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Bioactive
Terms modified by Bioactive Selected AbstractsIlicic Acid as a Natural Quiron for the Efficient Preparation of Bioactive ,- and ,-EudesmolEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 21 2009Alejandro F. Barrero Abstract An efficient procedure for the isolation of the sesquiterpene ilicic acid (3) on a multigram scale of extracts obtained from aerial parts of Inula viscosa (Asteraceae) was developed. Acid 3 is an appropriate starting material for short, enantiospecific syntheses of ,-eudesmol (1) and ,-eudesmol (2), natural products featuring significant antiangiogenic and anti-Alzheimer properties. Synthesis of 1 was achieved in six steps and the synthesis of 2 in seven, producing overall yields of 52 and 41,%, respectively.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source] Bioactive and Degradable Composite Microparticulates for the Tissue Cell Population and Osteogenic DevelopmentADVANCED ENGINEERING MATERIALS, Issue 10 2009Hye-Sun Yu Bioactive and degradable composite microspheres (bioactive glass,synthetic biopolymer) were produced to deliver tissue cells and to aid their osteogenic development targeted for hard tissues. Cellular population (left, SEM cell image at day 3) and osteoblastic differentiation (right, immunofluorescence staining with bone marker at day 14) on the microspheres was evident, suggesting the composite microspheres provided effective 3D substrate conditions for hard tissue regeneration. [source] Evolutions, Revolutions and Trends in Biomaterials Science , A Perspective,ADVANCED ENGINEERING MATERIALS, Issue 12 2007D. Jandt Abstract Despite a number of shortcomings biomaterials for implants have not changed much during the last decades. Yet, there is a revolution ongoing in fundamental biomaterials science research, which introduces new concepts and may help to answer a number of open questions. Bioactive and biomimetic nanomaterials in zero, one or two dimensions may be at the brink of transfer to clinical testing and application. These materials will in the future intervene actively in biological processes, such as protein adsorption, cell binding and growth. [source] Spatiotemporal Control over Molecular Delivery and Cellular Encapsulation from Electropolymerized Micro- and Nanopatterned Surfaces,ADVANCED FUNCTIONAL MATERIALS, Issue 18 2009Eric Stern Abstract Bioactive, patterned micro- and nanoscale surfaces that can be spatially engineered for three-dimensional ligand presentation and sustained release of signaling molecules represent a critical advance for the development of next-generation diagnostic and therapeutic devices. Lithography is ideally suited to patterning such surfaces due to its precise, easily scalable, high-throughput nature; however, to date polymers patterned by these techniques have not demonstrated the capacity for sustained release of bioactive agents. Here a class of lithographically defined, electropolymerized polymers with monodisperse micro- and nanopatterned features capable of sustained release of bioactive drugs and proteins is demonstrated. It is shown that precise control can be achieved over the loading capacity and release rates of encapsulated agents and this aspect is illustrated using a fabricated surface releasing a model antigen (ovalbumin) and a cytokine (interleukin-2) for induction of a specific immune response. Furthermore, the ability of this technique to enable three-dimensional control over cellular encapsulation is demonstrated. The efficacy of the described approach is buttressed by its simplicity, versatility, and reproducibility, rendering it ideally suited for biomaterials engineering. [source] Three-Dimensional Bioactive and Biodegradable Scaffolds Fabricated by Surface-Selective Laser Sintering ,ADVANCED MATERIALS, Issue 3 2005N. Antonov Surface-selective laser sintering (SSLS) has been developed for fabrication of three-dimensional polymer composite scaffolds with precise dimensions and intricate structure (see Figure), which are bioactive and biodegradable. SSLS allows sintering of polymer powders by melting only the surface layers of particles, which prevents overheating of internal domains, allowing incorporation of bioactive molecules into the structures. [source] Bioactive and mechanically strong Bioglass®-poly(D,L -lactic acid) composite coatings on surgical suturesJOURNAL OF BIOMEDICAL MATERIALS RESEARCH, Issue 2 2006Q. Z. Chen Abstract New coating processes have been investigated for degradable (Vicryl®) and nondegradable (Mersilk®) sutures with the aim to develop Bioglass® coated polymer fibers for wound healing and tissue engineering scaffold applications. First, the aqueous phase of a Bioglass® particle slurry was replaced with a poly(D,L -lactic acid) (PDLLA) polymer dissolved in solvent dimethyle carbonate (DMC) to act as third phase. SEM observations indicated that this alteration significantly improved the homogeneity of the coatings. Second, a new coating strategy involving two steps was developed: the sutures were first coated with a Bioglass®,PDLLA composite film followed by a second PDLLA coating. This two-step process of coating has addressed the problem of poor adherence of Bioglass® particles on suture surfaces. The coated sutures were knotted to determine qualitatively the mechanical integrity of the coatings. The results indicated that adhesion strength of coatings obtained by the two-step method was remarkably enhanced. A comparative assessment of the bioactivity of one-step and two-step produced coatings was carried out in vitro using acellular simulated body fluid (SBF) for up to 28 days. Coatings produced by the two-step process were found to have similar bioactivity as the one-step produced coatings. The novel Bioglass®/PDLLA/Vicryl® and Bioglass®/PDLLA/Mersilk® composite sutures are promising bioactive materials for wound healing and tissue engineering applications. