate induces root branching and inhibits primary root growth in Capsicum chinense Jacq.

    Science.gov (United States)

    Celis-Arámburo, Teresita de Jesús; Carrillo-Pech, Mildred; Castro-Concha, Lizbeth A; Miranda-Ham, María de Lourdes; Martínez-Estévez, Manuel; Echevarría-Machado, Ileana

    2011-12-01

    The effects of nitrate (NO₃⁻) on the root system are complex and depend on several factors, such as the concentration available to the plant, endogenous nitrogen status and the sensitivity of the species. Though these effects have been widely documented on Arabidopsis and cereals, no reports are available in the Capsicum genus. In this paper, we have determined the effect of an exogenous in vitro application of this nutrient on root growth in habanero pepper (Capsicum chinense Jacq.). Exposure to NO₃⁻ inhibited primary root growth in both, dose- and time-dependent manners. The highest inhibition was attained with 0.1 mM NO₃⁻ between the fourth and fifth days of treatment. Inhibition of primary root growth was observed by exposing the root to both homogeneous and heterogeneous conditions of the nutrient; in contrast, ammonium was not able to induce similar changes. NO₃⁻-induced inhibition of primary root growth was reversed by treating the roots with IAA or NPA, a polar auxin transport inhibitor. Heterogeneous NO₃⁻ application stimulated the formation and elongation of lateral roots in the segment where the nutrient was present, and this response was influenced by exogenous phytohormones. These results demonstrate that habanero pepper responds to NO₃⁻ in a similar fashion to other species with certain particular differences. Therefore, studies in this model could help to elucidate the mechanisms by which roots respond to NO₃⁻ in fluctuating soil environments. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

  2. Herbal extracts of Tribulus terrestris and Bergenia ligulata inhibit growth of calcium oxalate monohydrate crystals in vitro

    Science.gov (United States)

    Joshi, V. S.; Parekh, B. B.; Joshi, M. J.; Vaidya, A. B.

    2005-02-01

    A large number of people in this world are suffering from urinary stone problem. Calcium oxalate monohydrate (COM) and calcium oxalate dihydrate (COD) containing stones (calculi) are commonly found. In the present study, COM crystals were grown by a double diffusion gel growth technique using U-tubes. The gel was prepared from hydrated sodium metasilicate solution. The gel framework acts like a three-dimensional crucible in which the crystal nuclei are delicately held in the position of their formation, and nutrients are supplied for the growth. This technique can be utilized as a simplified screening static model to study the growth, inhibition and dissolution of urinary stones in vitro. The action of putative litholytic medicinal plants, Tribulus terrestris Linn. ( T.t) and Bergenia ligulata Linn. ( B.l.), has been studied in the growth of COM crystals. Tribulus terrestris and Bergenia ligulata are commonly used as herbal medicines for urinary calculi in India. To verify the inhibitive effect, aqueous extracts of Tribulus terrestris and Bergenia ligulata were added along with the supernatant solutions. The growth was measured and compared, with and without the aqueous extracts. Inhibition of COM crystal growth was observed in the herbal extracts. Maximum inhibition was observed in Bergenia ligulata followed by Tribulus terrestris. The results are discussed.

  3. Inhibition of connective tissue growth factor overexpression decreases growth of hepatocellular carcinoma cells in vitro and in vivo.

    Science.gov (United States)

    Jia, Xiao-Qin; Cheng, Hai-Qing; Li, Hong; Zhu, Yan; Li, Yu-Hua; Feng, Zhen-Qing; Zhang, Jian-Ping

    2011-11-01

    We have previously found that connective tissue growth factor (CTGF) is highly expressed in a rat model of liver cancer. Here, we examined expression of CTGF in human hepatocellular carcinoma (HCC) cells and its effect on cell growth. Real-time PCR was used to observe expression of CTGF in human HCC cell lines HepG2, SMMC-7721, MHCC-97H and LO2. siRNA for the CTGF gene was designed, synthesized and cloned into a Plk0.1-GFP-SP6 vector to construct a lentivirus-mediated shRNA/CTGF. CTGF mRNA and protein expression in HepG2 cells treated by CTGF-specific shRNA was evaluated by real-time PCR and Western blotting. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was utilized to evaluate the growth effect, and a colony formation assay was used for observing clonogenic growth. In vivo, tumor cell proliferation was evaluated in a nude mouse model of xenotransplantation. Statistical significance was determined by t test for comparison between two groups, or analysis of variance (ANOVA) for multiple groups. Immunohistochemical staining of CTGF was seen in 35 of 40 HCC samples (87.5%). CTGF was overexpressed 5-fold in 20 HCC tissues, compared with surrounding non-tumor liver tissue. CTGF mRNA level was 5 - 8-fold higher in HepG2, SMMC-7721 and MHCC-97H than in LO2 cells. This indicated that the inhibition rate of cell growth was 43% after knockdown of CTGF expression (P < 0.05). Soft agar colony formation assay showed that siRNA mediated knockdown of CTGF inhibited colony formation in soft agar of HepG2 cells (P < 0.05). The volume of tumors from CTGF-shRNA-expressing cells only accounted for 35% of the tumors from the scrambled control-infected HepG2 cells (P < 0.05). CTGF was overexpressed in human HCC cells and downregulation of CTGF inhibited HCC growth in vitro and in vivo. Knockdown of CTGF may be a potential therapeutic strategy for treatment of HCC.

  4. Picropodophyllin inhibits tumor growth of human nasopharyngeal carcinoma in a mouse model

    International Nuclear Information System (INIS)

    Yin, Shu-Cheng; Guo, Wei; Tao, Ze-Zhang

    2013-01-01

    Highlights: •We identified that PPP inhibits IGF-1R/Akt pathway in NPC cells. •PPP dose-dependently inhibits NPC cell proliferation in vitro. •PPP suppresses tumor growth of NPC in nude mice. •PPP have little effect on microtubule assembly. -- Abstract: Insulin-like growth factor-1 receptor (IGF-1R) is a cell membrane receptor with tyrosine kinase activity and plays important roles in cell transformation, tumor growth, tumor invasion, and metastasis. Picropodophyllin (PPP) is a selective IGF-1R inhibitor and shows promising antitumor effects for several human cancers. However, its antitumor effects in nasopharyngeal carcinoma (NPC) remain unclear. The purpose of this study is to investigate the antitumor activity of PPP in NPC using in vitro cell culture and in vivo animal model. We found that PPP dose-dependently decreased the IGF-induced phosphorylation and activity of IGF-1R and consequently reduced the phosphorylation of Akt, one downstream target of IGF-1R. In addition, PPP inhibited NPC cell proliferation in vitro. The half maximal inhibitory concentration (IC50) of PPP for NPC cell line CNE-2 was ⩽1 μM at 24 h after treatment and ⩽0.5 μM at 48 h after treatment, respectively. Moreover, administration of PPP by intraperitoneal injection significantly suppressed the tumor growth of xenografted NPC in nude mice. Taken together, these results suggest targeting IGF-1R by PPP may represent a new strategy for treatment of NPCs with positive IGF-1R expression

  5. Picropodophyllin inhibits tumor growth of human nasopharyngeal carcinoma in a mouse model

    Energy Technology Data Exchange (ETDEWEB)

    Yin, Shu-Cheng [Department of Otolaryngology – Head and Neck Surgery, Renmin Hospital of Wuhan University, Wuhan 430060 (China); Department of Otolaryngology – Head and Neck Surgery, Zhongnan Hospital of Wuhan University, Wuhan 430071 (China); Guo, Wei [Department of Otolaryngology – Head and Neck Surgery, Zhongnan Hospital of Wuhan University, Wuhan 430071 (China); Tao, Ze-Zhang, E-mail: zezhangtao@gmail.com [Department of Otolaryngology – Head and Neck Surgery, Renmin Hospital of Wuhan University, Wuhan 430060 (China)

    2013-09-13

    Highlights: •We identified that PPP inhibits IGF-1R/Akt pathway in NPC cells. •PPP dose-dependently inhibits NPC cell proliferation in vitro. •PPP suppresses tumor growth of NPC in nude mice. •PPP have little effect on microtubule assembly. -- Abstract: Insulin-like growth factor-1 receptor (IGF-1R) is a cell membrane receptor with tyrosine kinase activity and plays important roles in cell transformation, tumor growth, tumor invasion, and metastasis. Picropodophyllin (PPP) is a selective IGF-1R inhibitor and shows promising antitumor effects for several human cancers. However, its antitumor effects in nasopharyngeal carcinoma (NPC) remain unclear. The purpose of this study is to investigate the antitumor activity of PPP in NPC using in vitro cell culture and in vivo animal model. We found that PPP dose-dependently decreased the IGF-induced phosphorylation and activity of IGF-1R and consequently reduced the phosphorylation of Akt, one downstream target of IGF-1R. In addition, PPP inhibited NPC cell proliferation in vitro. The half maximal inhibitory concentration (IC50) of PPP for NPC cell line CNE-2 was ⩽1 μM at 24 h after treatment and ⩽0.5 μM at 48 h after treatment, respectively. Moreover, administration of PPP by intraperitoneal injection significantly suppressed the tumor growth of xenografted NPC in nude mice. Taken together, these results suggest targeting IGF-1R by PPP may represent a new strategy for treatment of NPCs with positive IGF-1R expression.

  6. A novel rabbit anti-hepatocyte growth factor monoclonal neutralizing antibody inhibits tumor growth in prostate cancer cells and mouse xenografts

    International Nuclear Information System (INIS)

    Yu, Yanlan; Chen, Yicheng; Ding, Guoqing; Wang, Mingchao; Wu, Haiyang; Xu, Liwei; Rui, Xuefang; Zhang, Zhigen

    2015-01-01

    The hepatocyte growth factor and its receptor c-Met are correlated with castration-resistance in prostate cancer. Although HGF has been considered as an attractive target for therapeutic antibodies, the lack of cross-reactivity of monoclonal antibodies with human/mouse HGFs is a major obstacle in preclinical developments. We generated a panel of anti-HGF RabMAbs either blocking HGF/c-Met interaction or inhibiting c-Met phosphorylation. We selected one RabMAb with mouse cross-reactivity and demonstrated that it blocked HGF-stimulated downstream activation in PC-3 and DU145 cells. Anti-HGF RabMAb inhibited not only the growth of PC-3 cells but also HGF-dependent proliferation in HUVECs. We further demonstrated the efficacy and potency of the anti-HGF RabMAb in tumor xenograft mice models. Through these in vitro and in vivo experiments, we explored a novel therapeutic antibody for advanced prostate cancer. - Highlights: • HGF is an attractive target for castration-refractory prostate cancer. • We generated and characterized a panel of anti-HGF rabbit monoclonal antibodies. • More than half of these anti-HGF RabMAbs was cross-reactive with mouse HGF. • Anti-HGF RabMAb blocks HGF-stimulated phosphorylation and cell growth in vitro. • Anti-HGF RabMAb inhibits tumor growth and angiogenesis in xenograft mice

  7. A novel rabbit anti-hepatocyte growth factor monoclonal neutralizing antibody inhibits tumor growth in prostate cancer cells and mouse xenografts

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Yanlan; Chen, Yicheng; Ding, Guoqing; Wang, Mingchao; Wu, Haiyang; Xu, Liwei; Rui, Xuefang; Zhang, Zhigen, E-mail: srrshurology@163.com

    2015-08-14

    The hepatocyte growth factor and its receptor c-Met are correlated with castration-resistance in prostate cancer. Although HGF has been considered as an attractive target for therapeutic antibodies, the lack of cross-reactivity of monoclonal antibodies with human/mouse HGFs is a major obstacle in preclinical developments. We generated a panel of anti-HGF RabMAbs either blocking HGF/c-Met interaction or inhibiting c-Met phosphorylation. We selected one RabMAb with mouse cross-reactivity and demonstrated that it blocked HGF-stimulated downstream activation in PC-3 and DU145 cells. Anti-HGF RabMAb inhibited not only the growth of PC-3 cells but also HGF-dependent proliferation in HUVECs. We further demonstrated the efficacy and potency of the anti-HGF RabMAb in tumor xenograft mice models. Through these in vitro and in vivo experiments, we explored a novel therapeutic antibody for advanced prostate cancer. - Highlights: • HGF is an attractive target for castration-refractory prostate cancer. • We generated and characterized a panel of anti-HGF rabbit monoclonal antibodies. • More than half of these anti-HGF RabMAbs was cross-reactive with mouse HGF. • Anti-HGF RabMAb blocks HGF-stimulated phosphorylation and cell growth in vitro. • Anti-HGF RabMAb inhibits tumor growth and angiogenesis in xenograft mice.

  8. Co-aggregation and growth inhibition of probiotic lactobacilli and clinical isolates of mutans streptococci: An in vitro study

    DEFF Research Database (Denmark)

    Keller, Mette Kirstine; Hassl F, Pamela; Stecks N-Blicks, Christina

    2011-01-01

    -free and caries-susceptible individuals. Conclusions. The selected lactobacilli displayed co-aggregation activity and inhibited growth of clinical mutans streptococci. The growth inhibition was strain-specific and dependent on pH and cell concentration. The findings indicate that the outcome of lactobacilli...

  9. Transactivation of the TIEG1 confers growth inhibition of transforming growth factor-β-susceptible hepatocellular carcinoma cells

    Science.gov (United States)

    Jiang, Lei; Lai, Yiu-Kay; Zhang, Jin-Fang; Chan, Chu-Yan; Lu, Gang; Lin, Marie CM; He, Ming-Liang; Li, Ji-Cheng; Kung, Hsiang-Fu

    2012-01-01

    AIM: To investigate the role of transforming growth factor (TGF)-β-inducible early gene 1 (TIEG1) in TGF-β-induced growth inhibition in hepatocellular carcinoma (HCC) cells. METHODS: Human hepatocyte and HCC cell lines with varied susceptibilities to TGF-β1 were tested by methylthiazoletetrazolium (MTT) assay. The expression changes of Smad2, Smad3, Smad4, Smad7, TIEG1 and TIEG2 gene following treatment with TGF-β1 in a TGF-β-sensitive hepatocyte cell line (MIHA), a TGF-β-sensitive hepatoma cell line (Hep3B) and two TGF-β-insensitive hepatoma cell lines (HepG2 and Bel7404) were examined. SiRNA targeting TIEG1 was transfected into Hep3B cells and the sensitivity of cells to TGF-β1 was examined. Overexpression of TIEG1 was induced by lentiviral-mediated transduction in TGF-β1-resistant hepatoma cell lines (Bel7404 and HepG2). MTT assay and 4’,6-Diamidino-2-phenylindole staining were used to identify cell viability and apoptosis, respectively. The expression level of stathmin was measured by reverse transcriptase polymerase chain reaction and Western-blotting analysis, and stathmin promoter activity by TIEG1 was monitored by a luciferase reporter gene system. RESULTS: TIEG1 was significantly upregulated by TGF-β1 in the TGF-β1-sensitive HCC cell line, Hep3B, but not in the resistant cell lines. The suppression of TIEG1 by siRNAs decreased the sensitivity of Hep3B cells to TGF-β1, whereas the overexpression of TIEG1 mediated growth inhibition and apoptosis in TGF-β1-resistant HCC cell lines, which resembled those of TGF-β1-sensitive HCC cells treated with TGF-β1. Our data further suggested that stathmin was a direct target of TIEG1, as stathmin was significantly downregulated by TIEG1 overexpression, and stathmin promoter activity was inhibited by TIEG1 in a dose-dependent manner. CONCLUSION: Our data suggest that transactivation of TIEG1 conferred growth inhibition of TGF-β-susceptible human HCC cells. PMID:22563190

  10. Glyphosate and AMPA inhibit cancer cell growth through inhibiting intracellular glycine synthesis

    Directory of Open Access Journals (Sweden)

    Li Q

    2013-07-01

    Full Text Available Qingli Li,1,2 Mark J Lambrechts,1 Qiuyang Zhang,1 Sen Liu,1 Dongxia Ge,1 Rutie Yin,2 Mingrong Xi,2 Zongbing You1 1Departments of Structural and Cellular Biology and Orthopaedic Surgery, Tulane Cancer Center and Louisiana Cancer Research Consortium, Tulane Center for Stem Cell Research and Regenerative Medicine, and Tulane Center for Aging, Tulane University Health Sciences Center, New Orleans, LA, USA; 2Department of Obstetrics and Gynecology, West China Second University Hospital, Sichuan University, Chengdu, People’s Republic of China Abstract: Glycine is a nonessential amino acid that is reversibly converted from serine intracellularly by serine hydroxymethyltransferase. Glyphosate and its degradation product, aminomethylphosphonic acid (AMPA, are analogs to glycine, thus they may inhibit serine hydroxymethyltransferase to decrease intracellular glycine synthesis. In this study, we found that glyphosate and AMPA inhibited cell growth in eight human cancer cell lines but not in two immortalized human normal prostatic epithelial cell lines. AMPA arrested C4-2B and PC-3 cancer cells in the G1/G0 phase and inhibited entry into the S phase of the cell cycle. AMPA also promoted apoptosis in C4-2B and PC-3 cancer cell lines. AMPA upregulated p53 and p21 protein levels as well as procaspase 9 protein levels in C4-2B cells, whereas it downregulated cyclin D3 protein levels. AMPA also activated caspase 3 and induced cleavage of poly (adenosine diphosphate [ADP]-ribose polymerase. This study provides the first evidence that glyphosate and AMPA can inhibit proliferation and promote apoptosis of cancer cells but not normal cells, suggesting that they have potentials to be developed into a new anticancer therapy. Keywords: serine hydroxymethyltransferase, prostate cancer, apoptosis

  11. Licoricidin inhibits the growth of SW480 human colorectal adenocarcinoma cells in vitro and in vivo by inducing cycle arrest, apoptosis and autophagy

    Energy Technology Data Exchange (ETDEWEB)

    Ji, Shuai [State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, 38 Xueyuan Road, Beijing 100191 (China); Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, School of Pharmacy, Xuzhou Medical University, 209 Tongshan Road, Xuzhou 221004 (China); Tang, Shunan; Li, Kai; Li, Ziwei; Liang, Wenfei; Qiao, Xue; Wang, Qi [State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, 38 Xueyuan Road, Beijing 100191 (China); Yu, Siwang, E-mail: swang_yu@bjmu.edu.cn [State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, 38 Xueyuan Road, Beijing 100191 (China); Ye, Min, E-mail: yemin@bjmu.edu.cn [State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, 38 Xueyuan Road, Beijing 100191 (China)

    2017-07-01

    Licorice (Glycyrrhiza uralensis Fisch.) possesses significant anti-cancer activities, but the active ingredients and underlying mechanisms have not been revealed. By screening the cytotoxic activities of 122 licorice compounds against SW480 human colorectal adenocarcinoma cells, we found that licoricidin (LCD) inhibited SW480 cell viability with an IC{sub 50} value of 7.2 μM. Further studies indicated that LCD significantly induced G1/S cell cycle arrest and apoptosis in SW480 cells, accompanied by inhibition of cyclins/CDK1 expression and activation of caspase-dependent pro-apoptotic signaling. Meanwhile, LCD promoted autophagy in SW480 cells, and activated AMPK signaling and inhibited Akt/mTOR pathway. Overexpression of a dominant-negative AMPKα2 abolished LCD-induced inhibition of Akt/mTOR, autophagic and pro-apoptotic signaling pathways, and significantly reversed loss of cell viability, suggesting activation of AMPK is essential for the anti-cancer activity of LCD. In vivo anti-tumor experiments indicated that LCD (20 mg/kg, i.p.) significantly inhibited the growth of SW480 xenografts in nude mice with an inhibitory rate of 43.5%. In addition, we obtained the glycosylated product LCDG by microbial transformation, and found that glycosylation slightly enhanced the in vivo anti-cancer activities of LCD. This study indicates that LCD could inhibit SW480 cells by inducing cycle arrest, apoptosis and autophagy, and is a potential chemopreventive or chemotherapeutic agent against colorectal cancer. - Highlights: • Molecular mechanisms for cytotoxic activity of licoricidin (LCD) were investigated. • LCD promoted autophagy of SW480 cells through AMPK and Akt/mTOR signaling pathways. • Both LCD and its glucoside showed in vivo anti-colorectal cancer activities.

  12. A comparison of various Gibbs energy dissipation correlations for predicting microbial growth yields

    Energy Technology Data Exchange (ETDEWEB)

    Liu, J.-S. [Laboratory of Chemical and Biochemical Engineering, Swiss Federal Institute of Technology, EPFL, CH-1015 Lausanne (Switzerland); Vojinovic, V. [Laboratory of Chemical and Biochemical Engineering, Swiss Federal Institute of Technology, EPFL, CH-1015 Lausanne (Switzerland); Patino, R. [Cinvestav-Merida, Departamento de Fisica Aplicada, Km. 6 carretera antigua a Progreso, AP 73 Cordemex, 97310 Merida, Yucatan (Mexico); Maskow, Th. [UFZ Centre for Environmental Research, Department of Environmental Microbiology, Permoserstrasse 15, D-04318 Leipzig (Germany); Stockar, U. von [Laboratory of Chemical and Biochemical Engineering, Swiss Federal Institute of Technology, EPFL, CH-1015 Lausanne (Switzerland)]. E-mail: urs.vonStockar@epfl.ch

    2007-06-25

    Thermodynamic analysis may be applied in order to predict microbial growth yields roughly, based on an empirical correlation of the Gibbs energy of the overall growth reaction or Gibbs energy dissipation. Due to the well-known trade-off between high biomass yield and high Gibbs energy dissipation necessary for fast growth, an optimal range of Gibbs energy dissipation exists and it can be correlated to physical characteristics of the growth substrates. A database previously available in the literature has been extended significantly in order to test such correlations. An analysis of the relationship between biomass yield and Gibbs energy dissipation reveals that one does not need a very precise estimation of the latter to predict the former roughly. Approximating the Gibbs energy dissipation with a constant universal value of -500 kJ C-mol{sup -1} of dry biomass grown predicts many experimental growth yields nearly as well as a carefully designed, complex correlation available from the literature, even though a number of predictions are grossly out of range. A new correlation for Gibbs energy dissipation is proposed which is just as accurate as the complex literature correlation despite its dramatically simpler structure.

  13. A comparison of various Gibbs energy dissipation correlations for predicting microbial growth yields

    International Nuclear Information System (INIS)

    Liu, J.-S.; Vojinovic, V.; Patino, R.; Maskow, Th.; Stockar, U. von

    2007-01-01

    Thermodynamic analysis may be applied in order to predict microbial growth yields roughly, based on an empirical correlation of the Gibbs energy of the overall growth reaction or Gibbs energy dissipation. Due to the well-known trade-off between high biomass yield and high Gibbs energy dissipation necessary for fast growth, an optimal range of Gibbs energy dissipation exists and it can be correlated to physical characteristics of the growth substrates. A database previously available in the literature has been extended significantly in order to test such correlations. An analysis of the relationship between biomass yield and Gibbs energy dissipation reveals that one does not need a very precise estimation of the latter to predict the former roughly. Approximating the Gibbs energy dissipation with a constant universal value of -500 kJ C-mol -1 of dry biomass grown predicts many experimental growth yields nearly as well as a carefully designed, complex correlation available from the literature, even though a number of predictions are grossly out of range. A new correlation for Gibbs energy dissipation is proposed which is just as accurate as the complex literature correlation despite its dramatically simpler structure

  14. Paeoniflorin inhibits the growth of bladder carcinoma via deactivation of STAT3

    Directory of Open Access Journals (Sweden)

    Yang Jianhui

    2018-06-01

    Full Text Available Bladder cancer (BCa is one of the most common urinary cancers. The present study aims to investigate whether Paeoniflorin (Pae can exert inhibitory effects on BCa. The results showed that Pae inhibited proliferation of human BCa cell lines in a concentration- and time-dependent manner. Pae and cisplatin (Cis synergistically inhibited the growth of tumours in RT4-bearing mice. Pae treatment neutralized the body loss induced by Cis. Moreover, Pae induced apoptosis in RT4 cells and increased the activities of caspase3, caspase8 and caspase9. Western blotting and immunohistochemical analysis revealed that the phosphorylated signal transducer and activator of transcription-3 (p-STAT3 level were decreased in Pae-treated RT4 cells and Pae-treated tumour-bearing mice. Furthermore, STAT3 transcriptional target B-cell lymphoma-2 was decreased in Pae-treated RT4 cells. Interestingly, Pae prevented translocation of STAT3 to the nucleus in RT4 cells. Collectively, Pae inhibits the growth of BCa, at least in part, via a STAT3 pathway.

  15. Bee Venom Promotes Hair Growth in Association with Inhibiting 5α-Reductase Expression.

    Science.gov (United States)

    Park, Seeun; Erdogan, Sedef; Hwang, Dahyun; Hwang, Seonwook; Han, Eun Hye; Lim, Young-Hee

    2016-06-01

    Alopecia is an important issue that can occur in people of all ages. Recent studies show that bee venom can be used to treat certain diseases including rheumatoid arthritis, neuralgia, and multiple sclerosis. In this study, we investigated the preventive effect of bee venom on alopecia, which was measured by applying bee venom (0.001, 0.005, 0.01%) or minoxidil (2%) as a positive control to the dorsal skin of female C57BL/6 mice for 19 d. Growth factors responsible for hair growth were analyzed by quantitative real-time PCR and Western blot analysis using mice skins and human dermal papilla cells (hDPCs). Bee venom promoted hair growth and inhibited transition from the anagen to catagen phase. In both anagen phase mice and dexamethasone-induced catagen phase mice, hair growth was increased dose dependently compared with controls. Bee venom inhibited the expression of SRD5A2, which encodes a type II 5α-reductase that plays a major role in the conversion of testosterone into dihydrotestosterone. Moreover, bee venom stimulated proliferation of hDPCs and several growth factors (insulin-like growth factor 1 receptor (IGF-1R), vascular endothelial growth factor (VEGF), fibroblast growth factor (FGF)2 and 7) in bee venom-treated hDPCs dose dependently compared with the control group. In conclusion, bee venom is a potentially potent 5α-reductase inhibitor and hair growth promoter.

  16. Long-Term Coffee Monoculture Alters Soil Chemical Properties and Microbial Communities.

    Science.gov (United States)

    Zhao, Qingyun; Xiong, Wu; Xing, Yizhang; Sun, Yan; Lin, Xingjun; Dong, Yunping

    2018-04-17

    Long-term monoculture severely inhibits coffee plant growth, decreases its yield and results in serious economic losses in China. Here, we selected four replanted coffee fields with 4, 18, 26 and 57 years of monoculture history in Hainan China to investigate the influence of continuous cropping on soil chemical properties and microbial communities. Results showed long-term monoculture decreased soil pH and organic matter content and increased soil EC. Soil bacterial and fungal richness decreased with continuous coffee cropping. Principal coordinate analysis suggested monoculture time was a major determinant of bacterial and fungal community structures. Relative abundances of bacterial Proteobacteria, Bacteroidetes and Nitrospira and fungal Ascomycota phyla decreased over time. At genus level, potentially beneficial microbes such as Nitrospira and Trichoderma, significantly declined over time and showed positive relationships with coffee plant growth in pots. In conclusion, continuous coffee cropping decreased soil pH, organic matter content, potentially beneficial microbes and increased soil EC, which might lead to the poor growth of coffee plants in pots and decline of coffee yields in fields. Thus, developing sustainable agriculture to improve soil pH, organic matter content, microbial activity and reduce the salt stress under continuous cropping system is important for coffee production in China.

  17. Platycodin D inhibits tumor growth by antiangiogenic activity via blocking VEGFR2-mediated signaling pathway

    Energy Technology Data Exchange (ETDEWEB)

    Luan, Xin; Gao, Yun-Ge; Guan, Ying-Yun; Xu, Jian-Rong; Lu, Qin [Department of Pharmacology, Institute of Medical Sciences, Shanghai Jiao Tong University School of Medicine (SJTU-SM), Shanghai 200025 (China); Zhao, Mei [Department of Pharmacy, Shanghai Institute of Health Sciences and Health School Attached to SJTU-SM, 279 Zhouzhu Road, Shanghai 201318 (China); Liu, Ya-Rong; Liu, Hai-Jun [Department of Pharmacology, Institute of Medical Sciences, Shanghai Jiao Tong University School of Medicine (SJTU-SM), Shanghai 200025 (China); Fang, Chao, E-mail: fangchao100@hotmail.com [Department of Pharmacology, Institute of Medical Sciences, Shanghai Jiao Tong University School of Medicine (SJTU-SM), Shanghai 200025 (China); Chen, Hong-Zhuan, E-mail: hongzhuan_chen@hotmail.com [Department of Pharmacology, Institute of Medical Sciences, Shanghai Jiao Tong University School of Medicine (SJTU-SM), Shanghai 200025 (China)

    2014-11-15

    Platycodin D (PD) is an active component mainly isolated from the root of Platycodon grandiflorum. Recent studies proved that PD exhibited inhibitory effect on proliferation, migration, invasion and xenograft growth of diverse cancer cell lines. However, whether PD is suppressive for angiogenesis, an important hallmark in cancer development, remains unknown. Here, we found that PD could dose-dependently inhibit human umbilical vein endothelial cell (HUVEC) proliferation, motility, migration and tube formation. PD also significantly inhibited angiogenesis in the chick embryo chorioallantoic membrane (CAM). Moreover, the antiangiogenic activity of PD contributed to its in vivo anticancer potency shown in the decreased microvessel density and delayed growth of HCT-15 xenograft in mice with no overt toxicity. Western blot analysis indicated that PD inhibited the phosphorylation of VEGFR2 and its downstream protein kinase including PLCγ1, JAK2, FAK, Src, and Akt in endothelial cells. Molecular docking simulation showed that PD formed hydrogen bonds and hydrophobic interactions within the ATP binding pocket of VEGFR2 kinase domain. The present study firstly revealed the high antiangiogenic activity and the underlying molecular basis of PD, suggesting that PD may be a potential antiangiogenic agent for angiogenesis-related diseases. - Highlights: • Platycodin D inhibits HUVEC proliferation, motility, migration and tube formation. • Platycodin D inhibits the angiogenesis in chick embryo chorioallantoic membrane. • Platycodin D suppresses the angiogenesis and growth of HCT-15 xenograft in mice. • Platycodin D inhibits the phosphorylation of VEGFR2 and downstream kinases in HUVEC.

  18. Platycodin D inhibits tumor growth by antiangiogenic activity via blocking VEGFR2-mediated signaling pathway

    International Nuclear Information System (INIS)

    Luan, Xin; Gao, Yun-Ge; Guan, Ying-Yun; Xu, Jian-Rong; Lu, Qin; Zhao, Mei; Liu, Ya-Rong; Liu, Hai-Jun; Fang, Chao; Chen, Hong-Zhuan

    2014-01-01

    Platycodin D (PD) is an active component mainly isolated from the root of Platycodon grandiflorum. Recent studies proved that PD exhibited inhibitory effect on proliferation, migration, invasion and xenograft growth of diverse cancer cell lines. However, whether PD is suppressive for angiogenesis, an important hallmark in cancer development, remains unknown. Here, we found that PD could dose-dependently inhibit human umbilical vein endothelial cell (HUVEC) proliferation, motility, migration and tube formation. PD also significantly inhibited angiogenesis in the chick embryo chorioallantoic membrane (CAM). Moreover, the antiangiogenic activity of PD contributed to its in vivo anticancer potency shown in the decreased microvessel density and delayed growth of HCT-15 xenograft in mice with no overt toxicity. Western blot analysis indicated that PD inhibited the phosphorylation of VEGFR2 and its downstream protein kinase including PLCγ1, JAK2, FAK, Src, and Akt in endothelial cells. Molecular docking simulation showed that PD formed hydrogen bonds and hydrophobic interactions within the ATP binding pocket of VEGFR2 kinase domain. The present study firstly revealed the high antiangiogenic activity and the underlying molecular basis of PD, suggesting that PD may be a potential antiangiogenic agent for angiogenesis-related diseases. - Highlights: • Platycodin D inhibits HUVEC proliferation, motility, migration and tube formation. • Platycodin D inhibits the angiogenesis in chick embryo chorioallantoic membrane. • Platycodin D suppresses the angiogenesis and growth of HCT-15 xenograft in mice. • Platycodin D inhibits the phosphorylation of VEGFR2 and downstream kinases in HUVEC

  19. The rhizobacterium Arthrobacter agilis produces dimethylhexadecylamine, a compound that inhibits growth of phytopathogenic fungi in vitro.

    Science.gov (United States)

    Velázquez-Becerra, Crisanto; Macías-Rodríguez, Lourdes I; López-Bucio, José; Flores-Cortez, Idolina; Santoyo, Gustavo; Hernández-Soberano, Christian; Valencia-Cantero, Eduardo

    2013-12-01

    Plant diseases caused by fungal pathogens such as Botrytis cinerea and the oomycete Phytophthora cinnamomi affect agricultural production worldwide. Control of these pests can be done by the use of fungicides such as captan, which may have deleterious effects on human health. This study demonstrates that the rhizobacterium Arthrobacter agilis UMCV2 produces volatile organic compounds that inhibit the growth of B. cinerea in vitro. A single compound from the volatile blends, namely dimethylhexadecylamine (DMHDA), could inhibit the growth of both B. cinerea and P. cinnamomi when supplied to the growth medium in low concentrations. DMHDA also inhibited the growth of beneficial fungi Trichoderma virens and Trichoderma atroviride but at much higher concentrations. DMHDA-related aminolipids containing 4, 8, 10, 12, and 14 carbons in the alkyl chain were tested for their inhibitory effect on the growth of the pathogens. The results show that the most active compound from those tested was dimethyldodecylamine. This effect correlates with a decrease in the number of membrane lipids present in the mycelium of the pathogen including eicosanoic acid, (Z)-9-hexadecenoic acid, methyl ester, and (Z)-9-octadecenoic acid, methyl ester. Strawberry leaflets treated with DMHDA were not injured by the compound. These data indicate that DMHDA and related compounds, which can be produced by microorganisms may effectively inhibit the proliferation of certain plant pathogens.

  20. Aminomethylphosphonic acid inhibits growth and metastasis of human prostate cancer in an orthotopic xenograft mouse model.

    Science.gov (United States)

    Parajuli, Keshab Raj; Zhang, Qiuyang; Liu, Sen; You, Zongbing

    2016-03-01

    Aminomethylphosphonic acid (AMPA) has been shown to inhibit prostate cancer cell growth in vitro. The purpose of the present study was to determine if AMPA could inhibit growth and metastasis of prostate cancer in vivo. Human prostate cancer PC-3-LacZ-luciferase cells were implanted into the ventral lateral lobes of the prostate in 39 athymic Nu/Nu nude male mice. Seven days later, mice were randomized into the control group (n = 14, treated intraperitoneally with phosphate buffered saline), low dose group (n = 10, treated intraperitoneally with AMPA at 400 mg/kg body weight/day), and high dose group (n = 15, treated intraperitoneally with AMPA at 800 mg/kg body weight/day). Tumor growth and metastasis were examined every 4-7 days by bioluminescence imaging of live mice. We found that AMPA treatment significantly inhibited growth and metastasis of orthotopic xenograft prostate tumors and prolonged the survival time of the mice. AMPA treatment decreased expression of BIRC2 and activated caspase 3, leading to increased apoptosis in the prostate tumors. AMPA treatment decreased expression of cyclin D1. AMPA treatment also reduced angiogenesis in the prostate tumors. Taken together, these results demonstrate that AMPA can inhibit prostate cancer growth and metastasis, suggesting that AMPA may be developed into a therapeutic agent for the treatment of prostate cancer.

  1. Bifurcations of a periodically forced microbial continuous culture model with restrained growth rate

    Science.gov (United States)

    Ren, Jingli; Yuan, Qigang

    2017-08-01

    A three dimensional microbial continuous culture model with a restrained microbial growth rate is studied in this paper. Two types of dilution rates are considered to investigate the dynamic behaviors of the model. For the unforced system, fold bifurcation and Hopf bifurcation are detected, and numerical simulations reveal that the system undergoes degenerate Hopf bifurcation. When the system is periodically forced, bifurcation diagrams for periodic solutions of period-one and period-two are given by researching the Poincaré map, corresponding to different bifurcation cases in the unforced system. Stable and unstable quasiperiodic solutions are obtained by Neimark-Sacker bifurcation with different parameter values. Periodic solutions of various periods can occur or disappear and even change their stability, when the Poincaré map of the forced system undergoes Neimark-Sacker bifurcation, flip bifurcation, and fold bifurcation. Chaotic attractors generated by a cascade of period doublings and some phase portraits are given at last.

  2. Towards the understanding of microbial metabolism in relation to microbial enhanced oil recovery

    DEFF Research Database (Denmark)

    Halim, Amalia Yunita; Nielsen, Sidsel Marie; Nielsen, Kristian Fog

    2017-01-01

    In this study, Bacillus licheniformis 421 was used as a model organism to understand the effects of microbial cell growth and metabolite production under anaerobic conditions in relation to microbial enhanced oil recovery. The bacterium was able to grow anaerobically on different carbon compounds...

