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Culture Media (culture + media)
Kinds of Culture Media Selected AbstractsTrade and associated groups in the English tourism policy arenaINTERNATIONAL JOURNAL OF TOURISM RESEARCH, Issue 6 2001Duncan Tyler Abstract The role and influence of trade and associated groups in England's tourism policy environment is of increasing importance given recent changes in the consultative processes undertaken by the Department of Culture Media and Sport (the government department sponsoring the tourism industry in Parliament). Yet researchers working within the realm of tourism studies have paid little attention to their characteristics, objectives and tactics. This article, therefore, sets out to address these issues by drawing on the results of phase one of a two-phase research project into the influence of trade and associated groups on policy development. The article reports the findings of a survey into the objectives and tactics used by the groups in policy communications and links this to structural changes in the landscape of the tourism policy. In doing this it suggests how certain relationships have developed between government and groups, how groups collaborate on policy issues and how this may have influenced the direction of tourism policy in the England. Using the results of this research and an analysis of government policy related announcements over the past two years we hypothesise on how successful the groups have been to data, and proposes areas for future research. Copyright © 2001 John Wiley & Sons, Ltd. [source] The United Kingdom's Immunity from Seizure LegislationTHE MODERN LAW REVIEW, Issue 5 2009Anna O'Connell The UK's Department for Culture Media and Sport (DCMS) has introduced legislation to provide immunity from seizure for cultural objects on temporary loan from other countries to approved museums and galleries in the UK. The legislation is aimed at facilitating the cross-border lending of objects and bringing the UK into line with other countries such as the United States, France and Germany, that already afford such legal immunity. In the absence of immunity legislation in the UK, many museums and private lenders had been reluctant to loan their objects because of the risk that they might be seized by creditors seeking to settle financial disputes or by claimants contesting ownership of the works. This article examines whether the new law will be effective to provide museums and lenders with the protection they have been hoping for and asks whether it goes too far in depriving claimants of legal rights and remedies. [source] Cover Picture: Electrophoresis 22'2009ELECTROPHORESIS, Issue 22 2009Article first published online: 25 NOV 200 Issue no. 22 is a Special Issue on "CE and CEC Innovations" consisting of 24 important contributions in various areas of CE and CEC that are grouped into five different parts. Part I has 7 articles on novel "Stationary Phases for CEC". Part II is on "CE of Microorganisms and their Components and Interactions", and has 4 research articles. "Enantioseparations" constitute part III and has 3 research articles dealing with different chiral species and chiral CE systems. Part IV has 3 contributions on "Detection Approaches in CE". Part V is on "Capillary Coating, Affinity and Separation Media , Applications" and contains 7 research articles dealing with the separations of proteins, lipoproteins, bioactive inflammatory cytokines, inorganic and small organic anions, non-steroidal anti-inflammatory drugs, cell culture media and ancient DNA samples." [source] Growth-induced changes in the proteome of Helicobacter pyloriELECTROPHORESIS, Issue 5-6 2006Christina Uwins Abstract Helicobacter pylori is a major human pathogen that is responsible for a number of gastrointestinal infections. We have used 2-DE to characterise protein synthesis in bacteria grown either on solid agar-based media or in each of two broth culture media (Brucella and brain heart infusion (BHI) broth). Significant differences were observed in the proteomes of bacteria grown either on agar-based or in broth media. Major changes in protein abundance were identified using principal component analysis (PCA), which delineated the profiles derived for the three key growth conditions (i.e. agar plates, Brucella and BHI broth). Proteins detected across the gel series were identified by peptide mass mapping and Edman sequencing. A number of proteins associated with protein synthesis in general as well as specific amino acid synthesis were depressed in broth-grown bacteria compared to plate-grown bacteria. A similar reduction was also observed in the abundance of proteins involved in detoxification. Two of the most abundant spots, identified as UreB and GroEL, in plate-grown bacteria showed a >140-fold drop in abundance in bacteria grown in Brucella broth compared to bacteria grown on agar plates. Two protein spots induced in bacteria grown in broth culture were both identified as glyceraldehyde 3-phosphate dehydrogenase based on their N -terminal amino acid sequences derived by Edman degradation. The underlying causes of the changes in the proteins abundance were not clear, but it was likely that a significant proportion of the changes were due to the alkaline pH of the broth culture media. [source] Interference of quorum sensing in Pseudomonas syringae by bacterial epiphytes that limit iron availabilityENVIRONMENTAL MICROBIOLOGY, Issue 6 2010Glenn F. J. Dulla Summary Leaf surfaces harbour bacterial epiphytes that are capable of influencing the quorum sensing (QS) system, density determination through detection of diffusible signal molecules, of the plant-pathogen Pseudomonas syringae pv. syringae (Pss) which controls expression of extracellular polysaccharide production, motility and other factors contributing to virulence to plants. Approximately 11% of the bacterial epiphytes recovered from a variety of plants produced a diffusible factor capable of inhibiting the QS system of Pss as indicated by suppression of ahlI. Blockage of QS by these interfering strains correlated strongly with