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2006 [source] Bioactive brominated diterpenes from the marine red alga Jania Rubens (L.) Lamx.PHYTOTHERAPY RESEARCH, Issue 4 2004Nagwa E. Awad Abstract Seven brominated diterpenes of the parguerene and isoparguerene series were isolated for the ,rst time from the red alga Jania rubens (L.) Lamx., collected from the Red Sea coast at Hurghada, Egypt. The diterpenes were identi,ed as isoparguerol (1), isoparguerol-16-acetate (2), isoparguerol-7,16-diacetate (3), parguerol-16-acetate (4), parguerol-7,16-diacetate (5), deoxyparguerol (6) and deoxyparguerol-7-acetate (7). The isolated diterpenes had a marked antitumour activity. Isoparguerol derivatives were slightly more effective than parguerol derivatives. Moreover, the data implied that the cytotoxicity of these compounds were dependent on the number of acetoxy groups. Also, anthelmintic activities of the isolated compounds on earthworms (Allolobophora caliginosa) were studied. Copyright © 2004 John Wiley & Sons, Ltd. [source] Delivery of bioactive, gel-isolated proteins into live cellsELECTROPHORESIS, Issue 9 2003Jennifer E. Taylor Abstract The delivery of proteins into live cells is a promising strategy for the targeted modulation of protein-protein interactions and the manipulation of specific cellular functions. Cellular delivery can be facilitated by complexing the protein of interest with carrier molecules. Recently, an amphipatic peptide was identified, Pep-1 (KETWWETWWTE WSQPKKKRKV), which crosses the plasma membrane of many cell types to carry and deliver proteins as large as antibodies. Pep-1 effectively delivers proteins in solution; but Pep-1 is not suitable for delivering sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) isolated proteins because Pep-1 complexes with cargo proteins are destroyed by SDS. Here, we report cellular delivery of SDS-PAGE-isolated proteins, without causing cellular damage, by using a nonionic detergent, Triton X-100, as carrier. To determine the specificity of our method, we separated antibodies against different intracellular targets by nonreducing SDS-PAGE. Following electrophoresis, the antibody bands were detected by zinc-imidazole reverse staining, excised, in-gel refolded with Triton X-100, and eluted in detergent-free phosphate-buffered saline. When overlaid on cultured NIH 3T3 cells, the antibodies penetrated the cells localizing to their corresponding intracellular targets. These results are proof-of-principle for the delivery of gel-isolated bioactive proteins into cultured cells and suggest new ways for experimental protein therapy and for studying protein-protein interactions using gel-isolated protein. [source] Apatite Deposition on NaOH-Treated PEEK and UHMWPE Films for Sclera Materials in Artificial Cornea Implants,ADVANCED ENGINEERING MATERIALS, Issue 7 2010Monica Pino Abstract Cornea implants consist of a clear optic portion with a surrounding ring known as the skirt, which needs to integrate with the sclera. However, currently used skirt materials lead to poor tissue integration. Improvements in this respect may be achieved by using a bioactive skirt material that adapts to the metabolic activity of the cornea. Polyether etherketone (PEEK) and ultra-high molecular weight polyethylene (UHMWPE) might provide interesting alternatives, if they can be rendered bioactive. We, therefore, investigated the potential of surface-modifying PEEK and UHMWPE films through the use of a two-step treatment. This process involved a suitable chemical surface modification (via immersion in NaOH), with subsequent formation of apatite layers on the polymers' surfaces through exposure to supersaturated simulated body fluid (1.5 SBF). In the present work the effect of 5 and 10,M NaOH on formation of the apatite layer has been investigated with regard to wettability and topography features. In addition, the chemical stability of the apatite layer formed has been analyzed. Our data demonstrate that with an increase in NaOH concentration the wettability of the polymer increased, whilst some changes to the polymer film topography (increase/decrease in roughness) were observed. Most beneficially, the apatite layer that subsequently was grown on pre-treated PEEK and UHMWPE films through immersion in 1.5 SBF contained phosphate and carbonate ions, in similar ratios to those found in the apatite in dentine, thus, promising good in vivo bioactivity of these polymer films,a necessity if they are to be integrated into artificial