  3. Washout and non-washout solutions of a system describing microbial fermentation process under the influence of growth inhibitions and maximal concentration of yeast cells.

    Science.gov (United States)

    Kasbawati; Gunawan, Agus Yodi; Sidarto, Kuntjoro Adjie

    2017-07-01

    An unstructured model for the growth of yeast cell on glucose due to growth inhibitions by substrate, products, and cell density is discussed. The proposed model describes the dynamical behavior of fermentation system that shows multiple steady states for a certain regime of operating parameters such as inlet glucose and dilution rate. Two types of steady state solutions are found, namely washout and non-washout solutions. Furthermore, different numerical impositions to the two parameters put in evidence three results regarding non-washout solution: a unique locally stable non-washout solution, a unique locally stable non-washout solution towards which other nearby solutions exhibit damped oscillations, and multiple non-washout solutions where one is locally stable while the other is unstable. It is also found an optimal inlet glucose which produces the highest cell and ethanol concentration. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Impact of (+/-)-catechin on soil microbial communities.

    Science.gov (United States)

    Inderjit; Kaur, Rajwant; Kaur, Surinder; Callaway, Ragan M

    2009-01-01

    Catechin is a highly studied but controversial allelochemical reported as a component of the root exudates of Centaurea maculosa. Initial reports of high and consistent exudation rates and soil concentrations have been shown to be highly inaccurate, but the chemical has been found in root exudates at and much less frequently in soil but sporadically at high concentrations. Part of the problem of detection and measuring phytotoxicity in natural soils may be due to the confounding effect of soil microbes, and little is known about interactions between catechin and soil microbes. Here we tested the effect of catechin on soil microbial communities and the feedback of these effects to two plant species. We found that catechin inhibits microbial activity in the soil we tested, and by doing so appears to promote plant growth in the microbe-free environment. This is in striking contrast to other in vitro studies, emphasizing the highly conditional effects of the chemical and suggesting that the phytotoxic effects of catechin may be exerted through the microbes in some soils.

  5. Inhibition of microbial concrete corrosion by Acidithiobacillus thiooxidans with functionalised zeolite-A coating.

    Science.gov (United States)

    Haile, Tesfaalem; Nakhla, George

    2009-01-01

    The inhibition of the corrosive action of Acidithiobacillus thiooxidans on concrete specimens coated by functionalised zeolite-A containing 14% zinc and 5% silver by weight was studied. Uncoated concrete specimens, epoxy-coated concrete specimens (EP), and functionalised zeolite-A coated concrete specimens with epoxy to zeolite weight ratios of 3:1 (Z1), 2:2 (Z2) and 1:3 (Z3) were studied. Specimens were characterised by x-ray powder diffraction and field emission scanning electron microscopy for the identification of corrosion products and morphological changes. Biomass growth at the conclusion of the 32-day experiments was 4, 179 and 193 mg volatile suspended solids g(-1) sulphur for the uncoated, EP and Z1 specimens, whereas that of Z2 and Z3 were negligible. In the uncoated, EP and Z1 specimens, sulphate production rates were 0.83, 9.1 and 8.8 mM SO(4)(2-) day(-1) and the specific growth rates, mu, were 0.14, 0.57 and 0.47 day(-1), respectively. The corresponding values for Z2 and Z3 were negligible due to their bacterial inhibition characteristics.

  6. Long-chain fatty acids inhibition and adaptation process in anaerobic thermophilic digestion: Batch tests, microbial community structure and mathematical modelling

    DEFF Research Database (Denmark)

    Paltsi, Jordi; Illa, J.; Prenafeta-Boldu, F.X.

    2010-01-01

    Biomass samples taken during the continuous operation of thermophilic anaerobic digestors fed with manure and exposed to successive inhibitory pulses of long-chain fatty acids (LCFA) were characterized in terms of specific metabolic activities and 16S rDNA DGGE profiling of the microbial community....... Population profiles of eubacterial and archaeal 16S rDNA genes revealed that no significant shift on microbial community composition took place upon biomass exposure to LCFA. DNA sequencing of predominant DGGE bands showed close phylogenetic affinity to ribotypes characteristic from specific beta...... kinetics considering the relation between LCFA inhibitory substrate concentration and specific biomass content, as an approximation to the adsorption process, improved the model fitting and provided a better insight on the physical nature of the LCFA inhibition process. (C) 2009 Elsevier Ltd. All rights...

  7. Effect of different film packaging on microbial growth in minimally processed cactus pear (Opuntia ficus-indica).

    Science.gov (United States)

    Palma, A; Mangia, N P; Fadda, A; Barberis, A; Schirra, M; D'Aquino, S

    2013-01-01

    Microorganisms are natural contaminants of fresh produce and minimally processed products, and contamination arises from a number of sources, including the environment, postharvest handling and processing. Fresh-cut products are particularly susceptible to microbial contaminations because of the changes occurring in the tissues during processing. In package gas composition of modified atmosphere packaging (MAP) in combination with low storage temperatures besides reducing physiological activity of packaged produce, can also delay pathogen growth. Present study investigated on the effect of MAPs, achieved with different plastic films, on microbial growth of minimally processed cactus pear (Opuntio ficus-indica) fruit. Five different plastic materials were used for packaging the manually peeled fruit. That is: a) polypropylene film (Termoplast MY 40 micron thickness, O2 transmission rate 300 cc/m2/24h); b) polyethylene film (Bolphane BHE, 11 micron thickness, O2 transmission rate 19000 cc/m2/24h); c) polypropylene laser-perforated films (Mach Packaging) with 8, 16 or 32 100-micron holes. Total aerobic psychrophilic, mesophilic microorganisms, Enterobacteriaceae, yeast, mould populations and in-package CO2, O2 and C2H4 were determined at each storage time. Different final gas compositions, ranging from 7.8 KPa to 17.1 KPa O2, and 12.7 KPa to 2.6 KPa CO2, were achieved with MY and micro perforated films, respectively. Differences were detected in the mesophilic, Enterobacteriaceae and yeast loads, while no difference was detected in psychrophilic microorganisms. At the end of storage, microbial load in fruits sealed with MY film was significantly lower than in those sealed with BHE and micro perforated films. Furthermore, fruits packed with micro-perforated films showed the highest microbial load. This occurrence may in part be related to in-package gas composition and in part to a continuous contamination of microorganisms through micro-holes.

  8. Alignment of microbial fitness with engineered product formation: obligatory coupling between acetate production and photoautotrophic growth.

    Science.gov (United States)

    Du, Wei; Jongbloets, Joeri A; van Boxtel, Coco; Pineda Hernández, Hugo; Lips, David; Oliver, Brett G; Hellingwerf, Klaas J; Branco Dos Santos, Filipe

    2018-01-01

    Microbial bioengineering has the potential to become a key contributor to the future development of human society by providing sustainable, novel, and cost-effective production pipelines. However, the sustained productivity of genetically engineered strains is often a challenge, as spontaneous non-producing mutants tend to grow faster and take over the population. Novel strategies to prevent this issue of strain instability are urgently needed. In this study, we propose a novel strategy applicable to all microbial production systems for which a genome-scale metabolic model is available that aligns the production of native metabolites to the formation of biomass. Based on well-established constraint-based analysis techniques such as OptKnock and FVA, we developed an in silico pipeline-FRUITS-that specifically 'Finds Reactions Usable in Tapping Side-products'. It analyses a metabolic network to identify compounds produced in anabolism that are suitable to be coupled to growth by deletion of their re-utilization pathway(s), and computes their respective biomass and product formation rates. When applied to Synechocystis sp. PCC6803, a model cyanobacterium explored for sustainable bioproduction, a total of nine target metabolites were identified. We tested our approach for one of these compounds, acetate, which is used in a wide range of industrial applications. The model-guided engineered strain shows an obligatory coupling between acetate production and photoautotrophic growth as predicted. Furthermore, the stability of acetate productivity in this strain was confirmed by performing prolonged turbidostat cultivations. This work demonstrates a novel approach to stabilize the production of target compounds in cyanobacteria that culminated in the first report of a photoautotrophic growth-coupled cell factory. The method developed is generic and can easily be extended to any other modeled microbial production system.

  9. Growth Inhibition by Bupivacaine Is Associated with Inactivation of Ribosomal Protein S6 Kinase 1

    Science.gov (United States)

    Beigh, Mushtaq Ahmad; Showkat, Mehvish; Bashir, Basharat; Bashir, Asma; Hussain, Mahboob ul; Andrabi, Khurshid Iqbal

    2014-01-01

    Bupivacaine is an amide type long acting local anesthetic used for epidural anesthesia and nerve blockade in patients. Use of bupivacaine is associated with severe cytotoxicity and apoptosis along with inhibition of cell growth and proliferation. Although inhibition of Erk, Akt, and AMPK seemingly appears to mediate some of the bupivacaine effects, potential downstream targets that mediate its effect remain unknown. S6 kinase 1 is a common downstream effector of several growth regulatory pathways involved in cell growth and proliferation known to be affected by bupivacaine. We have accordingly attempted to relate the growth inhibitory effects of bupivacaine with the status of S6K1 activity and we present evidence that decrease in cell growth and proliferation by bupivacaine is mediated through inactivation of S6 kinase 1 in a concentration and time dependent manner. We also show that ectopic expression of constitutively active S6 kinase 1 imparts substantial protection from bupivacaine induced cytotoxicity. Inactivation of S6K1 though associated with loss of putative mTOR mediated phosphorylation did not correspond with loss of similar phosphorylations in 4EBP1 indicating that S6K1 inhibition was not mediated through inactivation of mTORC1 signaling pathway or its down regulation. PMID:24605337

  10. Parameter estimations in predictive microbiology: Statistically sound modelling of the microbial growth rate.

    Science.gov (United States)

    Akkermans, Simen; Logist, Filip; Van Impe, Jan F

    2018-04-01

    When building models to describe the effect of environmental conditions on the microbial growth rate, parameter estimations can be performed either with a one-step method, i.e., directly on the cell density measurements, or in a two-step method, i.e., via the estimated growth rates. The two-step method is often preferred due to its simplicity. The current research demonstrates that the two-step method is, however, only valid if the correct data transformation is applied and a strict experimental protocol is followed for all experiments. Based on a simulation study and a mathematical derivation, it was demonstrated that the logarithm of the growth rate should be used as a variance stabilizing transformation. Moreover, the one-step method leads to a more accurate estimation of the model parameters and a better approximation of the confidence intervals on the estimated parameters. Therefore, the one-step method is preferred and the two-step method should be avoided. Copyright © 2017. Published by Elsevier Ltd.

  11. Biomechanical ordering and buckling due to microbial growth confined at oil-water interfaces

    Science.gov (United States)

    Juarez, Gabriel; Stocker, Roman

    2015-11-01

    Bacteria are unicellular organisms that often exist as densely populated, surface-associated communities. Bacteria are also environmental colloids and spontaneously attach and self-assemble at liquid-liquid interfaces. Here, we present results on the growth dynamics of individual rod-shaped bacteria confined to finite oil-water interfaces of varying curvature. Through experiments using microfluidic chambers and time-lapse microscopy, we study the formation of macroscopic structures observed as adsorbed bacteria grow, divide, and self-assemble in a nematic phase due to biomechanical interactions. The continued growth at the interface leads to a jammed monolayer of cells, which then causes the interface to buckle and undergo large deformations including wrinkling and tubulation. These observations highlight the interplay between physical environment, such as confinement and interface curvature, and active biological processes, such as growth, at the scale of individual agents and shape our understanding of macroscale processes such as microbial degradation of oil in the ocean.

  12. Preventing microbial growth on pall-rings when upgrading biogas using absorption with water wash

    Energy Technology Data Exchange (ETDEWEB)

    Haakansson, Anna

    2006-07-15

    For produced biogas to be usable as vehicle fuel it has to be upgraded to a higher energy content. This is accomplished by elevation of the methane concentration through removal of carbon dioxide. Absorption with water wash is the most common upgrading method used in Sweden today. The upgrading technique is based on the fact that carbon dioxide is more soluble in water than methane. Upgrading plants that utilises this method have problems with microbial growth in the system. This growth eventually leads to a stop in operation due to the gradually drop in upgrading capacity. The aim of this thesis were to evaluate the possibility to through some kind of water treatment maintain an acceptable level of growth or altogether prevent it in order to maintain an acceptable process capacity and thereby avoid the need to clean. Through collection of literature the implementation possibilities were evaluated with regard to efficiency, economic sustainability and if there would be a release of any harmful substances. In order to prevent the microbial growth in the columns the treatment should either focus on removing microorganisms or limit the accessible nutrients. For the single pass system it is concluded that the treatment should reduce the biofilm formation and be employed in an intermittent way. Among the evaluated treatments focusing on the reduction of microorganisms the addition of peracetic acid seems to be the most promising one. For the regenerating system the treatment method could focus on either one. As for the single pass system peracetic acid could be added to reduce the amount of microorganism. To reduce the amount of organic matter an advanced oxidation process could be deployed with the advantage that it also could remove the microorganisms.

  13. AI-2 of Aggregatibacter actinomycetemcomitans Inhibits Candida albicans Biofilm Formation

    Directory of Open Access Journals (Sweden)

    Endang W. Bachtiar

    2014-07-01

    Full Text Available Aggregatibacter actinomycetemcomitans, a Gram-negative bacterium, and Candida albicans, a polymorphic fungus, are both commensals of the oral cavity but both are opportunistic pathogens that can cause oral diseases. A. actinomycetemcomitans produces a quorum-sensing molecule called autoinducer-2 (AI-2, synthesized by LuxS, that plays an important role in expression of virulence factors, in intra- but also in interspecies communication. The aim of this study was to investigate the role of AI-2 based signaling in the interactions between C. albicans and A. actinomycetemcomitans. A. actinomycetemcomitans adhered to C. albicans and inhibited biofilm formation by means of a molecule that was secreted during growth. C. albicans biofilm formation increased significantly when co-cultured with A. actinomycetemcomitans luxS, lacking AI-2 production. Addition of wild-type-derived spent medium or synthetic AI-2 to spent medium of the luxS strain, restored inhibition of C. albicans biofilm formation to wild-type levels. Addition of synthetic AI-2 significantly inhibited hypha formation of C. albicans possibly explaining the inhibition of biofilm formation. AI-2 of A. actinomycetemcomitans is synthesized by LuxS, accumulates during growth and inhibits C. albicans hypha- and biofilm formation. Identifying the molecular mechanisms underlying the interaction between bacteria and fungi may provide important insight into the balance within complex oral microbial communities.

  14. Water Deficit and Abscisic Acid Cause Differential Inhibition of Shoot versus Root Growth in Soybean Seedlings 1

    Science.gov (United States)

    Creelman, Robert A.; Mason, Hugh S.; Bensen, Robert J.; Boyer, John S.; Mullet, John E.

    1990-01-01

    Roots often continue to elongate while shoot growth is inhibited in plants subjected to low-water potentials. The cause of this differential response to water deficit was investigated. We examined hypocotyl and root growth, polysome status and mRNA populations, and abscisic acid (ABA) content in etiolated soybean (Glycine max [L.] Merr. cv Williams) seedlings whose growth was inhibited by transfer to low-water potential vermiculite or exogenous ABA. Both treatments affected growth and dry weight in a similar fashion. Maximum inhibition of hypocotyl growth occurred when internal ABA levels (modulated by ABA application) reached the endogenous level found in the elongating zone of seedlings grown in water-deficient vermiculite. Conversely, root growth was affected to only a slight extent in low-water potential seedlings and by most ABA treatments (in some, growth was promoted). In every seedling section examined, transfer of seedlings into low-water potential vermiculite caused ABA levels to increase approximately 5- to 10-fold over that found in well-watered seedlings. Changes in soluble sugar content, polysome status, and polysome mRNA translation products seen in low-water potential seedlings did not occur with ABA treatments sufficient to cause significant inhibition of hypocotyl elongation. These data suggest that both variation in endogenous ABA levels, and differing sensitivity to ABA in hypocotyls and roots can modulate root/shoot growth ratios. However, exogenous ABA did not induce changes in sugar accumulation, polysome status, and mRNA populations seen after transfer into low-water potential vermiculite. Images Figure 6 Figure 7 PMID:16667248

  15. Inhibition of fibroblast growth by Notch1 signaling is mediated by induction of Wnt11-dependent WISP-1.

    Directory of Open Access Journals (Sweden)

    Zhao-Jun Liu

    Full Text Available Fibroblasts are an integral component of stroma and important source of growth factors and extracellular matrix (ECM. They play a prominent role in maintaining tissue homeostasis and in wound healing and tumor growth. Notch signaling regulates biological function in a variety of cells. To elucidate the physiological function of Notch signaling in fibroblasts, we ablated Notch1 in mouse (Notch1(Flox/Flox embryonic fibroblasts (MEFs. Notch1-deficient (Notch1(-/- MEFs displayed faster growth and motility rate compared to Notch1(Flox/Flox MEFs. Such phenotypic changes, however, were reversible by reconstitution of Notch1 activation via overexpression of the intracellular domain of Notch1 (NICD1 in Notch1-deficient MEFs. In contrast, constitutive activation of Notch1 signaling by introducing NICD1 into primary human dermal fibroblasts (FF2441, which caused pan-Notch activation, inhibited cell growth and motility, whereas cellular inhibition was relievable when the Notch activation was countered with dominant-negative mutant of Master-mind like 1 (DN-MAML-1. Functionally, "Notch-activated" stromal fibroblasts could inhibit tumor cell growth/invasion. Moreover, Notch activation induced expression of Wnt-induced secreted proteins-1 (WISP-1/CCN4 in FF2441 cells while deletion of Notch1 in MEFs resulted in an opposite effect. Notably, WISP-1 suppressed fibroblast proliferation, and was responsible for mediating Notch1's inhibitory effect since siRNA-mediated blockade of WISP-1 expression could relieve cell growth inhibition. Notch1-induced WISP-1 expression appeared to be Wnt11-dependent, but Wnt1-independent. Blockade of Wnt11 expression resulted in decreased WISP-1 expression and liberated Notch-induced cell growth inhibition. These findings indicated that inhibition of fibroblast proliferation by Notch pathway activation is mediated, at least in part, through regulating Wnt1-independent, but Wnt11-dependent WISP-1 expression.

  16. Dioscin inhibits colon tumor growth and tumor angiogenesis through regulating VEGFR2 and AKT/MAPK signaling pathways

    Energy Technology Data Exchange (ETDEWEB)

    Tong, Qingyi [Regenerative Medicine Research Center, State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, Chengdu, Sichuan 610041 (China); Qing, Yong, E-mail: qingyongxy@yahoo.co.jp [Department of Pharmacology, West China School of Pharmacy, Sichuan University, Chengdu, Sichuan 610041 (China); Wu, Yang [State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, Chengdu, Sichuan 610041 (China); Hu, Xiaojuan; Jiang, Lei [Department of Pharmacology, West China School of Pharmacy, Sichuan University, Chengdu, Sichuan 610041 (China); Wu, Xiaohua, E-mail: wuxh@scu.edu.cn [Regenerative Medicine Research Center, State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, Chengdu, Sichuan 610041 (China)

    2014-12-01

    Dioscin has shown cytotoxicity against cancer cells, but its in vivo effects and the mechanisms have not elucidated yet. The purpose of the current study was to assess the antitumor effects and the molecular mechanisms of dioscin. We showed that dioscin could inhibit tumor growth in vivo and has no toxicity at the test condition. The growth suppression was accompanied by obvious blood vessel decrease within solid tumors. We also found dioscin treatment inhibited the proliferation of cancer and endothelial cell lines, and most sensitive to primary cultured human umbilical vein endothelial cells (HUVECs). What's more, analysis of HUVECs migration, invasion, and tube formation exhibited that dioscin has significantly inhibitive effects to these actions. Further analysis of blood vessel formation in the matrigel plugs indicated that dioscin could inhibit VEGF-induced blood vessel formation in vivo. We also identified that dioscin could suppress the downstream protein kinases of VEGFR2, including Src, FAK, AKT and Erk1/2, accompanied by the increase of phosphorylated P38MAPK. The results potently suggest that dioscin may be a potential anticancer drug, which efficiently inhibits angiogenesis induced by VEGFR2 signaling pathway as well as AKT/MAPK pathways. - Highlights: • Dioscin inhibits tumor growth in vivo and does not exhibit any toxicity. • Dioscin inhibits angiogenesis within solid tumors. • Dioscin inhibits the proliferation, migration, invasion, and tube formation of HUVECs. • Dioscin inhibits VEGF–induced blood vessel formation in vivo. • Dioscin inhibits VEGFR2 signaling pathway as well as AKT/MAPK pathway.

  17. KAEMPFEROL, A FLAVONOID COMPOUND FROM GYNURA MEDICA INDUCED APOPTOSIS AND GROWTH INHIBITION IN MCF-7 BREAST CANCER CELL

    OpenAIRE

    Yi, Xiaofang; Zuo, Jiangcheng; Tan, Chao; Xian, Sheng; Luo, Chunhua; Chen, Sai; Yu, Liangfang; Luo, Yucheng

    2016-01-01

    Background: Kaempferol, a natural flavonoid, has been shown to induce cancer cell apoptosis and cell growth inhibition in several tumors. Previously we have conducted a full investigation on the chemical constituents of Gynura medica, kaempferol and its glycosides are the major constituents of G. medica. Here we investigated the growth inhibition and apoptosis induction effect of kaempferol extracted from G. medica. Materials and Methods: The inhibition effects of kaempferol were evaluated by...

  18. Synergistic growth inhibition by sorafenib and vitamin K2 in human hepatocellular carcinoma cells.

    Science.gov (United States)

    Zhang, Yafei; Zhang, Bicheng; Zhang, Anran; Zhao, Yong; Zhao, Jie; Liu, Jian; Gao, Jianfei; Fang, Dianchun; Rao, Zhiguo

    2012-09-01

    Sorafenib is an oral multikinase inhibitor that has been proven effective as a single-agent therapy in hepatocellular carcinoma, and there is a strong rationale for investigating its use in combination with other agents. Vitamin K2 is nearly non-toxic to humans and has been shown to inhibit the growth of hepatocellular carcinoma. In this study, we evaluated the effects of a combination of sorafenib and vitamin K2 on the growth of hepatocellular carcinoma cells. Flow cytometry, 3-(4,5-dimethyl-2-thiazolyl-2,5-diphenyl-2H-tetrazolium bromide) and nude mouse xenograft assays were used to examine the effects of sorafenib and vitamin K2 on the growth of hepatocellular carcinoma cells. Western blotting was used to elucidate the possible mechanisms underlying these effects. Assays for 3-(4,5-dimethyl-2-thiazolyl-2,5-diphenyl-2H-tetrazolium bromide) revealed a strong synergistic growth-inhibitory effect between sorafenib and vitamin K2. Flow cytometry showed an increase in cell cycle arrest and apoptosis after treatment with a combination of these two drugs at low concentrations. Sorafenib-mediated inhibition of extracellular signal-regulated kinase phosphorylation was promoted by vitamin K2, and downregulation of Mcl-1, which is required for sorafenib-induced apoptosis, was observed after combined treatment. Vitamin K2 also attenuated the downregulation of p21 expression induced by sorafenib, which may represent the mechanism by which vitamin K2 promotes the inhibitory effects of sorafenib on cell proliferation. Moreover, the combination of sorafenib and vitamin K2 significantly inhibited the growth of hepatocellular carcinoma xenografts in nude mice. Our results determined that combined treatment with sorafenib and vitamin K2 can work synergistically to inhibit the growth of hepatocellular carcinoma cells. This finding raises the possibility that this combined treatment strategy might be promising as a new therapy against hepatocellular carcinoma, especially for patients

  19. Synergistic growth inhibition of cancer cells harboring the RET/PTC1 ...

    Indian Academy of Sciences (India)

    Synergistic growth inhibition of cancer cells harboring the RET/PTC1 oncogene by staurosporine and rotenone involves enhanced cell death. ANTÓNIO PEDRO GONÇALVES, ARNALDO VIDEIRA, VALDEMAR MÁXIMO and PAULA SOARES. J. Biosci. 36(4), September 2011, 639-648, © Indian Academy of Sciences.

  20. Niclosamide inhibits epithelial-mesenchymal transition and tumor growth in lapatinib-resistant human epidermal growth factor receptor 2-positive breast cancer.

    Science.gov (United States)

    Liu, Junjun; Chen, Xiaosong; Ward, Toby; Mao, Yan; Bockhorn, Jessica; Liu, Xiaofei; Wang, Gen; Pegram, Mark; Shen, Kunwei

    2016-02-01

    Acquired resistance to lapatinib, a human epidermal growth factor receptor 2 kinase inhibitor, remains a clinical problem for women with human epidermal growth factor receptor 2-positive advanced breast cancer, as metastasis is commonly observed in these patients. Niclosamide, an anti-helminthic agent, has recently been shown to exhibit cytotoxicity to tumor cells with stem-like characteristics. This study was designed to identify the mechanisms underlying lapatinib resistance and to determine whether niclosamide inhibits lapatinib resistance by reversing epithelial-mesenchymal transition. Here, two human epidermal growth factor receptor 2-positive breast cancer cell lines, SKBR3 and BT474, were exposed to increasing concentrations of lapatinib to establish lapatinib-resistant cultures. Lapatinib-resistant SKBR3 and BT474 cells exhibited up-regulation of the phenotypic epithelial-mesenchymal transition markers Snail, vimentin and α-smooth muscle actin, accompanied by activation of nuclear factor-кB and Src and a concomitant increase in stem cell marker expression (CD44(high)/CD24(low)), compared to naive lapatinib-sensitive SKBR3 and BT474 cells, respectively. Interestingly, niclosamide reversed epithelial-mesenchymal transition, induced apoptosis and inhibited cell growth by perturbing aberrant signaling pathway activation in lapatinib-resistant human epidermal growth factor receptor 2-positive cells. The ability of niclosamide to alleviate stem-like phenotype development and invasion was confirmed. Collectively, our results demonstrate that lapatinib resistance correlates with epithelial-mesenchymal transition and that niclosamide inhibits lapatinib-resistant cell viability and epithelial-mesenchymal transition. These findings suggest a role of niclosamide or derivatives optimized for more favorable bioavailability not only in reversing lapatinib resistance but also in reducing metastatic potential during the treatment of human epidermal growth factor receptor

  1. Intracellular accumulation of mannopine, an opine produced by crown gall tumors, transiently inhibits growth of Agrobacterium tumefaciens.

    Science.gov (United States)

    Kim, K S; Baek, C H; Lee, J K; Yang, J M; Farrand, S K

    2001-06-01

    pYDH208, a cosmid clone from the octopine-mannityl opine-type tumor-inducing (Ti) plasmid pTi15955 confers utilization of mannopine (MOP) and agropine (AGR) on Agrobacterium tumefaciens strain NT1. NT1 harboring pYDH208 with an insertion mutation in mocC, which codes for MOP oxidoreductase, not only fails to utilize MOP as a sole carbon source, but also was inhibited in its growth by MOP and AGR. In contrast, the growth of mutants with insertions in other tested moc genes was not inhibited by either opine. Growth of strains NT1 or UIA5, a derivative of C58 that lacks pAtC58, was not inhibited by MOP, but growth of NT1 or UIA5 harboring pRE10, which codes for the MOP transport system, was inhibited by the opine. When a clone expressing mocC was introduced, the growth of strain NT1(pRE10) was not inhibited by MOP, although UIA5(pRE10) was still weakly inhibited. In strain NT1(pRE10, mocC), santhopine (SOP), produced by the oxidation of MOP by MocC, was further degraded by functions encoded by pAtC58. These results suggest that MOP and, to a lesser extent, SOP are inhibitory when accumulated intracellularly. The growth of NT1(pRE10), as measured by turbidity and viable cell counts, ceased upon the addition of MOP but restarted in a few hours. Regrowth was partly the result of the outgrowth of spontaneous MOP-resistant mutants and partly the adaptation of cells to MOP in the medium. Chrysopine, isochrysopine, and analogs of MOP in which the glutamine residue is substituted with other amino acids were barely taken up by NT1(pRE10) and were not inhibitory to growth of the strain. Sugar analogs of MOP were inhibitory, and those containing sugars in the D form were more inhibitory than those containing sugars in the L form. MOP analogs containing hexose sugars were more inhibitory than those containing sugars with three, four, or five carbon atoms. Mutants of NT1(pRE10) that are resistant to MOP arose in the zone of growth inhibition. Genetic and physiological analyses

  2. Profiling of Indigenous Microbial Community Dynamics and Metabolic Activity During Enrichment in Molasses-Supplemented Crude Oil-Brine Mixtures for Improved Understanding of Microbial Enhanced Oil Recovery.

    Science.gov (United States)

    Halim, Amalia Yunita; Pedersen, Dorthe Skou; Nielsen, Sidsel Marie; Lantz, Anna Eliasson

    2015-06-01

    Anaerobic incubations using crude oil and brine from a North Sea reservoir were conducted to gain increased understanding of indigenous microbial community development, metabolite production, and the effects on the oil-brine system after addition of a complex carbon source, molasses, with or without nitrate to boost microbial growth. Growth of the indigenous microbes was stimulated by addition of molasses. Pyrosequencing showed that specifically Anaerobaculum, Petrotoga, and Methanothermococcus were enriched. Addition of nitrate favored the growth of Petrotoga over Anaerobaculum. The microbial growth caused changes in the crude oil-brine system: formation of oil emulsions, and reduction of interfacial tension (IFT). Reduction in IFT was associated with microbes being present at the oil-brine interphase. These findings suggest that stimulation of indigenous microbial growth by addition of molasses has potential as microbial enhanced oil recovery (MEOR) strategy in North Sea oil reservoirs.

  3. Microbial Communities: Tracing Growth Processes from Antarctic Lakes to Early Earth to Other Planets

    Science.gov (United States)

    Sumner, D. Y.

    2014-12-01

    Life in the Universe is dominated by microbes: they are numerically the most abundant cells in our bodies and in Earth's biosphere, and they are the only life that might be present elsewhere in our solar system. Life beyond our solar system could include macroscopic organisms, but everything we understand about the origin of life suggests it must start with microbes. Thus, understanding microbial ecosystems, in the absence of macroscopic organisms, is critical to understanding early life on Earth and life elsewhere in the Universe - if it exists. But what are the general principles of microbial ecology in the absence of predation? What happens when each cell is a chemical factory that can swap among metabolic processes in response to environmental and emergent cues? Geobiologists and astrobiologists are addressing these questions in diverse ways using both Earth's modern biosphere and its fossil record. Modern microbial communities in shallow, ice-covered lakes, Antarctica (Fig.), provide a model for high productivity microbial ecosystems with no to low predation. In these lakes, photosynthetic communities create macroscopic pinnacles and domes, sometime lithified into stromatolites. They provide an ecological, geochemical and morphological model for Precambrian microbial communities in low sedimentation, low current environments. Insights from these communities include new growth processes for ancient mats, especially some that grew prior to the oxidation of Earth's atmosphere. The diversity of biosignatures created in these communities also provides context for models of life under ice elsewhere in our solar system such as paleolakes on Mars and on icy moons. Results from the Mars Science Laboratory (MSL) team document formerly habitable fluvial and lacustrine environments. Lacustrine environments, in particular, are favorable for preserving biosignatures, and continued investigations by MSL will provide a deeper understanding of the duration of habitable

  4. Pumpkin seed extract: Cell growth inhibition of hyperplastic and cancer cells, independent of steroid hormone receptors.

    Science.gov (United States)

    Medjakovic, Svjetlana; Hobiger, Stefanie; Ardjomand-Woelkart, Karin; Bucar, Franz; Jungbauer, Alois

    2016-04-01

    Pumpkin seeds have been known in folk medicine as remedy for kidney, bladder and prostate disorders since centuries. Nevertheless, pumpkin research provides insufficient data to back up traditional beliefs of ethnomedical practice. The bioactivity of a hydro-ethanolic extract of pumpkin seeds from the Styrian pumpkin, Cucurbita pepo L. subsp. pepo var. styriaca, was investigated. As pumpkin seed extracts are standardized to cucurbitin, this compound was also tested. Transactivational activity was evaluated for human androgen receptor, estrogen receptor and progesterone receptor with in vitro yeast assays. Cell viability tests with prostate cancer cells, breast cancer cells, colorectal adenocarcinoma cells and a hyperplastic cell line from benign prostate hyperplasia tissue were performed. As model for non-hyperplastic cells, effects on cell viability were tested with a human dermal fibroblast cell line (HDF-5). No transactivational activity was found for human androgen receptor, estrogen receptor and progesterone receptor, for both, extract and cucurbitin. A cell growth inhibition of ~40-50% was observed for all cell lines, with the exception of HDF-5, which showed with ~20% much lower cell growth inhibition. Given the receptor status of some cell lines, a steroid-hormone receptor independent growth inhibiting effect can be assumed. The cell growth inhibition for fast growing cells together with the cell growth inhibition of prostate-, breast- and colon cancer cells corroborates the ethnomedical use of pumpkin seeds for a treatment of benign prostate hyperplasia. Moreover, due to the lack of androgenic activity, pumpkin seed applications can be regarded as safe for the prostate. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  5. Sulindac metabolites inhibit epidermal growth factor receptor activation and expression

    Directory of Open Access Journals (Sweden)

    Ahnen Dennis

    2005-01-01

    Full Text Available Abstract Background Regular use of nonsteroidal anti-inflammatory drugs (NSAIDs is associated with a decreased mortality from colorectal cancer (CRC. NSAIDs induce apoptotic cell death in colon cancer cells in vitro and inhibit growth of neoplastic colonic mucosa in vivo however, the biochemical mechanisms required for these growth inhibitory effects are not well defined. We previously reported that metabolites of the NSAID sulindac downregulate extracellular-signal regulated kinase 1/2 (ERK1/2 signaling and that this effect is both necessary and sufficient for the apoptotic effects of these drugs. The goal of this project was to specifically test the hypothesis that sulindac metabolites block activation and/or expression of the epidermal growth factor (EGF receptor (EGFR. Methods HT29 human colon cancer cells were treated with EGF, alone, or in the presence of sulindac sulfide or sulindac sulfone. Cells lysates were assayed by immunoblotting for phosphorylated EGFR (pEGFR, pY1068, total EGFR, phosphorylated ERK1/2 (pERK1/2, total ERK1/2, activated caspase-3, and α-tubulin. Results EGF treatment rapidly induced phosphorylation of both EGFR and ERK1/2 in HT29 colon cancer cells. Pretreatment with sulindac metabolites for 24 h blocked EGF-induced phosphorylation of both EGFR and ERK1/2 and decreased total EGFR protein expression. Under basal conditions, downregulation of pEGFR and total EGFR was detected as early as 12 h following sulindac sulfide treatment and persisted through at least 48 h. Sulindac sulfone induced downregulation of pEGFR and total EGFR was detected as early as 1 h and 24 h, respectively, following drug treatment, and persisted through at least 72 h. EGFR downregulation by sulindac metabolites was observed in three different CRC cell lines, occurred prior to the observed downregulation of pERK1/2 and induction of apoptosis by these drugs, and was not dependent of caspase activation. Conclusion These results suggest that

  6. Inhibition of Estrogen-induced Growth of Breast Cancer by Targeting Mitochondrial Oxidants

    National Research Council Canada - National Science Library

    Roy, Deodutta; Felty, Quentin; Kunkle, Brian

    2008-01-01

    ...) Anchorage-independent cell growth, and (c) tumor spheroid formation using new 3D HuBiogel bioassay whether estrogen induced conversion of normal cells to transformed cells is inhibited by treatment with antioxidants, over expression of MnSOD...

  7. Chalcones from Chinese liquorice inhibit proliferation of T cells and production of cytokines

    DEFF Research Database (Denmark)

    Barfod, Lea; Kemp, Kåre; Hansen, Majbritt

    2002-01-01

    Licochalcone A (LicA), an oxygenated chalcone, has been shown to inhibit the growth of both parasites and bacteria. In this study, we investigated the effect of LicA and four synthetic analogues on the activity of human peripheral blood mononuclear cell proliferation and cytokine production. Four...... out of five chalcones tested inhibited the proliferation of lymphocytes measured by thymidine incorporation and by flow cytometry. The production of pro- and anti-inflammatory cytokines from monocytes and T cells was also inhibited by four of five chalcones. Furthermore, intracellular detection...... of cytokines revealed that the chalcones inhibited the production rather than the release of the cytokines. Taken together, these results indicate that LicA and some analogues may have immunomodulatory effects, and may thus be candidates not only as anti-microbial agents, but also for the treatment of other...

  8. Growth reduction of Listeria spp. caused by undefined industrial red smear cheese cultures and bacteriocin-producing Brevibacterium lines as evaluated in situ on soft cheese.