their ability to limit iron availability to Pss. A direct relationship between the ability of isogenic Escherichia coli strains to sequester iron via their production of different siderophores and their ability to suppress QS in Pss was also observed. Quorum sensing induction was inversely related to iron availability in culture media supplemented with iron chelators or with FeCl3. Co-inoculation of interfering strains with Pss onto leaves increased the number of resultant disease lesions over twofold compared with that on plants inoculated with Pss alone. Transposon-generated mutants of interfering strains in which QS inhibition was blocked did not increase disease when co-inoculated with Pss. Increased disease incidence was also not observed when a non-motile mutant of Pss was co-inoculated onto plants with QS interfering bacteria suggesting that these strains enhanced the motility of Pss in an iron-dependent manner, leading to an apparent increase in virulence of this pathogen. Considerable cross-talk mediated by iron scavenging apparently occurs on plants, thereby altering the behaviour of bacteria such as Pss that exhibit important QS-dependent traits in this habitat. [source] Antimony biomethylation in culture media revisited in the light of solubility and chemical speciation considerationsENVIRONMENTAL TOXICOLOGY, Issue 5 2010Montserrat Filella Abstract Laboratory culture experiments have shown that antimony biomethylation can result from bacterial and fungal activity under both aerobic and anaerobic conditions. However, in the light of our current knowledge of antimony solubility and equilibria, critical analysis of the conditions used in published laboratory studies reveals that solution chemistry was generally overlooked and oversaturated solutions were used. As a result, it is very difficult, if not impossible, to establish reliable observed effect-concentration relationships in the experiments published. © 2010 Wiley Periodicals, Inc. Environ Toxicol 2010. [source] Extraction and purification of the zwitterions cylindrospermopsin and deoxycylindrospermopsin from Cylindrospermopsis raciborskiiENVIRONMENTAL TOXICOLOGY, Issue 5 2001R. L. G. Norris Abstract The hepatotoxin cylindrospermopsin (CYN) has been isolated from the cyanobacterium Cylindrospermopsis raciborskii (C. raci.). Efforts to study this toxin have been hampered by the time-consuming requirement to extract it from cultures of the organism. It is usually extracted from lyophilized cells collected from a laboratory culture. Our preliminary work suggested far more of the toxin is available in solution in the culture media than in the cells collected. We have therefore investigated the use of commercially available solid phase extraction sorbents to extract CYN from culture media in which C. raci. has been grown. A range of reverse phase and ion-exchange sorbents were tested across a range of pHs for their ability to retain CYN without success. Subsequently, graphitized carbon cartridges were found to retain CYN strongly. Elution with 5% formic acid in methanol allowed the CYN to be regained for final purification by HPLC. Deoxy-CYN, an analog of CYN can also be extracted using this procedure. © 2001 John Wiley & Sons, Inc. Environ Toxicol 16: 391,396, 2001 [source] Selection and identification of bacterial strains with methyl- tert -butyl ether, ethyl- tert -butyl ether, and tert -amyl methyl ether degrading capacitiesENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 11 2008Jessica Purswani Abstract Nine bacterial strains isolated from two hydrocarbon-contaminated soils were selected because of their capacity for growth in culture media amended with 200 mg/L of one of the following gasoline oxygenates: Methyl- tert -butyl ether (MTBE), ethyl- tert -butyl ether (ETBE), and tert -amyl methyl ether (TAME). These strains were identified by amplification of their 16S rRNA gene, using fD1 and rD1 primers, and were tested for their capacity to grow and biotransform these oxygenates in both mineral and cometabolic media. The isolates were classified as Bacillus simplex, Bacillus drentensis, Arthrobacter sp., Acinetobacter calcoaceticus, Acinetobacter sp., Gordonia amicalis (two strains), Nocardioides sp., and Rhodococcus ruber. Arthrobacter sp. (strain MG) and A. calcoaceticus (strain M10) consumed 100 (cometabolic medium) and 82 mg/L (mineral medium) of oxygenate TAME in 21 d, respectively, under aerobic conditions. Rhodococcus ruber (strain E10) was observed to use MTBE and ETBE as the sole carbon and energy source, whereas G. amicalis (strain T3) used TAME as the sole carbon and energy source for growth. All the bacterial strains transformed oxygenates better in the presence of an alternative carbon source (ethanol) with the exception of A. calcoaceticus (strain M10). The capacity of the selected strains to remove MTBE, ETBE, and TAME looks promising for application in bioremediation technologies. [source] Intraclonal variability in Daphnia acetylcholinesterase activity: The implications for its applicability as a biomarkerENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 9 2003Liane Biehl Printes Abstract The relationship between individual growth and acetylcholinesterase (AChE) activity was evaluated for Daphnia magna. Analysis on the influence of two different culture media on baseline AChE activity was performed with Daphnia similis. The results indicated an inverse relationship between D. magna body length and AChE activity. An increase in total protein, which was not proportional to an increase in the rate of the substrate hydrolysis (, absorbance/min), seems to be the reason for this inverse size versus AChE activity relationship. Therefore, toxicants such as phenobarbital, which affect protein and size but not AChE activity directly, have an overall affect on AChE activity. In contrast, the AChE inhibitor parathion altered AChE activity but not protein. Culture medium also had a significant affect on AChE activity in D. similis. Changes in total protein seem to be the main reason for the variations in baseline AChE activity in Daphnia observed in the