cornea. [source] Bovine Serum Albumin and Lysozyme Adsorption on Calcium Phosphate ParticlesADVANCED ENGINEERING MATERIALS, Issue 1-2 2010Berit Mueller Two model proteins that are oppositely charged at neutral pH , bovine serum albumin (BSA) and lysozyme, with acidic and alkaline isoelectric points, respectively , are used to investigate the protein adsorption behaviour of hydroxyapatite and beta-tricalcium phosphate (, -TCP) particles. Both calcium phosphate based particles are highly relevant for the fabrication of bioactive and resorbable bone implants. The investigations are carried out by combining zeta potential and Vis spectroscopy measurements. The changes of zeta potential and isoelectric point are determined as a function of added protein. Both proteins form a monolayer on , -TCP, while on hydroxyapatite only semi-monolayers were measured. For BSA, a side-on adsorption mode is suggested, whereas end-on adsorption appears to be most likely for lysozyme. The zeta potential curves as a function of adsorbed protein show that plateaus of the protein amounts adsorbed increase with charge saturation. In addition, the spatial charge distribution of both proteins is modelled to get a further understanding of the initial adsorption orientation of the biomolecules, supporting the findings from the experimental data. The reported findings can be transferred to the adsorption behaviour of a variety of proteins on calcium phosphate surfaces and are helpful for the fabrication of bone-analogous calcium phosphate/protein nanocomposites. [source] Novel Spiroheterocycles by Aziridination of ,-Methylene-,- and -,-lactamsEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 14 2007M. Antonietta Loreto Abstract New potentially bioactive ,-spiroaziridino-,- and -,-lactams have been prepared by treatment of ,-methylene-,- and -,-lactams with ethyl N -{[(4-nitrophenyl)sulfonyl]oxy}carbamate (NsONHCO2Et) in the presence of CaO. These compounds, through reductive aziridine ring opening, can be intermediates for the synthesis of ,- and ,-aminolactams, which are useful as conformational constraints in peptides. The above procedure has been successfully extended to one ,-methyleneoxindole to obtain a new spirooxindole derivative, a potential precursor of natural alkaloids. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source] Effective Methods for the Synthesis of N -Methyl , -Amino Acids from All Twenty Common , -Amino Acids Using 1,3-Oxazolidin-5-ones and 1,3-Oxazinan-6-onesHELVETICA CHIMICA ACTA, Issue 11 2006Andrew Abstract N -Methyl , -amino acids are generally required for application in the synthesis of potentially bioactive modified peptides and other oligomers. Previous work highlighted the reductive cleavage of 1,3-oxazolidin-5-ones to synthesise N -methyl , -amino acids. Starting from , -amino acids, two approaches were used to prepare the corresponding N -methyl , -amino acids. First, , -amino acids were converted to N -methyl , -amino acids by the so-called ,1,3-oxazolidin-5-one strategy', and these were then homologated by the Arndt,Eistert procedure to afford N -protected N -methyl , -amino acids derived from the 20 common , -amino acids. These compounds were prepared in yields of 23,57% (relative to N -methyl , -amino acid). In a second approach, twelve N -protected , -amino acids could be directly homologated by the Arndt,Eistert procedure, and the resulting , -amino acids were converted to the 1,3-oxazinan-6-ones in 30,45% yield. Finally, reductive cleavage afforded the desired N -methyl , -amino acids in 41,63% yield. One sterically congested , -amino acid, 3-methyl-3-aminobutanoic acid, did give a high yield (95%) of the 1,3-oxazinan-6-one (65), and subsequent reductive cleavage gave the corresponding AIBN-derived N -methyl , -amino acid 61 in 71% yield (Scheme,2). Thus, our protocols allow the ready preparation of all N -methyl , -amino acids derived from the 20 proteinogenic , -amino acids. [source] Preparation, Bioactivity, and Drug Release of Hierarchical Nanoporous Bioactive Glass Ultrathin FibersADVANCED MATERIALS, Issue 6 2010Youliang Hong Hierarchical nanoporous bioactive glass ultrathin fibers with different pore diameters from 1.5-nm micropores up to 65-nm macropores are synthesized using P123,PEO co-templates and an electrospinning technique (see image). Experiments demonstrate that the prepared bioactive glass fibers are highly homogenous and bioactive and their nanopores can control drug release well. [source] Bioactivity of novel carboxymethyl chitosan scaffold incorporating MTA in a tooth modelINTERNATIONAL ENDODONTIC JOURNAL, Issue 10 2010R. Budiraharjo Budiraharjo R, Neoh KG, Kang ET, Kishen A. Bioactivity of novel carboxymethyl chitosan scaffold incorporating MTA in a tooth model. International Endodontic Journal, 43, 930,939, 2010. Abstract Aim, To characterise the bioactivity of a novel carboxymethyl chitosan (CMCS) scaffold with and without incorporating mineral trioxide aggregate (MTA) in a tooth model. Methodology, Cross-linked CMCS scaffold (CaC) and MTA-coated CaC (CaMT) scaffold were prepared by freeze-drying. The bioactivity of the scaffolds was tested in vitro in four different mineralisation solutions (bulk system) and