    Science.gov (United States)

    Eppert, I; Valdés-Stauber, N; Götz, H; Busse, M; Scherer, S

    1997-01-01

    The undefined microbial floras derived from the surface of ripe cheese which are used for the ripening of commercial red smear cheeses have a strong impact on the growth of Listeria spp. In some cases, these microbial consortia inhibit Listeria almost completely. From such undefined industrial cheese-ripening floras, linocin M18-producing (lin+) (N. Valdés-Stauber and S. Scherer, Appl. Environ. Microbiol. 60:3809-3814, 1994) and -nonproducing Brevibacterium linens strains were isolated and used as single-strain starter cultures on model red smear cheeses to evaluate their potential inhibitory effects on Listeria strains in situ. On cheeses ripened with lin+ strains, a growth reduction of L. ivanovii and L. monocytogenes of 1 to 2 log units was observed compared to cheeses ripened with lin strains. Linocin M18 activity was detected in cheeses ripened with lin+ strains but was not found in those ripened with lin strains. We suggest that production of linocin M18 contributes to the growth reduction of Listeria observed on model red smear cheeses but is unsufficient to explain the almost complete inhibition of Listeria caused by some undefined microbial floras derived from the surface of ripe cheeses. PMID:9406400

  9. Microbial ecology of phototrophic biofilms

    NARCIS (Netherlands)

    Roeselers, G.

    2007-01-01

    Biofilms are layered structures of microbial cells and an extracellular matrix of polymeric substances, associated with surfaces and interfaces. Biofilms trap nutrients for growth of the enclosed microbial community and help prevent detachment of cells from surfaces in flowing systems. Phototrophic

  10. Oridonin inhibits breast cancer growth and metastasis through blocking the Notch signaling

    Directory of Open Access Journals (Sweden)

    Shixin Xia

    2017-05-01

    Full Text Available Background: Oridonin is a diterpenoid isolated from Rabdosia rubescens with potent anticancer activity. The aim of our study is to investigate the role of oridonin to inhibit growth and metastasis of human breast cancer cells. Methods: The effect of oridonin on proliferation was evaluated by MTT assay, cell migration and invasion were evaluated by transwell migration and invasion assays in human breast cancer cells. The inhibitive effect of oridonin in vivo was determined by using xenografted nude mice. In addition, the expression of Notch receptors (Notch 1–4 was detected by western blot. Results: Oridonin inhibited human breast cancer cells in vitro and in vivo. In addition, oridonin significantly induced human breast cancer cells apoptosis. Furthermore, the oridonin treatment not only inhibited cancer cell migration and invasion, but more significantly, decreased the expression of Notch 1-4 protein. Conclusion: Our results suggest that the inhibitive effect of oridonin is likely to be driven by the inhibition of Notch signaling pathway and the resulting increased apoptosis.

  11. Targeting tumor multicellular aggregation through IGPR-1 inhibits colon cancer growth and improves chemotherapy.

    Science.gov (United States)

    Woolf, N; Pearson, B E; Bondzie, P A; Meyer, R D; Lavaei, M; Belkina, A C; Chitalia, V; Rahimi, N

    2017-09-18

    Adhesion to extracellular matrix (ECM) is crucially important for survival of normal epithelial cells as detachment from ECM triggers specific apoptosis known as anoikis. As tumor cells lose the requirement for anchorage to ECM, they rely on cell-cell adhesion 'multicellular aggregation' for survival. Multicellular aggregation of tumor cells also significantly determines the sensitivity of tumor cells to the cytotoxic effects of chemotherapeutics. In this report, we demonstrate that expression of immunoglobulin containing and proline-rich receptor-1 (IGPR-1) is upregulated in human primary colon cancer. Our study demonstrates that IGPR-1 promotes tumor multicellular aggregation, and interfering with its adhesive function inhibits multicellular aggregation and, increases cell death. IGPR-1 supports colon carcinoma tumor xenograft growth in mouse, and inhibiting its activity by shRNA or blocking antibody inhibits tumor growth. More importantly, IGPR-1 regulates sensitivity of tumor cells to the chemotherapeutic agent, doxorubicin/adriamycin by a mechanism that involves doxorubicin-induced AKT activation and phosphorylation of IGPR-1 at Ser220. Our findings offer novel insight into IGPR-1's role in colorectal tumor growth, tumor chemosensitivity, and as a possible novel anti-cancer target.

  12. Sequestered Alkaloid Defenses in the Dendrobatid Poison Frog Oophaga pumilio Provide Variable Protection from Microbial Pathogens.

    Science.gov (United States)

    Hovey, Kyle J; Seiter, Emily M; Johnson, Erin E; Saporito, Ralph A

    2018-03-01

    Most amphibians produce their own defensive chemicals; however, poison frogs sequester their alkaloid-based defenses from dietary arthropods. Alkaloids function as a defense against predators, and certain types appear to inhibit microbial growth. Alkaloid defenses vary considerably among populations of poison frogs, reflecting geographic differences in availability of dietary arthropods. Consequently, environmentally driven differences in frog defenses may have significant implications regarding their protection against pathogens. While natural alkaloid mixtures in dendrobatid poison frogs have recently been shown to inhibit growth of non-pathogenic microbes, no studies have examined the effectiveness of alkaloids against microbes that infect these frogs. Herein, we examined how alkaloid defenses in the dendrobatid poison frog, Oophaga pumilio, affect growth of the known anuran pathogens Aeromonas hydrophila and Klebsiella pneumoniae. Frogs were collected from five locations throughout Costa Rica that are known to vary in their alkaloid profiles. Alkaloids were isolated from individual skins, and extracts were assayed against both pathogens. Microbe subcultures were inoculated with extracted alkaloids to create dose-response curves. Subsequent spectrophotometry and cell counting assays were used to assess growth inhibition. GC-MS was used to characterize and quantify alkaloids in frog extracts, and our results suggest that variation in alkaloid defenses lead to differences in inhibition of these pathogens. The present study provides the first evidence that alkaloid variation in a dendrobatid poison frog is associated with differences in inhibition of anuran pathogens, and offers further support that alkaloid defenses in poison frogs confer protection against both pathogens and predators.

  13. Salicylic acid antagonizes abscisic acid inhibition of shoot growth and cell cycle progression in rice

    Science.gov (United States)

    Meguro, Ayano; Sato, Yutaka

    2014-04-01

    We analysed effects of abscisic acid (ABA, a negative regulatory hormone), alone and in combination with positive or neutral hormones, including salicylic acid (SA), on rice growth and expression of cell cycle-related genes. ABA significantly inhibited shoot growth and induced expression of OsKRP4, OsKRP5, and OsKRP6. A yeast two-hybrid assay showed that OsKRP4, OsKRP5, and OsKRP6 interacted with OsCDKA;1 and/or OsCDKA;2. When SA was simultaneously supplied with ABA, the antagonistic effect of SA completely blocked ABA inhibition. SA also blocked ABA inhibition of DNA replication and thymidine incorporation in the shoot apical meristem. These results suggest that ABA arrests cell cycle progression by inducing expression of OsKRP4, OsKRP5, and OsKRP6, which inhibit the G1/S transition, and that SA antagonizes ABA by blocking expression of OsKRP genes.

  14. Microbial growth in Acrocomia aculeata pulp oil, Jatropha curcas oil, and their respective biodiesels under simulated storage conditions

    Directory of Open Access Journals (Sweden)

    Juciana Clarice Cazarolli

    2016-12-01

    Full Text Available With increasing demands for biodiesel in Brazil, diverse oil feedstocks have been investigated for their potentials for biodiesel production. Due to the high biodegradability of natural oils and their respective biodiesels, microbial growths and consequent deterioration of final product quality are generally observed during storage. This study was aimed at evaluating the susceptibility of Acrocomia aculeata pulp oil and Jatropha curcas oil as well as their respective biodiesels to biodeterioration during a simulated storage period. The experiment was conducted in microcosms containing oil/biodiesel and an aqueous phase over 30 d. The levels of microbial contamination included biodiesel and oil as received, inoculated with fungi, and sterile. Samples were collected every 7 d to measure pH, surface tension, acidity index, and microbial biomass. The initial and final ester contents of the biodiesels were also determined by gas chromatography. The major microbial biomass was detected in A. aculeata pulp and J. curcas biodiesels. Significant reductions in pH values were observed for treatments with A. aculeata pulp biodiesel as a carbon source (p

  15. Do the ban on use of anti-microbial growth promoter impact on technical change and the efficiency of slaughter-pig production

    DEFF Research Database (Denmark)

    Lawson, Lartey; Otto, Lars; Jensen, Peter Vig

    2005-01-01

    infections, and in effect stimu-lated the utilization of feedstuff and reduced the mortality rate. However, fears for increas-ing bacteria resistance with subsequent health hazards for humans and livestock has lead to societal debates about the pros and cons of its use in livestock production. Antibiotic......This study aims at investigating the effects of the ban on the use of anti-microbial growth promoters in the production of “Finishing Pigs” for slaughter. We investigate if the ban on the use of anti-microbial growth promoters has for specialised pig-producers altered the productivity of inputs......, technical change and the efficiency of production. This paper complements an earlier paper that investigated the impact of the ban on weaned-pig produc-tion. Background: The study is motivated by the fact that antimicrobial growth promoters have been known world wide to protect livestock from bacteria...

  16. Green tea polyphenol epigallocatechin-3-gallate suppresses melanoma growth by inhibiting inflammasome and IL-1β secretion

    International Nuclear Information System (INIS)

    Ellis, Lixia Z.; Liu, Weimin; Luo, Yuchun; Okamoto, Miyako; Qu, Dovina; Dunn, Jeffrey H.; Fujita, Mayumi

    2011-01-01

    Highlights: ► EGCG inhibits melanoma cell growth at physiological doses (0.1–1 μM). ► EGCG inhibits melanoma cell growth via inflammasomes and IL-1β suppression. ► Inflammasomes and IL-1β could be potential targets for future melanoma therapeutics. -- Abstract: Epigallocatechin-3-gallate (EGCG), the major polyphenolic component of green tea, has been demonstrated to possess anti-inflammatory, antioxidant, anti-mutagenic and anti-carcinogenic properties. The anti-melanoma effect of EGCG has been previously suggested, but no clear mechanism of action has been established. In this study, we demonstrated that EGCG inhibits melanoma cell growth at physiological doses (0.1–1 μM). In the search for mechanisms of EGCG-mediated melanoma cell suppression, we found that NF-κB was inhibited, and that reduced NF-κB activity was associated with decreased IL-1β secretion from melanoma cells. Since inflammasomes are involved in IL-1β secretion, we investigated whether IL-1β suppression was mediated by inflammasomes, and found that EGCG treatment led to downregulation of the inflammasome component, NLRP1, and reduced caspase-1 activation. Furthermore, silencing the expression of NLRP1 abolished EGCG-induced inhibition of tumor cell proliferation both in vitro and in vivo, suggesting a key role of inflammasomes in EGCG efficacy. This paper provides a novel mechanism for EGCG-induced melanoma inhibition: inflammasome downregulation → decreased IL-1β secretion → decreased NF-κB activities → decreased cell growth. In addition, it suggests inflammasomes and IL-1β could be potential targets for future melanoma therapeutics.

  17. Invited review: Essential oils as modifiers of rumen microbial fermentation.

    Science.gov (United States)

    Calsamiglia, S; Busquet, M; Cardozo, P W; Castillejos, L; Ferret, A

    2007-06-01

    Microorganisms in the rumen degrade nutrients to produce volatile fatty acids and synthesize microbial protein as an energy and protein supply for the ruminant, respectively. However, this fermentation process has energy (losses of methane) and protein (losses of ammonia N) inefficiencies that may limit production performance and contribute to the release of pollutants to the environment. Antibiotic ionophores have been very successful in reducing these energy and protein losses in the rumen, but the use of antibiotics in animal feeds is facing reduced social acceptance, and their use has been banned in the European Union since January 2006. For this reason, scientists have become interested in evaluating other alternatives to control specific microbial populations to modulate rumen fermentation. Essential oils can interact with microbial cell membranes and inhibit the growth of some gram-positive and gram-negative bacteria. As a result of such inhibition, the addition of some plant extracts to the rumen results in an inhibition of deamination and methanogenesis, resulting in lower ammonia N, methane, and acetate, and in higher propionate and butyrate concentrations. Results have indicated that garlic oil, cinnamaldehyde (the main active component of cinnamon oil), eugenol (the main active component of the clove bud), capsaicin (the active component of hot peppers), and anise oil, among others, may increase propionate production, reduce acetate or methane production, and modify proteolysis, peptidolysis, or deamination in the rumen. However, the effects of some of these essential oils are pH and diet dependent, and their use may be beneficial only under specific conditions and production systems. For example, capsaicin appears to have small effects in high-forage diets, whereas the changes observed in high-concentrate diets (increases in dry matter intake and total VFA, and reduction in the acetateto-propionate ratio and ammonia N concentration) may be beneficial

  18. FXR blocks the growth of liver cancer cells through inhibiting mTOR-s6K pathway

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Xiongfei, E-mail: xiongfeihuang@hotmail.com [Department of Pathology and Institute of Oncology, Preclinical School, Fujian Medical University, Fuzhou 350108, Fujian (China); Key Laboratory of Ministry of Education for Gastrointestinal Cancer, Fujian Medical University, Fuzhou 350108, Fujian (China); Zeng, Yeting [Department of Pathology and Institute of Oncology, Preclinical School, Fujian Medical University, Fuzhou 350108, Fujian (China); Wang, Xinrui [Department of Biochemistry and Molecular Biology, Fujian Medical University, Fuzhou 350108, Fujian (China); Ma, Xiaoxiao [Department of Diabetes Complications and Metabolism, Diabetes & Metabolism Research Institute, Beckman Research Institute, City of Hope, CA 91010 (United States); Li, Qianqian; Li, Ningbo; Su, Hongying [Department of Pathology and Institute of Oncology, Preclinical School, Fujian Medical University, Fuzhou 350108, Fujian (China); Huang, Wendong [Department of Diabetes Complications and Metabolism, Diabetes & Metabolism Research Institute, Beckman Research Institute, City of Hope, CA 91010 (United States)

    2016-05-27

    The nuclear receptor Farnesoid X Receptor (FXR) is likely a tumor suppressor in liver tissue but its molecular mechanism of suppression is not well understood. In this study, the gene expression profile of human liver cancer cells was investigated by microarray. Bioinformatics analysis of these data revealed that FXR might regulate the mTOR/S6K signaling pathway. This was confirmed by altering the expression level of FXR in liver cancer cells. Overexpression of FXR prevented the growth of cells and induced cell cycle arrest, which was enhanced by the mTOR/S6K inhibitor rapamycin. FXR upregulation also intensified the inhibition of cell growth by rapamycin. Downregulation of FXR produced the opposite effect. Finally, we found that ectopic expression of FXR in SK-Hep-1 xenografts inhibits tumor growth and reduces expression of the phosphorylated protein S6K. Taken together, our data provide the first evidence that FXR suppresses proliferation of human liver cancer cells via the inhibition of the mTOR/S6K signaling pathway. FXR expression can be used as a biomarker of personalized mTOR inhibitor treatment assessment for liver cancer patients. -- Highlights: •FXR inhibits the proliferation of liver cancer cells by prolonging G0/G1 phase. •Microarray results indicate that mTOR-S6k signaling is involved in cellular processes in which FXR plays an important role. •FXR blocks the growth of liver cancer cells via the inhibition of the mTOR/S6K signaling pathway in vitro and in vivo.

  19. FXR blocks the growth of liver cancer cells through inhibiting mTOR-s6K pathway

    International Nuclear Information System (INIS)

    Huang, Xiongfei; Zeng, Yeting; Wang, Xinrui; Ma, Xiaoxiao; Li, Qianqian; Li, Ningbo; Su, Hongying; Huang, Wendong

    2016-01-01

    The nuclear receptor Farnesoid X Receptor (FXR) is likely a tumor suppressor in liver tissue but its molecular mechanism of suppression is not well understood. In this study, the gene expression profile of human liver cancer cells was investigated by microarray. Bioinformatics analysis of these data revealed that FXR might regulate the mTOR/S6K signaling pathway. This was confirmed by altering the expression level of FXR in liver cancer cells. Overexpression of FXR prevented the growth of cells and induced cell cycle arrest, which was enhanced by the mTOR/S6K inhibitor rapamycin. FXR upregulation also intensified the inhibition of cell growth by rapamycin. Downregulation of FXR produced the opposite effect. Finally, we found that ectopic expression of FXR in SK-Hep-1 xenografts inhibits tumor growth and reduces expression of the phosphorylated protein S6K. Taken together, our data provide the first evidence that FXR suppresses proliferation of human liver cancer cells via the inhibition of the mTOR/S6K signaling pathway. FXR expression can be used as a biomarker of personalized mTOR inhibitor treatment assessment for liver cancer patients. -- Highlights: •FXR inhibits the proliferation of liver cancer cells by prolonging G0/G1 phase. •Microarray results indicate that mTOR-S6k signaling is involved in cellular processes in which FXR plays an important role. •FXR blocks the growth of liver cancer cells via the inhibition of the mTOR/S6K signaling pathway in vitro and in vivo.

  20. Inhibition of Hedgehog signaling antagonizes serous ovarian cancer growth in a primary xenograft model.

    Directory of Open Access Journals (Sweden)

    Christopher K McCann

    Full Text Available Recent evidence links aberrant activation of Hedgehog (Hh signaling with the pathogenesis of several cancers including medulloblastoma, basal cell, small cell lung, pancreatic, prostate and ovarian. This investigation was designed to determine if inhibition of this pathway could inhibit serous ovarian cancer growth.We utilized an in vivo pre-clinical model of serous ovarian cancer to characterize the anti-tumor activity of Hh pathway inhibitors cyclopamine and a clinically applicable derivative, IPI-926. Primary human serous ovarian tumor tissue was used to generate tumor xenografts in mice that were subsequently treated with cyclopamine or IPI-926.Both compounds demonstrated significant anti-tumor activity as single agents. When IPI-926 was used in combination with paclitaxel and carboplatinum (T/C, no synergistic effect was observed, though sustained treatment with IPI-926 after cessation of T/C continued to suppress tumor growth. Hh pathway activity was analyzed by RT-PCR to assess changes in Gli1 transcript levels. A single dose of IPI-926 inhibited mouse stromal Gli1 transcript levels at 24 hours with unchanged human intra-tumor Gli1 levels. Chronic IPI-926 therapy for 21 days, however, inhibited Hh signaling in both mouse stromal and human tumor cells. Expression data from the micro-dissected stroma in human serous ovarian tumors confirmed the presence of Gli1 transcript and a significant association between elevated Gli1 transcript levels and worsened survival.IPI-926 treatment inhibits serous tumor growth suggesting the Hh signaling pathway contributes to the pathogenesis of ovarian cancer and may hold promise as a novel therapeutic target, especially in the maintenance setting.

  1. Extraction of solubles from plant biomass for use as microbial growth stimulant and methods related thereto

    Energy Technology Data Exchange (ETDEWEB)

    Lau, Ming Woei

    2015-12-08

    A method for producing a microbial growth stimulant (MGS) from a plant biomass is described. In one embodiment, an ammonium hydroxide solution is used to extract a solution of proteins and ammonia from the biomass. Some of the proteins and ammonia are separated from the extracted solution to provide the MGS solution. The removed ammonia can be recycled and the proteins are useful as animal feeds. In one embodiment, the method comprises extracting solubles from pretreated lignocellulosic biomass with a cellulase enzyme-producing growth medium (such T. reesei) in the presence of water and an aqueous extract.

  2. Impact of (±)-catechin on soil microbial communities

    Science.gov (United States)

    Kaur, Rajwant; Kaur, Surinder

    2009-01-01

    Catechin is a highly studied but controversial allelochemical reported as a component of the root exudates of Centaurea maculosa. Initial reports of high and consistent exudation rates and soil concentrations have been shown to be highly inaccurate, but the chemical has been found in root exudates at and much less frequently in soil but sporadically at high concentrations. Part of the problem of detection and measuring phytotoxicity in natural soils may be due to the confounding effect of soil microbes, and little is known about interactions between catechin and soil microbes. Here we tested the effect of catechin on soil microbial communities and the feedback of these effects to two plant species. We found that catechin inhibits microbial activity in the soil we tested, and by doing so appears to promote plant growth in the microbe-free environment. This is in striking contrast to other in vitro studies, emphasizing the highly conditional effects of the chemical and suggesting that the phytotoxic effects of catechin may be exerted through the microbes in some soils. PMID:19704908

  3. Microbial Community Structure of Casing Soil During Mushroom Growth

    Institute of Scientific and Technical Information of China (English)

    CAI Wei-Ming; YAO Huai-Ying; FENG Wei-Lin; JIN Qun-Li; LIU Yue-Yan; LI Nan-Yi; ZHENG Zhong

    2009-01-01

    The culturable bacterial population and phospholipid fatty acid (PLFA)profile of casing soil were investigated at different mushroom (Agaricus bisporusI cropping stages.The change in soil bacterial PLFAs was always accompanied by a change in the soil culturable bacterial population in the first flush.Comparatively higher culturable bacterial population and bacterial PLFAs were found in the casing soil at the primordia formation stage of the first flush.There was a significant increase in the ratio of fungal to bacterial PLFAs during mushroom growth.Multivariate analysis of PLFA data demonstrated that the mushroom cropping stage could considerably affect the microbial community structure of the casing soil.The bacterial population increased significantly from casing soil application to the primordia formation stage of the first flush.Casing soil application resulted in an increase in the ratio of gram-negative bacterial PLFAs to gram-positive bacterial PLFAs,suggesting that some gram-negative bacteria might play an important role in mushroom sporophore initiation.

  4. Pu-erh Tea Inhibits Tumor Cell Growth by Down-Regulating Mutant p53

    Science.gov (United States)

    Zhao, Lanjun; Jia, Shuting; Tang, Wenru; Sheng, Jun; Luo, Ying

    2011-01-01

    Pu-erh tea is a kind of fermented tea with the incorporation of microorganisms’ metabolites. Unlike green tea, the chemical characteristics and bioactivities of Pu-erh tea are still not well understood. Using water extracts of Pu-erh tea, we analyzed the tumor cell growth inhibition activities on several genetically engineered mouse tumor cell lines. We found that at the concentration that did not affect wild type mouse embryo fibroblasts (MEFs) growth, Pu-erh tea extracts could inhibit tumor cell growth by down-regulated S phase and cause G1 or G2 arrest. Further study showed that Pu-erh tea extracts down-regulated the expression of mutant p53 in tumor cells at the protein level as well as mRNA level. The same concentration of Pu-erh tea solution did not cause p53 stabilization or activation of its downstream pathways in wild type cells. We also found that Pu-erh tea treatment could slightly down-regulate both HSP70 and HSP90 protein levels in tumor cells. These data revealed the action of Pu-erh tea on tumor cells and provided the possible mechanism for Pu-erh tea action, which explained its selectivity in inhibiting tumor cells without affecting wild type cells. Our data sheds light on the application of Pu-erh tea as an anti-tumor agent with low side effects. PMID:22174618

  5. Spring thaw ionic pulses boost nutrient availability and microbial growth in entombed Antarctic Dry Valley cryoconite holes.

    Science.gov (United States)

    Telling, Jon; Anesio, Alexandre M; Tranter, Martyn; Fountain, Andrew G; Nylen, Thomas; Hawkings, Jon; Singh, Virendra B; Kaur, Preeti; Musilova, Michaela; Wadham, Jemma L

    2014-01-01

    The seasonal melting of ice entombed cryoconite holes on McMurdo Dry Valley glaciers provides oases for life in the harsh environmental conditions of the polar desert where surface air temperatures only occasionally exceed 0°C during the Austral summer. Here we follow temporal changes in cryoconite hole biogeochemistry on Canada Glacier from fully frozen conditions through the initial stages of spring thaw toward fully melted holes. The cryoconite holes had a mean isolation age from the glacial drainage system of 3.4 years, with an increasing mass of aqueous nutrients (dissolved organic carbon, total nitrogen, total phosphorus) with longer isolation age. During the initial melt there was a mean nine times enrichment in dissolved chloride relative to mean concentrations of the initial frozen holes indicative of an ionic pulse, with similar mean nine times enrichments in nitrite, ammonium, and dissolved organic matter. Nitrate was enriched twelve times and dissolved organic nitrogen six times, suggesting net nitrification, while lower enrichments for dissolved organic phosphorus and phosphate were consistent with net microbial phosphorus uptake. Rates of bacterial production were significantly elevated during the ionic pulse, likely due to the increased nutrient availability. There was no concomitant increase in photosynthesis rates, with a net depletion of dissolved inorganic carbon suggesting inorganic carbon limitation. Potential nitrogen fixation was detected in fully melted holes where it could be an important source of nitrogen to support microbial growth, but not during the ionic pulse where nitrogen availability was higher. This study demonstrates that ionic pulses significantly alter the timing and magnitude of microbial activity within entombed cryoconite holes, and adds credence to hypotheses that ionic enrichments during freeze-thaw can elevate rates of microbial growth and activity in other icy habitats, such as ice veins and subglacial regelation zones.

  6. Spring thaw ionic pulses boost nutrient availability and microbial growth in entombed Antarctic Dry Valley cryoconite holes

    Directory of Open Access Journals (Sweden)

    Jon eTelling

    2014-12-01

    Full Text Available The seasonal melting of ice entombed cryoconite holes on McMurdo Dry Valley glaciers provides oases for life in the harsh environmental conditions of the polar desert where surface air temperatures only occasionally exceed 0°C during the Austral summer. Here we follow temporal changes in cryoconite hole biogeochemistry on Canada Glacier from fully frozen conditions through the initial stages of spring thaw towards fully melted holes. The cryoconite holes had a mean isolation age from the glacial drainage system of 3.4 years, with an increasing mass of aqueous nutrients (dissolved organic carbon, total nitrogen, total phosphorus with longer isolation age. During the initial melt there was a mean nine times enrichment in dissolved chloride relative to mean concentrations of the initial frozen holes indicative of an ionic pulse, with similar mean nine times enrichments in nitrite, ammonium, and dissolved organic matter. Nitrate was enriched twelve times and dissolved organic nitrogen six times, suggesting net nitrification, while lower enrichments for dissolved organic phosphorus and phosphate were consistent with net microbial phosphorus uptake. Rates of bacterial production were significantly elevated during the ionic pulse, likely due to the increased nutrient availability. There was no concomitant increase in photosynthesis rates, with a net depletion of dissolved inorganic carbon suggesting inorganic carbon limitation. Potential nitrogen fixation was detected in fully melted holes where it could be an important source of nitrogen to support microbial growth, but not during the ionic pulse where nitrogen availability was higher. This study demonstrates that ionic pulses significantly alter the timing and magnitude of microbial activity within entombed cryoconite holes, and adds credence to hypotheses that ionic enrichments during freeze-thaw can elevate rates of microbial growth and activity in other icy habitats, such as ice veins and

  7. Microbial changes and growth of Listeria monocytogenes during chilled storage of brined shrimp ( Pandalus borealis )

    DEFF Research Database (Denmark)

    Mejlholm, Ole; Kjeldgaard, J.; Modberg, A.

    2008-01-01

    Thirteen storage trials and ten challenge tests were carried out to examine microbial changes, spoilage and the potential growth of Listeria monocytogenes in brined shrimp (Pandalus borealis). Shrimp in brine as well as brined and drained shrimp in modified atmosphere packaging (MAP) were produced...... and lactic acids were studied. Furthermore, the effect of adding diacetate to brined shrimp was evaluated. A single batch of cooked and peeled shrimp was used to study both industrially and manually processed brined shrimp with respect to the effect of process hygiene on microbial changes and the shelf life...... of products. Concentrations of microorganisms on newly produced brined shrimp from an industrial scale processing line were 1.0-2.3 log (CFU g(-1)) higher than comparable concentrations in manually processed samples. This resulted in a substantially shorter shelf life and a more diverse spoilage microflora...

  8. Effects of degradable protein and non-fibre carbohydrates on microbial growth and fermentation in the rumen simulating fermenter (Rusitec

    Directory of Open Access Journals (Sweden)

    Xiang H. Zhao

    2015-05-01

    Full Text Available A rumen simulation technique (Rusitec apparatus with eight 800 ml fermentation vessels was used to investigate the effects of rumen degradable protein (RDP level and non-fibre carbohydrate (NFC type on ruminal fermentation, microbial growth, and populations of ruminal cellulolytic bacteria. Treatments consisted of two NFC types (starch and pectin supplemented with 0 g/d (low RDP or 1.56 g/d (high RDP sodium caseinate. Apparent disappearance of dry matter and organic matter was greater for pectin than for starch treatment (P<0.01 with low or high RDP. A NFC × RDP interaction was observed for neutral detergent fibre disappearance (P=0.01, which was lower for pectin than for starch only under low RDP conditions. Compared with starch, pectin treatment increased the copy numbers of Ruminococcus albus (P≤0.01 and Ruminococcus flavefaciens (P≤0.09, the molar proportion of acetate (P<0.01, the acetate:propionate ratio (P<0.01, and methane production (P<0.01, but reduced the propionate proportion (P<0.01. Increasing dietary RDP increased the production of total VFA (P=0.01, methane (P<0.01, ammonia N (P<0.01, and microbial N (P<0.01. Significant NFC × RDP interaction and interaction tendency were observed for ammonia N production (P=0.01 and daily N flow of total microorganisms (P=0.07, which did not differ under low RDP conditions, but pectin produced greater microbial N and less ammonia N than starch with increased RDP. Results showed NFC type, RDP level, and their interaction affected ruminal fermentation and microbial growth, and under sufficient ruminal degradable N pectin had greater advantage in microbial N synthesis than starch in vitro.

  9. Irisin inhibition of growth hormone secretion in cultured tilapia pituitary cells.

    Science.gov (United States)

    Lian, Anji; Li, Xin; Jiang, Quan

    2017-01-05

    Irisin, the product of fibronectin type III domain-containing protein 5 (FNDC5) gene, is well-documented to be a regulator of energy metabolism. At present, not much is known about its biological function in non-mammalian species. In this study, a full-length tilapia FDNC5 was cloned and its tissue expression pattern has been confirmed. Based on the sequence obtained, we produced and purified recombinant irisin which could induce uncoupling protein 1 (UCP1) gene expression in tilapia hepatocytes. Further, the rabbit polyclonal irisin antiserum was produced and its specificity was confirmed by antiserum preabsorption. In tilapia pituitary cells, irisin inhibited growth hormone (GH) gene expression and secretion and triggered rapid phosphorylation of Akt, Erk1/2, and p38 MAPK. Furthermore, irisin-inhibited GH mRNA expression could be prevented by inhibiting PI3K/Akt, MEK1/2, and p38 MAPK, respectively. Apparently, fish irisin can act directly at the pituitary level to inhibit GH transcript expression via multiple signaling pathways. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  10. Stochastic cellular automata model of neurosphere growth: Roles of proliferative potential, contact inhibition, cell death, and phagocytosis.

    Science.gov (United States)

    Sipahi, Rifat; Zupanc, Günther K H

    2018-05-14

    Neural stem and progenitor cells isolated from the central nervous system form, under specific culture conditions, clonal cell clusters known as neurospheres. The neurosphere assay has proven to be a powerful in vitro system to study the behavior of such cells and the development of their progeny. However, the theory of neurosphere growth has remained poorly understood. To overcome this limitation, we have, in the present paper, developed a cellular automata model, with which we examined the effects of proliferative potential, contact inhibition, cell death, and clearance of dead cells on growth rate, final size, and composition of neurospheres. Simulations based on this model indicated that the proliferative potential of the founder cell and its progenitors has a major influence on neurosphere size. On the other hand, contact inhibition of proliferation limits the final size, and reduces the growth rate, of neurospheres. The effect of this inhibition is particularly dramatic when a stem cell becomes encapsulated by differentiated or other non-proliferating cells, thereby suppressing any further mitotic division - despite the existing proliferative potential of the stem cell. Conversely, clearance of dead cells through phagocytosis is predicted to accelerate growth by reducing contact inhibition. A surprising prediction derived from our model is that cell death, while resulting in a decrease in growth rate and final size of neurospheres, increases the degree of differentiation of neurosphere cells. It is likely that the cellular automata model developed as part of the present investigation is applicable to the study of tissue growth in a wide range of systems. Copyright © 2018 Elsevier Ltd. All rights reserved.

  11. A systems biology framework for modeling metabolic enzyme inhibition of Mycobacterium tuberculosis

    Directory of Open Access Journals (Sweden)

    Reifman Jaques

    2009-09-01

    Full Text Available Abstract Background Because metabolism is fundamental in sustaining microbial life, drugs that target pathogen-specific metabolic enzymes and pathways can be very effective. In particular, the metabolic challenges faced by intracellular pathogens, such as Mycobacterium tuberculosis, residing in the infected host provide novel opportunities for therapeutic intervention. Results We developed a mathematical framework to simulate the effects on the growth of a pathogen when enzymes in its metabolic pathways are inhibited. Combining detailed models of enzyme kinetics, a complete metabolic network description as modeled by flux balance analysis, and a dynamic cell population growth model, we quantitatively modeled and predicted the dose-response of the 3-nitropropionate inhibitor on the growth of M. tuberculosis in a medium whose carbon source was restricted to fatty acids, and that of the 5'-O-(N-salicylsulfamoyl adenosine inhibitor in a medium with low-iron concentration. Conclusion The predicted results quantitatively reproduced the experimentally measured dose-response curves, ranging over three orders of magnitude in inhibitor concentration. Thus, by allowing for detailed specifications of the underlying enzymatic kinetics, metabolic reactions/constraints, and growth media, our model captured the essential chemical and biological factors that determine the effects of drug inhibition on in vitro growth of M. tuberculosis cells.

  12. Nitric oxide participates in cold-inhibited Camellia sinensis pollen germination and tube growth partly via cGMP in vitro.

    Directory of Open Access Journals (Sweden)

    Yu-Hua Wang

    Full Text Available Nitric oxide (NO plays essential roles in many biotic and abiotic stresses in plant development procedures, including pollen tube growth. Here, effects of NO on cold stress inhibited pollen germination and tube growth in Camellia sinensis were investigated in vitro. The NO production, NO synthase (NOS-like activity, cGMP content and proline (Pro accumulation upon treatment with NO scavenger cPTIO, NOS inhibitor L-NNA, NO donor DEA NONOate, guanylate cyclase (GC inhibitor ODQ or phosphodiesterase (PDE inhibitor Viagra at 25°C (control or 4°C were analyzed. Exposure to 4°C for 2 h reduced pollen germination and tube growth along with increase of NOS-like activity, NO production and cGMP content in pollen tubes. DEA NONOate treatment inhibited pollen germination and tube growth in a dose-dependent manner under control and reinforced the inhibition under cold stress, during which NO production and cGMP content promoted in pollen tubes. L-NNA and cPTIO markedly reduced the generation of NO induced by cold or NO donor along with partly reverse of cold- or NO donor-inhibited pollen germination and tube growth. Furthermore, ODQ reduced the cGMP content under cold stress and NO donor treatment in pollen tubes. Meanwhile, ODQ disrupted the reinforcement of NO donor on the inhibition of pollen germination and tube growth under cold condition. Additionally, Pro accumulation of pollen tubes was reduced by ODQ compared with that receiving NO donor under cold or control condition. Effects of cPTIO and L-NNA in improving cold-treated pollen germination and pollen tube growth could be lowered by Viagra. Moreover, the inhibitory effects of cPTIO and L-NNA on Pro accumulation were partly reversed by Viagra. These data suggest that NO production from NOS-like enzyme reaction decreased the cold-responsive pollen germination, inhibited tube growth and reduced Pro accumulation, partly via cGMP signaling pathway in C. sinensis.

  13. Effects of Hangeshashinto on Growth of Oral Microorganisms

    Directory of Open Access Journals (Sweden)

    Haruka Fukamachi

    2015-01-01

    Full Text Available Oral mucositis (OM in cancer patients induced by chemotherapy or radiotherapy has a significant impact on quality of life, and causes considerable morbidity. Oral microorganisms are likely to intensify the inflammatory process and aggravate the formation of ulcers. Hangeshashinto (HST, a Japanese kampo medicine, has been reported to be effective when used as a gargle for the treatment of OM. To clarify the effects of HST on oral microorganisms, we assessed its antimicrobial activity against 27 microbial species, including 19 oral bacteria and one fungus. HST extract inhibited the growth of Gram-negative bacteria, including Fusobacterium nucleatum, Porphyromonas gingivalis, Porphyromonas endodontalis, Prevotella intermedia, Prevotella melaninogenica, Tannerella forsythia, Treponema denticola, and Porphyromonas asaccharolytica, though inhibitory effects were less pronounced for Gram-positive bacteria and the fungal strain. We then investigated the effects of antibacterial activities on 15 purified ingredients of HST and determined that baicalein, berberine, coptisine, [6]-shogaol, and homogentisic acid actively inhibited the growth of these bacteria. These findings showed that HST inhibits the growth of specific Gram-negative periodontopathogenic bacteria, which are significant pathogens in OM, without disturbing the normal oral flora. Our data suggest that HST may be a useful treatment for OM in patients undergoing anticancer treatment.

  14. Effect of dry mycelium of Penicillium chrysogenum fertilizer on soil microbial community composition, enzyme activities and snap bean growth.