different evaluations performed in this work. Therefore, AChE activity in Daphnia must be interpreted carefully, and variations related to changes in total protein must be taken into account when applying this enzyme as a biomarker in biological monitoring. [source] Basic fibrobrast growth factor induces the secretion of vascular endothelial growth factor by human aortic smooth muscle cells but not by endothelial cellsEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 10 2003F. Belgore Abstract Background, Endothelial cell dysfunction and smooth muscle cell (SMC) proliferation are major events in atherogenesis. Both cells are a source of growth factors that mediate cellular proliferation and chemotaxis. Inappropriate production of, and/or response to, these growth factors (such as vascular endothelial growth factor, VEGF, and basic fibroblast growth factor (bFGF)) may contribute to atherogenesis and therefore to disease progression. Methods, Production of VEGF and its soluble receptor (sFlt-1) by human SMCs and human umbilical endothelial cells (HUVECs) after stimulation with bFGF were examined by ELISA of cell culture media and by Western blotting. Results, Smooth muscle cells produced significantly more VEGF than HUVECs (P < 0·05) after 24 h of culture with bFGF levels , 0·001 µg mL,1. bFGF induced dose-dependent production of VEGF by SMCs, where maximum production was present in 1 µg mL,1 of bFGF. Conversely, the SMCs produced less sFlt-1 than HUVECs (P < 0·05). However, bFGF induced dose-dependent phosphorylation of Flt1 and another VEGF receptor, KDR, in HUVECs but not SMCs. There was no VEGF or sFLT-1 after 6 h of culture in any dose of bFGF in either type of cell. Conclusions, Differences in the production of VEGF and sFlt-1 by SMCs and HUVECs are consistent with the role of these cells in angiogenesis. Induction of VEGF production and expression by bFGF in these cells indicates that this growth factor may participate in angiogenesis indirectly by the induction of VEGF. The production of sFlt-1 by both cell types is in agreement with the notion that sFlt-1 may be involved in the regulation of VEGF activity. Additionally, the ability of bFGF to induce dose-dependent phosphorylation of KDR in HUVECs highlights the important role of bFGF in VEGF-mediated angiogenic processes. [source] Neurogenesis in explants from the walls of the lateral ventricle of adult bovine brain: role of endogenous IGF-1 as a survival factorEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 2 2003M. Pérez-Martín Abstract Previous studies have shown the existence of proliferating cells in explants from bovine (Bos Taurus) lateral ventricle walls that were maintained for several days in vitro in the absence of serum and growth factors. In this study we have characterized the nature of new cells and have assessed whether the insulin-like growth factor-1 (IGF-1) receptor regulates their survival and/or proliferation. The explants were composed of the ependymal layer and attached subependymal cells. Ependymal cells in culture were labelled with glial markers (S-100, vimentin, GFAP, BLBP, 3A7 and 3CB2) and did not incorporate bromodeoxiuridine when this molecule was added to the culture media. Most subependymal cells were immunoreactive for ,III-tubulin, a neuronal marker, and did incorporate bromodeoxiuridine. Subependymal neurons displayed immunoreactivity for IGF-1 and its receptor and expressed IGF-1 mRNA, indicating that IGF-1 is produced in the explants and may act on new neurons. Addition to the culture media of an IGF-1 receptor antagonist, the peptide JB1, did not affect the incorporation of bromodeoxiuridine to proliferating subependymal cells. However, JB1 significantly increased the number of TUNEL positive cells in the subependymal zone, suggesting that IGF-1 receptor is involved in the survival of subependymal neurons. In conclusion, these findings indicate that neurogenesis is maintained in explants from the lateral cerebral ventricle of adult bovine brains and that IGF-1 is locally produced in the explants and may regulate the survival of the proliferating neurons. [source] mTOR as a potential therapeutic target for treatment of keloids and excessive scarsEXPERIMENTAL DERMATOLOGY, Issue 5 2007C. T. Ong Abstract:, Keloid is a dermal fibroproliferative disorder characterized by excessive deposition of extracellular matrix (ECM) components such as collagen, glycoproteins and fibronectin. The mammalian target of rapamycin (mTOR) is a serine/theronine kinase which plays an important role in the regulation of metabolic processes and translation rates. Published reports have shown mTOR as regulator of collagen expression and its inhibition induces a decrease in ECM deposition. Our aim was to investigate the role of mTOR in keloid pathogenesis and investigate the effect of rapamycin on proliferating cell nuclear antigen (PCNA), cyclin D1, collagen, fibronectin and alpha-smooth muscle actin (, -SMA) expression in normal fibroblasts (NF) and keloid fibroblasts (KF). Tissue extracts obtained from keloid scar demonstrated elevated expression of mTOR, p70KDa S6 kinase (p70S6K) and their activated forms, suggesting an activated state in keloid scars. Serum stimulation highlighted the heightened responsiveness of KF to mitogens and the importance of mTOR and p70S6K during early phase of wound healing. Application of rapamycin to monoculture NF and KF, dose- and time-dependently downregulates the expression of cytoplasmic PCNA, cyclin D1, fibronectin, collagen and , -SMA, demonstrating the anti-proliferative effect and therapeutic potential of rapamycin in the treatment of keloid scars. The inhibitory effect of rapamycin was found to be reversible following recovery in the expression of proteins following the removal of rapamycin from the culture media. These results demonstrate the important role of mTOR in the regulation of cell cycle and the expression of ECM proteins: fibronectin, collagen and , -SMA. [source] Docosahexaenoic acid stabilizes soluble amyloid-, protofibrils and sustains amyloid-,-induced neurotoxicity in vitroFEBS JOURNAL, Issue 4 