ex vivo in simulated body fluid (SBF) in the tooth model. After mineralisation, the mineral deposits on the scaffolds were analysed using scanning electron microscopy, energy dispersive X-ray, and inductively coupled plasma mass spectroscopy. All data were statistically analysed using the two-sample t -test (P < 0.05). Results, Hydroxyapatite (HAP) deposition was observed on CaC and CaMT scaffolds after 1 week of mineralisation in the tooth model and in the bulk system. The deposition was significantly higher (P < 0.05) on CaMT scaffold than that on CaC scaffold. The amount of HAP formed in the tooth model was significantly lower (P < 0.05) than that in the bulk solution. Conclusions, The CMCS scaffolds are bioactive and capable of biomineralisation by forming HAP within a tooth model ex vivo. The bioactivity of the CMCS scaffold can be enhanced by incorporating MTA. [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] Three-Dimensional Bioactive and Biodegradable Scaffolds Fabricated by Surface-Selective Laser Sintering ,ADVANCED MATERIALS, Issue 3 2005N. Antonov Surface-selective laser sintering (SSLS) has been developed for fabrication of three-dimensional polymer composite scaffolds with precise dimensions and intricate structure (see Figure), which are bioactive and biodegradable. SSLS allows sintering of polymer powders by melting only the surface layers of particles, which prevents overheating of internal domains, allowing incorporation of bioactive molecules into the structures. [source] Tobramycin and Gentamycin elution analysis between two in situ polymerizable orthopedic compositesJOURNAL OF BIOMEDICAL MATERIALS RESEARCH, Issue 1 2003M. DiCicco Abstract This research analyzed Tobramycin and Gentamycin elution characteristics for two antibiotic-impregnated bone composites: PMMA-based Simplex P® and the novel, hybrid, bioactive, CORTOSSÔ. Experimental results were correlated with composite hydrophilicity and antibiotic phase partitioning behaviors. The phase partitioning experiment was conducted to understand antibiotic solubility in aqueous environments. By comparing experimental results with calculated data, antibiotic release behavior was predicted. Total Tobramycin elution percentages from CORTOSS and Simplex P were 12.5 and 6.4%, respectively. Total Gentamycin elution percentages from CORTOSS and Simplex P were 6.95 and 10.17%, respectively. Phase partitioning data indicate 100% of Tobramycin remains in aqueous phases, being extremely hydrophilic. This is supported by its calculated theoretical value (log P = , 7.32). Results suggest that Tobramycin elution can be attributed to composite hydrophilicity as well as its high degree of hydrophilicity. Fifteen percent of Gentamycin distributes in hydrophobic phases (log P = , 4.22). Despite a lower Gentamycin hydrophilicity, its release was affected by its complexation with polar salts in the leaching buffer, thereby increasing its elution potential, making it appreciably water soluble. CORTOSS is more hydrophilic; therefore the migration of aqueous liquids into the polymer network of CORTOSS facilitates greater antibiotic elution compared with hydrophobic Simplex P. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 65B: 137,149, 2003 [source] In vitro change in mechanical strength of ,-tricalcium phosphate/copolymerized poly- L -lactide composites and their application for guided bone regenerationJOURNAL OF BIOMEDICAL MATERIALS RESEARCH, Issue 2 2002Masanori Kikuchi Abstract Novel composites of bioactive ,-tricalcium phosphate [Ca3(PO4)2] and biodegradable copolymerized poly- L -lactide (CPLA) were prepared by a heat-kneading method. The mechanical and chemical changes of the composites were evaluated in vitro by soaking in physiological saline and Dulbecco's phosphate buffered saline. When soaked in physiological saline, the 3-point mechanical strength decreased rapidly from 60 to 30 MPa in the initial 4 weeks and then gradually reached a plateau; the initial decrease in the mechanical strength was ascribed to the dissolution of ,-tricalcium phosphate from the surface. The mechanical properties evident at 8,12 weeks were sufficient for the composites to be used as a biodegradable material for regeneration of bone because the hydrolysis of CPLA was inhibited in both physiological saline and phosphate-buffered saline as a result of a pH-buffering effect. Composite membranes 250-,m thick were used to regenerate large bone defects in beagle dogs: 10 × 10 × 10 mm3 in volume in the mandible and 20 mm in length in the tibia. The afflicted areas covered with the composite membranes were almost perfectly filled with new bone 12 weeks after the operation, whereas those covered with a CPLA membrane or without any membranes were invaded by soft tissue. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 62: 265,272, 2002 [source] Sustained low-dose growth hormone therapy optimizes bioactive insulin-like growth factor-I level and may enhance CD4 T-cell number in HIV infectionJOURNAL OF MEDICAL VIROLOGY, Issue 2 2010Ove Andersen Abstract High-dose recombinant human growth hormone (rhGH) (2,6,mg/day) regimes may facilitate T-cell restoration in patients infected with human immunodeficiency virus (HIV) on highly active antiretroviral therapy (HAART). However, high-dose rhGH regimens increase insulin-like growth factor-I (IGF-I) to supra-physiological levels associated with severe side effects. The present study investigated whether lower doses of rhGH may improve T-cell restoration in patients infected with HIV following an expedient response of total and bioactive (i.e., free) IGF-I. A previous 16-week pilot-study included six HIV-infected patients on stable HAART to receive rhGH 0.7,mg/day, which increased total (+117%, P,<,0.01) and free (+155%, P,<,0.01) IGF-I levels. The study was extended to examine whether continuous use of low-dose rhGH (0.7,mg/day until week 60; 0.4,mg/day from week 60 to week 140) would maintain expedient IGF-I levels and improve CD4 T-cell response. Total and free IGF-I increased at week 36 (+97%, P,<,0.01 and +125%, P,<,0.01, respectively) and week 60 (+77%, P,=,0.01 and +125%, P,<,0.01) compared to baseline levels (161,±,15 and 0.75,±,0.11,µg/L). CD4 T-cell number increased at week 36 (+15%, P,<,0.05) and week 60 (+31%, P,=,0.01) compared to baseline levels (456,±,55,cells/µL). Following rhGH dose reduction, total IGF-I and CD4 T-cell number remained increased at week 88 (+44%, P,=,0.01 and +33%, P,<,0.01) and week 140 (+46%, P,=,0.07 and +36%, P,=,0.02) compared to baseline levels. These data support the notion that low-dose rhGH regimens may increase expediently total and bioactive IGF-I and improve T-cell restoration in patients infected with HIV on HAART. J. Med. Virol. 82:197,205, 2010. © 2009 Wiley-Liss, Inc. [source] An ultrastructural study of cellular response to variation in porosity in phase-pure hydroxyapatiteJOURNAL OF MICROSCOPY, Issue 2 2004B. ANNAZ Summary Hydroxyapatite has been shown to be biocompatible and bioactive. Incorporation of porosity has been shown to enhance osteointegration; however, difficulty in controlling the extent and type of porosity has limited investigation into determining the role of both macro- and microporosity. The current investigation reports on the synthesis of four types of phase-pure hydroxyapatite with varying levels of porosity (HA1,HA4), and with defined levels of macro- and microporosities. Transmission electron microscopy was used to evaluate qualitatively the effect of these two parameters on cell,material interactions following a 30-day incubation period. Biological mineralization was observed within vesicles and the needle-like minerals were confirmed as hydroxyapatite using X-ray microanalysis. This demonstrated the suitability of primary human osteoblast-like cells as a tool to assess the extent of mineralization. Furthermore, internalization of hydroxyapatite particles was observed. Our findings show that the variation in macro- and microporosity does not affect the extent of cell,material interaction, with collagen synthesis evident in all samples. [source] Pharmaceutical strategies to prevent ventilator-associated pneumoniaJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 4 2003Roisin McCrory ABSTRACT The increasing incidence of hospital-acquired (nosocomial) infection is a disturbing phenomenon resulting in significant patient mortality and putting considerable strain on healthcare budgets and personnel. One particularly serious aspect of nosocomial infection is that of ventilator-associated pneumonia (VAP). This arises in patients who receive mechanical ventilation within the intensive care unit. The quoted incidence of VAP varies widely (5,67%) and the reported mortality of patients with VAP is in the range of 24,71%. This review will examine the many factors that account for these wide ranges reported, including the patient population under investigation, the causative organism, the method of diagnosis, interventions employed and preventative strategies. The use of bioactive and drug-impregnated biomaterials for endotracheal tube construction is discussed as novel approaches to the prevention of VAP. [source] Pharmaceutical antibiotic compounds in soils , a reviewJOURNAL OF PLANT NUTRITION AND SOIL SCIENCE, Issue 2 2003Sören Thiele-Bruhn Antibiotics are highly effective, bioactive substances. As a result of their consumption, excretion, and persistence, they are disseminated mostly via excrements and enter the soils and other environmental compartments. Resulting residual concentrations in soils range from a few ,g upto g kg,1 and correspond to those found for pesticides. Numerous antibiotic molecules comprise of a non-polar core combined with polar functional moieties. Many antibiotics are amphiphilic or amphoteric and ionize. However, physicochemical properties vary widely among compounds from the various structural classes. Existing analytical methods for environmental samples often combine an extraction with acidic buffered solvents and the use of LC-MS for determination. In soils, adsorption of antibiotics to the organic and mineral exchange sites is mostly due to charge transfer and ion interactions and not to hydrophobic partitioning. Sorption is strongly influenced by the pH of the medium and governs the mobility and transport of the antibiotics. In particular for the strongly adsorbed antibiotics, fast leaching through soils by macropore or