    Science.gov (United States)

    Wang, Bing; Liu, Huiling; Cai, Chen; Thabit, Mohamed; Wang, Pu; Li, Guomin; Duan, Ziheng

    2016-10-01

    The dry mycelium fertilizer (DMF) was produced from penicillin fermentation fungi mycelium (PFFM) following an acid-heating pretreatment to degrade the residual penicillin. In this study, it was applied into soil as fertilizer to investigate its effects on soil properties, phytotoxicity, microbial community composition, enzyme activities, and growth of snap bean in greenhouse. As the results show, pH, total nitrogen, total phosphorus, total potassium, and organic matter of soil with DMF treatments were generally higher than CON treatment. In addition, the applied DMF did not cause heavy metal and residual drug pollution of the modified soil. The lowest GI values (<0.3) were recorded at DMF8 (36 kg DMF/plat) on the first days after applying the fertilizer, indicating that severe phytotoxicity appeared in the DMF8-modified soil. Results of microbial population and enzyme activities illustrated that DMF was rapidly decomposed and the decomposition process significantly affected microbial growth and enzyme activities. The DMF-modified soil phytotoxicity decreased at the late fertilization time. DMF1 was considered as the optimum amount of DMF dose based on principal component analysis scores. Plant height and plant yield of snap bean were remarkably enhanced with the optimum DMF dose.

  15. Inheritance and gene expression of a root-growth inhibiting mutant in rice (Oryza sativa L.)

    International Nuclear Information System (INIS)

    Kitano, H.; Futsuhara, Y.

    1990-01-01

    Full text: A root-growth inhibiting mutant was induced in the dwarf mutant line, 'Fukei 71', through ethylene-imine. The mutant is characterised by the excessive inhibition of both seminal and crown roots elongation just after germination, although its shoots grow nearly normal. To study the genetics, the mutant was crossed with its original line 'Fukei 71' and some other normal cultivars. Results show that the root-growth inhibition is controlled by a recessive gene (rt), independent of the dwarf gene, d-50(t) locus in Fukei 71. For elucidating the gene action on root morphogenesis, histological and cytological experiments were carried out using a longitudinal and transverse thin section of seminal and/or crown root tips. Observations suggest that the rt gene affects the normal formation of the epidermal system which is differentiated from the protoderm of the root apical meristem. (author)

  16. Proceedings of the 8. International Symposium on Microbial Ecology : microbial biosystems : new frontiers

    International Nuclear Information System (INIS)

    Bell, C.R.; Brylinsky, M.; Johnson-Green, P.

    2000-01-01

    A wide range of disciplines were presented at this conference which reflected the importance of microbial ecology and provided an understanding of the factors that determine the growth and activities of microorganisms. The conference attracted 1444 delegates from 54 countries. The research emerging from the rapidly expanding frontier of microbial ecosystems was presented in 62 oral presentation and 817 poster presentations. The two volumes of these proceedings presented a total of 27 areas in microbial ecology, some of which included terrestrial biosystems, aquatic, estuarine, surface and subsurface microbial ecology. Other topics included bioremediation, microbial ecology in industry and microbial ecology of oil fields. Some of the papers highlighted the research that is underway to determine the feasibility of using microorganisms for enhanced oil recovery (EOR). Research has shown that microbial EOR can increase production at lower costs than conventional oil recovery. The use of bacteria has also proven to be a feasible treatment method in the biodegradation of hydrocarbons associated with oil spills. refs., tabs., figs

  17. [Inhibition of Bacillus coagulans growth in laboratory media and in fruit purees].

    Science.gov (United States)

    Cerrutti, P; Alzamora, S M; de Huergo, M S

    2000-01-01

    The growth of two strains of B. coagulans was inhibited in laboratory media at pH banana puree (pH approximately equal to 5.0) but acidification of the puree at pH = 3.5 was enough to prevent growth. The addition of up to 3,000 ppm vainillin ("natural" preservative) or 1,000 ppm potassium sorbate (traditional preservative) at pH higher than the inhibitory level previously determined could not prevent growth of B. coagulans in laboratory or in fruits, but 100 ppm lysozyme retarded growth in laboratory media at different pH levels (from 4.5 to 6.7) and in banana puree. As lysozyme showed to be effective at pH < or = 6.7, it might be used to prevent growth of B. coagulans at an eventual increment of pH during storage.

  18. Overexpression of Hiwi Inhibits the Growth and Migration of Chronic Myeloid Leukemia Cells.

    Science.gov (United States)

    Wang, Yalin; Jiang, Yan; Ma, Ning; Sang, Bailu; Hu, Xiaolin; Cong, Xiaofeng; Liu, Ziling

    2015-09-01

    Chronic myeloid leukemia (CML) is a hematopoietic malignancy characterized by dysregulated growth and proliferation of hematopoietic stem/progenitor cells in bone marrow and excessive expansion of hematopoietic compartments in peripheral blood. Expression deletion of Hiwi, a human Piwi homolog, has been reported to be implicated in leukemogenesis. We here explored Hiwi's role in CML pathogenesis by determining how and whether its forced overexpression could affect CML cell growth and migration. The present results showed that lentivirus-mediated overexpression of Hiwi significantly suppressed cell proliferation and induced obvious apoptosis in K562 cells, a CML line cell line. Tumors in BALB/c nude mice generated by the K562 cells expressing Hiwi were much smaller than those formed by the control cells. Like in vitro, Hiwi upregulation induced cell apoptosis in the tumor tissues in vivo. Additionally, Hiwi elevation suppressed K562 cell migration and inhibited the activity and expression of matrix metalloproteinase-2 and -9. In summary, our study demonstrates that Hiwi overexpression inhibits CML cell growth and migration, providing insights into its role in CML pathogenesis.

  19. The Arabidopsis transcription factor ABIG1 relays ABA signaled growth inhibition and drought induced senescence.

    Science.gov (United States)

    Liu, Tie; Longhurst, Adam D; Talavera-Rauh, Franklin; Hokin, Samuel A; Barton, M Kathryn

    2016-10-04

    Drought inhibits plant growth and can also induce premature senescence. Here we identify a transcription factor, ABA INSENSITIVE GROWTH 1 (ABIG1) required for abscisic acid (ABA) mediated growth inhibition, but not for stomatal closure. ABIG1 mRNA levels are increased both in response to drought and in response to ABA treatment. When treated with ABA, abig1 mutants remain greener and produce more leaves than comparable wild-type plants. When challenged with drought, abig1 mutants have fewer yellow, senesced leaves than wild-type. Induction of ABIG1 transcription mimics ABA treatment and regulates a set of genes implicated in stress responses. We propose a model in which drought acts through ABA to increase ABIG1 transcription which in turn restricts new shoot growth and promotes leaf senescence. The results have implications for plant breeding: the existence of a mutant that is both ABA resistant and drought resistant points to new strategies for isolating drought resistant genetic varieties.

  20. Turnover of microbial lipids in the deep biosphere and growth of benthic archaeal populations.

    Science.gov (United States)

    Xie, Sitan; Lipp, Julius S; Wegener, Gunter; Ferdelman, Timothy G; Hinrichs, Kai-Uwe

    2013-04-09

    Deep subseafloor sediments host a microbial biosphere with unknown impact on global biogeochemical cycles. This study tests previous evidence based on microbial intact polar lipids (IPLs) as proxies of live biomass, suggesting that Archaea dominate the marine sedimentary biosphere. We devised a sensitive radiotracer assay to measure the decay rate of ([(14)C]glucosyl)-diphytanylglyceroldiether (GlcDGD) as an analog of archaeal IPLs in continental margin sediments. The degradation kinetics were incorporated in model simulations that constrained the fossil fraction of subseafloor IPLs and rates of archaeal turnover. Simulating the top 1 km in a generic continental margin sediment column, we estimated degradation rate constants of GlcDGD being one to two orders of magnitude lower than those of bacterial IPLs, with half-lives of GlcDGD increasing with depth to 310 ky. Given estimated microbial community turnover times of 1.6-73 ky in sediments deeper than 1 m, 50-96% of archaeal IPLs represent fossil signals. Consequently, previous lipid-based estimates of global subseafloor biomass probably are too high, and the widely observed dominance of archaeal IPLs does not rule out a deep biosphere dominated by Bacteria. Reverse modeling of existing concentration profiles suggest that archaeal IPL synthesis rates decline from around 1,000 pg⋅mL(-1) sediment⋅y(-1) at the surface to 0.2 pg⋅mL(-1)⋅y(-1) at 1 km depth, equivalent to production of 7 × 10(5) to 140 archaeal cells⋅mL(-1) sediment⋅y(-1), respectively. These constraints on microbial growth are an important step toward understanding the relationship between the deep biosphere and the carbon cycle.

  1. Sorafenib inhibits tumor growth and vascularization of rhabdomyosarcoma cells by blocking IGF-1R-mediated signaling

    Directory of Open Access Journals (Sweden)

    Wessen Maruwge

    2008-11-01

    Full Text Available Wessen Maruwge1, Pádraig D’Arcy1, Annika Folin1,2, Slavica Brnjic1, Johan Wejde1, Anthony Davis1, Fredrik Erlandsson3, Jonas Bergh1,2, Bertha Brodin11Department of Oncology and Pathology, Karolinska Institutet, Stockholm, Sweden; 2Radiumhemmet, Karolinska University Hospital, Stockholm, Sweden; 3Bayer Pharmaceutical Corporation, SwedenAbstract: The growth of many soft tissue sarcomas is dependent on aberrant growth factor signaling, which promotes their proliferation and motility. With this in mind, we evaluated the effect of sorafenib, a receptor tyrosine kinase inhibitor, on cell growth and apoptosis in sarcoma cell lines of various histological subtypes. We found that sorafenib effectively inhibited cell proliferation in rhabdomyosarcoma, synovial sarcoma and Ewing’s sarcoma with IC50 values <5 µM. Sorafenib effectively induced growth arrest in rhabdomyosarcoma cells, which was concurrent with inhibition of Akt and Erk signaling. Studies of ligand-induced phosphorylation of Erk and Akt in rhabdomyosarcoma cells showed that insulin-like growth factor-1 is a potent activator, which can be blocked by treatment with sorafenib. In vivo sorafenib treatment of rhabdomyosarcoma xenografts had a significant inhibitory effect on tumor growth, which was associated with inhibited vascularization and enhanced necrosis in the adjacent tumor stroma. Our results demonstrate that in vitro and in vivo growth of rhabdomyosarcoma can be suppressed by treatment with sorafenib, and suggests the possibilities of using sorafenib as a potential adjuvant therapy for the treatment of rhabdomyosarcoma.Keywords: soft tissue sarcoma, kinase inhibitors, targeted therapy, vascularization

  2. Exposure to polystyrene nanoplastic leads to inhibition of anaerobic digestion system.

    Science.gov (United States)

    Fu, Shan-Fei; Ding, Jian-Nan; Zhang, Yun; Li, Yi-Fei; Zhu, Rong; Yuan, Xian-Zheng; Zou, Hua

    2018-06-01

    In this study, impacts of nanoplastic on the pure and mixed anaerobic digestion systems were investigated. Results showed the growth and metabolism of Acetobacteroides hydrogenigenes were partly inhibited by nanoplastic existed in the pure anaerobic digestion system. The anaerobic digestion of sewage sludge was also obviously inhibited by nanoplastic existed in the mixed anaerobic digestion system. Both the methane yield and methane production rate of the mixed anaerobic digestion system showed negative correlation with the nanoplastic concentration. Compared with anaerobic digestion system without nanoplastic, methane yield and maximum daily methane yield at the nanoplastic concentration of 0.2g/L decreased for 14.4% and 40.7%, respectively. In addition, the start-up of mixed anaerobic digestion system was prolonged by addition of nanoplastic. Microbial community structure analysis indicated the microbial community structures were also affected by nanoplastic existed in the system. At the nanoplastic concentration of 0.2g/L, the relative abundances of family Cloacamonaceae, Porphyromonadaceae, Anaerolinaceae and Gracilibacteraceae decreased partly. Conversely, the relative abundances of family Anaerolinaceae, Clostridiaceae, Geobacteraceae, Dethiosulfovibrionaceae and Desulfobulbaceae improved partly. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Linking genes to microbial growth kinetics: an integrated biochemical systems engineering approach.

    Science.gov (United States)

    Koutinas, Michalis; Kiparissides, Alexandros; Silva-Rocha, Rafael; Lam, Ming-Chi; Martins Dos Santos, Vitor A P; de Lorenzo, Victor; Pistikopoulos, Efstratios N; Mantalaris, Athanasios

    2011-07-01

    The majority of models describing the kinetic properties of a microorganism for a given substrate are unstructured and empirical. They are formulated in this manner so that the complex mechanism of cell growth is simplified. Herein, a novel approach for modelling microbial growth kinetics is proposed, linking biomass growth and substrate consumption rates to the gene regulatory programmes that control these processes. A dynamic model of the TOL (pWW0) plasmid of Pseudomonas putida mt-2 has been developed, describing the molecular interactions that lead to the transcription of the upper and meta operons, known to produce the enzymes for the oxidative catabolism of m-xylene. The genetic circuit model was combined with a growth kinetic model decoupling biomass growth and substrate consumption rates, which are expressed as independent functions of the rate-limiting enzymes produced by the operons. Estimation of model parameters and validation of the model's predictive capability were successfully performed in batch cultures of mt-2 fed with different concentrations of m-xylene, as confirmed by relative mRNA concentration measurements of the promoters encoded in TOL. The growth formation and substrate utilisation patterns could not be accurately described by traditional Monod-type models for a wide range of conditions, demonstrating the critical importance of gene regulation for the development of advanced models closely predicting complex bioprocesses. In contrast, the proposed strategy, which utilises quantitative information pertaining to upstream molecular events that control the production of rate-limiting enzymes, predicts the catabolism of a substrate and biomass formation and could be of central importance for the design of optimal bioprocesses. Copyright © 2011 Elsevier Inc. All rights reserved.

  4. Production of rhamnolipids by Pseudomonas aeruginosa is inhibited by H2S but resumes in a co-culture with P. stutzeri: applications for microbial enhanced oil recovery.

    Science.gov (United States)

    Zhao, Feng; Ma, Fang; Shi, Rongjiu; Zhang, Jie; Han, Siqin; Zhang, Ying

    2015-09-01

    Sulfate-reducing bacteria and H2S exist widely in oil production systems, and in situ production of rhamnolipids is promising for microbial enhanced oil recovery (MEOR). However, information of the effect of S(2-) on rhamnolipids production is scarce. Two facultative anaerobic rhamnolipids-producing bacterial strains, Pseudomonas aeruginosa SG and WJ-1, were used. Above 10 mg S(2-)/l, both cell growth and rhamnolipids production were inhibited. A large inoculum (9%, v/v) failed to completely relieve the inhibitory effect of 10 mg S(2-)/l. Below 30 mg S(2-)/l, both strains resumed rhamnolipid production through co-culturing with the denitrifying and sulphide-removing strain Pseudomonas stutzeri DQ1. H2S has a direct but reversible inhibitory effect on rhamnolipids production. Control of H2S in oilfields is indispensable to MEOR, and the co-culture method is effective in restoring rhamnolipid production in presence of S(2-).

  5. Population density of Beauveria bassiana in soil under the action of fungicides and native microbial populations

    Directory of Open Access Journals (Sweden)

    Flávia Barbosa Soares

    2017-08-01

    Full Text Available This study investigated whether populations of naturally-occurring soil bacteria, fungi and actinomycetes influence the effect of fungicides on the survival and growth of Beauveria bassiana. The toxicity of methyl thiophanate, pyraclostrobin, mancozeb and copper oxychloride at the recommended doses was analyzed in culture medium and in soil inoculated with fungus at various time points after addition of fungicides. All fungicides completely inhibited the growth and sporulation of B. bassiana in the culture medium. The fungicides were less toxic in soil, emphasizing the action of the microbial populations, which interfered with the toxic effects of these products to the fungus. Actinomycetes had the greatest influence on the entomopathogen, inhibiting it or degrading the fungicides to contribute to the survival and growth of B. bassiana in soil. Native populations of fungi and bacteria had a smaller influence on the population density of B. bassiana and the action of fungicides towards entomopathogen. The toxic effect of the fungicides was greater when added to the soil one hour before or after inoculation than at 48h after inoculation.

  6. Effects of soil organic matter on the development of the microbial polycyclic aromatic hydrocarbons (PAHs) degradation potentials

    International Nuclear Information System (INIS)

    Yang, Y.; Zhang, N.; Xue, M.; Lu, S.T.; Tao, S.

    2011-01-01

    The microbial activity in soils was a critical factor governing the degradation of organic micro-pollutants. The present study was conducted to analyze the effects of soil organic matter on the development of degradation potentials for polycyclic aromatic hydrocarbons (PAHs). Most of the degradation kinetics for PAHs by the indigenous microorganisms developed in soils can be fitted with the Logistic growth models. The microbial activities were relatively lower in the soils with the lowest and highest organic matter content, which were likely due to the nutrition limit and PAH sequestration. The microbial activities developed in humic acid (HA) were much higher than those developed in humin, which was demonstrated to be able to sequester organic pollutants stronger. The results suggested that the nutrition support and sequestration were the two major mechanisms, that soil organic matter influenced the development of microbial PAHs degradation potentials. - Research highlights: → PAH degradation kinetics obey Logistic model. → Degradation potentials depend on soil organic carbon content. → Humin inhibits the development of PAH degradation activity. → Nutrition support and sequestration regulate microbial degradation capacity. - Soil organic matter regulated PAH degradation potentials through nutrition support and sequestration.

  7. Microbial biofilm growth on irradiated, spent nuclear fuel cladding

    International Nuclear Information System (INIS)

    Bruhn, D.F.; Frank, S.M.; Roberto, F.F.; Pinhero, P.J.; Johnson, S.G.

    2009-01-01

    A fundamental criticism regarding the potential for microbial influenced corrosion in spent nuclear fuel cladding or storage containers concerns whether the required microorganisms can, in fact, survive radiation fields inherent in these materials. This study was performed to unequivocally answer this critique by addressing the potential for biofilm formation, the precursor to microbial-influenced corrosion, in radiation fields representative of spent nuclear fuel storage environments. This study involved the formation of a microbial biofilm on irradiated spent nuclear fuel cladding within a hot cell environment. This was accomplished by introducing 22 species of bacteria, in nutrient-rich media, to test vessels containing irradiated cladding sections and that was then surrounded by radioactive source material. The overall dose rate exceeded 2 Gy/h gamma/beta radiation with the total dose received by some of the bacteria reaching 5 x 10 3 Gy. This study provides evidence for the formation of biofilms on spent-fuel materials, and the implication of microbial influenced corrosion in the storage and permanent deposition of spent nuclear fuel in repository environments

  8. The effect of the Falcon 460 EC fungicide on soil microbial communities, enzyme activities and plant growth.

    Science.gov (United States)

    Baćmaga, Małgorzata; Wyszkowska, Jadwiga; Kucharski, Jan

    2016-10-01

    Fungicides are considered to be effective crop protection chemicals in modern agriculture. However, they can also exert toxic effects on non-target organisms, including soil-dwelling microbes. Therefore, the environmental fate of fungicides has to be closely monitored. The aim of this study was to evaluate the influence of the Falcon 460 EC fungicide on microbial diversity, enzyme activity and resistance, and plant growth. Samples of sandy loam with pH KCl 7.0 were collected for laboratory analyses on experimental days 30, 60 and 90. Falcon 460 EC was applied to soil in the following doses: control (soil without the fungicide), dose recommended by the manufacturer, 30-fold higher than the recommended dose, 150-fold higher than the recommended dose and 300-fold higher than the recommended dose. The observed differences in the values of the colony development index and the eco-physiological index indicate that the mixture of spiroxamine, tebuconazole and triadimenol modified the biological diversity of the analyzed groups of soil microorganisms. Bacteria of the genus Bacillus and fungi of the genera Penicillium and Rhizopus were isolated from fungicide-contaminated soil. The tested fungicide inhibited the activity of dehydrogenases, catalase, urease, acid phosphatase and alkaline phosphatase. The greatest changes were induced by the highest fungicide dose 300-fold higher than the recommended dose. Dehydrogenases were most resistant to soil contamination. The Phytotoxkit test revealed that the analyzed fungicide inhibits seed germination capacity and root elongation. The results of this study indicate that excessive doses of the Falcon 460 EC fungicide 30-fold higher than the recommended dose to 300-fold higher than the recommended dose) can induce changes in the biological activity of soil. The analyzed microbiological and biochemical parameters are reliable indicators of the fungicide's toxic effects on soil quality.

  9. Inhibition of uropathogenic biofilm growth on silicone rubber in human urine by lactobacilli - a teleologic approach

    NARCIS (Netherlands)

    Velraeds, MMC; van de Belt-Gritter, B; Busscher, HJ; Reid, G; van der Mei, HC

    2000-01-01

    The ability of three Lactobacillus strains to inhibit the adhesion and growth of naturally occurring uropathogens on silicone rubber was investigated in human urine. The importance of biosurfactant production by Lactobacillus in discouraging uropathogen growth was determined in relation to the

  10. Role of pigment epithelium-derived factor in the involution of hemangioma: Autocrine growth inhibition of hemangioma-derived endothelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kyung-Jin [Department of Pharmacology, College of Medicine, Seoul National University, Seoul 110-799 (Korea, Republic of); Department of Biomedical Science, College of Medicine, Seoul National University, Seoul 110-799 (Korea, Republic of); Yun, Jang-Hyuk; Heo, Jong-Ik [Department of Pharmacology, College of Medicine, Seoul National University, Seoul 110-799 (Korea, Republic of); Lee, Eun Hui [Department of Physiology, College of Medicine, The Catholic University of Korea, Seoul 137-701 (Korea, Republic of); Min, Hye Sook [Department of Pathology, Seoul National University Hospital, Seoul 110-744 (Korea, Republic of); Choi, Tae Hyun, E-mail: psthchoi@snu.ac.kr [Department of Plastic and Reconstructive Surgery, Seoul National University Children’s Hospital, Seoul 110-744 (Korea, Republic of); Department of Pediatric Plastic and Reconstructive Surgery, Seoul National University Children’s Hospital, Seoul 110-744 (Korea, Republic of); Cho, Chung-Hyun, E-mail: iamhyun@snu.ac.kr [Department of Pharmacology, College of Medicine, Seoul National University, Seoul 110-799 (Korea, Republic of); Department of Biomedical Science, College of Medicine, Seoul National University, Seoul 110-799 (Korea, Republic of); Ischemic/Hypoxic Disease Institute, College of Medicine, Seoul National University, Seoul 110-799 (Korea, Republic of); Cancer Research Institute, College of Medicine, Seoul National University, Seoul 110-799 (Korea, Republic of)

    2014-11-14

    Highlights: • PEDF was expressed and induced during the involuting phase of IH. • PEDF inhibited the cell growth of the involuting HemECs in an autocrine manner. • PEDF suppression restored the impaired cell growth of the involuting HemECs. - Abstract: Hemangioma is a benign tumor derived from abnormal blood vessel growth. Unlike other vascular tumor counterparts, a hemangioma is known to proliferate during its early stage but it is followed by a stage of involution where regression of the tumor occurs. The critical onset leading to the involution of hemangioma is currently not well understood. This study focused on the molecular identities of the involution of hemangioma. We demonstrated that a soluble factor released from the involuting phase of hemangioma-derived endothelial cells (HemECs) and identified pigment epithelium-derived factor (PEDF) as an anti-angiogenic factor that was associated with the growth inhibition of the involuting HemECs. The growth inhibition of the involuting HemECs was reversed by suppression of PEDF in the involuting HemECs. Furthermore, we found that PEDF was more up-regulated in the involuting phase of hemangioma tissues than in the proliferating or the involuted. Taken together, we propose that PEDF accelerates the involution of hemangioma by growth inhibition of HemECs in an autocrine manner. The regulatory mechanism of PEDF expression could be a potential therapeutic target to treat hemangiomas.

  11. Growth inhibition of Listeria spp. on Camembert cheese by bacteria producing inhibitory substances.

    Science.gov (United States)

    Sulzer, G; Busse, M

    1991-12-01

    Bacterial strains exhibiting antimicrobial activity towards other bacteria are quite common in nature. During the past few years several genera have been shown to exert inhibitory action against Listeria. spp. In the present work strains of Enterococcus, Lactobacillus and Lactococcus were tested for their influence on the development of Listeria spp. on Camembert cheese. Partial or complete inhibition of growth of Listeria spp. was observed using various inhibitory bacteria. Complete inhibition occurred when the inhibitory strain was used as a starter culture and there was a low level of contamination with Listeria spp. during the first stage of ripening. Very little inhibition occurred if the inhibitory strain was added together with the starter culture.

  12. In vitro antimicrobial activity of root canal sealers and calcium hydroxide paste

    Directory of Open Access Journals (Sweden)

    Alessandro L Cavalcanti

    2010-01-01

    Full Text Available Aim: To evaluate the in vitro antimicrobial activity of different root canal sealers and calcium hydroxide (CH paste. Materials and Methods: The sample was composed of two sealers (Fill Canal® and Sealer 26® , one CH cement (Hydro C® , and a CH paste. The agar diffusion test was performed in Petri dishes inoculated with the following microorganisms: Streptococcus salivarius, Streptococcus oralis, Streptococcus mitis, Lactobacillus casei, Streptococcus mutans, Candida albicans, Candida krusei, and Candida tropicalis. The diameters of the zones of microbial growth inhibition were measured after 24 h. The tests were performed in triplicate. Data were analyzed statistically by ANOVA and Tukey′s test at 5% significance level. Results: Fill Canal® exhibited the largest mean zone of microbial growth inhibition against the Candida species and differed significantly from the other groups (P < 0.001. When inhibition was observed against S. mitis and S. oralis, the CH paste presented a larger mean zone of microbial growth inhibition than those of the other materials (P < 0.05. Regarding the inhibition of S. mutans, a statistically significant difference was observed only between the CH paste and Hydro C® (P < 0.05; the paste produced the largest mean zone of microbial growth inhibition against this microorganism. Regarding the inhibition of S. salivarius, Fill Canal® presented smaller mean zone of microbial growth inhibition than Sealer 26® and CH paste (P < 0.05. Conclusion: All the materials presented zones of microbial growth inhibition against all the test bacteria. Fill Canal® presented the largest mean zone of inhibition against the Candida species. For the Streptococcus cultures, none of the sealers presented inhibition superior to that of the CH paste.

  13. Rapamycin causes growth arrest and inhibition of invasion in human chondrosarcoma cells.

    Science.gov (United States)

    Song, Jian; Wang, Xiaobo; Zhu, Jiaxue; Liu, Jun

    2016-01-01

    Chondrosarcoma is a highly malignant tumor that is characterized by a potent capacity to invade locally and cause distant metastasis and notable for its lack of response to conventional chemotherapy or radiotherapy. Rapamycin, the inhibitor of mammalian target of rapamycin (mTOR), is a valuable drug with diverse clinical applications and regulates many cellular processes. However, the effects of rapamycin on cell growth and invasion of human chondrosarcoma cells are not well known. We determined the effect of rapamycin on cell proliferation, cell cycle arrest and invasion by using MTS, flow cytometry and invasion assays in two human chondrosarcoma cell lines, SW1353 and JJ012. Cell cycle regulatory and invasion-related genes' expression analysis was performed by quantitative RT-PCR (qRT-PCR). We also evaluated the effect of rapamycin on tumor growth by using mice xenograph models. Rapamycin significantly inhibited the cell proliferation, induced cell cycle arrest and decreased the invasion ability of human chondrosarcoma cells. Meanwhile, rapamycin modulated the cell cycle regulatory and invasion-related genes' expression. Furthermore, the tumor growth of mice xenograph models with human chondrosarcoma cells was significantly inhibited by rapamycin. These results provided further insight into the role of rapamycin in chondrosarcoma. Therefore, rapamycin targeted therapy may be a potential treatment strategy for chondrosarcoma.

  14. Chlorpyrifos and chlorpyrifos-oxon inhibit axonal growth by interfering with the morphogenic activity of acetylcholinesterase

    International Nuclear Information System (INIS)

    Yang Dongren; Howard, Angela; Bruun, Donald; Ajua-Alemanj, Mispa; Pickart, Cecile; Lein, Pamela J.

    2008-01-01

    A primary role of acetylcholinesterase (AChE) is regulation of cholinergic neurotransmission by hydrolysis of synaptic acetylcholine. In the developing nervous system, however, AChE also functions as a morphogenic factor to promote axonal growth. This raises the question of whether organophosphorus pesticides (OPs) that are known to selectively bind to and inactivate the enzymatic function of AChE also interfere with its morphogenic function to perturb axonogenesis. To test this hypothesis, we exposed primary cultures of sensory neurons derived from embryonic rat dorsal root ganglia (DRG) to chlorpyrifos (CPF) or its oxon metabolite (CPFO). Both OPs significantly decreased axonal length at concentrations that had no effect on cell viability, protein synthesis or the enzymatic activity of AChE. Comparative analyses of the effects of CPF and CPFO on axonal growth in DRG neurons cultured from AChE nullizygous (AChE -/- ) versus wild type (AChE +/+ ) mice indicated that while these OPs inhibited axonal growth in AChE +/+ DRG neurons, they had no effect on axonal growth in AChE -/- DRG neurons. However, transfection of AChE -/- DRG neurons with cDNA encoding full-length AChE restored the wild type response to the axon inhibitory effects of OPs. These data indicate that inhibition of axonal growth by OPs requires AChE, but the mechanism involves inhibition of the morphogenic rather than enzymatic activity of AChE. These findings suggest a novel mechanism for explaining not only the functional deficits observed in children and animals following developmental exposure to OPs, but also the increased vulnerability of the developing nervous system to OPs

  15. Quantitative inhibition of soil C and N cycling by ectomycorrhizal fungi under field condition

    Science.gov (United States)

    Averill, C.; Hawkes, C.

    2014-12-01

    Ectomycorrhizal (ECM) ecosystems store more carbon than non-ectomycorrhizal ecosystems at global scale. Recent theoretical and empirical work suggests the presence of ECM fungi allows plants to compete directly with decomposers for soil nitrogen (N) via exo-enzyme synthesis. Experimental ECM exclusion often results in a release from competition of saprotrophic decomposers, allowing for increased C-degrading enzyme production, increased microbial biomass, and eventually declines in soil C stocks. Our knowledge of this phenomenon is limited, however, to the presence or absence of ECM fungi. It remains unknown if competitive repression of saprotrophic microbes and soil C cycling by ECM fungi varies with ECM abundance. This is particularly relevant to global change experiments when manipulations alter plant C allocation to ECM symbionts. To test if variation in ECM abundance alters the competitive inhibition of saprotrophic soil microbes (quantitative inhibition) we established experimental ECM exclusion treatments along an ECM abundance gradient. We dug trenches to experimentally exclude ECM fungi, allowing us to test for competitive release of soil saprotrophs from competition. To control for disturbance we placed in-growth bags both inside and outside of trenches. Consistent with the quantitative inhibition hypothesis, sites with more ECM fungi had significantly less microbial biomass per unit soil C and lower rates of N mineralization. Consistent with a release from competition, C-degrading enzyme activities were higher and gross proteolytic rates were lower per unit microbial biomass inside compared to outside trenches. We interpret this to reflect increased microbial investment in C-acquisition and decreased investment in N-acquisition in the absence of ECM fungi. Furthermore, the increase in C-degrading enzymes per unit microbial biomass was significantly greater in sites with the most abundant ECM fungi. Based on these results, ECM-saprotroph competition does

  16. Influence of mechanical disintegration on the microbial growth of aerobic sludge biomass: A comparative study of ultrasonic and shear gap homogenizers by oxygen uptake measurements.

    Science.gov (United States)

    Divyalakshmi, P; Murugan, D; Sivarajan, M; Saravanan, P; Lajapathi Rai, C

    2015-11-01

    Wastewater treatment plant incorporates physical, chemical and biological processes to treat and remove the contaminants. The main drawback of conventional activated sludge process is the huge production of excess sludge, which is an unavoidable byproduct. The treatment and disposal of excess sludge costs about 60% of the total operating cost. The ideal way to reduce excess sludge production during wastewater treatment is by preventing biomass formation within the aerobic treatment train rather than post treatment of the generated sludge. In the present investigation two different mechanical devices namely, Ultrasonic and Shear Gap homogenizers have been employed to disintegrate the aerobic biomass. This study is intended to restrict the multiplication of microbial biomass and at the same time degrade the organics present in wastewater by increasing the oxidative capacity of microorganisms. The disintegrability on biomass was determined by biochemical methods. Degree of inactivation provides the information on inability of microorganisms to consume oxygen upon disruption. The soluble COD quantifies the extent of release of intra cellular compounds. The participation of disintegrated microorganism in wastewater treatment process was carried out in two identical respirometeric reactors. The results show that Ultrasonic homogenizer is very effective in the disruption of microorganisms leading to a maximum microbial growth reduction of 27%. On the other hand, Shear gap homogenizer does not favor the sludge growth reduction rather it facilitates the growth. This study also shows that for better microbial growth reduction, floc size reduction alone is not sufficient but also microbial disruption is essential. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. Apyrase inhibitors enhance the ability of diverse fungicides to inhibit the growth of different plant-pathogenic fungi.

    Science.gov (United States)

    Kumar Tripathy, Manas; Weeraratne, Gayani; Clark, Greg; Roux, Stanley J

    2017-09-01

    A previous study has demonstrated that the treatment of Arabidopsis plants with chemical inhibitors of apyrase enzymes increases their sensitivity to herbicides. In this study, we found that the addition of the same or related apyrase inhibitors could potentiate the ability of different fungicides to inhibit the growth of five different pathogenic fungi in plate growth assays. The growth of all five fungi was partially inhibited by three commonly used fungicides: copper octanoate, myclobutanil and propiconazole. However, when these fungicides were individually tested in combination with any one of four different apyrase inhibitors (AI.1, AI.10, AI.13 or AI.15), their potency to inhibit the growth of five fungal pathogens was increased significantly relative to their application alone. The apyrase inhibitors were most effective in potentiating the ability of copper octanoate to inhibit fungal growth, and least effective in combination with propiconazole. Among the five pathogens assayed, that most sensitive to the fungicide-potentiating effects of the inhibitors was Sclerotinia sclerotiorum. Overall, among the 60 treatment combinations tested (five pathogens, four apyrase inhibitors, three fungicides), the addition of apyrase inhibitors increased significantly the sensitivity of fungi to the fungicide treatments in 53 of the combinations. Consistent with their predicted mode of action, inhibitors AI.1, AI.10 and AI.13 each increased the level of propiconazole retained in one of the fungi, suggesting that they could partially block the ability of efflux transporters to remove propiconazole from these fungi. © 2016 BSPP AND JOHN WILEY & SONS LTD.

  18. Transcriptional and post-transcriptional upregulation of p27 mediates growth inhibition of isorhapontigenin (ISO) on human bladder cancer cells.

    Science.gov (United States)

    Jiang, Guosong; Huang, Chao; Li, Jingxia; Huang, Haishan; Wang, Jingjing; Li, Yawei; Xie, Fei; Jin, Honglei; Zhu, Junlan; Huang, Chuanshu

    2018-03-08

    There are few approved drugs available for the treatment of muscle-invasive bladder cancer (MIBC). Recently, we have demonstrated that isorhapontigenin (ISO), a new derivative isolated from the Chinese herb Gnetum cleistostachyum, effectively induces cell-cycle arrest at the G0/G1 phase and inhibits anchorage-independent cell growth through the miR-137/Sp1/cyclin D1 axis in human MIBC cells. Herein, we found that treatment of bladder cancer (BC) cells with ISO resulted in a significant upregulation of p27, which was also observed in ISO-treated mouse BCs that were induced by N-butyl-N-(4-hydroxybutyl) nitrosamine (BBN). Importantly, knockdown of p27 caused a decline in the ISO-induced G0-G1 growth arrest and reversed ISO suppression of anchorage-independent growth in BC cells. Mechanistic studies revealed that ISO promoted p27 expression at mRNA transcription level through increasing direct binding of forkhead box class O1 (FOXO1) to its promoter, while knockdown of FOXO1 attenuated ISO inhibition of BC cell growth. On the other hand, ISO upregulated the 3'-untranslated region (3'-UTR) activity of p27, which was accompanied by a reduction of miR-182 expression. In line with these observations, ectopic expression of miR-182 significantly blocked p27 3'-UTR activity, whereas mutation of the miR-182-binding site at p27 mRNA 3'-UTR effectively reversed this inhibition. Accordingly, ectopic expression of miR-182 also attenuated ISO upregulation of p27 expression and impaired ISO inhibition of BC cell growth. Our results not only provide novel insight into understanding of the underlying mechanism related to regulation of MIBC cell growth but also identify new roles and mechanisms underlying ISO inhibition of BC cell growth.