2007Ann-Sofi Johansson Enrichment of diet and culture media with the polyunsaturated fatty acid docosahexaenoic acid has been found to reduce the amyloid burden in mice and lower amyloid-, (A,) levels in both mice and cultured cells. However, the direct interaction of polyunsaturated fatty acids, such as docosahexaenoic acid, with A,, and their effect on A, aggregation has not been explored in detail. Therefore, we have investigated the effect of docosahexaenoic acid, arachidonic acid and the saturated fatty acid arachidic acid on monomer oligomerization into protofibrils and protofibril fibrillization into fibrils in vitro, using size exclusion chromatography. The polyunsaturated fatty acids docosahexaenoic acid and arachidonic acid at micellar concentrations stabilized soluble A,42 wild-type protofibrils, thereby hindering their conversion to insoluble fibrils. As a consequence, docosahexaenoic acid sustained amyloid-,-induced toxicity in PC12 cells over time, whereas A, without docosahexaenoic acid stabilization resulted in reduced toxicity, as A, formed fibrils. Arachidic acid had no effect on A, aggregation, and neither of the fatty acids had any protofibril-stabilizing effect on A,42 harboring the Arctic mutation (A,E22G). Consequently, A,Arctic-induced toxicity could not be sustained using docosahexaenoic acid. These results provide new insights into the toxicity of different A, aggregates and how endogenous lipids can affect A, aggregation. [source] Astrocyte-derived factors modulate the inhibitory effect of ethanol on dendritic developmentGLIA, Issue 4 2002Penelope A. Yanni Abstract Numerous studies in vivo and in vitro have demonstrated that ethanol disrupts neuromorphogenesis. However, it has not been determined what role, if any, is played by non-neuronal cells in mediating this effect. We recently reported that ethanol inhibits dendritic development in low-density cultures of fetal rat hippocampal pyramidal neurons (Yanni and Lindsley, 2000: Dev Brain Res 120:233,243). In this culture system, cortical astrocytes precondition neuronal culture media for 2 days before the addition of neurons, which then develop on a separate substrate in coculture with the astrocytes. To determine whether astrocyte response to ethanol mediates the effects of ethanol on neurons, the present study compared dendritic development of neurons after 6 days in medium containing 400 mg/dl ethanol in coculture with live astrocytes and in conditioned medium from astrocytes that were never exposed to ethanol. The same experiment was also performed with and without ethanol present during astrocyte preconditioning of the medium. The effects of ethanol differed depending on when it was added to the cultures relative to addition of newly dissociated neurons. However, the effects of ethanol were not related to whether neurons were cocultured with live astrocytes. When astrocytes preconditioned the medium normally, ethanol added at plating inhibited dendritic development of neurons regardless of whether they were maintained in coculture with live astrocytes or in conditioned medium. In surprising contrast, the presence of ethanol during astrocyte preconditioning of the media had a growth promoting effect on subsequent dendrite development despite the continued presence of ethanol in the medium. Thus, astrocytes release soluble factors in response to ethanol that can protect neurons from the inhibitory effects of ethanol on dendritic growth, but the timing of neuronal exposure to these factors, or their concentration, may influence their activity. GLIA 38:292,302, 2002. © 2002 Wiley-Liss, Inc. [source] Methodology and Transport Medium for Collection of Helicobacter pylori on a String Test in Remote LocationsHELICOBACTER, Issue 6 2005Helen M. Windsor ABSTRACT Background.,Helicobacter pylori can be isolated from patients using the string test but contaminating oral and nasopharyngeal microflora need to be suppressed by rapid plating out onto selective culture media. Recently, use of this diagnostic method was enhanced by using a novel transport medium to collect specimens from subjects in a remote Australian clinic over 1300 km from the laboratory. Methods., Retrieved string tests were transported to the laboratory in chilled polystyrene boxes in 5 ml screw-cap bottles with 3 ml of a brain heart infusion broth plus antibiotics. These were 20 g/ml vancomycin, 10 g/ml trimethoprim, 10 g/ml cefsulodin, and 10 g/ml amphotericin B. A comparison was made between subjects who gargled with a chlorhexidine mouthwash before swallowing the string test and those who did not. Results., Forty-five urea breath test-positive subjects were tested and H. pylori was isolated from 34 of them. Successful culture was achieved from string tests that were in transit for up to 29 hours and where the maximum temperature in the transport box was 14 °C. The additional use of a mouthwash had a marked effect on the isolation rate. H. pylori was cultured from 75% of subjects who gargled but only from 39% who did not. Conclusions., This methodology and transport medium can broaden the use of the string test to more remote geographic areas where endoscopy is not feasible so that H. pylori isolates may still be obtained for diagnostic and epidemiologic studies. The value of this promising methodology of collection and transport should be assessed in a controlled study. [source] Primary hepatocyte culture supports hepatitis C virus replication: A model for infection-associated hepatocarcinogenesis,HEPATOLOGY, Issue 6 2010Krishna Banaudha Analysis of progressive changes in hepatic gene expression that underlie hepatocarcinogenesis following hepatitis C virus (HCV) infection require examination of long-term cultures of normally differentiating primary human hepatocytes. We report a culture system of primary hepatocytes that support productive replication of infectious HCV. Hepatic functions were analyzed by reverse-transcription polymerase chain reaction amplification of total cell RNA from cultures maintained in serum-free defined medium for up to 190 days. Sustained hepatic function was assessed by