preferential transport facilitated by dissolved soil colloids seems to be the major transport process. Antibiotics of numerous classes are photodegraded. However, on soil surfaces this process if of minor influence. Compared to this, biotransformation yields a more effective degradation and inactivation of antibiotics. However, some metabolites still comprise of an antibiotic potency. Degradation of antibiotics is hampered by fixation to the soil matrix; persisting antibiotics were already determined in soils. Effects on soil organisms are very diverse, although all antibiotics are highly bioactive. The absence of effects might in parts be due to a lack of suitable test methods. However, dose and persistence time related effects especially on soil microorganisms are often observed that might cause shifts of the microbial community. Significant effects on soil fauna were only determined for anthelmintics. Due to the antibiotic effect, resistance in soil microorganisms can be provoked by antibiotics. Additionally, the administration of antibiotics mostly causes the formation of resistant microorganisms within the treated body. Hence, resistant microorganisms reach directly the soils with contaminated excrements. When pathogens are resistant or acquire resistance from commensal microorganisms via gene transfer, humans and animals are endangered to suffer from infections that cannot be treated with pharmacotherapy. The uptake into plants even of mobile antibiotics is small. However, effects on plant growth were determined for some species and antibiotics. Pharmazeutische Antibiotika in Böden , ein Überblick Antibiotika sind hochgradig wirksame, bioaktive Substanzen. Infolge ihrer Anwendung, Ausscheidung und Persistenz werden sie meist über die Exkremente in Böden und andere Umweltkompartimente eingetragen. Die resultierenden Rückstandskonzentrationen in Böden im Bereich von wenigen ,g bis zu g kg,1 entsprechen in etwa denen von Pflanzenschutzmitteln. Die Molekülstruktur von Antibiotika besteht häufig aus einem unpolaren Kern und polaren Randgruppen. Viele Antibiotika sind amphiphil oder amphoter und bilden Ionen, jedoch weisen die zahlreichen Antibiotika unterschiedlicher Strukturklassen stark divergierende physikochemische Eigenschaften auf. In den vorliegenden Nachweis"methoden für Umweltproben werden häufig sauer gepufferte Lösungsmittel zur Extraktion und eine Bestimmung mittels LC-MS kombiniert. Die Adsorption der Antibiotika an den organischen als auch an den mineralischen Bodenaustauschern erfolgt zumeist durch Ladungs- und Ionenwechselwirkungen und weniger durch hydrophobe Bindungen. Das Verteilungsverhalten hängt dabei entscheidend vom pH-Wert des Mediums ab und beeinflusst die Mobilität und Verlagerung der Antibiotika. Bei vielen, insbesondere stark adsorbierten Antibiotika sind v.,a. schnelle Fließvorgänge wie durch präferenziellen und Makroporenfluss sowie der Cotransport mit gelösten Bodenkolloiden von besonderer Bedeutung. Antibiotika vieler Strukturklassen können durch Licht abgebaut werden. Dieser Abbaupfad spielt auf Bodenoberflächen jedoch nur eine untergeordnete Rolle. Hingegen kommt es insbesondere durch biologische Transformationsprozesse zu einer intensiven Degradation und Inaktivierung der Antibiotika. Verschiedene Metaboliten weisen jedoch ebenfalls ein antibiotisches Potential auf. Der Abbau der Antibiotika wird durch die Festlegung in Böden gehemmt; dementsprechend wurde eine Persistenz verschiedener Antibiotika nachgewiesen. Trotz der starken bioaktiven Wirkung aller Antibiotika sind die festgestellten Effekte auf Bodenorganismen sehr unterschiedlich. Dies liegt nicht zuletzt an einem Mangel an geeigneten Testmethoden. In der Regel sind jedoch von Dosis und Wirkungsdauer abhängige Effekte insbesondere auf Mikroorganismen festzustellen, die zu Veränderungen der Mikroorganismenpopulation führen können. Lediglich durch Anthelmintika wurden deutliche Wirkungen auf Vertreter der Bodenfauna hervorgerufen. Infolge der antibiotischen Wirkung der Pharmazeutika kann eine Resistenzbildung bei Bodenorganismen ausgelöst werden. Zudem hat die Medikation von Antibiotika die Bildung resistenter Mikroorganismen bereits im behandelten Organismus zur Folge. Durch deren anschließende Ausscheidung gelangen resistente Keime auch direkt in die Böden. Handelt es sich um resistente Pathogene oder kommt es zur Übertragung der Resistenzgene zwischen kommensalen und pathogenen Mikroorganismen, so besteht das erhebliche Risiko einer nicht therapierbaren Infektion von Mensch und Tier. Die Aufnahme selbst mobiler Antibiotika in die Pflanzen ist sehr gering. Dennoch wurden bei einigen Pflanzenarten Wirkungen von Antibiotika auf das Wachstum nachgewiesen. [source] Characterization of Azerbaijani and Croatian brown naphthalaneJOURNAL OF SEPARATION SCIENCE, JSS, Issue 13 2005Andja Alajbeg Abstract In spite of the fact that noncolored (nonaromatic) naphthalane containing high sterane content has been proved as bioactive and efficient in the treatment of psoriasis vulgaris, brown naphthalanes, which contain aromatics, are still in use. Thousands of patients, who have been passing through the therapy, deserve thorough and permanent study of brown naphthalanes. For that