  19. RGS16 inhibits breast cancer cell growth by mitigating phosphatidylinositol 3-kinase signaling.

    Science.gov (United States)

    Liang, Genqing; Bansal, Geetanjali; Xie, Zhihui; Druey, Kirk M

    2009-08-07

    Aberrant activity of the phosphatidylinositol 3-kinase (PI3K) pathway supports growth of many tumors including those of breast, lung, and prostate. Resistance of breast cancer cells to targeted chemotherapies including tyrosine kinase inhibitors (TKI) has been linked to persistent PI3K activity, which may in part be due to increased membrane expression of epidermal growth factor (EGF) receptors (HER2 and HER3). Recently we found that proteins of the RGS (regulator of G protein signaling) family suppress PI3K activity downstream of the receptor by sequestering its p85alpha subunit from signaling complexes. Because a substantial percentage of breast tumors have RGS16 mutations and reduced RGS16 protein expression, we investigated the link between regulation of PI3K activity by RGS16 and breast cancer cell growth. RGS16 overexpression in MCF7 breast cancer cells inhibited EGF-induced proliferation and Akt phosphorylation, whereas shRNA-mediated extinction of RGS16 augmented cell growth and resistance to TKI treatment. Exposure to TKI also reduced RGS16 expression in MCF7 and BT474 cell lines. RGS16 bound the amino-terminal SH2 and inter-SH2 domains of p85alpha and inhibited its interaction with the EGF receptor-associated adapter protein Gab1. These results suggest that the loss of RGS16 in some breast tumors enhances PI3K signaling elicited by growth factors and thereby promotes proliferation and TKI evasion downstream of HER activation.

  20. Tiamulin inhibits breast cancer growth and pulmonary metastasis by decreasing the activity of CD73.

    Science.gov (United States)

    Yang, Xu; Pei, Shimin; Wang, Huanan; Jin, Yipeng; Yu, Fang; Zhou, Bin; Zhang, Hong; Zhang, Di; Lin, Degui

    2017-04-11

    Metastasis is the leading cause of death in breast cancer patients. CD73, also known as ecto-5'-nucleotidase, plays a critical role in cancer development including metastasis. The existing researches indicate that overexpression of CD73 promotes growth and metastasis of breast cancer. Therefore, CD73 inhibitor can offer a promising treatment for breast cancer. Here, we determined whether tiamulin, which was found to inhibit CD73, was able to suppress breast cancer development and explored the related mechanisms. We firstly measured the effect of tiamulin hydrogen fumarate (THF) on CD73 using high performance liquid chromatography (HPLC). Then, we investigated cell proliferation, migration and invasion in MDA-MB-231 human breast cancer cell line and 4 T1 mouse breast cancer cell line treated with THF by migration assay, invasion assay and activity assay. Besides, we examined the effect of THF on syngeneic mammary tumors of mice by immunohistochemistry. Our data demonstrated that THF inhibited CD73 by decreasing the activity instead of the expression of CD73. In vitro, THF inhibited the proliferation, migration and invasion of MDA-MB-231 and 4 T1 cells by suppressing CD73 activity. In vivo, animal experiments showed that THF treatment resulted in significant reduction in syngeneic tumor growth, microvascular density and lung metastasis rate. Our results indicate that THF inhibits growth and metastasis of breast cancer by blocking the activity of CD73, which may offer a promising treatment for breast cancer therapy.

  1. Vaginal lactobacilli inhibiting growth of Gardnerella vaginalis, Mobiluncus and other bacterial species cultured from vaginal content of women with bacterial vaginosis.

    Science.gov (United States)

    Skarin, A; Sylwan, J

    1986-12-01

    On a solid agar medium the growth-inhibitory effect of 9 Lactobacillus strains cultured from vaginal content was tested on bacteria cultured from vaginal content of women with bacterial vaginosis: Mobiluncus, Gardnerella vaginalis, Bacteroides and anaerobic cocci. Inhibition zones were observed in the growth of all of the strains isolated from women with bacterial vaginosis around all lactobacilli. The inhibitory effect of the lactobacilli was further tested on various anaerobic and facultatively anaerobic species, both type strains and fresh extragenitally cultured strains. Four Bacteroides fragilis strains as well as 2 out of 4 Staphylococcus aureus strains were clearly inhibited by the lactobacilli. The inhibition zones were generally wider at pH 5.5 than at 6.0. For all inhibited strains, (the S. aureus excepted) a low pH on the agar around the lactobacilli correlated to wider growth-inhibition zones.

  2. Bio-protective potential of lactic acid bacteria: Effect of and on changes of the microbial community in vacuum-packaged chilled beef

    Directory of Open Access Journals (Sweden)

    Yimin Zhang

    2018-04-01

    Full Text Available Objective This study was to determine the bacterial diversity and monitor the community dynamic changes during storage of vacuum-packaged sliced raw beef as affected by Lactobacillus sakei and Lactobacillus curvatus. Methods L. sakei and L. curvatus were separately incubated in vacuumed-packaged raw beef as bio-protective cultures to inhibit the naturally contaminating microbial load. Dynamic changes of the microbial diversity of inoculated or non-inoculated (control samples were monitored at 4°C for 0 to 38 days, using polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE. Results The DGGE profiles of DNA directly extracted from non-inoculated control samples highlighted the order of appearance of spoilage bacteria during storage, showing that Enterbacteriaceae and Pseudomonas fragi emerged early, then Brochothrix thermosphacta shared the dominant position, and finally, Pseudomonas putida showed up became predominant. Compared with control, the inoculation of either L. sakei or L. curvatus significantly lowered the complexity of microbial diversity and inhibited the growth of spoilage bacteria (p<0.05. Interestingly, we also found that the dominant position of L. curvatus was replaced by indigenous L. sakei after 13 d for L. curvatus-inoculated samples. Plate counts on selective agars further showed that inoculation with L. sakei or L. curvatus obviously reduced the viable counts of Enterbacteraceae, Pseudomonas spp. and B. thermosphacta during later storage (p< 0.05, with L. sakei exerting greater inhibitory effect. Inoculation with both bio-protective cultures also significantly decreased the total volatile basic nitrogen values of stored samples (p<0.05. Conclusion Taken together, the results proved the benefits of inoculation with lactic acid bacteria especially L. sakei as a potential way to inhibit growth of spoilage-related bacteria and improve the shelf life of vacuum-packaged raw beef.

  3. Instability of the Null Steady State: The Fundamental Problem of Inhibiting Malignant Cell Growth

    Science.gov (United States)

    Varfolomeev, S. D.; Lukovenkov, A. V.

    2018-07-01

    Mathematical modeling of the process of inhibiting malignant growth by common chemotherapeutic agents and biological therapeutics is used to investigate the effect kinetic parameters of the model have on the outcome of treatment. It is shown that the ultimate suppression of growth, i.e., the formation of a stable steady-state with no cancer cells, cannot be attained if only the means of classical chemotherapy are used.

  4. KAEMPFEROL, A FLAVONOID COMPOUND FROM GYNURA MEDICA INDUCED APOPTOSIS AND GROWTH INHIBITION IN MCF-7 BREAST CANCER CELL.

    Science.gov (United States)

    Yi, Xiaofang; Zuo, Jiangcheng; Tan, Chao; Xian, Sheng; Luo, Chunhua; Chen, Sai; Yu, Liangfang; Luo, Yucheng

    2016-01-01

    Kaempferol, a natural flavonoid, has been shown to induce cancer cell apoptosis and cell growth inhibition in several tumors. Previously we have conducted a full investigation on the chemical constituents of Gynura medica , kaempferol and its glycosides are the major constituents of G. medica . Here we investigated the growth inhibition and apoptosis induction effect of kaempferol extracted from G. medica . The inhibition effects of kaempferol were evaluated by MTS assay and soft agar colony formation assay. Fluorescence staining and western blotting were be used to study the apoptosis. The structure was identified by 1 H- NMR), 13 C-NMR and ESI-MS analyses. Our results showed that kaempferol's inhibition of MCF-7 breast cancer cell growth may through inducing apoptosis and downregulation of Bcl2 expression. Kaempferol is a promising cancer preventive and therapeutic agent for breast cancer. List of non-standard abbreviations: MTS: 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, HPLC: High-performance liquid chromatography, NMR: Nuclear Magnetic Resonance, ESI-MS Electrospray Ionization Mass Spectral, PARP: Poly ADP-ribose polymerase.

  5. DEVELOPMENT OF AN ENVIRONMENTALLY BENIGN MICROBIAL INHIBITOR TO CONTROL INTERNAL PIPELINE CORROSION

    Energy Technology Data Exchange (ETDEWEB)

    Bill W. Bogan; Brigid M. Lamb; Gemma Husmillo; Kristine Lowe; J. Robert Paterek; John J. Kilbane II

    2004-12-01

    The overall program objective is to develop and evaluate environmentally benign agents or products that are effective in the prevention, inhibition, and mitigation of microbially influenced corrosion (MIC) in the internal surfaces of metallic natural gas pipelines. The goal is to develop one or more environmentally benign (a.k.a. ''green'') products that can be applied to maintain the structure and dependability of the natural gas infrastructure. Various chemicals that inhibit the growth and/or the metabolism of corrosion-associated microbes such as sulfate reducing bacteria, denitrifying bacteria, and methanogenic bacteria were evaluated to determine their ability to inhibit corrosion in experiments utilizing pure and mixed bacterial cultures, and planktonic cultures as well as mature biofilms. Planktonic cultures are easier to inhibit than mature biofilms but several compounds were shown to be effective in decreasing the amount of metal corrosion. Of the compounds tested hexane extracts of Capsicum pepper plants and molybdate were the most effective inhibitors of sulfate reducing bacteria, bismuth nitrate was the most effective inhibitor of nitrate reducing bacteria, and 4-((pyridine-2-yl)methylamino)benzoic acid (PMBA) was the most effective inhibitor of methanogenic bacteria. All of these compounds were demonstrated to minimize corrosion due to MIC, at least in some circumstances. The results obtained in this project are consistent with the hypothesis that any compound that disrupts the metabolism of any of the major microbial groups present in corrosion-associated biofilms shows promise in limiting the amount/rate of corrosion. This approach of controlling MIC by controlling the metabolism of biofilms is more environmentally benign than the current approach involving the use of potent biocides, and warrants further investigation.

  6. Venom of the Peruvian snake Bothriopsis oligolepis: Detection of antibacterial activity and involvement of proteolytic enzymes and C-type lectins in growth inhibition of Staphylococcus aureus.

    Science.gov (United States)

    Sulca, M A; Remuzgo, C; Cárdenas, J; Kiyota, S; Cheng, E; Bemquerer, M P; Machini, M T

    2017-08-01

    There is a rising interest in snake venoms proteins (SVPs) because these macromolecules are related to pharmacological properties that manifest themselves during poisoning and can lead to secondary microbial infections. Interestingly, researchers have somehow neglected the antimicrobial activity of SVPs. The aims of this study were: (i) to verify whether the venom of the Peruvian snake Bothriopsis oligolepis displays such activity; (ii) to isolate and identify some of its antimicrobial constituents. Liquid growth inhibition assays revealed that the crude venom inhibited the growth of Gram-positive and Gram-negative bacteria, but not of Candida species. Fractionation of the venom by anion-exchange chromatography provided fractions P2, P4 and P8 active against S. aureus. Fractionation of P2 or P8 by gel-filtration chromatography and of P4 by RP-HPLC furnished the sub-fractions P2-I, P8-II and P4-II, respectively, being those fractions active against S. aureus. Analyses of these sub-fractions by SDS-PAGE under denaturing/reducing conditions evidenced SVPs with 59-73, 27 and 14-28 kDa, respectively. Their in-gel tryptic digestion gave peptide fragments, whose sequencing by MALDI-TOF/MS followed by protein BLAST analysis allowed identifying PIII metalloprotease(s) [SVMP(s)] in P2-I, serine protease(s) [SVSP(s)] in P4-II and lectin(s) in P8-II. Detection of gelatinolytic activity in P2-I and P4-II reinforced the existence of PIII-SVMP(s) and SVSP(s), respectively. Activation of the coagulation cascade intrinsic pathway by P8-II (probably by interaction with factors IX and/or X as some snake C-type lectins do) supported the presence of C-type lectin(s). Altogether, these new findings reveal that the venom of the Peruvian snake Bothriopsis oligolepis displays antibacterial activity and that the isolated SVMP(s), SVSP(s) and C-type lectin(s) are associated to its ability to inhibit the growth of S. aureus. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Microbial activity in aquatic environments measured by dimethyl sulfoxide reduction and intercomparison with commonly used methods.

    Science.gov (United States)

    Griebler, C; Slezak, D

    2001-01-01

    A new method to determine microbial (bacterial and fungal) activity in various freshwater habitats is described. Based on microbial reduction of dimethyl sulfoxide (DMSO) to dimethyl sulfide (DMS), our DMSO reduction method allows measurement of the respiratory activity in interstitial water, as well as in the water column. DMSO is added to water samples at a concentration (0.75% [vol/vol] or 106 mM) high enough to compete with other naturally occurring electron acceptors, as determined with oxygen and nitrate, without stimulating or inhibiting microbial activity. Addition of NaN(3), KCN, and formaldehyde, as well as autoclaving, inhibited the production of DMS, which proves that the reduction of DMSO is a biotic process. DMSO reduction is readily detectable via the formation of DMS even at low microbial activities. All water samples showed significant DMSO reduction over several hours. Microbially reduced DMSO is recovered in the form of DMS from water samples by a purge and trap system and is quantified by gas chromatography and detection with a flame photometric detector. The DMSO reduction method was compared with other methods commonly used for assessment of microbial activity. DMSO reduction activity correlated well with bacterial production in predator-free batch cultures. Cell-production-specific DMSO reduction rates did not differ significantly in batch cultures with different nutrient regimes but were different in different growth phases. Overall, a cell-production-specific DMSO reduction rate of 1.26 x 10(-17) +/- 0. 12 x 10(-17) mol of DMS per produced cell (mean +/- standard error; R(2) = 0.78) was calculated. We suggest that the relationship of DMSO reduction rates to thymidine and leucine incorporation is linear (the R(2) values ranged from 0.783 to 0.944), whereas there is an exponential relationship between DMSO reduction rates and glucose uptake, as well as incorporation (the R(2) values ranged from 0.821 to 0.931). Based on our results, we

  8. Inhibition of Epidermal Growth Factor Receptor and Vascular Endothelial Growth Factor Receptor Phosphorylation on Tumor-Associated Endothelial Cells Leads to Treatment of Orthotopic Human Colon Cancer in Nude Mice

    Directory of Open Access Journals (Sweden)

    Takamitsu Sasaki

    2007-12-01

    Full Text Available The purpose of our study was to determine whether the dual inhibition of epidermal growth factor receptor (EGFR and vascular endothelial growth factor receptor (VEGFR signaling pathways in tumor-associated endothelial cells can inhibit the progressive growth of human colon carcinoma in the cecum of nude mice. SW620CE2 human colon cancer cells growing in culture and orthotopically in the cecum of nude mice expressed a high level of transforming growth factor alpha (TGF-α and vascular endothelial growth factor (VEGF but were negative for EGFR, human epidermal growth factor receptor 2 (HER2, VEGFR. Double immunofluorescence staining revealed that tumorassociated endothelial cells expressed EGFR, VEGFR2, phosphorylated EGFR (pEGFR, phosphorylated VEGFR (pVEGFR. Treatment of mice with either 7H-pyrrolo [2,3-d]-pyrimidine lead scaffold (AEE788; an inhibitor of EGFR and VEGFR tyrosine kinase or CPT-11 as single agents significantly inhibited the growth of cecal tumors (P < .01; this decrease was even more pronounced with AEE788 combined with CPT-11 (P < .001. AEE788 alone or combined with CPT-11 also inhibited the expression of pEGFR and pVEGFR on tumor-associated endothelial cells, significantly decreased vascularization and tumor cell proliferation, increased the level of apoptosis in both tumorassociated endothelial cells and tumor cells. These data demonstrate that targeting EGFR and VEGFR signaling on tumor-associated endothelial cells provides a viable approach for the treatment of colon cancer.

  9. Epidermal growth factor (EGF) inhibits stimulated thyroid hormone secretion in the mouse

    International Nuclear Information System (INIS)

    Ahren, B.

    1987-01-01

    It is known that epidermal growth factor (EGF) inhibits iodide uptake in the thyroid follicular cells and lowers plasma levels of thyroid hormones upon infusion into sheep and ewes. In this study, the effects of EGF on basal and stimulated thyroid hormone secretion were investigated in the mouse. Mice were pretreated with 125 I and thyroxine; the subsequent release of 125 I is an estimation of thyroid hormone secretion. It was found that basal radioiodine secretion was not altered by intravenous injection of EGF (5 micrograms/animal). However, the radioiodine secretion stimulated by both TSH (120 microU/animal) and vasoactive intestinal peptide (VIP; 5 micrograms/animal) were inhibited by EGF (5 micrograms/animal). At a lower dose level (0.5 microgram/animal), EGF had no influence on stimulated radioiodine secretion. In conclusion, EGF inhibits stimulated thyroid hormone secretion in the mouse

  10. Steviol reduces MDCK Cyst formation and growth by inhibiting CFTR channel activity and promoting proteasome-mediated CFTR degradation.

    Directory of Open Access Journals (Sweden)

    Chaowalit Yuajit

    Full Text Available Cyst enlargement in polycystic kidney disease (PKD involves cAMP-activated proliferation of cyst-lining epithelial cells and transepithelial fluid secretion into the cyst lumen via cystic fibrosis transmembrane conductance regulator (CFTR chloride channel. This study aimed to investigate an inhibitory effect and detailed mechanisms of steviol and its derivatives on cyst growth using a cyst model in Madin-Darby canine kidney (MDCK cells. Among 4 steviol-related compounds tested, steviol was found to be the most potent at inhibiting MDCK cyst growth. Steviol inhibition of cyst growth was dose-dependent; steviol (100 microM reversibly inhibited cyst formation and cyst growth by 72.53.6% and 38.2±8.5%, respectively. Steviol at doses up to 200 microM had no effect on MDCK cell viability, proliferation and apoptosis. However, steviol acutely inhibited forskolin-stimulated apical chloride current in MDCK epithelia, measured with the Ussing chamber technique, in a dose-dependent manner. Prolonged treatment (24 h with steviol (100 microM also strongly inhibited forskolin-stimulated apical chloride current, in part by reducing CFTR protein expression in MDCK cells. Interestingly, proteasome inhibitor, MG-132, abolished the effect of steviol on CFTR protein expression. Immunofluorescence studies demonstrated that prolonged treatment (24 h with steviol (100 microM markedly reduced CFTR expression at the plasma membrane. Taken together, the data suggest that steviol retards MDCK cyst progression in two ways: first by directly inhibiting CFTR chloride channel activity and second by reducing CFTR expression, in part, by promoting proteasomal degradation of CFTR. Steviol and related compounds therefore represent drug candidates for treatment of polycystic kidney disease.

  11. Inhibition of dipeptidyl peptidase 4 regulates microvascular endothelial growth induced by inflammatory cytokines

    International Nuclear Information System (INIS)

    Takasawa, Wataru; Ohnuma, Kei; Hatano, Ryo; Endo, Yuko; Dang, Nam H.; Morimoto, Chikao

    2010-01-01

    Research highlights: → TNF-α or IL-1β induces EC proliferation with reduction of CD26 expression. → CD26 siRNA or DPP-4 inhibition enhances TNF-α or IL-1β-induced EC proliferation. → Loss of CD26/DPP-4 enhances aortic sprouting induced by TNF-α or IL-1β. → Capillary formation induced by TNF-α or IL-1β is enahced in the CD26 -/- mice. -- Abstract: CD26/DPP-4 is abundantly expressed on capillary of inflamed lesion as well as effector T cells. Recently, CD26/dipeptidyl peptidase 4 (DPP-4) inhibition has been used as a novel oral therapeutic approach for patients with type 2 diabetes. While accumulating data indicate that vascular inflammation is a key feature of both micro- and macro-vascular complications in diabetes, the direct role of CD26/DPP-4 in endothelial biology is to be elucidated. We herein showed that proinflammatory cytokines such as tumor necrosis factor or interleukin-1 reduce expression of CD26 on microvascular endothelial cells, and that genetical or pharmacological inhibition of CD26/DPP-4 enhances endothelial growth both in vitro and in vivo. With DPP-4 inhibitors being used widely in the treatment of type 2 diabetes, our data strongly suggest that DPP-4 inhibition plays a pivotal role in endothelial growth and may have a potential role in the recovery of local circulation following diabetic vascular complications.

  12. Inhibition of oxidative stress-elicited AKT activation facilitates PPARγ agonist-mediated inhibition of stem cell character and tumor growth of liver cancer cells.

    Directory of Open Access Journals (Sweden)

    Lanlan Liu

    Full Text Available Emerging evidence suggests that tumor-initiating cells (TICs are the most malignant cell subpopulation in tumors because of their resistance to chemotherapy or radiation treatment. Targeting TICs may be a key innovation for cancer treatment. In this study, we found that PPARγ agonists inhibited the cancer stem cell-like phenotype and attenuated tumor growth of human hepatocellular carcinoma (HCC cells. Reactive oxygen species (ROS initiated by NOX2 upregulation were partially responsible for the inhibitory effects mediated by PPARγ agonists. However, PPARγ agonist-mediated ROS production significantly activated AKT, which in turn promoted TIC survival by limiting ROS generation. Inhibition of AKT, by either pharmacological inhibitors or AKT siRNA, significantly enhanced PPARγ agonist-mediated inhibition of cell proliferation and stem cell-like properties in HCC cells. Importantly, in nude mice inoculated with HCC Huh7 cells, we demonstrated a synergistic inhibitory effect of the PPARγ agonist rosiglitazone and the AKT inhibitor triciribine on tumor growth. In conclusion, we observed a negative feedback loop between oxidative stress and AKT hyperactivation in PPARγ agonist-mediated suppressive effects on HCCs. Combinatory application of an AKT inhibitor and a PPARγ agonist may provide a new strategy for inhibition of stem cell-like properties in HCCs and treatment of liver cancer.

  13. Novel Midkine Inhibitor iMDK Inhibits Tumor Growth and Angiogenesis in Oral Squamous Cell Carcinoma.

    Science.gov (United States)

    Masui, Masanori; Okui, Tatsuo; Shimo, Tsuyoshi; Takabatake, Kiyofumi; Fukazawa, Takuya; Matsumoto, Kenichi; Kurio, Naito; Ibaragi, Soichiro; Naomoto, Yoshio; Nagatsuka, Hitoshi; Sasaki, Akira

    2016-06-01

    Midkine is a heparin-binding growth factor highly expressed in various human malignant tumors. However, its role in the growth of oral squamous cell carcinoma is not well understood. In this study, we analyzed the antitumor effect of a novel midkine inhibitor (iMDK) against oral squamous cell carcinoma. Administration of iMDK induced a robust antitumor response and suppressed cluster of differentiation 31 (CD31) expression in oral squamous cell carcinoma HSC-2 cells and SAS cells xenograft models. iMDK inhibited the proliferation of these cells dose-dependently, as well as the expression of midkine and phospho-extracellular signal-regulated kinase in HSC-2 and SAS cells. Moreover, iMDK significantly inhibited vascular endothelial growth factor and induced tube growth of human umbilical vein endothelial cells in a dose-dependent fashion. These findings suggest that midkine is critically involved in oral squamous cell carcinoma and iMDK can be effectively used for the treatment of oral squamous cell carcinoma. Copyright© 2016 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

  14. Ibrutinib Inhibits ERBB Receptor Tyrosine Kinases and HER2-Amplified Breast Cancer Cell Growth.

    Science.gov (United States)

    Chen, Jun; Kinoshita, Taisei; Sukbuntherng, Juthamas; Chang, Betty Y; Elias, Laurence

    2016-12-01

    Ibrutinib is a potent, small-molecule Bruton tyrosine kinase (BTK) inhibitor developed for the treatment of B-cell malignancies. Ibrutinib covalently binds to Cys481 in the ATP-binding domain of BTK. This cysteine residue is conserved among 9 other tyrosine kinases, including HER2 and EGFR, which can be targeted. Screening large panels of cell lines demonstrated that ibrutinib was growth inhibitory against some solid tumor cells, including those inhibited by other HER2/EGFR inhibitors. Among sensitive cell lines, breast cancer lines with HER2 overexpression were most potently inhibited by ibrutinib (ibrutinib coincided with downregulation of phosphorylation on HER2 and EGFR and their downstream targets, AKT and ERK. Irreversible inhibition of HER2 and EGFR in breast cancer cells was established after 30-minute incubation above 100 nmol/L or following 2-hour incubation at lower concentrations. Furthermore, ibrutinib inhibited recombinant HER2 and EGFR activity that was resistant to dialysis and rapid dilution, suggesting an irreversible interaction. The dual activity toward TEC family (BTK and ITK) and ERBB family kinases was unique to ibrutinib, as ERBB inhibitors do not inhibit or covalently bind BTK or ITK. Xenograft studies with HER2 + MDA-MB-453 and BT-474 cells in mice in conjunction with determination of pharmacokinetics demonstrated significant exposure-dependent inhibition of growth and key signaling molecules at levels that are clinically achievable. Ibrutinib's unique dual spectrum of activity against both TEC family and ERBB kinases suggests broader applications of ibrutinib in oncology. Mol Cancer Ther; 15(12); 2835-44. ©2016 AACR. ©2016 American Association for Cancer Research.

  15. Antibiotics and Manure Effects on Microbial Communities Responsible for Nitrous Oxide Emissions from Grasslands

    Science.gov (United States)

    Semedo, M.; Song, B.; Sparrer, T.; Crozier, C.; Tobias, C. R.; Phillips, R. L.

    2015-12-01

    Agroecosystems are major contributors of nitrous oxide (N2O) emissions. Denitrification and nitrification are the primary pathways of N2O emission in soils. However, there is uncertainty regarding the organisms responsible for N2O production. Bacteria were previously considered the only microbial N2O source, however, current studies indicate that fungi also produce N2O by denitrification. Denitrifying bacteria can be a source or sink of N2O depending on the presence and expression of nitrous oxide reductase genes (nosZ), encoding for the enzyme converting N2O to N2. Fungal denitrification may produce only N2O as an end product due to missing the nosZ gene. Animal manures applied to agricultural fields can transfer antibiotics to soils as a result of antibiotic use in the livestock industry. These antibiotics target mostly bacteria and may promote fungal growth. The growth inhibition of denitrifying bacteria may favor fungal denitrifiers potentially enhancing N2O emissions. Our objective is to examine the effects of antibiotic exposure and manure fertilization on the microbial communities responsible for N2 and N2O production in grasslands. Soil slurry incubations were conducted with tetracycline at different concentrations. A mesocosm experiment was also performed with soil cores exposed to tetracycline and cow manure. Production of N2O and N2 was measured using gas chromatography with electron capture detector (GC-ECD) and isotope ratio mass spectrometry (IRMS), respectively. Antibiotic inhibition of soil N2 production was found to be dose dependent, reaching up to 80% inhibition with 1g Kg-1 of tetracycline treatment, while N2O production was enhanced up to 8 times. These results suggest higher fungal denitrification with a concomitant decrease in bacterial denitrification after antibiotic exposure. We also found higher N2O fluxes in the soil mesocosms treated with manure plus tetracycline. Quantitative PCR (qPCR) will be conducted to examine the changes in

  16. Parafibromin inhibits cancer cell growth and causes G1 phase arrest

    International Nuclear Information System (INIS)

    Zhang Chun; Kong Dong; Tan, M.-H.; Pappas, Donald L.; Wang, P.-F.; Chen, Jindong; Farber, Leslie; Zhang Nian; Koo, H.-M.; Weinreich, Michael; Williams, Bart O.; Teh, B.T.

    2006-01-01

    The HRPT2 (hereditary hyperparathyroidism type 2) tumor suppressor gene encodes a ubiquitously expressed 531 amino acid protein termed parafibromin. Inactivation of parafibromin predisposes one to the development of HPT-JT syndrome. To date, the role of parafibromin in tumorigenesis is largely unknown. Here, we report that parafibromin is a nuclear protein that possesses anti-proliferative properties. We show that overexpression of parafibromin inhibits colony formation and cellular proliferation, and induces cell cycle arrest in the G1 phase. Moreover, HPT-JT syndrome-derived mutations in HRPT2 behave in a dominant-negative manner by abolishing the ability of parafibromin to suppress cell proliferation. These findings suggest that parafibromin has a critical role in cell growth, and mutations in HRPT2 can directly inhibit this role

  17. Praziquantel synergistically enhances paclitaxel efficacy to inhibit cancer cell growth.

    Directory of Open Access Journals (Sweden)

    Zhen Hua Wu

    Full Text Available The major challenges we are facing in cancer therapy with paclitaxel (PTX are the drug resistance and severe side effects. Massive efforts have been made to overcome these clinical challenges by combining PTX with other drugs. In this study, we reported the first preclinical data that praziquantel (PZQ, an anti-parasite agent, could greatly enhance the anticancer efficacy of PTX in various cancer cell lines, including PTX-resistant cell lines. Based on the combination index value, we demonstrated that PZQ synergistically enhanced PTX-induced cell growth inhibition. The co-treatment of PZQ and PTX also induced significant mitotic arrest and activated the apoptotic cascade. Moreover, PZQ combined with PTX resulted in a more pronounced inhibition of tumor growth compared with either drug alone in a mouse xenograft model. We tried to investigate the possible mechanisms of this synergistic efficacy induced by PZQ and PTX, and we found that the co-treatment of the two drugs could markedly decrease expression of X-linked inhibitor of apoptosis protein (XIAP, an anti-apoptotic protein. Our data further demonstrated that down-regulation of XIAP was required for the synergistic interaction between PZQ and PTX. Together, this study suggested that the combination of PZQ and PTX may represent a novel and effective anticancer strategy for optimizing PTX therapy.

  18. Bacterial growth and substrate degradation by BTX-oxidizing culture in response to salt stress.

    Science.gov (United States)

    Lee, Chi-Yuan; Lin, Ching-Hsing

    2006-01-01

    Interactions between microbial growth and substrate degradation are important in determining the performance of trickle-bed bioreactors (TBB), especially when salt is added to reduce biomass formation in order to alleviate media clogging. This study was aimed at quantifying salinity effects on bacterial growth and substrate degradation, and at acquiring kinetic information in order to improve the design and operation of TBB. Experiment works began by cultivating a mixed culture in a chemostat reactor receiving artificial influent containing a mixture of benzene, toluene, and xylene (BTX), followed by using the enrichment culture to degrade the individual BTX substrates under a particular salinity, which ranged 0-50 g l(-1) in batch mode. Then, the measured concentrations of biomass and residual substrate versus time were analyzed with the microbial kinetics; moreover, the obtained microbial kinetic constants under various salinities were modeled using noncompetitive inhibition kinetics. For the three substrates the observed bacterial yields appeared to be decreased from 0.51-0.74 to 0.20-0.22 mg mg(-1) and the maximum specific rate of substrate utilization, q, declined from 0.25-0.42 to 0.07-0.11 h(-1), as the salinity increased from 0 to 50 NaCl g l(-1). The NaCl acted as noncompetitive inhibitor, where the modeling inhibitions of the coefficients, K ( T(S)), were 22.7-29.7 g l(-1) for substrate degradation and K ( T(mu)), 13.0-19.0 g l(-1), for biomass formation. The calculated ratios for the bacterial maintenance rate, m (S), to q, further indicated that the percentage energy spent on maintenance increased from 19-24 to 86-91% as salinity level increased from 0 to 50 g l(-1). These results revealed that the bacterial growth was more inhibited than substrate degradation by the BTX oxidizers under the tested salinity levels. The findings from this study demonstrate the potential of applying NaCl salt to control excessive biomass formation in biotrickling filters.

  19. Arecoline inhibits endothelial cell growth and migration and the attachment to mononuclear cells

    Directory of Open Access Journals (Sweden)

    Shuei-Kuen Tseng

    2014-09-01

    Conclusion: Arecoline impaired vascular endothelial cells by inhibiting their growth and migration and their adhesion to U937 mononuclear cells. These results reveal that arecoline may contribute to the pathogenesis of oral submucous fibrosis and cardiovascular diseases by affecting endothelial cell function in BQ chewers.

  20. Inhibition of the mitogenic response to platelet-derived growth factor by terbinafine

    International Nuclear Information System (INIS)

    St Denny, I.H.; Glinka, K.G.; Nemecek, G.M.; Stuetz, A.

    1987-01-01

    Terbinafine (T;(E)-N-(6,6-dimethyl-2-hepten-4-ynyl)-N-methyl-1-naphthalenemethanamine), an antimycotic which inhibits fungal squalene epoxidase activity, was examined for its effects on platelet-derived growth factor (PDGF)-stimulated mitogenesis. The inclusion of 1.5-5μM T in fibroblast incubation media was associated with increased [ 3 H]thymidine incorporation into DNA in the presence and absence of PDGF. However, T at concentrations above 6μM reduced DNA synthesis in control and PDGF-exposed cultures to nearly undetectable levels. Under a phase-contrast microscope, fibroblasts appeared morphologically normal at T concentrations as high as 25 μM. Neither the uptake of [ 3 H]thymidine nor the specific binding of 125 I-PDGF to fibroblast receptors was significantly affected by 10 μM T. Furthermore, concentrations of T which antagonized the mitogenic response to PDGF also interfered with fibroblast growth factor-induced mitogenesis. Together, these data suggest that T has the ability to inhibit the in vitro action of PDGF via a post-receptor mechanism

  1. Inhibition of the mitogenic response to platelet-derived growth factor by terbinafine

    Energy Technology Data Exchange (ETDEWEB)

    St. Denny, I.H.; Glinka, K.G.; Nemecek, G.M. (Sandoz Research Institute, East Hanover, NJ (USA)); Stuetz, A. (Sandoz Forschungsinstitut, Vienna (Austria))

    1987-05-01

    Terbinafine (T;(E)-N-(6,6-dimethyl-2-hepten-4-ynyl)-N-methyl-1-naphthalenemethanamine), an antimycotic which inhibits fungal squalene epoxidase activity, was examined for its effects on platelet-derived growth factor (PDGF)-stimulated mitogenesis. The inclusion of 1.5-5{mu}M T in fibroblast incubation media was associated with increased ({sup 3}H)thymidine incorporation into DNA in the presence and absence of PDGF. However, T at concentrations above 6{mu}M reduced DNA synthesis in control and PDGF-exposed cultures to nearly undetectable levels. Under a phase-contrast microscope, fibroblasts appeared morphologically normal at T concentrations as high as 25 {mu}M. Neither the uptake of ({sup 3}H)thymidine nor the specific binding of {sup 125}I-PDGF to fibroblast receptors was significantly affected by 10 {mu}M T. Furthermore, concentrations of T which antagonized the mitogenic response to PDGF also interfered with fibroblast growth factor-induced mitogenesis. Together, these data suggest that T has the ability to inhibit the in vitro action of PDGF via a post-receptor mechanism.

  2. Mobile phone radiation inhibits Vigna radiata (mung bean) root growth by inducing oxidative stress

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Ved Parkash [Department of Environment and Vocational Studies, Panjab University, Chandigarh 160014 (India); Department of Zoology, Panjab University, Chandigarh 160014 (India); Singh, Harminder Pal, E-mail: hpsingh_01@yahoo.com [Department of Environment and Vocational Studies, Panjab University, Chandigarh 160014 (India); Kohli, Ravinder Kumar; Batish, Daizy Rani [Department of Botany, Panjab University, Chandigarh 160014 (India)

    2009-10-15

    During the last couple of decades, there has been a tremendous increase in the use of cell phones. It has significantly added to the rapidly increasing EMF smog, an unprecedented type of pollution consisting of radiation in the environment, thereby prompting the scientists to study the effects on humans. However, not many studies have been conducted to explore the effects of cell phone EMFr on growth and biochemical changes in plants. We investigated whether EMFr from cell phones inhibit growth of Vigna radiata (mung bean) through induction of conventional stress responses. Effects of cell phone EMFr (power density: 8.55 {mu}W cm{sup -2}; 900 MHz band width; for 1/2, 1, 2, and 4 h) were determined by measuring the generation of reactive oxygen species (ROS) in terms of malondialdehyde and hydrogen peroxide (H{sub 2}O{sub 2}) content, root oxidizability and changes in levels of antioxidant enzymes. Our results showed that cell phone EMFr significantly inhibited the germination (at {>=}2 h), and radicle and plumule growths ({>=}1 h) in mung bean in a time-dependent manner. Further, cell phone EMFr enhanced MDA content (indicating lipid peroxidation), and increased H{sub 2}O{sub 2} accumulation and root oxidizability in mung bean roots, thereby inducing oxidative stress and cellular damage. In response to EMFr, there was a significant upregulation in the activities of scavenging enzymes, such as superoxide dismutases, ascorbate peroxidases, guaiacol peroxidases, catalases and glutathione reductases, in mung bean roots. The study concluded that cell phone EMFr inhibit root growth of mung bean by inducing ROS-generated oxidative stress despite increased activities of antioxidant enzymes.