expression of albumin, alpha-fetoprotein, cytochrome P4502E1, cytokeratin-18, type-1 collagen, transforming growth factor-beta 1, matrix metalloproteinase-2 (MMP-2), MMP-13, and interferon alpha-receptors 1 and 2. Normally differentiated human primary hepatocytes supported productive replication of infectious clones of HCV genotypes 1a, 1b, and 2a; virus infection was inhibited by antibodies against CD81 virus entry factor. Virus released into the culture media of HCV-infected primary hepatocytes repeatedly passage to naďve hepatocytes. Replication of the three HCV genotypes shows interferon sensitivity observed in natural infections. Conclusion: Sustained cultures of physiologic host cells for the propagation of infectious HCV strains should accelerate studies of host response to HCV infection and progressive liver disease. Hepatology 2010;51:1922,1932 [source] Dual-association of gnotobiotic Il-10,/, mice with 2 nonpathogenic commensal bacteria induces aggressive pancolitisINFLAMMATORY BOWEL DISEASES, Issue 12 2007Sandra C. Kim MD Abstract Background: Monoassociating gnotobiotic IL-10-deficient (,/,) mice with either nonpathogenic Enterococcus faecalis or a nonpathogenic Escherichia coli strain induces T-cell-mediated colitis with different kinetics and anatomical location (E. faecalis: late onset, distal colonic; E. coli: early onset, cecal). Hypothesis: E. faecalis and E. coli act in an additive manner to induce more aggressive colitis than disease induced by each bacterial species independently. Methods: Germ-free (GF) inbred 129S6/SvEv IL-10,/, and wildtype (WT) mice inoculated with nonpathogenic E. faecalis and/or E. coli were killed 3,7 weeks later. Colonic segments were scored histologically for inflammation (0 to 4) or incubated in media overnight to measure spontaneous IL-12/IL-23p40 secretion. Bacterial species were quantified by serial dilution and plated on culture media. Mesenteric lymph node (MLN) CD4+ cells were stimulated with antigen-presenting cells pulsed with bacterial lysate (E. faecalis, E. coli, Bacteroides vulgatus) or KLH (unrelated antigen control). IFN-, and IL-17 levels were measured in the supernatants. Results: Dual-associated IL-10,/, (but not WT) mice developed mild-to-moderate pancolitis by 3 weeks that progressed to severe distal colonic-predominant pancolitis with reactive atypia and duodenal inflammation by 7 weeks. NF-,B was activated in the duodenum and colon in dual-associated IL-10,/, × NF-,BEGFP mice. The aggressiveness of intestinal inflammation and the degree of antigen-specific CD4+ cell activation were greater in dual- versus monoassociated IL-10,/, mice. Conclusion: Two commensal bacteria that individually induce phenotypically distinct colitis in gnotobiotic IL-10,/, mice act additively to induce aggressive pancolitis and duodenal inflammation. (Inflamm Bowel Dis 2007) [source] Assessment of bioactive and bio-adhesive therapies to enhance stem cell attachment to root surface dentineINTERNATIONAL ENDODONTIC JOURNAL, Issue 7 2009M. A. Elseed Abstract Aim, To compare bioactive and bio-adhesive therapies to enhance stem cell attachment to the root dentine of human teeth. Methodology, Dentine slabs (n = 72) were cut from the lower 3 mm of the roots of extracted human permanent teeth. The root dentine slabs were untreated, or coated with bio-adhesive, or human recombinant transforming growth factor-beta1 (hrTGF-B1), or human recombinant bone morphogenic protein-2 (hrBMP-2). The dentine slabs were placed with the root surface in contact with confluent periodontal stem cell (PSC) cultures using aseptic techniques. The cells and dentine slabs were submerged in culture media for 4, 24 and 72 h. The specimens were fixed in formalin, dehydrated and processed for scanning electron microscopy (SEM). Results, SEM micrographs at ×2000 magnification revealed PSC extensive adherence to root dentine for all of the bio-adhesive and bioactive treatments. The addition of bioactive molecules did not improve PSC attachment. Few cells attached to the negative control treatments. Conclusions, Bio-adhesive and bioactive growth factors were not needed to promote PSC attachment to the root dentine of human teeth, because it already appears to have good natural properties to promote PSC attachment. This suggests PSC can be used for the clinical replantation of avulsed teeth without the need for bio-adhesive and bioactive treatments. [source] Pigment and amylase production in Penicillium sp NIOM-02 and its radical scavenging activityINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 12 2009Mohan Appasaheb Dhale Abstract Penicillium sp NIOM-02 was isolated from the marine sediment, produced red pigment. The pigment extracted from this fungus scavenged 2, 2-diphenyl-1-pycrylhydrazyl (DPPH) radical. Penicillium sp NIOM-02 grown in media containing corn steep liquor scavenged 72,88% of DPPH radical. During solid-state fermentation on wheat (S1), the fungus produced more pigment (9.232 OD Units). Penicillium sp NIOM-02 grown on sugarcane bagasse scavenged 91% of DPPH radicals. It secreted more amylase (246 U mg,1) in culture medium No. 5 and the zymogram analysis revealed its molecular mass (53 kDa). The taka-amylase like character of amylase was determined by acarbose incorporated studies in the culture media. Production of pigment and radical scavenging activity of Penicillium sp NIOM-02, suggested its applications in food, pharmaceuticals and nutraceutical industries. [source] Bacterial dormancy in Campylobacter: abstract theory or cause for concern?INTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 6 2001John E. Moore For the past 100 years, since the birth of modern microbiology, this discipline has predominantly relied on the ability to culture micro-organisms in vitro on artificial synthetic culture media under controlled conditions in the laboratory. However, sometimes it is not possible to detect foodborne pathogens using such conventional techniques. Employment of these techniques can also lead to a delay in detection of pathogens. The ,viable but non-culturable' (VNC) cellular form has been demonstrated