reason, two frequently used brown naphthalane preparations, one of the Azerbaijani (N1) and the other of the Croatian (N2) origin, were studied. The samples underwent the study by means of GC, OT LC, and normal-phase HPLC, as separation techniques. In addition, some bulk properties, elemental composition, and group composition by 1H NMR were determined. GC-MS served in compound types, especially in sterane detection. Both of the samples were found to be unresolved complex mixtures, relatively poor in n -alkanes. Isoalkanes, cycloalkanes, and aromatic compounds, in a great variety of isomers and homologs, made the majority of both of the samples. N1 was a dark, viscous, nontransparent fluid with a strong petroleum smell. Aromatics, which made 53% mass by OT LC and 54% mass by 1H NMR were found to be composed of mono-, di-, and tri+-aromatic compounds. Tri+-aromatic compounds were three to four times more abundant in N1 than in N2. Beside hydrocarbons, N1 comprised some organic compounds with polar functional groups. Also, some asphaltenes were found in it. N1 contained well-presented steranes, which are thought to be bioactive naphthalane ingredients. N2 was a pale brown liquid, with smell similar to gasoline. It contained somewhat lower percentage of aromatics (46% mass) and comparatively lower percentage of tri+ fused aromatics among which carcinogens might be expected. N2 was almost purely composed of hydrocarbons. It seemed to contain low content of steranes due to relatively low upper temperature of the distillation range applied in N2 preparation. [source] Fabrication of a Porous Bioactive Glass,Ceramic Using Room-Temperature Freeze CastingJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 8 2006Ju-Ha Song The room-temperature freeze-casting method was used to fabricate porous bioactive glass,ceramics. In this method, a glass/camphene slurry prepared at 60°C was cast into a mold at 20°C, resulting in the production of a rigid green body that was comprised of three-dimensional dendritic camphene networks surrounded by highly concentrated glass powder walls. After the sublimation of camphene, the samples were sintered for 3 h at elevated temperatures ranging from 700° to 1100°C. As the sintering temperature was increased to 1000°C, the densification of the glass,ceramic wall was remarkably enhanced, while its highly porous structure was preserved. The sample sintered at 1000°C showed a high porosity of 53% and pore channels with a size of several tens of micrometers, as well as dense glass,ceramic walls. In addition, the fabricated samples effectively induced the deposition of apatite on their surfaces when immersed in simulated body fluid, implying that they are very bioactive. [source] Prosaposin-derived peptides enhanced sprouting of sensory neurons in vitro and induced sprouting at motor endplates in vivoJOURNAL OF THE PERIPHERAL NERVOUS SYSTEM, Issue 3 2000W. Marie Campana Abstract Prosaposin exhibits neurotrophic factor properties that are localized to a 12-amino acid sequence located in the amino terminal portion of the saposin C domain. Prosaptides are peptides derived from the neurotrophic portion of prosaposin; these have been previously reported to be bioactive in neuroblastoma cell lines in vitro. We report that prosaptides were also bioactive in explants of adult primary sensory neurons by dose-dependently increasing both the number (3- to 4-fold) and elongation of these neurites by 50%. Local injection of prosaptides into the gluteus muscle of adult mice also induced sprouting at the motor endplate. Our results indicate that prosaptides are potent neuritogenic factors for both sensory and motor neurons of adult peripheral nerve. [source] Composition and properties of biologically active pectic polysaccharides from leek (Allium porrum)JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 12 2010Maria Kratchanova Abstract BACKGROUND: Leek (Allium porrum) is very commonly used vegetable in Bulgaria and is distinctive with high content of bioactive components1. Previously2 we obtained five crude pectic polysaccharides from leek through consecutive extraction. Some of them appeared to be good stimulators of the immune system. Schols and Voragen3 investigated the composition of modified hairy regions of pectic polysaccharides isolated from leek cell walls. Samuelson et al.4 identified the polysaccharide structures encountered in hairy regions as bioactive. The aim of this work was to study the isolation, composition and biological activities of pectic polysaccharides from leek. RESULTS: Two pectic polysaccharides from leek were isolated through consecutive water and acid extraction. The water extractable pectin had higher polyuronic content, higher protein content and lower neutral sugar content. It was found that next to galacturonic acid they also contain glucuronic acid in ratio 9:1 for the water- and 3:1 for the acid-extractable polysaccharide. The main neutral sugar was galactose. The water-extractable pectic polysaccharide had higher molecular weight (106 Da) and homogeneity. It was shown that the pectic polysaccharides from leek have considerable immunostimulating activities. CONCLUSION: Leek polysaccharides have relatively high galacturonic