  3. Mobile phone radiation inhibits Vigna radiata (mung bean) root growth by inducing oxidative stress

    International Nuclear Information System (INIS)

    Sharma, Ved Parkash; Singh, Harminder Pal; Kohli, Ravinder Kumar; Batish, Daizy Rani

    2009-01-01

    During the last couple of decades, there has been a tremendous increase in the use of cell phones. It has significantly added to the rapidly increasing EMF smog, an unprecedented type of pollution consisting of radiation in the environment, thereby prompting the scientists to study the effects on humans. However, not many studies have been conducted to explore the effects of cell phone EMFr on growth and biochemical changes in plants. We investigated whether EMFr from cell phones inhibit growth of Vigna radiata (mung bean) through induction of conventional stress responses. Effects of cell phone EMFr (power density: 8.55 μW cm -2 ; 900 MHz band width; for 1/2, 1, 2, and 4 h) were determined by measuring the generation of reactive oxygen species (ROS) in terms of malondialdehyde and hydrogen peroxide (H 2 O 2 ) content, root oxidizability and changes in levels of antioxidant enzymes. Our results showed that cell phone EMFr significantly inhibited the germination (at ≥2 h), and radicle and plumule growths (≥1 h) in mung bean in a time-dependent manner. Further, cell phone EMFr enhanced MDA content (indicating lipid peroxidation), and increased H 2 O 2 accumulation and root oxidizability in mung bean roots, thereby inducing oxidative stress and cellular damage. In response to EMFr, there was a significant upregulation in the activities of scavenging enzymes, such as superoxide dismutases, ascorbate peroxidases, guaiacol peroxidases, catalases and glutathione reductases, in mung bean roots. The study concluded that cell phone EMFr inhibit root growth of mung bean by inducing ROS-generated oxidative stress despite increased activities of antioxidant enzymes.

  4. Microbial biofilm formation and its consequences for the CELSS program

    Science.gov (United States)

    Mitchell, R.

    1994-01-01

    A major goal of the Controlled Ecology Life Support System (CELSS) program is to provide reliable and efficient life support systems for long-duration space flights. A principal focus of the program is on the growth of higher plants in growth chambers. These crops should be grown without the risk of damage from microbial contamination. While it is unlikely that plant pathogens will pose a risk, there are serious hazards associated with microorganisms carried in the nutrient delivery systems and in the atmosphere of the growth chamber. Our experience in surface microbiology showed that colonization of surfaces with microorganisms is extremely rapid even when the inoculum is small. After initial colonization extensive biofilms accumulate on moist surfaces. These microbial films metabolize actively and slough off continuously to the air and water. During plant growth in the CELSS program, microbial biofilms have the potential to foul sensors and to plug nutrient delivery systems. In addition both metabolic products of microbial growth and degradation products of materials being considered for use as nutrient reservoirs and for delivery are likely sources of chemicals known to adversly affect plant growth.

  5. MICROBIAL SURFACTANTS IN ENVIRONMENTAL TECHNOLOGIES

    Directory of Open Access Journals (Sweden)

    T. P. Pirog

    2015-08-01

    Full Text Available It was shown literature and own experimental data concerning the use of microbial surface active glycolipids (rhamno-, sophoro- and trehalose lipids and lipopeptides for water and soil purification from oil and other hydrocarbons, removing toxic heavy metals (Cu2+, Cd2+, Ni2+, Pb2+, degradation of complex pollution (oil and other hydrocarbons with heavy metals, and the role of microbial surfactants in phytoremediation processes. The factors that limit the use of microbial surfactants in environmental technologies are discussed. Thus, at certain concentrations biosurfactant can exhibit antimicrobial properties and inhibit microorganisms destructing xenobiotics. Microbial biodegradability of surfactants may also reduce the effectiveness of bioremediation. Development of effective technologies using microbial surfactants should include the following steps: monitoring of contaminated sites to determine the nature of pollution and analysis of the autochthonous microbiota; determining the mode of surfactant introduction (exogenous addition of stimulation of surfactant synthesis by autochthonous microbiota; establishing an optimal concentration of surfactant to prevent exhibition of antimicrobial properties and rapid biodegradation; research both in laboratory and field conditions.

  6. Simultaneous inhibition of sulfate-reducing bacteria, removal of H2S and production of rhamnolipid by recombinant Pseudomonas stutzeri Rhl: Applications for microbial enhanced oil recovery.

    Science.gov (United States)

    Zhao, Feng; Zhou, Ji-Dong; Ma, Fang; Shi, Rong-Jiu; Han, Si-Qin; Zhang, Jie; Zhang, Ying

    2016-05-01

    Sulfate-reducing bacteria (SRB) are widely existed in oil production system, and its H2S product inhibits rhamnolipid producing bacteria. In-situ production of rhamnolipid is promising for microbial enhanced oil recovery. Inhibition of SRB, removal of H2S and production of rhamnolipid by recombinant Pseudomonas stutzeri Rhl were investigated. Strain Rhl can simultaneously remove S(2-) (>92%) and produce rhamnolipid (>136mg/l) under S(2-) stress below 33.3mg/l. Rhl reduced the SRB numbers from 10(9) to 10(5)cells/ml, and the production of H2S was delayed and decreased to below 2mg/l. Rhl also produced rhamnolipid and removed S(2-) under laboratory simulated oil reservoir conditions. High-throughput sequencing data demonstrated that addition of strain Rhl significantly changed the original microbial communities of oilfield production water and decreased the species and abundance of SRB. Bioaugmentation of strain Rhl in oilfield is promising for simultaneous control of SRB, removal of S(2-) and enhance oil recovery. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Magnolol Inhibits the Growth of Non-Small Cell Lung Cancer via Inhibiting Microtubule Polymerization

    Directory of Open Access Journals (Sweden)

    Jia Shen

    2017-07-01

    Full Text Available Background: The tubulin/microtubule system, which is an integral component of the cytoskeleton, plays an essential role in mitosis. Targeting mitotic progression by disturbing microtubule dynamics is a rational strategy for cancer treatment. Methods: Microtubule polymerization assay was performed to examine the effect of Magnolol (a novel natural phenolic compound isolated from Magnolia obovata on cellular microtubule polymerization in human non-small cell lung cancer (NSCLC cells. Cell cycle analysis, mitotic index assay, cell proliferation assay, colony formation assay, western blotting analysis of cell cycle regulators, Annexin V-FITC/PI staining, and live/dead viability staining were carried out to investigate the Magnolol’s inhibitory effect on proliferation and viability of NSCLS cells in vitro. Xenograft model of human A549 NSCLC tumor was used to determine the Magnolol’s efficacy in vivo. Results: Magnolol treatment effectively inhibited cell proliferation and colony formation of NSCLC cells. Further study proved that Magnolol induced the mitotic phase arrest and inhibited G2/M progression in a dose-dependent manner, which were mechanistically associated with expression alteration of a series of cell cycle regulators. Furthermore, Magnolol treatment disrupted the cellular microtubule organization via inhibiting the polymerization of microtubule. We also found treatment with NSCLC cells with Magnolol resulted in apoptosis activation through a p53-independent pathway, and autophgy induction via down-regulation of the Akt/mTOR pathway. Finally, Magnolol treatment significantly suppressed the NSCLC tumor growth in mouse xenograft model in vivo. Conclusion: These findings identify Magnolol as a promising candidate with anti-microtubule polymerization activity for NSCLC treatment.

  8. Iron inhibits hydroxyapatite crystal growth in vitro.

    Science.gov (United States)

    Guggenbuhl, Pascal; Filmon, Robert; Mabilleau, Guillaume; Baslé, Michel F; Chappard, Daniel

    2008-07-01

    Hemochromatosis is a known cause of osteoporosis in which the pathophysiology of bone loss is largely unknown and the role of iron remains questionable. We have investigated the effects of iron on the growth of hydroxyapatite crystals in vitro on carboxymethylated poly(2-hydroxyethyl methacrylate) pellets. This noncellular and enzyme-independent model mimics the calcification of woven bone (composed of calcospherites made of hydroxyapatite crystals). Polymer pellets were incubated with body fluid containing iron at increasing concentrations (20, 40, 60 micromol/L). Hydroxyapatite growth was studied by chemical analysis, scanning electron microscopy, and Raman microscopy. When incubated in body fluid containing iron, significant differences were observed with control pellets. Iron was detected at a concentration of 5.41- to 7.16-fold that of controls. In pellets incubated with iron, there was a approximately 3- to 4-fold decrease of Ca and P and a approximately 1.3- to 1.4-fold increase in the Ca/P ratio. There was no significant difference among the iron groups of pellets, but a trend to a decrease of Ca with the increase of iron concentration was noted. Calcospherite diameters were significantly lower on pellets incubated with iron. Raman microspectroscopy showed a decrease in crystallinity (measured by the full width of the half height of the 960 Deltacm(-1) band) with a significant increase in carbonate substitution (measured by the intensity ratio of 1071 to 960 Deltacm(-1) band). Energy dispersive x-ray analysis identified iron in the calcospherites. In vitro, iron is capable to inhibit bone crystal growth with significant changes in crystallinity and carbonate substitution.

  9. Microbial analysis of meatballs cooled with vacuum and conventional cooling.

    Science.gov (United States)

    Ozturk, Hande Mutlu; Ozturk, Harun Kemal; Koçar, Gunnur

    2017-08-01

    Vacuum cooling is a rapid evaporative cooling technique and can be used for pre-cooling of leafy vegetables, mushroom, bakery, fishery, sauces, cooked food, meat and particulate foods. The aim of this study was to apply the vacuum cooling and the conventional cooling techniques for the cooling of the meatball and to show the vacuum pressure effect on the cooling time, the temperature decrease and microbial growth rate. The results of the vacuum cooling and the conventional cooling (cooling in the refrigerator) were compared with each other for different temperatures. The study shows that the conventional cooling was much slower than the vacuum cooling. Moreover, the microbial growth rate of the vacuum cooling was extremely low compared with the conventional cooling. Thus, the lowest microbial growth occurred at 0.7 kPa and the highest microbial growth was observed at 1.5 kPa for the vacuum cooling. The mass loss ratio for the conventional cooling and vacuum cooling was about 5 and 9% respectively.

  10. Quercetin inhibits angiogenesis through thrombospondin-1 upregulation to antagonize human prostate cancer PC-3 cell growth in vitro and in vivo.

    Science.gov (United States)

    Yang, Feiya; Jiang, Xian; Song, Liming; Wang, Huiping; Mei, Zhu; Xu, Zhiqing; Xing, Nianzeng

    2016-03-01

    The rapid growth, morbidity and mortality of prostate cancer, and the lack of effective treatment have attracted great interests of researchers to find novel cancer therapies aiming to inhibit angiogenesis and tumor growth. Quercetin is a flavonoid compound that widely exists in the nature. Our previous study preliminarily demonstrated that quercetin effectively inhibited human prostate cancer cell xenograft tumor growth by inhibiting angiogenesis. Thrombospondin-1 (TSP-1) is the first reported endogenous anti-angiogenic factor that can inhibit angiogenesis and tumorigenesis. However, the relationship between quercetin inhibiting angiogenesis and TSP-1 upregulation in prostate cancer has not been determined. Thus, we explored the important role of TSP-1 upregulation in reducing angiogenesis and anti-prostate cancer effect of quercetin both in vitro and in vivo for the first time. After the selected doses were used for a certain time, quercetin i) significantly inhibited PC-3 and human umbilical vein endothelial cells (HUVECs) proliferation, migration and invasion in a dose-dependent manner; ⅱ) effectively inhibited prostate cancer PC-3 cell xenograft tumor growth by 37.5% with 75 mg/kg as compared to vehicle control group, more effective than 25 (22.85%) and 50 mg/kg (29.6%); ⅲ) was well tolerated by BALB/c mice and no obvious toxic reactions were observed; ⅳ) greatly reduced angiogenesis and led to higher TSP-1 protein and mRNA expression both in vitro and in vivo in a dose-dependent manner. Therefore, quercetin could increase TSP-1 expression to inhibit angiogenesis resulting in antagonizing prostate cancer PC-3 cell and xenograft tumor growth. The present study can lay a good basis for the subsequent concrete mechanism study and raise the possibility of applying quercetin to clinical for human prostate cancer in the near future.

  11. Inhibition of fungal growth with extreme low oxygen levels

    DEFF Research Database (Denmark)

    Nielsen, Per Væggemose; Haasum, Iben

    1998-01-01

    Fungal spoilage of foods is effectively controlled by removal of oxygen from the package, especially if this is combined with elevated carbon dioxide (CO2) levels. However, great uncertainty exist on just how low the residual oxygen levels in the package must be especially when carbon dioxide lev...... food with low CO2 levels. Active packaging with oxygen absorbers may be considered for these products. The packaging solution must also reflect the micro flora of the product.......Fungal spoilage of foods is effectively controlled by removal of oxygen from the package, especially if this is combined with elevated carbon dioxide (CO2) levels. However, great uncertainty exist on just how low the residual oxygen levels in the package must be especially when carbon dioxide...... Penicillia and Aspergilli were also inhibited by oxygen levels less than 0.5%, but less than 0.01% was required to efficiently inhibit these fungi. Most resistant to very low oxygen levels was the Fusarium species.These results shows that very low oxygen levels are required to avoid fungal growth in package...

  12. Bovine Lactoferrin and Lactoferrin-Derived Peptides Inhibit the Growth of Vibrio cholerae and Other Vibrio species

    Directory of Open Access Journals (Sweden)

    Erika Acosta-Smith

    2018-01-01

    Full Text Available Vibrio is a genus of Gram-negative bacteria, some of which can cause serious infectious diseases. Vibrio infections are associated with the consumption of contaminated food and classified in Vibrio cholera infections and non-cholera Vibrio infections. In the present study, we investigate whether bovine lactoferrin (bLF and several synthetic peptides corresponding to bLF sequences, are able to inhibit the growth or have bactericidal effect against V. cholerae and other Vibrio species. The antibacterial activity of LF and LF-peptides was assessed by kinetics of growth or determination of colony forming unit in bacteria treated with the peptides and antibiotics. To get insight in the mode of action, the interaction between bLF and bLF-peptides (coupled to FITC and V. cholera was evaluated. The damage of effector-induced bacterial membrane permeability was measured by inclusion of the fluorescent dye propidium iodide using flow cytometry, whereas the bacterial ultrastructural damage in bacteria treated was observed by transmission electron microscopy. The results showed that bLF and LFchimera inhibited the growth of the V. cholerae strains; LFchimera permeabilized the bacteria which membranes were seriously damaged. Assays with a multidrug-resistant strain of Vibrio species indicated that combination of sub-lethal doses of LFchimera with ampicillin or tetracycline strongly reduced the concentration of the antibiotics to reach 95% growth inhibition. Furthermore, LFchimera were effective to inhibit the V. cholerae counts and damage due to this bacterium in a model mice. These data suggest that LFchimera and bLF are potential candidates to combat the V. cholerae and other multidrug resistant Vibrio species.

  13. Bovine Lactoferrin and Lactoferrin-Derived Peptides Inhibit the Growth of Vibrio cholerae and Other Vibrio species

    Science.gov (United States)

    Acosta-Smith, Erika; Viveros-Jiménez, Karina; Canizalez-Román, Adrian; Reyes-Lopez, Magda; Bolscher, Jan G. M.; Nazmi, Kamran; Flores-Villaseñor, Hector; Alapizco-Castro, Gerardo; de la Garza, Mireya; Martínez-Garcia, Jesús J.; Velazquez-Roman, Jorge; Leon-Sicairos, Nidia

    2018-01-01

    Vibrio is a genus of Gram-negative bacteria, some of which can cause serious infectious diseases. Vibrio infections are associated with the consumption of contaminated food and classified in Vibrio cholera infections and non-cholera Vibrio infections. In the present study, we investigate whether bovine lactoferrin (bLF) and several synthetic peptides corresponding to bLF sequences, are able to inhibit the growth or have bactericidal effect against V. cholerae and other Vibrio species. The antibacterial activity of LF and LF-peptides was assessed by kinetics of growth or determination of colony forming unit in bacteria treated with the peptides and antibiotics. To get insight in the mode of action, the interaction between bLF and bLF-peptides (coupled to FITC) and V. cholera was evaluated. The damage of effector-induced bacterial membrane permeability was measured by inclusion of the fluorescent dye propidium iodide using flow cytometry, whereas the bacterial ultrastructural damage in bacteria treated was observed by transmission electron microscopy. The results showed that bLF and LFchimera inhibited the growth of the V. cholerae strains; LFchimera permeabilized the bacteria which membranes were seriously damaged. Assays with a multidrug-resistant strain of Vibrio species indicated that combination of sub-lethal doses of LFchimera with ampicillin or tetracycline strongly reduced the concentration of the antibiotics to reach 95% growth inhibition. Furthermore, LFchimera were effective to inhibit the V. cholerae counts and damage due to this bacterium in a model mice. These data suggest that LFchimera and bLF are potential candidates to combat the V. cholerae and other multidrug resistant Vibrio species. PMID:29375503

  14. Inhibition of growth hormone and prolactin secretion by a serine proteinase inhibitor

    International Nuclear Information System (INIS)

    Rappay, G.; Nagy, I.; Makara, G.B.; Horvath, G.; Karteszi, M.; Bacsy, E.; Stark, E.

    1984-01-01

    The action of the tripeptide aldehyde t-butyloxycarbonyl-DPhe-Pro-Arg-H (boc-fPR-H), belonging to a family of serine proteinase inhibitors, on the release of immunoreactive prolactin (iPRL) and growth hormone (iGH) has been studied. In rat anterior pituitary cell cultures and pituitary quarters 1 mM boc-fPR-H inhibited basal iPRL and iGH release. Thyroliberin-induced iPRL release by cultured cells was also markedly inhibited with a concomitant accumulation of intracellular iPRL. During the short- and long-term exposure of cells to boc-fPR-H there were no changes in total cell protein contents and in activities of some lysosomal marker enzymes. The marked inhibition of basal as well as stimulated hormone release in the presence of the enzyme inhibitor might suggest that at least a portion of the hormones is released via a proteolytic enzyme-dependent process

  15. Inhibition of a ubiquitously expressed pectin methyl esterase in Solanum tuberosum L. affects plant growth, leaf growth polarity, and ion partitioning.

    Science.gov (United States)

    Pilling, J; Willmitzer, L; Bücking, H; Fisahn, J

    2004-05-01

    Two pectin methyl esterases (PMEs; EC 3.1.1.11) from Solanum tuberosum were isolated and their expression characterised. One partial clone ( pest1) was expressed in leaves and fruit tissue, while pest2 was a functional full-length clone and was expressed ubiquitously, with a preference for aerial organs. Potato plants were transformed with a chimeric antisense construct that was designed to simultaneously inhibit pest1 and pest2 transcript accumulation; however, reduction of mRNA levels was confined to pest2. The decrease in pest2 transcript was accompanied by up to 50% inhibition of total PME activity, which was probably due to the reduction of only one PME isoform. PME inhibition affected plant development as reflected by smaller stem elongation rates of selected transformants when compared with control plants, leading to a reduction in height throughout the entire course of development. Expansion rates of young developing leaves were measured simultaneously by two displacement transducers in the direction of the leaf tip (proximal-distal axis) and in the perpendicular direction (medial-lateral axis). Significant differences in leaf growth patterns were detected between wild-type and transgenic plants. We suggest that these visual phenotypes could be correlated with modifications of ion accumulation and partitioning within the transgenic plants. The ion-binding capacities of cell walls from PME-inhibited plants were specifically modified as they preferentially bound more sodium, but less potassium and calcium. X-ray microanalysis also indicated an increase in the concentration of several ions within the leaf apoplast of transgenic plants. Moreover, quantification of the total content of major cations revealed differences specific for a given element between the leaves of PME-inhibited and wild-type plants. Reduced growth rates might also be due to effects of PME inhibition on pectin metabolism, predominantly illustrated by an accumulation of galacturonic acid

  16. SKLB188 inhibits the growth of head and neck squamous cell carcinoma by suppressing EGFR signalling.

    Science.gov (United States)

    Barzegar, Mansoureh; Ma, Shuang; Zhang, Chao; Chen, Xin; Gu, Ying; Shang, Chaowei; Jiang, Xiaojuan; Yang, Jiao; Nathan, Cherie-Ann; Yang, Shengyong; Huang, Shile

    2017-10-10

    Overexpression of epidermal growth factor receptor (EGFR) occurs in approximately 90% of head and neck squamous cell carcinoma (HNSCC), and is correlated with poor prognosis. Thus, targeting EGFR is a promising strategy for treatment of HNSCC. Several small molecule EGFR inhibitors have been tested in clinical trials for treatment of HNSCC, but none of them are more effective than the current chemotherapeutic drugs. Thus, it is urgently needed to develop novel EGFR inhibitors for HNSCC treatment. By screening an in-house focused library containing approximately 650 000 known kinase inhibitors and kinase inhibitor-like compounds containing common kinase inhibitor core scaffolds, we identified SKLB188 as a lead compound for inhibition of EGFR. The anticancer effects of SKLB188 on HNSCC cells were investigated by in vitro cell growth, cell cycle and apoptosis assays, as well as in vivo FaDu xenograft mouse model. Molecular docking, in vitro kinase profiling and western blotting were performed to characterise EGFR as the molecular target. SKLB188 inhibited HNSCC cell proliferation by inducing G 1 cell cycle arrest, which was associated with downregulating the expression of Cdc25A, cyclins D1/A and cyclin-dependent kinases (CDK2/4), and upregulating the expression of cyclin-dependent kinase (CDK) inhibitors (p21 Cip1 and p27 Kip1 ), leading to decreased phosphorylation of Rb. SKLB188 also induced caspase-dependent apoptosis of HNSCC cells by downregulating the expression of Mcl-1 and survivin. Molecular docking revealed that SKLB188 could bind to the kinase domain of EGFR through hydrogen bonds and hydrophobic interactions. In vitro kinase assay showed that SKLB188 inhibited the activity of a recombinant human EGFR very potently (IC 50 =5 nM). Western blot analysis demonstrated that SKLB188 inhibited the phosphorylation of EGFR and its downstream targets, extracellular signal-regulated protein kinases 1 and 2 (Erk1/2) and Akt in the cells. In addition, SKLB188 dose

  17. Prevention of microbial biofilms - the contribution of micro and nanostructured materials.

    Science.gov (United States)

    Grumezescu, Alexandru Mihai; Chifiriuc, Carmen Mariana

    2014-01-01

    Microbial biofilms are associated with drastically enhanced resistance to most of the antimicrobial agents and with frequent treatment failures, generating the search for novel strategies which can eradicate infections by preventing the persistent colonization of the hospital environment, medical devices or human tissues. Some of the current approaches for fighting biofilms are represented by the development of novel biomaterials with increased resistance to microbial colonization and by the improvement of the current therapeutic solutions with the aid of nano (bio)technology. This special issues includes papers describing the applications of nanotechnology and biomaterials science for the development of improved drug delivery systems and nanostructured surfaces for the prevention and treatment of medical biofilms. Nanomaterials display unique and well-defined physical and chemical properties making them useful for biomedical applications, such as: very high surface area to volume ratio, biocompatibility, biodegradation, safety for human ingestion, capacity to support surface modification and therefore, to be combined with other bioactive molecules or substrata and more importantly being seemingly not attracting antimicrobial resistance. The use of biomaterials is significantly contributing to the reduction of the excessive use of antibiotics, and consequently to the decrease of the emergence rate of resistant microorganisms, as well as of the associated toxic effects. Various biomaterials with intrinsic antimicrobial activity (inorganic nanoparticles, polymers, composites), medical devices for drug delivery, as well as factors influencing their antimicrobial properties are presented. One of the presented papers reviews the recent literature on the use of magnetic nanoparticles (MNP)-based nanomaterials in antimicrobial applications for biomedicine, focusing on the growth inhibition and killing of bacteria and fungi, and, on viral inactivation. The anti

  18. Growth inhibition and radiosensitization of Celecoxib in nasopharyngeal caricnoma cell line CNE-2

    International Nuclear Information System (INIS)

    Xu Xinhua; Yi Fang; Fu Xiangyang; Zhang Xiaohong; Wang Yanlin; Zhang Changju; Du Jingtao

    2009-01-01

    Objective: To investigate the growth inhibition and radiosensitization of Celecoxib in human nasopharyngeal carcinoma cell line CNE-2. Methods: CNE-2 growth inhibition by Celecoxib was evaluated by MTT method. Apoptosis-related changes in morphology were observed by transmission electron microscopy(TEM). Cell cycle distribution and apoptosis rate were measured by flowcytometry(FCM). The expression of COX-2 protein was observed by SP method after the treatment of Celecoxib. Cells were randomly planted into four groups: irradiation control (Ci), drug group (Cd), irradiation group (R), and Celecoxib plus irradiation group (D + R). Single irradiation of 2,4,6,8, and 10 Gy were administered for colonogenic assay. Cell cycle distribution and apoptosis rate were analyzed at 6 Gy irradiation. Results: The growth of CNE-2 cell was inhibited by celecoxib in a dose-and time-dependent manner, the IC 50 was 80 μmol/L. After the treatment, cell ratio of G 0 and G 1 phases wasinereased (47.03 ± 2.76 vs 56.17 ± 1.95, t=4.68, P=0.010), whereas the ratio of S and G 2 /M phases was decreased (33.07 ± 1.86 vs 24.87 ± 1.76, t=5.54,P =0.010;19.30 ± 0.53:17.73 ± 0.83, t=2.75, P=0.050), and the apoptosis rate was increased (1.57 ± 0.47:10.47 ± 0.31,t=27.39, P=0.000) in a dose-dependent manner. Apoptosis with nuclear chromatin condensation, fragmentation and cell shrinkage was found by TEM. SP method showed that Celeib decreased COX-2 expression (17.48 ± 0.34 vs 12.82 ± 0.51, t=13.20, P=0.00). The sensitivity ratio (D 0 ) was 1.15. FCM showed that the percentage of cells in G 2 /M phase was significanty more in R and D + R groups than in Ci and Cd groups (68.00 ± 1.65, 54.27 ± 5.74,17.60 ± 0.80,14.86 ± 1.23, t=47.70,P=0.000; t=11.63, P=0.000), and also significantly different between R group and D + R group (t=3.99, P= 0.020). The apoptosis rate was higher in R and D + R groups than Ci and Cd groups(4.83 ± 0.97,9.50 ± 1.35,1.33 ± 0.86 and 2.28 ± 0.42, t=4.67, P=0.010; t

  19. Phenobarbital indirectly activates the constitutive active androstane receptor (CAR) by inhibition of epidermal growth factor receptor signaling.

    Science.gov (United States)

    Mutoh, Shingo; Sobhany, Mack; Moore, Rick; Perera, Lalith; Pedersen, Lee; Sueyoshi, Tatsuya; Negishi, Masahiko

    2013-05-07

    Phenobarbital is a central nervous system depressant that also indirectly activates nuclear receptor constitutive active androstane receptor (CAR), which promotes drug and energy metabolism, as well as cell growth (and death), in the liver. We found that phenobarbital activated CAR by inhibiting epidermal growth factor receptor (EGFR) signaling. Phenobarbital bound to EGFR and potently inhibited the binding of EGF, which prevented the activation of EGFR. This abrogation of EGFR signaling induced the dephosphorylation of receptor for activated C kinase 1 (RACK1) at Tyr(52), which then promoted the dephosphorylation of CAR at Thr(38) by the catalytic core subunit of protein phosphatase 2A. The findings demonstrated that the phenobarbital-induced mechanism of CAR dephosphorylation and activation is mediated through its direct interaction with and inhibition of EGFR.

  20. Growth Inhibition of Cronobacter sakazakii in Experimentally Contaminated Powdered Infant Formula by Kefir Supernatant.

    Science.gov (United States)

    Kim, Dong-Hyeon; Chon, Jung-Whan; Kang, Il-Byeong; Kim, Hyunsook; Kim, Hong-Seok; Song, Kwang-Young; Seo, Kun-Ho

    2015-09-01

    Kefir is a type of fermented milk containing lactic and acetic acid bacteria and yeast. In this study, we evaluated the antimicrobial activity of kefir supernatant against Cronobacter sakazakii in powdered infant formula (PIF). In a spot-on-lawn test, the growth of 20 C. sakazakii strains, including 10 clinical and 10 food isolates, was completely inhibited in the presence of kefir supernatant. Significant differences in the diameters of inhibition zones were observed upon treatment with kefir compared with the results for Lactobacillus kefiri and Candida kefyr culture supernatants or solutions of lactic and acetic acid and ethyl alcohol in the agar well diffusion test (P < 0.05). The addition of 100 μl of kefir supernatant to 1 ml of nutrient broth completely inhibited the growth of C. sakazakii, as evaluated by spectrophotometry. The antimicrobial activity of kefir supernatant in experimentally contaminated PIF was also tested; we found no viable C. sakazakii cells remaining in PIF rehydrated with 30% kefir supernatant solution for 1 h, demonstrating that the antimicrobial activity of kefir supernatant against C. sakazakii could be applied in real food samples.

  1. A bi-paratopic anti-EGFR nanobody efficiently inhibits solid tumour growth

    Science.gov (United States)

    Roovers, Rob C.; Vosjan, Maria J.W.D.; Laeremans, Toon; el Khoulati, Rachid; de Bruin, Renée C.G.; Ferguson, Kathryn M.; Verkleij, Arie J.; van Dongen, Guus A.M.S.; van Bergen en Henegouwen, Paul M. P.

    2014-01-01

    The epidermal growth factor receptor (EGFR) has been shown to be a valid cancer target for antibody-based therapy. At present, several anti-EGFR monoclonal antibodies (mAbs) have been successfully used, among which cetuximab and matuzumab. X-ray crystallography data show that these antibodies bind to different epitopes on the ecto-domain of EGFR, providing a rationale for the combined use of these two antibody specificities. We have previously reported on the successful isolation of antagonistic anti-EGFR nanobodies. In the present study, we aimed to improve on these molecules by combining nanobodies with specificities similar to both cetuximab and matuzumab into a single bi-paratopic molecule. Carefully designed phage nanobody selections resulted in two sets of nanobodies that specifically blocked the binding of either matuzumab or of cetuximab to EGFR and that did not compete for each others binding. A combination of nanobodies from both epitope groups into the bi-paratopic nanobody CONAN-1 was shown to block EGFR activation more efficiently than monovalent or bivalent (monospecific) nanobodies. In addition, this bi-paratopic nanobody potently inhibited EGF-dependent cell proliferation. Importantly, in an in vivo model of athymic mice bearing A431 xenografts, CONAN-1 inhibited tumour outgrowth with an almost similar potency as the whole mAb cetuximab, despite the fact that CONAN-1 is devoid of an Fc portion that could mediate immune effector functions. Compared to therapy using bivalent, mono-specific nanobodies, CONAN-1 was clearly more potent in tumour growth inhibition. These results show that the rational design of bi-paratopic nanobody-based anti-cancer therapeutics may yield potent lead molecules for further development. PMID:21520037

  2. Co-inhibition of epidermal growth factor receptor and insulin-like growth factor receptor 1 enhances radiosensitivity in human breast cancer cells

    International Nuclear Information System (INIS)

    Li, Ping; Veldwijk, Marlon R; Zhang, Qing; Li, Zhao-bin; Xu, Wen-cai; Fu, Shen

    2013-01-01

    Over-expression of epidermal growth factor receptor (EGFR) or insulin-like growth factor-1 receptor (IGF-1R) have been shown to closely correlate with radioresistance of breast cancer cells. This study aimed to investigate the impact of co-inhibition of EGFR and IGF-1R on the radiosensitivity of two breast cancer cells with different profiles of EGFR and IGF-1R expression. The MCF-7 (EGFR +/−, IGF-1R +++) and MDA-MB-468 (EGFR +++, IGF-1R +++) breast cancer cell lines were used. Radiosensitizing effects were determined by colony formation assay. Apoptosis and cell cycle distribution were measured by flow cytometry. Phospho-Akt and phospho-Erk1/2 were quantified by western blot. In vivo studies were conducted using MDA-MB-468 cells xenografted in nu/nu mice. In MDA-MB-468 cells, the inhibition of IGF-1R upregulated the p-EGFR expression. Either EGFR (AG1478) or IGF-1R inhibitor (AG1024) radiosensitized MDA-MB-468 cells. In MCF-7 cells, radiosensitivity was enhanced by AG1024, but not by AG1478. Synergistical radiosensitizing effect was observed by co-inhibition of EGFR and IGF-1R only in MDA-MB-468 cells with a DMF 10% of 1.90. The co-inhibition plus irradiation significantly induced more apoptosis and arrested the cells at G0/G1 phase in MDA-MB-468 cells. Only co-inhibition of EGFR and IGF-1R synergistically diminished the expression of p-Akt and p-Erk1/2 in MDA-MB-468 cells. In vivo studies further verified the radiosensitizing effects by co-inhibition of both pathways in a MDA-MB-468 xenograft model. Our data suggested that co-inhibition of EGFR and IGF-1R synergistically radiosensitized breast cancer cells with both EGFR and IGF-1R high expression. The approach may have an important therapeutic implication in the treatment of breast cancer patients with high expression of EGFR and IGF-1R

  3. Inhibition of nucleation and growth of ice by poly(vinyl alcohol) in vitrification solution.

    Science.gov (United States)

    Wang, Hai-Yan; Inada, Takaaki; Funakoshi, Kunio; Lu, Shu-Shen

    2009-08-01

    Control of ice formation is crucial in cryopreservation of biological substances. Successful vitrification using several additives that inhibit ice nucleation in vitrification solutions has previously been reported. Among these additives, here we focused on a synthetic polymer, poly(vinyl alcohol) (PVA), and investigated the effects of PVA on nucleation and growth of ice in 35% (w/w) aqueous 1,2-propanediol solution by using a differential scanning calorimetry (DSC) system equipped with a cryomicroscope. First, the freezing temperature of the solution was measured using the DSC system, and then the change in ice fraction in the solution during cooling was evaluated based on images obtained using the cryomicroscope, at different concentrations of PVA between 0% and 3% (w/w). Based on the ice fraction, the change in residual solution concentration during cooling was also evaluated and then plotted on the state diagram of aqueous 1,2-propanediol solution. Results indicated that, when the partially glassy and partially frozen state was intentionally allowed, the addition of PVA effectively inhibited not only ice nucleation but also ice growth in the vitrification solution. The effect of PVA on ice growth in the vitrification solution was explained based on kinetic limitations mainly due to mass transport. The interfacial kinetics also might limit ice growth in the vitrification solution only when the ice growth rate decreased below a critical value. This coincides with the fact that PVA exhibits a unique antifreeze activity in the same manner as antifreeze proteins when ice growth rate is lower than a critical value.

  4. Bacterial Signaling Nucleotides Inhibit Yeast Cell Growth by Impacting Mitochondrial and Other Specifically Eukaryotic Functions

    Directory of Open Access Journals (Sweden)

    Andy Hesketh

    2017-07-01

    Full Text Available We have engineered Saccharomyces cerevisiae to inducibly synthesize the prokaryotic signaling nucleotides cyclic di-GMP (cdiGMP, cdiAMP, and ppGpp in order to characterize the range of effects these nucleotides exert on eukaryotic cell function during bacterial pathogenesis. Synthetic genetic array (SGA and transcriptome analyses indicated that, while these compounds elicit some common reactions in yeast, there are also complex and distinctive responses to each of the three nucleotides. All three are capable of inhibiting eukaryotic cell growth, with the guanine nucleotides exhibiting stronger effects than cdiAMP. Mutations compromising mitochondrial function and chromatin remodeling show negative epistatic interactions with all three nucleotides. In contrast, certain mutations that cause defects in chromatin modification and ribosomal protein function show positive epistasis, alleviating growth inhibition by at least two of the three nucleotides. Uniquely, cdiGMP is lethal both to cells growing by respiration on acetate and to obligately fermentative petite mutants. cdiGMP is also synthetically lethal with the ribonucleotide reductase (RNR inhibitor hydroxyurea. Heterologous expression of the human ppGpp hydrolase Mesh1p prevented the accumulation of ppGpp in the engineered yeast and restored cell growth. Extensive in vivo interactions between bacterial signaling molecules and eukaryotic gene function occur, resulting in outcomes ranging from growth inhibition to death. cdiGMP functions through a mechanism that must be compensated by unhindered RNR activity or by functionally competent mitochondria. Mesh1p may be required for abrogating the damaging effects of ppGpp in human cells subjected to bacterial infection.