in Campylobacter jejuni, representing a resting or dormant stage, which is induced through cell stress including starvation. This form is extremely difficult to detect and generally requires complex and sophisticated technology which is usually not available in most routine food microbiology laboratories. This review aims at examining the role of this cell form in Campylobacter, including their historical evolution, formation, physiology, detection and to discuss the challenges that this form presents to food safety. [source] Medium, Explant and Genotype Factors Influencing Shoot Regeneration in Oilseed Brassica spp.JOURNAL OF AGRONOMY AND CROP SCIENCE, Issue 5 2003G. X. Tang Abstract The effects of culture media, explants and genotypes on shoot regeneration in oilseed Brassica species were examined in this study. The maximum shoot regeneration frequency was obtained in Murashige and Skoog medium supplemented with 3 mg l,1 6-benzylaminopurine and 0.15 mg l,1 1-naphthaleneacetic acid. The addition of 2.5 mg l,1 AgNO3 was very beneficial to shoot regeneration in B. napus and Ag2S2O3 (10 mg l,1) was even superior to AgNO3 (2.5 mg l,1). Explant age, explant type and carbon source also significantly affected shoot regeneration. Four-day-old seedlings of cotyledonary explants showed the maximum shoot regeneration frequency and number of shoots per explant. Of the four explants , peduncles, hypocotyls, cotyledons and leaf petioles , cotyledons produced the highest shoot regeneration frequency (56.67 %). Four carbon sources , glucose, maltose, starch and sucrose , were compared for their respective effects on shoot regeneration from cotyledonary explants. Sucrose appeared to be the best carbon source for shoot regeneration with the highest shoot regeneration frequency (76.00 %). Considerable variation in shoot regeneration from cotyledonary explants was observed both between and within Brassica species. The shoot regeneration frequency ranged from 10.00 % for cv. R5 (B. rapa) to 83.61 % for cv. N1 (B. napus). Two B. napus, one B. carinata and one B. juncea cultivars exhibited shoot regeneration frequency higher than 70 %. In terms of the number of shoots produced per explant, B. rapa showed the highest variation, ranging from 5.64 for cv. R3 to 1.33 for cv. R5. Normal plantlets were regenerated from all induced shoots and developed normally. The regenerated plants were fertile and identical with the source plants. [source] The persistence of bifidobacteria populations in a river measured by molecular and culture techniquesJOURNAL OF APPLIED MICROBIOLOGY, Issue 4 2009X. Bonjoch Abstract Aims:, To determine relative to faecal coliforms (FC) and sulfite-reducing clostridia (SRC), the environmental persistence of natural populations of Bifidobacterium spp. enumerated by culturing and quantitative polymerase chain reaction (q-PCR). Methods and Results:, Dialysis tubing containing river supplemented with overnight cultures of Bifidobacterium adolescentis (BA) and Bifidobacterium dentium (BD) or urban wastewater were suspended in a river for up to 10 days. At intervals, the contents of each dialysis tube were assayed using q-PCR assays for BA and BD, and selective culture media for FC, SRC, total bifidobacteria (TB), sorbitol-fermenting bifidobacteria (SFB) and cultivable BA. Mean summer T90 values were 251 h for SRC, 92 h for FC, 48 h for BA and BD by q-PCR, and 9 h for TB. Conclusions:,Bifidobacterium spp. was the population with the lowest persistence, showing seasonal differences in T90 when measured by culture techniques or by q-PCR. This difference in relative persistence is because of a longer persistence of molecular targets than cultivable cells. Significance and Impact of the Study:, The persistence of a viable bifidobacteria cells is shorter, but the longest persistence of molecular targets. This factor could be used for origin the faecal pollution in water for the development of microbial source tracking (MST). [source] A novel finding that Streptomyces clavuligerus can produce the antibiotic clavulanic acid using olive oil as a sole carbon sourceJOURNAL OF APPLIED MICROBIOLOGY, Issue 6 2008G. Efthimiou Abstract Aims:, This study aims to establish whether commercially available food oils can be used by Streptomyces clavuligerus as sole carbon sources for growth and clavulanic acid production. Methods and results:, Batch cultures in bioreactors showed that Strep. clavuligerus growth and clavulanic acid yields in a P-limited medium containing 0.6% (v/v) olive oil were respectively 2.5- and 2.6-fold higher than in a glycerol-containing medium used as control. Glycerol- and olive oil-grown cells present different macromolecular composition, particularly lipid and protein content. Conclusions:,Streptomyces clavuligerus uses olive oil as the sole carbon and energy source for growth and clavulanic acid production. Yields and production rates in olive oil are comparable to those reported for oil-containing complex media. Differences in yields and in the macromolecular composition indicate that different metabolic pathways convert substrate into product. Significance and impact of the study:, This is the first report of oils being used as the sole carbon source by Strep. clavuligerus. Apart from economic benefits, interesting questions are raised about Strep. clavuligerus physiology. Defined culture media allow physiological studies to be performed in the absence of interference by other compounds. Understanding how Strep. clavuligerus catabolises oils may have an economic impact in clavulanic acid production. [source] The application of chromogenic media in clinical microbiologyJOURNAL OF APPLIED MICROBIOLOGY, Issue 6 2007J.D. Perry Summary Since 1990, a wide range of chromogenic culture media has been made commercially available providing useful tools for diagnostic clinical microbiology. By the inclusion of chromogenic enzyme substrates targeting microbial enzymes, such media are able to target pathogens with high specificity. Examples of target pathogens include Staphylococcus aureus, Streptococcus agalactiae, Salmonella spp. and Candida