and glucuronic acid content and are distinguished with high biological activity. Copyright © 2010 Society of Chemical Industry [source] Review article: herbal treatment in gastrointestinal and liver disease,benefits and dangersALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 9 2001L. Langmead Herbal medicines are now used by up to 50% of the Western population, in a substantial minority of instances for the treatment or prevention of digestive disorders. Although most indications for the use of such remedies are anecdotally or traditionally derived, controlled trials suggest some benefits for ginger in nausea and vomiting, liquorice extracts in peptic ulceration, Chinese herbal medicine in irritable bowel syndrome, opium derivatives in diarrhoea and senna, ispaghula and sterculia in constipation. Herbal preparations contain many bioactive compounds with potentially deleterious as well as beneficial effects. There is clearly a need for greater education of patients and doctors about herbal therapy, for legislation to control the quality of herbal preparations, and in particular for further randomized controlled trials to establish the value and safety of such preparations in digestive and other disorders. [source] Dietary fiber as a versatile food component: An industrial perspectiveMOLECULAR NUTRITION & FOOD RESEARCH (FORMERLY NAHRUNG/FOOD), Issue 6 2005Robert J. Redgwell Abstract The continued emphasis on the importance of dietary fibers to the Western diet and the need for products with a lower calorific content is pressuring food companies to allocate more resources to the development of fiber-enriched products. The challenge to the industry is to accomplish this goal without sacrificing the organoleptic appeal of some of their core offerings. As future research details specific nutritional benefits of individual components of dietary fiber, food companies will need flexible alternatives in order to validate new ,functional' food claims and to respond rapidly to emerging trends in fiber-enriched products. These objectives will be achieved by understanding the physicochemical basis for the biotechnical functionality of fibers and by developing, and making available fibers which provide a broad spectrum of bioactive and texture modulating properties. [source] Synergistic interaction of physcion and chrysophanol on plant powdery mildewPEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 5 2007Xiaojun Yang Abstract The extract of the plant Rheum officinale Baill, mainly containing the anthraquinones physcion and chrysophanol, is highly active against plant powdery mildew. Experiments were conducted in the laboratory and greenhouse to determine the interaction of the two compounds on cucumber powdery mildew [Sphaerotheca fuliginea (Schlecht.) Poll] and on wheat powdery mildew [Blumeria graminis (DC.) Speer f. sp. tritici Marchal]. Physcion was much more bioactive than chrysophanol against these powdery mildews. There was a significant synergistic interaction between the two compounds on the diseases when the ratios of physcion to chrysophanol ranged from 1:9 to 5:5. The synergistic degree increased with increase in the chrysophanol proportion in the combination. The findings indicate that, in order to ensure constant efficacy of the extract on the disease, both the contents and the proportion of the main active ingredients physcion and chrysophanol have to be determined. Copyright © 2007 Society of Chemical Industry [source] Insecticidal activity of 23 essential oils and their major compounds against adult Lipaphis pseudobrassicae (Davis) (Aphididae: Homoptera)PEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 11 2005Blair J Sampson Abstract Essential oils from 23 species of plants comprising 14 genera and 4 plant families were obtained by Clevenger-type water distillation. The major compounds in these essential oils were identified with GC-MS and their insecticidal activity against adult turnip aphids, Lipaphis pseudobrassicae (Davis), tested with dosage-mortality bioassays. We examined mortality only for viviparous adults because sizeable aphid populations on crucifer (Brassicaceae) hosts are largely produced by these wingless, parthenogenic females. Twenty-two of the oils were directly applied to aphid females in randomized blocks at concentrations of 0.0, 1.0, 2.5, 5.0 and 10.0 mg ml,1. Essential oils mixed with a non-toxic emulsifying agent, dimethyl sulfoxide (DMSO), more easily penetrated the waxy insect cuticle. Probit analysis and LC50 at three different exposures showed aphids were quickly incapacitated and killed by aliphatic aldehydes, phenols and monocyclic terpenes contained in Bifora and Satureja oils and at applied concentrations as low as 0.3 to 1.0 mg ml,1. Only enough Pimpinella isaurica oil and its three phenylpropanoid fractions were available for testing at a single concentration of 10 mg ml,1. We could not spare any additional P. isaurica oil for testing at other concentrations. Phenylpropanoids isolated from P. isaurica oil when recombined or left naturally blended in the oil were highly bioactive against L. pseudobrassicae at 10 mg ml,1. Copyright © 2005 Society of Chemical Industry [source] | |||||||||||||||||||