  5. Inhibition of tomato shoot growth by over-irrigation is linked to nitrogen deficiency and ethylene.

    Science.gov (United States)

    Fiebig, Antje; Dodd, Ian C

    2016-01-01

    Although physiological effects of acute flooding have been well studied, chronic effects of suboptimal soil aeration caused by over-irrigation of containerized plants have not, despite its likely commercial significance. By automatically scheduling irrigation according to soil moisture thresholds, effects of over-irrigation on soil properties (oxygen concentration, temperature and moisture), leaf growth, gas exchange, phytohormone [abscisic acid (ABA) and ethylene] relations and nutrient status of tomato (Solanum lycopersicum Mill. cv. Ailsa Craig) were studied. Over-irrigation slowly increased soil moisture and decreased soil oxygen concentration by 4%. Soil temperature was approximately 1°C lower in the over-irrigated substrate. Over-irrigating tomato plants for 2 weeks significantly reduced shoot height (by 25%) and fresh weight and total leaf area (by 60-70%) compared with well-drained plants. Over-irrigation did not alter stomatal conductance, leaf water potential or foliar ABA concentrations, suggesting that growth inhibition was not hydraulically regulated or dependent on stomatal closure or changes in ABA. However, over-irrigation significantly increased foliar ethylene emission. Ethylene seemed to inhibit growth, as the partially ethylene-insensitive genotype Never ripe (Nr) was much less sensitive to over-irrigation than the wild type. Over-irrigation induced significant foliar nitrogen deficiency and daily supplementation of small volumes of 10 mM Ca(NO3 )2 to over-irrigated soil restored foliar nitrogen concentrations, ethylene emission and shoot fresh weight of over-irrigated plants to control levels. Thus reduced nitrogen uptake plays an important role in inhibiting growth of over-irrigated plants, in part by stimulating foliar ethylene emission. © 2015 Scandinavian Plant Physiology Society.

  6. Isthmin inhibits glioma growth through antiangiogenesis in vivo.

    Science.gov (United States)

    Yuan, Bangqing; Xian, Ronghua; Ma, Jianfang; Chen, Yujian; Lin, Chuangan; Song, Yaoming

    2012-09-01

    Among glioma treatment strategies, antiangiogenesis emerges as a meaningful and feasible treatment approach for inducing long-term survival. Isthmin is a gene highly expressed in the isthmus of the midbrain-hindbrain organizer in Xenopus, and has recently been identified as a novel angiogenesis inhibitor. However, the potential of isthmin on the glioma angiogenesis has not been well studied. In the present study, we demonstrated that the recombinant adenovirus isthmin (Ad-isthmin) could inhibit VEGF-stimulated endothelial cell proliferation and induce apoptosis through a caspase-dependent pathway. In addition, Ad-isthmin significantly suppressed glioma growth through antiangiogenesis without apparent side effects. Taken together, our results demonstrated that isthmin could act as a novel angiogenesis inhibitor and might be utilized in the glioma antiangiogenesis therapy.

  7. Role of microbial inoculation and industrial by-product phosphogypsum in growth and nutrient uptake of maize (Zea mays L.) grown in calcareous soil.

    Science.gov (United States)

    Al-Enazy, Abdul-Aziz R; Al-Oud, Saud S; Al-Barakah, Fahad N; Usman, Adel Ra

    2017-08-01

    Alkaline soils with high calcium carbonate and low organic matter are deficient in plant nutrient availability. Use of organic and bio-fertilizers has been suggested to improve their properties. Therefore, a greenhouse experiment was conducted to evaluate the integrative role of phosphogypsum (PG; added at 0.0, 10, 30, and 50 g PG kg -1 ), cow manure (CM; added at 50 g kg -1 ) and mixed microbial inoculation (Incl.; Azotobacter chroococcum, and phosphate-solubilizing bacteria Bacillus megaterium var. phosphaticum and Pseudomonas fluorescens) on growth and nutrients (N, P, K, Fe, Mn, Zn and Cu) uptake of maize (Zea mays L.) in calcareous soil. Treatment effects on soil chemical and biological properties and the Cd and Pb availability to maize plants were also investigated. Applying PG decreased soil pH. The soil available P increased when soil was inoculated and/or treated with CM, especially with PG. The total microbial count and dehydrogenase activity were enhanced with PG+CM+Incl. Inoculated soils treated with PG showed significant increases in NPK uptake and maize plant growth. However, the most investigated treatments showed significant decreases in shoot micronutrients. Cd and Pb were not detected in maize shoots. Applying PG with microbial inoculation improved macronutrient uptake and plant growth. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  8. Inhibition of Orobanche crenata seed germination and radicle growth by allelochemicals identified in cereals.

    Science.gov (United States)

    Fernández-Aparicio, Mónica; Cimmino, Alessio; Evidente, Antonio; Rubiales, Diego

    2013-10-16

    Orobanche crenata is a parasitic weed that causes severe yield losses in important grain and forage legume crops. Cereals have been reported to inhibit O. crenata parasitism when grown intercropped with susceptible legumes, but the responsible metabolites have not been identified. A number of metabolites have been reported in cereals that have allelopathic properties against weeds, pests, and pathogens. We tested the effect of several allelochemicals identified in cereals on O. crenata seed germination and radicle development. We found that 2-benzoxazolinone, its derivative 6-chloroacetyl-2-benzoxazolinone, and scopoletin significantly inhibited O. crenata seed germination. Benzoxazolinones, l-tryptophan, and coumalic acid caused the stronger inhibition of radicle growth. Also, other metabolites reduced radicle length, this inhibition being dose-dependent. Only scopoletin caused cell necrotic-like darkening in the young radicles. Prospects for their application to parasitic weed management are discussed.

  9. Calorimetric determination of inhibition of ice crystal growth by antifreeze protein in hydroxyethyl starch solutions.

    Science.gov (United States)

    Hansen, T N; Carpenter, J F

    1993-01-01

    Differential scanning calorimetry and cryomicroscopy were used to investigate the effects of type I antifreeze protein (AFP) from winter flounder on 58% solutions of hydroxyethyl starch. The glass, devitrification, and melt transitions noted during rewarming were unaffected by 100 micrograms/ml AFP. Isothermal annealing experiments were undertaken to detect the effects of AFP-induced inhibition of ice crystal growth using calorimetry. A premelt endothermic peak was detected during warming after the annealing procedure. Increasing the duration or the temperature of the annealing for the temperature range from -28 and -18 degrees C resulted in a gradual increase in the enthalpy of the premelt endotherm. This transition was unaffected by 100 micrograms/ml AFP. Annealing between -18 and -10 degrees C resulted in a gradual decrease in the premelt peak enthalpy. This process was inhibited by 100 micrograms/ml AFP. Cryomicroscopic examination of the samples revealed that AFP inhibited ice recrystallization during isothermal annealing at -10 degrees C. Annealing at lower temperatures resulted in minimal ice recrystallization and no visible effect of AFP. Thus, the 100 micrograms/ml AFP to have a detectable influence on thermal events in the calorimeter, conditions must be used that result in significant ice growth without AFP and visible inhibition of this process by AFP. Images FIGURE 8 PMID:7690257

  10. Growth inhibition of Chromatium D by L-methionine and its correlation to unusual accumulation of S-adenosyl-L-methionine in the cell

    Energy Technology Data Exchange (ETDEWEB)

    Sugimoto, Y; Nakatani, K; Shirakashi, T; Ohmori, H; Toraya, T [Kyoto Univ. (Japan). Faculty of Engineering

    1976-07-01

    L-Methionine strongly inhibited the growth of Chromatium D when added at a low concentration to the growth medium containing both sulfide and thiosulfate. S-Adenosyl-L-methionine inhibited the growth, irrespective of the coexistence of sulfide and thiosulfate. Upon addition of L-methionine to the growth media, the presence of both sulfide and thiosulfate in the media stimulated the in vivo conversion of L-methionine to S-adenosyl-L-methionine, and consequently increased the intracellular level of S-adenosyl-L-methionine. From these data, it was strongly suggested that the unusual accumulation of S-adenosyl-L-methionine in the cells of Chromatium D is responsible for the growth inhibition by L-methionine. The level of S-adenosyl-L-methionine synthetase (ATP: L-methionine S-adenosyltransferase, EC2.5.16) was significantly enhanced by adding L-methionine, sulfide and thiosulfate to the growth medium.

  11. Epidermal growth factor receptor-induced activato protein 1 activity controls density-dependent growht inhibition in normal rat kidney fibroblasts.

    NARCIS (Netherlands)

    Hornberg, J.J.; Dekker, H.; Peters, P.H.J.; Langerak, P.; Westerhoff, H.V.; Lankelma, J.; Zoelen, E.J.J.

    2006-01-01

    Density-dependent growth inhibition secures tissue homeostasis. Dysfunction of the mechanisms, which regulate this type of growth control is a major cause of neoplasia. In confluent normal rat kidney (NRK) fibroblasts, epidermal growth factor (EGF) receptor levels decline, ultimately rendering these

  12. Biotechnology in petroleum recovery. The microbial EOR

    Energy Technology Data Exchange (ETDEWEB)

    Sen, Ramkrishna [Department of Biotechnology, Indian Institute of Technology (IIT), Kharagpur, West Bengal 721302 (India)

    2008-12-15

    Biotechnology has played a significant role in enhancing crude oil recovery from the depleted oil reservoirs to solve stagnant petroleum production, after a three-stage recovery process employing mechanical, physical and chemical methods. Biotechnologically enhanced oil recovery processes, known as microbial enhanced oil recovery (MEOR), involve stimulating indigenous reservoir microbes or injecting specially selected consortia of natural bacteria into the reservoir to produce specific metabolic events that lead to improved oil recovery. This also involves flooding with oil recovery agents produced ex situ by industrial or pilot scale fermentation. This paper essentially reviews the operating mechanisms and the progress made in enhanced oil recovery through the use of microbes and their metabolic products. Improvement in oil recovery by injecting solvents and gases or by energizing the reservoir microflora to produce them in situ for carbonate rock dissolution and reservoir re-pressurization has been enunciated. The role of biosurfactants in oil mobilization through emulsification and that of biopolymers for selective plugging of oil-depleted zones and for biofilm formation have been delineated. The spoil sport played by sulfate-reducing bacteria (SRB) in MEOR has also been briefly reviewed. The importance of mathematical models used in predicting the applicability of an MEOR strategy and the microbial growth and transport has been qualitatively discussed. The results of some laboratory studies and worldwide field trials applying ex situ and in situ MEOR technologies were compiled and interpreted. However, the potential of the MEOR technologies has not been fully realized due to poor yield of the useful microbial metabolic products, growth inhibition by accumulated toxic metabolites and longer time of incubation. A complete evaluation and assessment of MEOR from an engineering standpoint based on economics, applicability and performance is required to further

  13. The effect of microbial inocula on the growth of black locust, Siberian elm and silver maple seedlings

    Directory of Open Access Journals (Sweden)

    Hajnal-Jafari Timea

    2014-01-01

    Full Text Available Growth and development of forest plants depend mostly on the soil microbial activity since no mineral or organic fertilizers are applied. Microbial processes can be activated and conditions for plants development improved with the introduction of selected microorganisms in the soil. With the aim of obtaining quality planting material in a shorter period of time, the effects of Azotobacter chroococcum and Streptomyces sp. on the early growth of black locust (Robinia pseudoacacia, Siberian elm (Ulmus pumila and silver-leaf maple (Acer dasycarpum were investigated in this study. Microorganisms were applied individually and in a mixture (1:1. Plant height was measured on the 90th, 120th and 180th day after planting. Plant diameter, as well as the number of actinomycetes and azotobacters was measured at the end of the vegetation period (180 days after planting. Applied microorganisms had a positive effect on the seedling height in all three plant species, with the best effect found in the black locust. Effectiveness of applied microorganisms on seedling diameter was the highest in the silver-leaf maple. The largest number of azotobacters was found in the rhizosphere of black locust. Number of microorganisms from both groups was increased in the inoculated variants. [Projekat Ministarstva nauke Republike Srbije, br. III 43002

  14. 40 CFR 798.5500 - Differential growth inhibition of repair proficient and repair deficient bacteria: “Bacterial DNA...

    Science.gov (United States)

    2010-07-01

    ... repair proficient and repair deficient bacteria: âBacterial DNA damage or repair tests.â 798.5500 Section... inhibition of repair proficient and repair deficient bacteria: “Bacterial DNA damage or repair tests.” (a... killing or growth inhibition of repair deficient bacteria in a set of repair proficient and deficient...

  15. Tracing and inhibiting growth of Staphylococcus aureus in barbecue cheese production after product recall.

    Science.gov (United States)

    Johler, S; Zurfluh, K; Stephan, R

    2016-05-01

    Staphylococcal food poisoning is one of the most prevalent causes of foodborne intoxication worldwide. It is caused by ingestion of enterotoxins formed by Staphylococcus aureus during growth in the food matrix. Following a recall of barbecue cheese due to the detection of staphylococcal enterotoxins in Switzerland in July 2015, we analyzed the production process of the respective dairy. Although most cheese-making processes involve acidification to inhibit the growth of pathogenic bacteria, barbecue cheese has to maintain a pH >6.0 to prevent undesired melting of the cheese. In addition, the dairy decided to retain the traditional manual production process of the barbecue cheese. In this study, therefore, we aimed to (1) trace Staph. aureus along the barbecue cheese production process, and (2) develop a sustainable strategy to inhibit growth of Staph. aureus and decrease the risk of staphylococcal food poisoning without changing the traditional production process. To this end, we traced Staph. aureus in a step-wise blinded process analysis on 4 different production days using spa (Staphylococcus protein A gene) typing, DNA microarray profiling, and pulsed-field gel electrophoresis analysis. We subsequently selected a new starter culture and used a model cheese production including a challenge test assay to assess its antagonistic effect on Staph. aureus growth, as well as its sensory and technological implications. We detected Staph. aureus in 30% (37/124) of the collected samples taken from the barbecue cheese production at the dairy. This included detection of Staph. aureus in the final product on all 4 production days, either after enrichment or using quantitative detection. We traced 2 enterotoxigenic Staph. aureus strains (t073/CC45 and t282/CC45) colonizing the nasal cavity and the forearms of the cheesemakers to the final product. In the challenge test assay, we were able to show that the new starter culture inhibited growth of Staph. aureus while meeting

  16. Human Sulfatase 2 inhibits in vivo tumor growth of MDA-MB-231 human breast cancer xenografts

    International Nuclear Information System (INIS)

    Peterson, Sarah M; Concino, Michael F; Liaw, Lucy; Martini, Paolo GV; Iskenderian, Andrea; Cook, Lynette; Romashko, Alla; Tobin, Kristen; Jones, Michael; Norton, Angela; Gómez-Yafal, Alicia; Heartlein, Michael W

    2010-01-01

    Extracellular human sulfatases modulate growth factor signaling by alteration of the heparin/heparan sulfate proteoglycan (HSPG) 6-O-sulfation state. HSPGs bind to numerous growth factor ligands including fibroblast growth factors (FGF), epidermal growth factors (EGF), and vascular endothelial growth factors (VEGF), and are critically important in the context of cancer cell growth, invasion, and metastasis. We hypothesized that sulfatase activity in the tumor microenvironment would regulate tumor growth in vivo. We established a model of stable expression of sulfatases in the human breast cancer cell line MDA-MB-231 and purified recombinant human Sulfatase 2 (rhSulf2) for exogenous administration. In vitro studies were performed to measure effects on breast cancer cell invasion and proliferation, and groups were statistically compared using Student's t-test. The effects of hSulf2 on tumor progression were tested using in vivo xenografts with two methods. First, MDA-MB-231 cells stably expressing hSulf1, hSulf2, or both hSulf1/hSulf2 were grown as xenografts and the resulting tumor growth and vascularization was compared to controls. Secondly, wild type MDA-MB-231 xenografts were treated by short-term intratumoral injection with rhSulf2 or vehicle during tumor growth. Ultrasound analysis was also used to complement caliper measurement to monitor tumor growth. In vivo studies were statistically analyzed using Student's t test. In vitro, stable expression of hSulf2 or administration of rhSulf2 in breast cancer cells decreased cell proliferation and invasion, corresponding to an inhibition of ERK activation. Stable expression of the sulfatases in xenografts significantly suppressed tumor growth, with complete regression of tumors expressing both hSulf1 and hSulf2 and significantly smaller tumor volumes in groups expressing hSulf1 or hSulf2 compared to control xenografts. Despite significant suppression of tumor volume, sulfatases did not affect vascular

  17. Pentose sugars inhibit metabolism and increase expression of an AgrD-type cyclic pentapeptide in Clostridium thermocellum.

    Science.gov (United States)

    Verbeke, Tobin J; Giannone, Richard J; Klingeman, Dawn M; Engle, Nancy L; Rydzak, Thomas; Guss, Adam M; Tschaplinski, Timothy J; Brown, Steven D; Hettich, Robert L; Elkins, James G

    2017-02-23

    Clostridium thermocellum could potentially be used as a microbial biocatalyst to produce renewable fuels directly from lignocellulosic biomass due to its ability to rapidly solubilize plant cell walls. While the organism readily ferments sugars derived from cellulose, pentose sugars from xylan are not metabolized. Here, we show that non-fermentable pentoses inhibit growth and end-product formation during fermentation of cellulose-derived sugars. Metabolomic experiments confirmed that xylose is transported intracellularly and reduced to the dead-end metabolite xylitol. Comparative RNA-seq analysis of xylose-inhibited cultures revealed several up-regulated genes potentially involved in pentose transport and metabolism, which were targeted for disruption. Deletion of the ATP-dependent transporter, CbpD partially alleviated xylose inhibition. A putative xylitol dehydrogenase, encoded by Clo1313_0076, was also deleted resulting in decreased total xylitol production and yield by 41% and 46%, respectively. Finally, xylose-induced inhibition corresponds with the up-regulation and biogenesis of a cyclical AgrD-type, pentapeptide. Medium supplementation with the mature cyclical pentapeptide also inhibits bacterial growth. Together, these findings provide new foundational insights needed for engineering improved pentose utilizing strains of C. thermocellum and reveal the first functional Agr-type cyclic peptide to be produced by a thermophilic member of the Firmicutes.

  18. Puerariae radix isoflavones and their metabolites inhibit growth and induce apoptosis in breast cancer cells

    International Nuclear Information System (INIS)

    Lin, Y.-J.; Hou, Y.C.; Lin, C.-H.; Hsu, Y.-A.; Sheu, Jim J.C.; Lai, C.-H.; Chen, B.-H.; Lee Chao, Pei-Dawn; Wan Lei; Tsai, F.-J.

    2009-01-01

    Puerariae radix (PR) is a popular natural herb and a traditional food in Asia, which has antithrombotic and anti-allergic properties and stimulates estrogenic activity. In the present study, we investigated the effects of the PR isoflavones puerarin, daidzein, and genistein on the growth of breast cancer cells. Our data revealed that after treatment with PR isoflavones, a dose-dependent inhibition of cell growth occurred in HS578T, MDA-MB-231, and MCF-7 cell lines. Results from cell cycle distribution and apoptosis assays revealed that PR isoflavones induced cell apoptosis through a caspase-3-dependent pathway and mediated cell cycle arrest in the G2/M phase. Furthermore, we observed that the serum metabolites of PR (daidzein sulfates/glucuronides) inhibited proliferation of the breast cancer cells at a 50% cell growth inhibition (GI 50 ) concentration of 2.35 μM. These results indicate that the daidzein constituent of PR can be metabolized to daidzein sulfates or daidzein glucuronides that exhibit anticancer activities. The protein expression levels of the active forms of caspase-9 and Bax in breast cancer cells were significantly increased by treatment with PR metabolites. These metabolites also increased the protein expression levels of p53 and p21. We therefore suggest that PR may act as a chemopreventive and/or chemotherapeutic agent against breast cancer by reducing cell viability and inducing apoptosis.

  19. Plant lectin can target receptors containing sialic acid, exemplified by podoplanin, to inhibit transformed cell growth and migration.

    Directory of Open Access Journals (Sweden)

    Jhon Alberto Ochoa-Alvarez

    Full Text Available Cancer is a leading cause of death of men and women worldwide. Tumor cell motility contributes to metastatic invasion that causes the vast majority of cancer deaths. Extracellular receptors modified by α2,3-sialic acids that promote this motility can serve as ideal chemotherapeutic targets. For example, the extracellular domain of the mucin receptor podoplanin (PDPN is highly O-glycosylated with α2,3-sialic acid linked to galactose. PDPN is activated by endogenous ligands to induce tumor cell motility and metastasis. Dietary lectins that target proteins containing α2,3-sialic acid inhibit tumor cell growth. However, anti-cancer lectins that have been examined thus far target receptors that have not been identified. We report here that a lectin from the seeds of Maackia amurensis (MASL with affinity for O-linked carbohydrate chains containing sialic acid targets PDPN to inhibit transformed cell growth and motility at nanomolar concentrations. Interestingly, the biological activity of this lectin survives gastrointestinal proteolysis and enters the cardiovascular system to inhibit melanoma cell growth, migration, and tumorigenesis. These studies demonstrate how lectins may be used to help develop dietary agents that target specific receptors to combat malignant cell growth.

  20. miR-449 overexpression inhibits papillary thyroid carcinoma cell growth by targeting RET kinase-β-catenin signaling pathway.

    Science.gov (United States)

    Li, Zongyu; Huang, Xin; Xu, Jinkai; Su, Qinghua; Zhao, Jun; Ma, Jiancang

    2016-10-01

    Papillary thyroid carcinoma (PTC) is the most common thyroid cancer and represent approximately 80% of all thyroid cancers. The present study is aimed to investigate the role of microRNA (miR)-449 in the progression of PTC. Our results revealed that miR-449 was underexpressed in the collected PTC specimens compared with non-cancerous PTC tissues. Overexpression of miR-449 induced a cell cycle arrest at G0/G1 phase and inhibited PTC cell growth in vitro. Further studies revealed that RET proto-oncogene (RET) is a novel miR-449 target, due to miR-449 bound directly to its 3'-untranslated region and miR-449 mimic reduced the protein expression of RET. Similar to the effects of miR-449 overexpression, RET downregulation inhibited cell growth, whereas RET overexpression reversed the inhibitive effect of miR-449 mimic. Furthermore, miR-449 overexpression inhibited the nuclear translocation of β-catenin and reduced the expression of several downstream genes, including c-Myc, cyclin D1, T cell-specific transcription factor (TCF) and lymphoid enhancer-binding factor 1 (LEF-1), and inactivated the β-catenin pathway in TPC-1 cells. Moreover, overexpression of β-catenin prevented miR-449-reduced cell cycle arrest and cell viability. In xenograft animal experiments, miR-449 overexpression effectively suppressed the tumor growth of PTC. Taken together, our research indicated that miR-449 functions as an anti-oncogene by targeting RET, and that miR-449 overexpression inhibited the growth of PTC by inactivating the β-catenin pathway. Thus, miR-449 may serve as a potential therapeutic strategy for the treatment of PTC.

  1. Calcite growth-rate inhibition by fulvic acids isolated from Big Soda Lake, Nevada, USA, The Suwannee River, Georgia, USA and by polycarboxylic acids

    Science.gov (United States)

    Reddy, Michael M.; Leenheer, Jerry

    2011-01-01

    Calcite crystallization rates are characterized using a constant solution composition at 25°C, pH=8.5, and calcite supersaturation (Ω) of 4.5 in the absence and presence of fulvic acids isolated from Big Soda Lake, Nevada (BSLFA), and a fulvic acid from the Suwannee River, Georgia (SRFA). Rates are also measured in the presence and absence of low-molar mass, aliphatic-alicyclic polycarboxylic acids (PCA). BSLFA inhibits calcite crystal-growth rates with increasing BSLFA concentration, suggesting that BSLFA adsorbs at growth sites on the calcite crystal surface. Calcite growth morphology in the presence of BSLFA differed from growth in its absence, supporting an adsorption mechanism of calcite-growth inhibition by BSLFA. Calcite growth-rate inhibition by BSLFA is consistent with a model indicating that polycarboxylic acid molecules present in BSLFA adsorb at growth sites on the calcite crystal surface. In contrast to published results for an unfractionated SRFA, there is dramatic calcite growth inhibition (at a concentration of 1 mg/L) by a SRFA fraction eluted by pH 5 solution from XAD-8 resin, indicating that calcite growth-rate inhibition is related to specific SRFA component fractions. A cyclic PCA, 1, 2, 3, 4, 5, 6-cyclohexane hexacarboxylic acid (CHXHCA) is a strong calcite growth-rate inhibitor at concentrations less than 0.1 mg/L. Two other cyclic PCAs, 1, 1 cyclopentanedicarboxylic acid (CPDCA) and 1, 1 cyclobutanedicarboxylic acid (CBDCA) with the carboxylic acid groups attached to the same ring carbon atom, have no effect on calcite growth rates up to concentrations of 10 mg/L. Organic matter ad-sorbed from the air onto the seed crystals has no effect on the measured calcite crystal-growth rates.

  2. Microbial Inoculants and Their Impact on Soil Microbial Communities: A Review

    Directory of Open Access Journals (Sweden)

    Darine Trabelsi

    2013-01-01

    Full Text Available The knowledge of the survival of inoculated fungal and bacterial strains in field and the effects of their release on the indigenous microbial communities has been of great interest since the practical use of selected natural or genetically modified microorganisms has been developed. Soil inoculation or seed bacterization may lead to changes in the structure of the indigenous microbial communities, which is important with regard to the safety of introduction of microbes into the environment. Many reports indicate that application of microbial inoculants can influence, at least temporarily, the resident microbial communities. However, the major concern remains regarding how the impact on taxonomic groups can be related to effects on functional capabilities of the soil microbial communities. These changes could be the result of direct effects resulting from trophic competitions and antagonistic/synergic interactions with the resident microbial populations, or indirect effects mediated by enhanced root growth and exudation. Combination of inoculants will not necessarily produce an additive or synergic effect, but rather a competitive process. The extent of the inoculation impact on the subsequent crops in relation to the buffering capacity of the plant-soil-biota is still not well documented and should be the focus of future research.

  3. Dietary microbial phytase exerts mixed effects on the gut health of tilapia: a possible reason for the null effect on growth promotion.

    Science.gov (United States)

    Hu, Jun; Ran, Chao; He, Suxu; Cao, Yanan; Yao, Bin; Ye, Yuantu; Zhang, Xuezhen; Zhou, Zhigang

    2016-06-01

    The present study evaluated the effects of dietary microbial phytase on the growth and gut health of hybrid tilapia (Oreochromis niloticus ♀×Oreochromis aureus ♂), focusing on the effect on intestinal histology, adhesive microbiota and expression of immune-related cytokine genes. Tilapia were fed either control diet or diet supplemented with microbial phytase (1000 U/kg). Each diet was randomly assigned to four groups of fish reared in cages (3×3×2 m). After 12 weeks of feeding, weight gain and feed conversion ratio of tilapia were not significantly improved by dietary microbial phytase supplementation. However, significantly higher level of P content in the scales, tighter and more regular intestinal mucosa folds were observed in the microbial phytase group and the microvilli density was significantly increased. The adhesive gut bacterial communities were strikingly altered by microbial phytase supplementation (0·41phytase, as indicated by the up-regulated intestinal expressions of the cytokine genes (tnf-α and tgf-β) and hsp70. In addition, the gut microvilli height was significantly decreased in the phytase group. These results indicate that dietary microbial phytase may exert mixed effects on hybrid tilapia, and can guide our future selection of phytases as aquafeed additives - that is, eliminating those that can stimulate intestinal inflammation.

  4. Bacteria isolated from bats inhibit the growth of Pseudogymnoascus destructans, the causative agent of white-nose syndrome.

    Science.gov (United States)

    Hoyt, Joseph R; Cheng, Tina L; Langwig, Kate E; Hee, Mallory M; Frick, Winifred F; Kilpatrick, A Marm

    2015-01-01

    Emerging infectious diseases are a key threat to wildlife. Several fungal skin pathogens have recently emerged and caused widespread mortality in several vertebrate groups, including amphibians, bats, rattlesnakes and humans. White-nose syndrome, caused by the fungal skin pathogen Pseudogymnoascus destructans, threatens several hibernating bat species with extinction and there are few effective treatment strategies. The skin microbiome is increasingly understood to play a large role in determining disease outcome. We isolated bacteria from the skin of four bat species, and co-cultured these isolates with P. destructans to identify bacteria that might inhibit or kill P. destructans. We then conducted two reciprocal challenge experiments in vitro with six bacterial isolates (all in the genus Pseudomonas) to quantify the effect of these bacteria on the growth of P. destructans. All six Pseudomonas isolates significantly inhibited growth of P. destructans compared to non-inhibitory control bacteria, and two isolates performed significantly better than others in suppressing P. destructans growth for at least 35 days. In both challenge experiments, the extent of suppression of P. destructans growth was dependent on the initial concentration of P. destructans and the initial concentration of the bacterial isolate. These results show that bacteria found naturally occurring on bats can inhibit the growth of P. destructans in vitro and should be studied further as a possible probiotic to protect bats from white-nose syndrome. In addition, the presence of these bacteria may influence disease outcomes among individuals, populations, and species.

  5. Bacteria isolated from bats inhibit the growth of Pseudogymnoascus destructans, the causative agent of white-nose syndrome.

    Directory of Open Access Journals (Sweden)

    Joseph R Hoyt

    Full Text Available Emerging infectious diseases are a key threat to wildlife. Several fungal skin pathogens have recently emerged and caused widespread mortality in several vertebrate groups, including amphibians, bats, rattlesnakes and humans. White-nose syndrome, caused by the fungal skin pathogen Pseudogymnoascus destructans, threatens several hibernating bat species with extinction and there are few effective treatment strategies. The skin microbiome is increasingly understood to play a large role in determining disease outcome. We isolated bacteria from the skin of four bat species, and co-cultured these isolates with P. destructans to identify bacteria that might inhibit or kill P. destructans. We then conducted two reciprocal challenge experiments in vitro with six bacterial isolates (all in the genus Pseudomonas to quantify the effect of these bacteria on the growth of P. destructans. All six Pseudomonas isolates significantly inhibited growth of P. destructans compared to non-inhibitory control bacteria, and two isolates performed significantly better than others in suppressing P. destructans growth for at least 35 days. In both challenge experiments, the extent of suppression of P. destructans growth was dependent on the initial concentration of P. destructans and the initial concentration of the bacterial isolate. These results show that bacteria found naturally occurring on bats can inhibit the growth of P. destructans in vitro and should be studied further as a possible probiotic to protect bats from white-nose syndrome. In addition, the presence of these bacteria may influence disease outcomes among individuals, populations, and species.

  6. Optimal design of multistage chemostats in series using different microbial growth kinetics

    Energy Technology Data Exchange (ETDEWEB)

    Qasim, Muhammad [Petroleum Engineering Technology, Abu Dhabi Polytechnic (United Arab Emirates)

    2013-07-01

    In this paper, the optimum design of multistage chemostats (CSTRs) was investigated. The optimal design was based on the minimum overall reactor volume using different volume for each chemostat. The paper investigates three different microbial growth kinetics; Monod kinetics, Contois kinetics and the Logistic equation. The total dimensionless residence time (theta Total) was set as the optimization objective function that was minimized by varying the intermediate dimensionless substrate concentration (alfa i). The effect of inlet substrate concentration (S0) to the first reactor on the optimized total dimensionless residence time was investigated at a constant conversion of 0.90. In addition, the effect of conversion on the optimized total dimensionless residence time was also investigated at constant inlet substrate concentration (S0). For each case, optimization was done using up to five chemostats in series.

  7. UV-B inhibition of hypocotyl growth in etiolated Arabidopsis thaliana seedlings is a consequence of cell cycle arrest initiated by photodimer accumulation

    Science.gov (United States)

    Biever, Jessica J.; Brinkman, Doug; Gardner, Gary

    2014-01-01

    Ultraviolet (UV) radiation is an important constituent of sunlight that determines plant morphology and growth. It induces photomorphogenic responses but also causes damage to DNA. Arabidopsis mutants of the endonucleases that function in nucleotide excision repair, xpf-3 and uvr1-1, showed hypersensitivity to UV-B (280–320nm) in terms of inhibition of hypocotyl growth. SOG1 is a transcription factor that functions in the DNA damage signalling response after γ-irradiation. xpf mutants that carry the sog1-1 mutation showed hypocotyl growth inhibition after UV-B irradiation similar to the wild type. A DNA replication inhibitor, hydroxyurea (HU), also inhibited hypocotyl growth in etiolated seedlings, but xpf-3 was not hypersensitive to HU. UV-B irradiation induced accumulation of the G2/M-specific cell cycle reporter construct CYCB1;1-GUS in wild-type Arabidopsis seedlings that was consistent with the expected accumulation of photodimers and coincided with the time course of hypocotyl growth inhibition after UV-B treatment. Etiolated mutants of UVR8, a recently described UV-B photoreceptor gene, irradiated with UV-B showed inhibition of hypocotyl growth that was not different from that of the wild type, but they lacked UV-B-specific expression of chalcone synthase (CHS), as expected from previous reports. CHS expression after UV-B irradiation was not different in xpf-3 compared with the wild type, nor was it altered after HU treatment. These results suggest that hypocotyl growth inhibition by UV-B light in etiolated Arabidopsis seedlings, a photomorphogenic response, is dictated by signals originating from UV-B absorption by DNA that lead to cell cycle arrest. This process occurs distinct from UVR8 and its signalling pathway responsible for CHS induction. PMID:24591052

  8. Dietary rice bran component γ-oryzanol inhibits tumor growth in tumor-bearing mice.

    Science.gov (United States)

    Kim, Sung Phil; Kang, Mi Young; Nam, Seok Hyun; Friedman, Mendel

    2012-06-01

    We investigated the effects of rice bran and components on tumor growth in mice. Mice fed standard diets supplemented with rice bran, γ-oryzanol, Ricetrienol®, ferulic acid, or phytic acid for 2 weeks were inoculated with CT-26 colon cancer cells and fed the same diet for two additional weeks. Tumor mass was significantly lower in the γ-oryzanol and less so in the phytic acid group. Tumor inhibition was associated with the following biomarkers: increases in cytolytic activity of splenic natural killer (NK) cells; partial restoration of nitric oxide production and phagocytosis in peritoneal macrophages increases in released the pro-inflammatory cytokines tumor necrosis factor-α, IL-1β, and IL-6 from macrophages; and reductions in the number of blood vessels inside the tumor. Pro-angiogenic biomarkers vascular endothelial growth factor (VEGF), cyclooxygenase-2 (COX-2), and 5-lipoxygenase-5 (5-LOX) were also significantly reduced in mRNA and protein expression by tumor genes. ELISA of tumor cells confirmed reduced expression of COX-2 and 5-LOX up to 30%. Reduced COX-2 and 5-LOX expression downregulated VEGF and inhibited neoangiogenesis inside the tumors. Induction of NK activity, activation of macrophages, and inhibition of angiogenesis seem to contribute to the inhibitory mechanism of tumor regression by γ-oryzanol. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. [Soil organic pollution characteristics and microbial properties in coal mining areas of Mentougou].

    Science.gov (United States)

    Jia, Jian-Li; Zhang, Yue; Wang, Chen; Li, Dong; Liu, Bo-Wen; Liu, Ying; Zhao, Le; Yang, Si-Qi

    2011-03-01

    Soil micro-ecosystem including organic pollution characteristics, basic physicochemical parameters, and microbial properties was analyzed which contaminated with organic pollutants in coal mining area. Results showed that the organic pollution level in coal mining area soils distributed from 0.4 to 1.5 mg/g dry soil, which was 1. 5-6 times as much as the background sample. Furthermore, the column chromatography and GC-MS analysis revealed that content of lightly components including saturated and aromatic hydrocarbons exceeded 40%, specifically was alkenes (> C15), hydrocarbon derivatives, and a small amount aromatic hydrocarbons. Totally, the components of organic pollutants extracted in soils were similar to which in coal gangue samples, illustrating the source of soil pollution to a certain extent in coal mining areas. The physicochemical factors such as nutrient level and moisture contents were not conducive to the growth and reproduction of microbe except pH level, which might show inhibition to microbial activities. Microbial density of pollutant soils in coal mining areas was totally low, with specific amount 10(4)-10(5) cell/g dry soil and FDA activity 2.0-2.9 mg/(g x min). Generally, the microbial density and activity were decreased as the enhancing pollution level. However, in-depth analysis was needed urgently because of the complex impact of environmental conditions like pH, moisture, and nutrition.

  10. A New Flavanone from Flemingia strobilifera (Linn) R. Br. and its ...

    African Journals Online (AJOL)

    elearning

    drugs vancomycin, linezolid, fluconazole and itraconazole were defined as the lowest concentration of drug that resulted in total inhibition of microbial growth. The MIC was defined as the minimum inhibitory concentration of the extract or compound that resulted in total inhibition of microbial growth. RESULTS. The. DCM.

  11. Nonsteroidal Anti-inflammatory Drugs (NSAIDS) Inhibit the Growth and Reproduction of Chaetomium globosum and Other Fungi Associated with Water-Damaged Buildings.

    Science.gov (United States)

    Dalmont, Kelsey; Biles, Charles L; Konsure, Heather; Dahal, Sujita; Rowsey, Tyler; Broge, Matthew; Poudyal, Shubhra; Gurung, Tara; Shrestha, Sabina; Biles, Caleb L; Cluck, Terry; Howard, Alisha

    2017-12-01

    Indoor mold due to water damage causes serious human respiratory disorders, and the remediation to homes, schools, and businesses is a major expense. Prevention of mold infestation of building materials would reduce health problems and building remediation costs. Nonsteroidal anti-inflammatory drugs (NSAIDs) inhibit yeasts and a limited number of filamentous fungi. The purpose of this research was to determine the possible inhibitory activity of nonsteroidal anti-inflammatory drugs (NSAIDs) on germination, fungal growth, and reproduction of Chaetomium globosum and other important filamentous fungi that occur in water-damaged buildings. Several NSAIDs were found to inhibit C. globosum germination, growth, and reproduction. The most effective NSAIDs inhibiting C. globosum were ibuprofen, diflunisal, and diclofenac. Fusarium oxysporum, Fusarium solani, Aspergillus niger, and Stachybotrys atra were also tested on the various media with similar results obtained. However, F. oxysporum and A. niger exhibited a higher level of resistance to aspirin and NaSAL when compared to the C. globosum isolates. The inhibition exhibited by NSAIDs was variable depending on growth media and stage of fungal development. These compounds have a great potential of inhibiting fungal growth on building materials such as gypsum board. Formulations of sprays or building materials with NSAID-like chemical treatments may hold promise in reducing mold in homes and buildings.