spp. The inclusion of multiple chromogenic substrates into culture media facilitates the differentiation of polymicrobial cultures, thus allowing for the development of improved media for diagnosis of urinary tract infections and media for the enhanced discrimination of yeasts. The purpose of this review is to provide some insight into how such media work and appraise their utility in routine clinical diagnostics, in comparison with conventional media. [source] Viable but non-culturable Listeria monocytogenes on parsley leaves and absence of recovery to a culturable stateJOURNAL OF APPLIED MICROBIOLOGY, Issue 4 2007N. Dreux Abstract Aims:, To investigate the presence of viable but non-culturable Listeria monocytogenes during survival on parsley leaves under low relative humidity (RH) and to evaluate the ability of L. monocytogenes to recover from VBNC to culturable state under satured humidity. Methods and Results:, Under low RH (47,69%) on parsley leaves, the initial number of L. monocytogenes populations counted on non selective media (109 L. monocytogenes per leaf on TSA) was reduced by 6 log10 scales in 15 days, whereas number of viable L. monocytogenes counted under the microscope was reduced by 3,4 log10 scales, indicating the presence of VBNC cells. This was demonstrated on three L. monocytogenes strains (EGDe, Bug 1995 and LmP60). Changing from low to 100% RH permitted an increase of the culturable counts of L. monocytogenes and this growth was observed only when residual culturable cells were present. Moreover, VBNC L. monocytogenes inoculated on parsley leaves did not become culturable after incubation under 100% RH. Conclusions:, Dry conditions induced VBNC L. monocytogenes on parsley leaves but these VBNC were likely unable to recover culturability after transfer to satured humidity. Significance and Impact of Study:, Enumeration on culture media presumably under-estimates the number of viable L. monocytogenes on fresh produce after exposure to low RH. [source] Characterization of dominant microbiota of a Ghanaian fermented milk product, nyarmie, by culture- and nonculture-based methodsJOURNAL OF APPLIED MICROBIOLOGY, Issue 6 2006M. Obodai Abstract Aims:, To characterize the predominant micro-organisms in a Ghanaian traditional fermented dairy product, nyarmie, made from cows' milk, using both culture- and nonculture-based methods. Methods and Results:, Samples of nyarmie were analysed from three production sites in Accra, by determining the counts on selective culture media. The microbial diversity occurring in nyarmie was also evaluated by 16S/18S ribosomal DNA PCR amplification and denaturing gradient gel electrophoresis. Results showed that nyarmie contained lactococci and lactobacilli in the range of 108 and 1010 CFU ml,1, respectively, and yeasts at around 107 CFU ml,1. The pH ranged between 3·49 and 4·25. The predominant lactic acid bacteria (LAB) in nyarmie were Leuconostocmesenteroides ssp. mesenteroides, Streptococcus thermophilus, Lactobacillus delbrueckii ssp. bulgaricus, Lact.helveticus, Lact. delbrueckii ssp. lactis and Lactococcus lactis, while Saccharomyces cerevisiae was the predominant yeast species. Lactobacillus delbrueckii ssp. delbrueckii was not detected by cultivation but its predominance was revealed by PCR-DGGE analysis. Conclusions:, The flora in products from different producers varied in the LAB composition present and may result in variations in product quality. Significance and Impact of the Study:, Development and use of starter cultures for nyarmie may be beneficial in improving the consistency of product quality. [source] Flocculation onset in Saccharomyces cerevisiae: the role of nutrientsJOURNAL OF APPLIED MICROBIOLOGY, Issue 2 2005S. Sampermans Abstract Aims:, To examine the role of the nutrients on the onset of flocculation in an ale-brewing strain, Saccharomyces cerevisiae NCYC 1195. Methods and Results:, Flocculation was evaluated using the method of Soares, E.V. and Vroman, A. [Journal of Applied Microbiology (2003) 95, 325]. For cells grown in chemically defined medium (yeast nitrogen base with glucose) or in rich medium (containing yeast extract, peptone and fermentable sugars: fructose or maltose), the onset of flocculation occurred after the end of exponential respiro-fermentative phase of growth being coincident with the attainment of the lower level of carbon source in the culture medium. Cells, in exponential respiro-fermentative phase of growth, transferred to a glucose-containing medium without nitrogen source, developed a flocculent phenotype, while these carbon source starved cells, in the presence of all other nutrients that support growth, did not flocculate. In addition, cells in exponential phase of growth, under catabolite repression, when transferred to a medium containing 0·2% (w/v) of fermentable sugar (fructose or maltose) or 2% (v/v) ethanol, showed a rapid triggering of flocculation, while when incubated in 2% (v/v) glycerol did not develop a flocculent phenotype. Conclusions:, The onset of flocculation occurs when a low sugar and/or nitrogen concentration is reached in culture media. The triggering of flocculation is an energetic dependent process influenced by the carbon source metabolism. The presence of external nitrogen source is not necessary for developing a flocculent phenotype. Significance and Impact of the Study:, This work contributes to the elucidation of the role of nutrients on the onset of flocculation in NewFlo phenotype yeast strains. This information might be useful to the brewing industry, in the control of yeast flocculation, as the time when the onset of flocculation occurs can determine the fermentation performance and the beer quality. [source] Bile salts and cholesterol induce changes in the lipid cell membrane of Lactobacillus reuteriJOURNAL OF APPLIED MICROBIOLOGY, Issue 1 2003M.P. Taranto Abstract Aims: The objective of this study was to evaluate the effect of bile salts and cholesterol in the lipid profile of Lactobacillus reuteri CRL 1098 and to determine the relationship existing between these changes: the in vitro removal of