  12. Raman spectrum reveals Mesenchymal stem cells inhibiting HL60 cells growth

    Science.gov (United States)

    Su, Xin; Fang, Shaoyin; Zhang, Daosen; Zhang, Qinnan; Lu, Xiaoxu; Tian, Jindong; Fan, Jinping; Zhong, Liyun

    2017-04-01

    Though some research results reveals that Mesenchymal stem cells (MSCs) have the ability of inhibiting tumor cells proliferation, it remains controversial about the precise interaction mechanism during MSCs and tumor cells co-culture. In this study, combing Raman spectroscopic data and principle component analysis (PCA), the biochemical changes of MSCs or Human promyelocytic leukemia (HL60) cells during their co-culture were presented. The obtained results showed that some main Raman peaks of HL60 assigned to nucleic acids or proteins were greatly higher in intensity in the late stage of co-culture than those in the early stage of co-culture while they were still lower relative to the control group, implicating that the effect of MSCs inhibiting HL60 proliferation appeared in the early stage but gradually lost the inhibiting ability in the late stage of co-culture. Moreover, some other peaks of HL60 assigned to proteins were decreased in intensity in the early stage of co-culture relative to the control group but rebounded to the level similar to the control group in the late stage, showing that the content and structure changes of these proteins might be generated in the early stage but returned to the original state in the late stage of co-culture. As a result, in the early stage of MSCs-HL60 co-culture, along with the level of Akt phosphorylation of HL60 was lowered relative to its control group, the proliferation rate of HL60 cells was decreased. And in the late stage of co-culture, along with the level of Akt phosphorylation was rebounded, the reverse transfer of Raman peaks within 875-880 cm- 1 appeared, thus MSCs lost the ability to inhibit HL60 growth and HL60 proliferation was increased. In addition, it was observed that the peak at 811 cm- 1, which is a marker of RNA, was higher in intensity in the late stage than that in the control group, indicating that MSCs might be differentiated into myofibroblast-like MSCs. In addition, PCA results also exhibited

  13. A fermented meat model system for studies of microbial aroma formation

    DEFF Research Database (Denmark)

    Tjener, Karsten; Stahnke, Louise Heller; Andersen, L.

    2003-01-01

    A fermented meat model system was developed, by which microbial formation of volatiles could be examined The model was evaluated against dry, fermented sausages with respect to microbial growth, pH and volatile profiles. Fast and slowly acidified sausages and models were produced using the starte......H, microbial growth and volatile profiles was similar to sausage production. Based on these findings, the model system was considered valid for studies of aroma formation of meat cultures for fermented sausage.......A fermented meat model system was developed, by which microbial formation of volatiles could be examined The model was evaluated against dry, fermented sausages with respect to microbial growth, pH and volatile profiles. Fast and slowly acidified sausages and models were produced using the starter...... cultures Pediococcus pentosaceus and Staphylococcus xylosus. Volatiles were collected and analysed by dynamic headspace sampling and GC MS. The analysis was primarily focused on volatiles arising from amino acid degradation and a total of 24 compounds, of which 19 were quantified, were used...

  14. Elemental economy: microbial strategies for optimizing growth in the face of nutrient limitation.

    Science.gov (United States)

    Merchant, Sabeeha S; Helmann, John D

    2012-01-01

    Microorganisms play a dominant role in the biogeochemical cycling of nutrients. They are rightly praised for their facility for fixing both carbon and nitrogen into organic matter, and microbial driven processes have tangibly altered the chemical composition of the biosphere and its surrounding atmosphere. Despite their prodigious capacity for molecular transformations, microorganisms are powerless in the face of the immutability of the elements. Limitations for specific elements, either fleeting or persisting over eons, have left an indelible trace on microbial genomes, physiology, and their very atomic composition. We here review the impact of elemental limitation on microbes, with a focus on selected genetic model systems and representative microbes from the ocean ecosystem. Evolutionary adaptations that enhance growth in the face of persistent or recurrent elemental limitations are evident from genome and proteome analyses. These range from the extreme (such as dispensing with a requirement for a hard to obtain element) to the extremely subtle (changes in protein amino acid sequences that slightly, but significantly, reduce cellular carbon, nitrogen, or sulfur demand). One near-universal adaptation is the development of sophisticated acclimation programs by which cells adjust their chemical composition in response to a changing environment. When specific elements become limiting, acclimation typically begins with an increased commitment to acquisition and a concomitant mobilization of stored resources. If elemental limitation persists, the cell implements austerity measures including elemental sparing and elemental recycling. Insights into these fundamental cellular properties have emerged from studies at many different levels, including ecology, biological oceanography, biogeochemistry, molecular genetics, genomics, and microbial physiology. Here, we present a synthesis of these diverse studies and attempt to discern some overarching themes. Copyright © 2012

  15. Structural specificity of chloroquine-hematin binding related to inhibition of hematin polymerization and parasite growth.

    Science.gov (United States)

    Vippagunta, S R; Dorn, A; Matile, H; Bhattacharjee, A K; Karle, J M; Ellis, W Y; Ridley, R G; Vennerstrom, J L

    1999-11-04

    Considerable data now support the hypothesis that chloroquine (CQ)-hematin binding in the parasite food vacuole leads to inhibition of hematin polymerization and parasite death by hematin poisoning. To better understand the structural specificity of CQ-hematin binding, 13 CQ analogues were chosen and their hematin binding affinity, inhibition of hematin polymerization, and inhibition of parasite growth were measured. As determined by isothermal titration calorimetry (ITC), the stoichiometry data and exothermic binding enthalpies indicated that, like CQ, these analogues bind to two or more hematin mu-oxo dimers in a cofacial pi-pi sandwich-type complex. Association constants (K(a)'s) ranged from 0.46 to 2.9 x 10(5) M(-1) compared to 4.0 x 10(5) M(-1) for CQ. Remarkably, we were not able to measure any significant interaction between hematin mu-oxo dimer and 11, the 6-chloro analogue of CQ. This result indicates that the 7-chloro substituent in CQ is a critical structural determinant in its binding affinity to hematin mu-oxo dimer. Molecular modeling experiments reinforce the view that the enthalpically favorable pi-pi interaction observed in the CQ-hematin mu-oxo dimer complex derives from a favorable alignment of the out-of-plane pi-electron density in CQ and hematin mu-oxo dimer at the points of intermolecular contact. For 4-aminoquinolines related to CQ, our data suggest that electron-withdrawing functional groups at the 7-position of the quinoline ring are required for activity against both hematin polymerization and parasite growth and that chlorine substitution at position 7 is optimal. Our results also confirm that the CQ diaminoalkyl side chain, especially the aliphatic tertiary nitrogen atom, is an important structural determinant in CQ drug resistance. For CQ analogues 1-13, the lack of correlation between K(a) and hematin polymerization IC(50) values suggests that other properties of the CQ-hematin mu-oxo dimer complex, rather than its association

  16. SL-01, an oral derivative of gemcitabine, inhibited human breast cancer growth through induction of apoptosis

    International Nuclear Information System (INIS)

    Li, Yuan-Yuan; Qin, Yi-Zhuo; Wang, Rui-Qi; Li, Wen-Bao; Qu, Xian-Jun

    2013-01-01

    Highlights: •SL-01 is an oral derivative of gemcitabine. •SL-01 possessed activity against human breast cancer growth via apoptotic induction. •SL-01’s activity was more potently than that of gemcitabine. •SL-01 inhibited cancer growth without toxicity to mice. -- Abstract: SL-01 is an oral derivative of gemcitabine that was synthesized by introducing the moiety of 3-(dodecyloxycarbonyl) pyrazine-2-carbonyl at N4-position on cytidine ring of gemcitabine. We aimed to evaluate the efficacy of SL-01 on human breast cancer growth. SL-01 significantly inhibited MCF-7 proliferation as estimated by colorimetric assay. Flow cytometry assay indicated the apoptotic induction and cell cycle arrest in G1 phase. SL-01 modulated the expressions of p-ATM, p53 and p21 and decrease of cyclin D1 in MCF-7 cells. Further experiments were performed in a MCF-7 xenografts mouse model. SL-01 by oral administration strongly inhibited MCF-7 xenografts growth. This effect of SL-01 might arise from its roles in the induction of apoptosis. Immunohistochemistry assay showed the increase of TUNEL staining cells. Western blotting indicated the modulation of apoptotic proteins in SL-01-treated xenografts. During the course of study, there was no evidence of toxicity to mice. In contrast, the decrease of neutrophil cells in peripheral and increase of AST and ALT levels in serum were observed in the gemcitabine-treated mice. Conclusion: SL-01 possessed similar activity against human breast cancer growth with gemcitabine, whereas, with lower toxicity to gemcitabine. SL-01 is a potent oral agent that may supplant the use of gemcitabine

  17. Chemotaxis-growth under the influence of lateral inhibition in a three-component reaction–diffusion system

    International Nuclear Information System (INIS)

    Kawaguchi, Satoshi

    2011-01-01

    In this study, we consider the effects of chemotaxis and lateral inhibition on an activator in a three-component reaction–diffusion system. Simulation results show that spot, planar and travelling front solutions in two dimensions are destabilized to form multibranch patterns. In order to analyse the stability of stationary solutions, a singular perturbation method is employed. The bifurcation diagrams suggest that chemotaxis and lateral inhibition cooperatively result in the destabilization of the stationary solutions. Our three-component model is compared with the two-component chemotaxis-growth model. Furthermore, the conditions for observing the cooperative effects of chemotaxis and lateral inhibition on an activator in experiments are inferred from the model

  18. Soil microbial community response to land use and various soil ...

    African Journals Online (AJOL)

    Soil microbial community response to land use and various soil elements in a city landscape of north China. ... African Journal of Biotechnology ... Legumes played an important role in stimulating the growth and reproduction of various soil microbial populations, accordingly promoting the microbial catabolic activity.

  19. Dynamics of culturable soil microbial communities during ...

    African Journals Online (AJOL)

    Ecological zones impacted significantly (P < 0.05) on bacterial proliferation, but not on fungal growth. Sampling period significantly (P < 0.05) affected microbial density and the semi-arid agroecozone was more supportive of microbial proliferation than the arid zone. A total of nine predominant fungal species belonging to ...

  20. Belinostat-induced apoptosis and growth inhibition in pancreatic cancer cells involve activation of TAK1-AMPK signaling axis

    International Nuclear Information System (INIS)

    Wang, Bing; Wang, Xin-bao; Chen, Li-yu; Huang, Ling; Dong, Rui-zen

    2013-01-01

    Highlights: •Belinostat activates AMPK in cultured pancreatic cancer cells. •Activation of AMPK is important for belinostat-induced cytotoxic effects. •ROS and TAK1 are involved in belinostat-induced AMPK activation. •AMPK activation mediates mTOR inhibition by belinostat. -- Abstract: Pancreatic cancer accounts for more than 250,000 deaths worldwide each year. Recent studies have shown that belinostat, a novel pan histone deacetylases inhibitor (HDACi) induces apoptosis and growth inhibition in pancreatic cancer cells. However, the underlying mechanisms are not fully understood. In the current study, we found that AMP-activated protein kinase (AMPK) activation was required for belinostat-induced apoptosis and anti-proliferation in PANC-1 pancreatic cancer cells. A significant AMPK activation was induced by belinostat in PANC-1 cells. Inhibition of AMPK by RNAi knockdown or dominant negative (DN) mutation significantly inhibited belinostat-induced apoptosis in PANC-1 cells. Reversely, AMPK activator AICAR and A-769662 exerted strong cytotoxicity in PANC-1 cells. Belinostat promoted reactive oxygen species (ROS) production in PANC-1 cells, increased ROS induced transforming growth factor-β-activating kinase 1 (TAK1)/AMPK association to activate AMPK. Meanwhile, anti-oxidants N-Acetyl-Cysteine (NAC) and MnTBAP as well as TAK1 shRNA knockdown suppressed belinostat-induced AMPK activation and PANC-1 cell apoptosis. In conclusion, we propose that belinostat-induced apoptosis and growth inhibition require the activation of ROS-TAK1-AMPK signaling axis in cultured pancreatic cancer cells

  1. Belinostat-induced apoptosis and growth inhibition in pancreatic cancer cells involve activation of TAK1-AMPK signaling axis

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Bing, E-mail: wangbin69@yahoo.com; Wang, Xin-bao; Chen, Li-yu; Huang, Ling; Dong, Rui-zen

    2013-07-19

    Highlights: •Belinostat activates AMPK in cultured pancreatic cancer cells. •Activation of AMPK is important for belinostat-induced cytotoxic effects. •ROS and TAK1 are involved in belinostat-induced AMPK activation. •AMPK activation mediates mTOR inhibition by belinostat. -- Abstract: Pancreatic cancer accounts for more than 250,000 deaths worldwide each year. Recent studies have shown that belinostat, a novel pan histone deacetylases inhibitor (HDACi) induces apoptosis and growth inhibition in pancreatic cancer cells. However, the underlying mechanisms are not fully understood. In the current study, we found that AMP-activated protein kinase (AMPK) activation was required for belinostat-induced apoptosis and anti-proliferation in PANC-1 pancreatic cancer cells. A significant AMPK activation was induced by belinostat in PANC-1 cells. Inhibition of AMPK by RNAi knockdown or dominant negative (DN) mutation significantly inhibited belinostat-induced apoptosis in PANC-1 cells. Reversely, AMPK activator AICAR and A-769662 exerted strong cytotoxicity in PANC-1 cells. Belinostat promoted reactive oxygen species (ROS) production in PANC-1 cells, increased ROS induced transforming growth factor-β-activating kinase 1 (TAK1)/AMPK association to activate AMPK. Meanwhile, anti-oxidants N-Acetyl-Cysteine (NAC) and MnTBAP as well as TAK1 shRNA knockdown suppressed belinostat-induced AMPK activation and PANC-1 cell apoptosis. In conclusion, we propose that belinostat-induced apoptosis and growth inhibition require the activation of ROS-TAK1-AMPK signaling axis in cultured pancreatic cancer cells.

  2. NO-donating aspirin inhibits the growth of leukemic Jurkat cells and modulates β-catenin expression

    International Nuclear Information System (INIS)

    Nath, Niharika; Labaze, Georges; Rigas, Basil; Kashfi, Khosrow

    2004-01-01

    β-Catenin has been implicated in leukemic cell proliferation. We compared the effects of aspirin (ASA) and the ortho, meta, and para positional isomers of NO-donating aspirin (NO-ASA) on cell growth and β-catenin expression in human Jurkat T leukemic cells. Cell growth inhibition was strong: IC 50 for p-, o-, and m- were 20 ± 1.6 (mean ± SEM), 15 ± 1.5, and 200 ± 12 μM, respectively, in contrast to that of ASA (3200 ± 375 μM). The para isomer of NO-ASA degraded β-catenin in a dose- and time-dependent manner coinciding with increasing expression of activated caspase-3. The caspase inhibitor ZVAD blocked β-catenin cleavage by p-NO-ASA and partially reversed cell growth inhibition by p-NO-ASA but not that by ASA. A denitrated analog of p-NO-ASA did not degrade β-catenin indicating the importance of the NO-donating moiety. Our findings suggest that NO-ASA merits further study as an agent against leukemia

  3. Synergistic Effects of Natural Medicinal Plant Extracts on Growth Inhibition of Carcinoma (KB) Cells under Oxidative Stress

    International Nuclear Information System (INIS)

    Kim, Jeong Hee; Ju, Eun Mi; Kim, Jin Kyu

    2000-01-01

    Medicinal plants with synergistic effects on growth inhibition of cancer cells under oxidative stress were screened in this study. Methanol extracts from 51 natural medicinal plants, which were reported to have anticancer effect on hepatoma, stomach cancer or colon cancers which are frequently found in Korean, were prepared and screened for their synergistic activity on growth inhibition of cancer cells under chemically-induced oxidative stress by using MTT assay. Twenty seven samples showed synergistic activity on the growth inhibition in various extent under chemically-induced oxidative stress. Among those samples, eleven samples, such as Melia azedarach, Agastache rugosa, Catalpa ovata, Prunus persica, Sinomenium acutum, Pulsatilla koreana, Oldenlandia diffiusa, Anthriscus sylvestris, Schizandra chinensis, Gleditsia sinensis, Cridium officinale, showed decrease in IC 50 values more than 50%, other 16 samples showed decrease in IC 50 values between 50-25%, compared with the value acquired when medicinal plant sample was used alone. Among those 11 samples, extract of Catalpa ovata showed the highest activity. IC 50 values were decrease to 61% and 28% when carcinoma cells were treated with Catalpa ovata extract in combination of 75 and 100 μM of hydrogen peroxide, respectively

  4. Biofilm growth on polyvinylchloride surface incubated in suboptimal microbial warm water and effect of sanitizers on biofilm removal post biofilm formation

    Science.gov (United States)

    An in vitro experiment was conducted to understand the nature of biofilm growth on polyvinyl chloride (PVC) surface when exposed to sub optimal quality microbial water (> 4 log10 cfu/ml) obtained from poultry drinking water source mimicking water in waterlines during the first week of poultry broodi...

  5. Inhibition of lipases from Chromobacterium viscosum and Rhizopus oryzae by tetrahydrolipstatin.

    Science.gov (United States)

    Potthoff, A P; Haalck, L; Spener, F

    1998-01-15

    Tetrahydrolipstatin is known as an inhibitor for pancreatic lipase but not for microbial lipases. In this paper we demonstrate that in the presence of water-insoluble substrates like tributyrin or olive oil, tetrahydrolipstatin inhibits the lipases of Chromobacterium viscosum and Rhizopus oryzae, although with different potency. In contrast to porcine pancreatic lipase, which forms an irreversible and covalent enzyme-inhibitor complex with tetrahydrolipstatin, the inhibition of the microbial lipases is reversible as the inhibitor can be removed from the enzyme-inhibitor complex by solvent extraction. Moreover, after inhibition of Chromobacterium viscosum lipase tetrahydrolipstatin remains chemically unchanged.

  6. Nicotine-induced retardation of chondrogenesis through down-regulation of IGF-1 signaling pathway to inhibit matrix synthesis of growth plate chondrocytes in fetal rats

    International Nuclear Information System (INIS)

    Deng, Yu; Cao, Hong; Cu, Fenglong; Xu, Dan; Lei, Youying; Tan, Yang; Magdalou, Jacques; Wang, Hui; Chen, Liaobin

    2013-01-01

    Previous studies have confirmed that maternal tobacco smoking causes intrauterine growth retardation (IUGR) and skeletal growth retardation. Among a multitude of chemicals associated with cigarette smoking, nicotine is one of the leading candidates for causing low birth weights. However, the possible mechanism of delayed chondrogenesis by prenatal nicotine exposure remains unclear. We investigated the effects of nicotine on fetal growth plate chondrocytes in vivo and in vitro. Rats were given 2.0 mg/kg·d of nicotine subcutaneously from gestational days 11 to 20. Prenatal nicotine exposure increased the levels of fetal blood corticosterone and resulted in fetal skeletal growth retardation. Moreover, nicotine exposure induced the inhibition of matrix synthesis and down-regulation of insulin-like growth factor 1 (IGF-1) signaling in fetal growth plates. The effects of nicotine on growth plates were studied in vitro by exposing fetal growth plate chondrocytes to 0, 1, 10, or 100 μM of nicotine for 10 days. Nicotine inhibited matrix synthesis and down-regulated IGF-1 signaling in chondrocytes in a concentration-dependent manner. These results suggest that prenatal nicotine exposure induces delayed chondrogenesis and that the mechanism may involve the down-regulation of IGF-1 signaling and the inhibition of matrix synthesis by growth plate chondrocytes. The present study aids in the characterization of delayed chondrogenesis caused by prenatal nicotine exposure, which might suggest a candidate mechanism for intrauterine origins of osteoporosis and osteoarthritis. - Highlights: ► Prenatal nicotine-exposure could induce delayed chondrogenesis in fetal rats. ► Nicotine inhibits matrix synthesis of fetal growth plate chondrocytes. ► Nicotine inhibits IGF-1 signaling pathway in fetal growth plate chondrocytes

  7. Nicotine-induced retardation of chondrogenesis through down-regulation of IGF-1 signaling pathway to inhibit matrix synthesis of growth plate chondrocytes in fetal rats

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Yu; Cao, Hong; Cu, Fenglong [Department of Orthopedic Surgery, Zhongnan Hospital of Wuhan University, Wuhan 430071 (China); Xu, Dan [Department of Pharmacology, Basic Medical School of Wuhan University, Wuhan 430071 (China); Research Center of Food and Drug Evaluation, Wuhan University, Wuhan 430071 (China); Lei, Youying [Department of Pharmacology, Basic Medical School of Wuhan University, Wuhan 430071 (China); Tan, Yang [Department of Orthopedic Surgery, Zhongnan Hospital of Wuhan University, Wuhan 430071 (China); Magdalou, Jacques [UMR 7561 CNRS-Nancy Université, Faculté de Médicine, Vandoeuvre-lès-Nancy (France); Wang, Hui [Department of Pharmacology, Basic Medical School of Wuhan University, Wuhan 430071 (China); Research Center of Food and Drug Evaluation, Wuhan University, Wuhan 430071 (China); Chen, Liaobin, E-mail: lbchen@whu.edu.cn [Department of Orthopedic Surgery, Zhongnan Hospital of Wuhan University, Wuhan 430071 (China)

    2013-05-15

    Previous studies have confirmed that maternal tobacco smoking causes intrauterine growth retardation (IUGR) and skeletal growth retardation. Among a multitude of chemicals associated with cigarette smoking, nicotine is one of the leading candidates for causing low birth weights. However, the possible mechanism of delayed chondrogenesis by prenatal nicotine exposure remains unclear. We investigated the effects of nicotine on fetal growth plate chondrocytes in vivo and in vitro. Rats were given 2.0 mg/kg·d of nicotine subcutaneously from gestational days 11 to 20. Prenatal nicotine exposure increased the levels of fetal blood corticosterone and resulted in fetal skeletal growth retardation. Moreover, nicotine exposure induced the inhibition of matrix synthesis and down-regulation of insulin-like growth factor 1 (IGF-1) signaling in fetal growth plates. The effects of nicotine on growth plates were studied in vitro by exposing fetal growth plate chondrocytes to 0, 1, 10, or 100 μM of nicotine for 10 days. Nicotine inhibited matrix synthesis and down-regulated IGF-1 signaling in chondrocytes in a concentration-dependent manner. These results suggest that prenatal nicotine exposure induces delayed chondrogenesis and that the mechanism may involve the down-regulation of IGF-1 signaling and the inhibition of matrix synthesis by growth plate chondrocytes. The present study aids in the characterization of delayed chondrogenesis caused by prenatal nicotine exposure, which might suggest a candidate mechanism for intrauterine origins of osteoporosis and osteoarthritis. - Highlights: ► Prenatal nicotine-exposure could induce delayed chondrogenesis in fetal rats. ► Nicotine inhibits matrix synthesis of fetal growth plate chondrocytes. ► Nicotine inhibits IGF-1 signaling pathway in fetal growth plate chondrocytes.

  8. Improved Performance in Mammalian Cell Perfusion Cultures by Growth Inhibition.

    Science.gov (United States)

    Wolf, Moritz K F; Closet, Aurélie; Bzowska, Monika; Bielser, Jean-Marc; Souquet, Jonathan; Broly, Hervé; Morbidelli, Massimo

    2018-05-21

    Mammalian cell perfusion cultures represent a promising alternative to the current fed-batch technology for the production of various biopharmaceuticals. Long-term operation at a fixed viable cell density (VCD) requires a viable culture and a constant removal of excessive cells. Product loss in the cell removing bleed stream deteriorates the process yield. In this study, the authors investigate the use of chemical and environmental growth inhibition on culture performance by either adding valeric acid (VA) to the production media or by reducing the culture temperature (33.0 °C) with respect to control conditions (36.5 °C, no VA). Low temperature significantly reduces cellular growth, thus, resulting in lower bleed rates accompanied by a reduced product loss of 11% compared to 26% under control conditions. Additionally, the cell specific productivity of the target protein improves and maintained stable leading to media savings per mass of product. VA shows initially an inhibitory effect on cellular growth. However, cells seemed to adapt to the presence of the inhibitor resulting in a recovery of the cellular growth. Cell cycle and Western blot analyses support the observed results. This work underlines the role of temperature as a key operating variable for the optimization of perfusion cultures. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. [Effects of antimicrobial drugs on soil microbial respiration].

    Science.gov (United States)

    Liu, Feng; Ying, Guang-Guo; Zhou, Qi-Xing; Tao, Ran; Su, Hao-Chang; Li, Xu

    2009-05-15

    The effects on soil microbial respiration of sulfonamides, tetracyclines, macrolides and so on were studied using the direct absorption method. The results show sulfamethazine, sulfamethoxazole, chlortetracycline, tetracycline, tylosin and trimethoprim inhibit soil respiration 34.33%, 34.43%, 2.71%, 3.08%, 7.13%, 38.08% respectively. Sulfamethoxazole and trimethoprim have the highest inhibition rates among all the antibiotics. In early incubation period (0-2 d), the concentrations above 10 mg x kg(-1) of sulfamethazine, sulfamethoxazole and trimethoprim remarkably decrease soil CO2 emission. The effects of these antibiotics vary with their concentrations too. Sulfamethoxazole and trimethoprim show good dose-response relationships. According to the standard of pesticide safety evaluation protocol, the six antibiotics pose a little risk to soil microbial environment.

  10. Inhibition of nuclear factor kappa-B signaling reduces growth in medulloblastoma in vivo

    Directory of Open Access Journals (Sweden)

    Deckard Lindsey A

    2011-04-01

    Full Text Available Abstract Background Medulloblastoma is a highly malignant pediatric brain tumor that requires surgery, whole brain and spine irradiation, and intense chemotherapy for treatment. A more sophisticated understanding of the pathophysiology of medulloblastoma is needed to successfully reduce the intensity of treatment and improve outcomes. Nuclear factor kappa-B (NFκB is a signaling pathway that controls transcriptional activation of genes important for tight regulation of many cellular processes and is aberrantly expressed in many types of cancer. Methods To test the importance of NFκB to medulloblastoma cell growth, the effects of multiple drugs that inhibit NFκB, pyrrolidine dithiocarbamate, diethyldithiocarbamate, sulfasalazine, curcumin and bortezomib, were studied in medulloblastoma cell lines compared to a malignant glioma cell line and normal neurons. Expression of endogenous NFκB was investigated in cultured cells, xenograft flank tumors, and primary human tumor samples. A dominant negative construct for the endogenous inhibitor of NFκB, IκB, was prepared from medulloblastoma cell lines and flank tumors were established to allow specific pathway inhibition. Results We report high constitutive activity of the canonical NFκB pathway, as seen by Western analysis of the NFκB subunit p65, in medulloblastoma tumors compared to normal brain. The p65 subunit of NFκB is extremely highly expressed in xenograft tumors from human medulloblastoma cell lines; though, conversely, the same cells in culture have minimal expression without specific stimulation. We demonstrate that pharmacological inhibition of NFκB in cell lines halts proliferation and leads to apoptosis. We show by immunohistochemical stain that phosphorylated p65 is found in the majority of primary tumor cells examined. Finally, expression of a dominant negative form of the endogenous inhibitor of NFκB, dnIκB, resulted in poor xenograft tumor growth, with average tumor volumes

  11. Isthmin is a novel secreted angiogenesis inhibitor that inhibits tumour growth in mice

    Science.gov (United States)

    Xiang, Wei; Ke, Zhiyuan; Zhang, Yong; Ho-Yuet Cheng, Grace; Irwan, Ishak Darryl; Sulochana, K N; Potturi, Padma; Wang, Zhengyuan; Yang, He; Wang, Jingyu; Zhuo, Lang; Kini, R Manjunatha; Ge, Ruowen

    2011-01-01

    Abstract Anti-angiogenesis represents a promising therapeutic strategy for the treatment of various malignancies. Isthmin (ISM) is a gene highly expressed in the isthmus of the midbrain–hindbrain organizer in Xenopus with no known functions. It encodes a secreted 60 kD protein containing a thrombospondin type 1 repeat domain in the central region and an adhesion-associated domain in MUC4 and other proteins (AMOP) domain at the C-terminal. In this work, we demonstrate that ISM is a novel angiogenesis inhibitor. Recombinant mouse ISM inhibited endothelial cell (EC) capillary network formation on Matrigel through its C-terminal AMOP domain. It also suppressed vascular endothelial growth factor (VEGF)-basic fibroblast growth factor (bFGF) induced in vivo angiogenesis in mouse. It mitigated VEGF-stimulated EC proliferation without affecting EC migration. Furthermore, ISM induced EC apoptosis in the presence of VEGF through a caspase-dependent pathway. ISM binds to αvβ5 integrin on EC surface and supports EC adhesion. Overexpression of ISM significantly suppressed mouse B16 melanoma tumour growth through inhibition of tumour angiogenesis without affecting tumour cell proliferation. Knockdown of isthmin in zebrafish embryos using morpholino antisense oligonucleotides led to disorganized intersegmen-tal vessels in the trunk. Our results demonstrate that ISM is a novel endogenous angiogenesis inhibitor with functions likely in physiological as well as pathological angiogenesis. PMID:19874420

  12. Growth inhibition and differentiation of murine melanoma B16-BL6 cells caused by the combination of cisplatin and caffeine.

    Science.gov (United States)

    Tsuchiya, H; Tomita, K; Yasutake, H; Ueda, Y; Tanaka, M; Sasaki, T

    1989-12-01

    We preliminarily investigated the combined effects of cisplatin and caffeine on murine melanoma B16-BL6 cells in vitro. When caffeine was added before or simultaneously with cisplatin, there was little growth inhibition. The addition of 2.0 mM caffeine after 1 h of exposure to cisplatin inhibited growth and induced cell differentiation. This treatment resulted in fewer cells, and the numbers of melanosomes and mitochondria and the amount of Golgi's complex and endoplasmic reticulum were increased. DNA histograms obtained by flow cytometry showed that cells treated with cisplatin alone accumulated in the G2/M phase, with a partial G2 block. The addition of 2.0 mM caffeine after 1 h of treatment with cisplatin reduced this block. Caffeine caused murine melanoma B16-BL6 cells treated with cisplatin to differentiate, and this inhibited growth.

  13. Efeito da adição de CO2 sobre o crescimento microbiano em macarrão tipo massa fresca Effect of CO2 addition on microbial growth in fresh pasta

    Directory of Open Access Journals (Sweden)

    Renato Souza Cruz

    2002-08-01

    Full Text Available O presente trabalho foi desenvolvido com o objetivo de avaliar o efeito da adição de CO2 sobre a qualidade do macarrão tipo massa fresca. O uso de atmosfera modificada no interior da embalagem, com concentrações mais elevadas de CO2, tem sido empregado comercialmente com a finalidade de inibir microrganismos, principalmente os aeróbios. Dessa forma, neste trabalho foi empregada uma nova técnica para a adição do CO2 no produto. Esta técnica consistiu em carbonatar a água que foi utilizada para a produção do macarrão tipo massa fresca, em substituição à injeção do gás CO2 na embalagem. Foram testadas as concentrações de 160 e 745mg/L de CO2. Os resultados mostraram, pelas análises microbiológicas, que o nível de 745mg/L de CO2 foi satisfatório para a inibição de bolores e leveduras durante os 50 dias de armazenamento a 7±1ºC. No entanto, não houve efeito na inibição de psicrotróficos e coliformes totais.The objective of this work was to evaluate CO2 addition on the inhibition of microbial growth in fresh pasta. Modified atmosphere packages using higher levels of CO2 have been commercially used to inhibit mainly aerobes microorganisms. Therefore, a new technique of adding CO2 directly to the product was tested promoting better contact between the dough and the gas. Carbon dioxide was dissolved in water at concentrations of 160 and 745mg/L and the carbonated water was mixed with the ingredients to produce the pasta. The results showed that 745mg/L of CO2 inhibited fungi and yeast growth in pasta stored at 7±1ºC up to 50 days, however, growth of psychrotrophics and coliforms was not affected.

  14. Splenectomy inhibits non-small cell lung cancer growth by modulating anti-tumor adaptive and innate immune response

    Science.gov (United States)

    Levy, Liran; Mishalian, Inbal; Bayuch, Rachel; Zolotarov, Lida; Michaeli, Janna; Fridlender, Zvi G

    2015-01-01

    It has been shown that inhibitors of the immune system reside in the spleen and inhibit the endogenous antitumor effects of the immune system. We hypothesized that splenectomy would inhibit the growth of relatively large non-small lung cancer (NSCLC) tumors by modulating the systemic inhibition of the immune system, and in particular Myeloid Derived Suppressor Cells (MDSC). The effect of splenectomy was evaluated in several murine lung cancer models. We found that splenectomy reduces tumor growth and the development of lung metastases, but only in advanced tumors. In immune-deficient NOD-SCID mice the effect of splenectomy on tumor growth and metastatic spread disappeared. Splenectomy significantly reduced the presence of MDSC, and especially monocytic-MDSC in the circulation and inside the tumor. Specific reduction of the CCR2+ subset of monocytic MDSC was demonstrated, and the importance of the CCL2-CCR2 axis was further shown by a marked reduction in CCL2 following splenectomy. These changes were followed by changes in the macrophages contents of the tumors to become more antitumorigenic, and by increased activation of CD8+ Cytotoxic T-cells (CTL). By MDSC depletion, and adoptive transfer of MDSCs, we demonstrated that the effect of splenectomy on tumor growth was substantially mediated by MDSC cells. We conclude that the spleen is an important contributor to tumor growth and metastases, and that splenectomy can blunt this effect by depletion of MDSC, changing the amount and characteristics of myeloid cells and enhancing activation of CTL. PMID:26137413

  15. Probiotic Lactobacillus sp. inhibit growth, biofilm formation and gene expression of caries-inducing Streptococcus mutans.

    Science.gov (United States)

    Wasfi, Reham; Abd El-Rahman, Ola A; Zafer, Mai M; Ashour, Hossam M

    2018-03-01

    Streptococcus mutans contributes significantly to dental caries, which arises from homoeostasic imbalance between host and microbiota. We hypothesized that Lactobacillus sp. inhibits growth, biofilm formation and gene expression of Streptococcus mutans. Antibacterial (agar diffusion method) and antibiofilm (crystal violet assay) characteristics of probiotic Lactobacillus sp. against Streptococcus mutans (ATCC 25175) were evaluated. We investigated whether Lactobacillus casei (ATCC 393), Lactobacillus reuteri (ATCC 23272), Lactobacillus plantarum (ATCC 14917) or Lactobacillus salivarius (ATCC 11741) inhibit expression of Streptococcus mutans genes involved in biofilm formation, quorum sensing or stress survival using quantitative real-time polymerase chain reaction (qPCR). Growth changes (OD600) in the presence of pH-neutralized, catalase-treated or trypsin-treated Lactobacillus sp. supernatants were assessed to identify roles of organic acids, peroxides and bacteriocin. Susceptibility testing indicated antibacterial (pH-dependent) and antibiofilm activities of Lactobacillus sp. against Streptococcus mutans. Scanning electron microscopy revealed reduction in microcolony formation and exopolysaccharide structural changes. Of the oral normal flora, L. salivarius exhibited the highest antibiofilm and peroxide-dependent antimicrobial activities. All biofilm-forming cells treated with Lactobacillus sp. supernatants showed reduced expression of genes involved in exopolysaccharide production, acid tolerance and quorum sensing. Thus, Lactobacillus sp. can inhibit tooth decay by limiting growth and virulence properties of Streptococcus mutans. © 2018 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

  16. Organic Oils as Seed Treatments for Soybeans to Inhibit Fungal Growth

    OpenAIRE

    Burgett, Alison

    2015-01-01

    Producing organic crops has become essential to satisfy the desires of the end consumer. To completely fulfill this task and meet the requirements of the National Organic Program in the U.S., the seeds planted must be organic. Seeds succumb to fungal infections without seed treatments. Organic seed treatments are not common. The purpose of this study is to test the ability of three organic oils (tea tree, coconut, and lemon) to act as organic seed treatments to inhibit fungal growth on soybea...

  17. Noninvasive optical inhibition with a red-shifted microbial rhodopsin

    DEFF Research Database (Denmark)

    Chuong, Amy S; Miri, Mitra L; Busskamp, Volker

    2014-01-01

    Optogenetic inhibition