cholesterol and the tolerance of the cells to acid and cold stress. Methods and Results:Lactobacillus reuteri CRL 1098 was grown in the following media: MRS (deMan Rogosa Sharpe; MC, control medium), MB (MC with bile salts), MCH (MC with sterile cholesterol) and MBCH (MC with bile salts and cholesterol). Fatty acids were determined by analytical gas,liquid chromatography, and phospholipids and glycolipids by colorimetric techniques. The cells from different culture media were subjected to cold and acid stress. The MB cultures displayed a decrease in phospholipids and a low ratio of saturated : unsaturated fatty acids. The presence of the unusual C18 : 0,10-OH and C18 : 0,10-oxo fatty acids was the prominent characteristic of the bile salts growing cells. The relative increase in glycolipids and the changes in the fatty acids profiles of the MB cells would be responsible for the cholesterol remotion. The changes induced by bile salts in the lipid profile did not improve the tolerance of L. reuteri CRL 1098 to freezing and acid stress. Conclusions: The changes in lipid profiles reported in this study would play a key role in the response of Lactobacilli to environmental stress. Significance and Impact of the Study: This work provides useful information about the effect of bile salts on the cell membrane of L. reuteri, a probiotic enterolactobacillus. The steady-state response of the cells subjected to bile stress seems to be the appropriate model for evaluating the bacterial behaviour in detergent-containing gastrointestinal tracts, where the bile salts stress would presumably be continuous. [source] TC -tuned biocompatible suspension of La0.73Sr0.27MnO3 for magnetic hyperthermiaJOURNAL OF BIOMEDICAL MATERIALS RESEARCH, Issue 2 2008N. K. Prasad Abstract La1,xSrxMnO3, a ferromagnet with high magnetization and Curie temperature TC below 70°C, enables its use for magnetic hyperthermia treatment of cancer with a possibility of in vivo temperature control. We found that La0.73Sr0.27MnO3 particles of size range 20,100 nm showed saturation magnetization around 38 emu/g at 20 kOe and a TC value of 45°C. Aqueous suspension of these nanoparticles was prepared using a polymer, acrypol 934, and the biocompatibility of the suspension was examined using HeLa cells. A good heating ability of the magnetic suspension was obtained in the presence of AC magnetic field, and it was found to increase with the amplitude of field. The suspension having concentration of 0.66 mg/mL (e.g., 0.66 mg of nanoparticles with acropyl per milliliter of culture media) was observed to be biocompatible even after 96 h of treatment, as estimated by sulforhodamine B and trypan blue dye exclusion assays. Further, the treatment with the aforementioned concentration did not alter the microtubule cytoskeleton or the nucleus of the cells. However, the bare particles (concentration of 0.66 mg of nanoparticles per milliliter of culture media, but without acropyl) decreased the viability of cell significantly. Our in vitro studies suggest that the suspension (concentration of 0.66 mg/mL) may further be analyzed for in vivo studies. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008 [source] Thiazide Diuretics Affect Osteocalcin Production in Human Osteoblasts at the Transcription Level Without Affecting Vitamin D3 ReceptorsJOURNAL OF BONE AND MINERAL RESEARCH, Issue 5 2000D. Lajeunesse Abstract Besides their natriuretic and calciuretic effect, thiazide diuretics have been shown to decrease bone loss rate and improve bone mineral density. Clinical evidence suggests a specific role of thiazides on osteoblasts, because it reduces serum osteocalcin (OC), an osteoblast-specific protein, yet the mechanisms implicated are unknown. We therefore investigated the role of hydrochlorothiazide (HCTZ) on OC production by the human osteoblast-like cell line MG-63. HCTZ dose-dependently (1,100 ,M) inhibited 1,25-dihydroxyvitamin D3 [1,25(OH)2D3]- induced OC release by these cells (maximal effect, ,40,50% and p < 0.005 by analysis of variance [ANOVA]) as measured by ELISA. This effect of HCTZ on OC release was caused by a direct effect on OC gene expression because Northern blot analysis revealed that OC messenger RNA (mRNA) levels were reduced in the presence of increasing doses of the diuretic (,47.2 ± 4.0%; p < 0.0001 by paired ANOVA with 100 ,M HCTZ). HCTZ (100 ,M) also stimulated calcium (Ca2+) uptake (8.26 ± 1.78 pmol/mg protein/15 minutes vs. 13.6 ± 0.49 pmol/mg protein/15 minutes; p < 0.05) in MG-63 cells. Reducing extracellular Ca2+ concentration with 0.5 mM EDTA or 0.5 mM ethylene glycol-bis(,-amino ethyl ether)- N,N,N',N' -tetraacetic acid (EGTA) only partly prevented the inhibitory effect of the diuretic on OC secretion (maximal effect, ,22.5 ± 6.9%), suggesting that thiazide-dependent Ca2+ influx is not sufficient to elicit the inhibition of OC secretion. Because OC production is strictly dependent on the presence of 1,25(OH)2D3 in human osteoblasts, we next evaluated the possible role of HCTZ on vitamin D3 receptors (VDR) at the mRNA and protein levels. Both Northern and Western blot analyses showed no effect of HCTZ (1,100 ,M) on VDR levels. The presence of EGTA in the culture media reduced slightly the VDR mRNA levels under basal condition but this was not modified in the presence of increasing levels of HCTZ. The OC gene promoter also is under the control of transcription factors such as Yin Yang 1 (YY1) and cFOS. Western blot analysis revealed no changes in YY1 levels in response to HCTZ either in the presence or in the absence of 0.5 mM EGTA in the culture media. In contrast, HCTZ induced a dose-dependent increase in cFOS levels (p < 0.002 by ANOVA), a situation prevented by incubation with EGTA. These studies indicate that HCTZ inhibits OC mRNA expression independently of an effect on VDR, YY1, or extracellular Ca2+ levels but involves changes in cFOS levels. As OC retards bone formation/mineralization, the inhibition of OC production by HCTZ could explain its preventive role in bone loss rate. (J Bone Miner Res 2000;15:894,901) [source] | ||||||||||||||||||||||||||||||||||||||||