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Various Media (various + media)
Selected AbstractsEffect of temperature and storage media on human periodontal ligament fibroblast viabilityDENTAL TRAUMATOLOGY, Issue 3 2010Beatriz Dulcineia Mendes Souza The purpose of this study was to compare the effectiveness of several storage media to preserve cultured periodontal ligament fibroblasts (PDLF) under different temperatures. The media tested were: sterile Hank's balanced salt solution (sHBSS), non-sterile HBSS (nHBSS), skimmed milk, Save-A-Tooth®, Minimum Essential Medium (MEM) and water (negative control). MEM at 37°C was used as positive control. PDLF were obtained from explants of extracted healthy human teeth. Plates containing confluent PDLF were soaked in the various media for 3, 6, 24, 48 and 72 h at 37°C and 20°C. After incubation, viability of the cells was determined using the tetrazolium salt-based colorimetric (MTT) assay and the Trypan Blue exclusion test after 6, 24, 48 and 72 h of incubation at 20°C. The results were analyzed statistically using Kruskal,Wallis, Scheffé and Mann,Whitney (, = 5%) tests. Results from the MTT assay at 37°C and 20°C showed that skimmed milk was the best storage medium for up to 24 and 48 h, respectively, followed by nHBSS and sHBSS. Results from the Trypan Blue exclusion test showed that the best storage media were milk, sHBSS and nHBSS, with no statistical differences, for any time period. The Save-A-Tooth® had a detrimental effect on cells after 24 h. The influence of temperature on the effectiveness of the storage media tested showed at 20°C a decreasing order of efficacy as follows: milk > sHBSS and nHBSS > MEM > Save-A-Tooth® > water while at 37°C it was: MEM > nHBSS > milk > sHBSS > Save-A-Tooth® > water. In conclusion, incubation temperature altered the effectiveness of the storage media and skimmed milk at 20°C was better than HBSS in maintaining PDLF viability. [source] Assessment of post-traumatic PDL cells viability by a novel collagenase assayDENTAL TRAUMATOLOGY, Issue 4 2002Roberta Pileggi Abstract,,,Both length of extra-alveolar time and type of storage media are significant factors that can affect the long-term prognosis for replanted teeth. Numerous studies have examined various media in an attempt to determine the ideal material for storage of the avulsed tooth. The purpose of this study was to compare the number of viable periodontium ligament (PDL) cells in different storage media using a collagenase assay. Thirty-three freshly extracted human teeth were divided into four experimental and two control groups. The positive and negative controls corresponded to 0 min and an 8-h dry time, respectively. The experimental teeth were stored dry for 30 min and then immersed in one of four media (Hank's balanced salt solution (HBSS), milk, saline, water) for 45 min. The teeth were then treated with dispase grade II and collagenase for 30 min. The number of viable and nonviable PDL cells was counted with a hemocytometer and analyzed. An anova demonstrated no statistically significant differences in the viability of PDL cells among saline, HBSS and milk. Within the parameters of this study, it appears that milk or saline is an equally viable alternative to HBSS for storage of avulsed teeth. [source] In vitro viability, mitogenicity and clonogenic capacity of periodontal ligament cells after storage in four media at room temperatureDENTAL TRAUMATOLOGY, Issue 2 2000M. Ashkenazi Abstract , The choice of storage medium for preserving traumatically avulsed teeth is important for the success of future replantation. The objective of this study was to compare the effectiveness of four recommended storage media (Hank's balanced salt solution [HBSS], culture medium, , minimal essential medium [,-MEM], and ViaSpan) to preserve cultured periodontal ligament fibroblasts (PDLF) at room temperature (22°C). PDLF were obtained from explants of extracted healthy human teeth. Plates with confluent PDLF were soaked in the various media for 2, 8 and 24 h at room temperature. A control group was incubated with culture medium at 37°C. After incubation, viability of the cells was determined by trypan blue exclusion test. Viable cells were then analyzed for mitogenic (with thymidine) and clonogenic capacity (by culturing one cell/well). Viability of PDLF stored up to 24 h was comparable in all tested media, and the differences were limited to 1%,3%. PDLF stored for up to 24 h in various media had statistically comparable mitogenicity to the control group. After 8 h of storage, the differences were limited to 2%,9%, except for the ,-MEM group which had 23%,29% lower mitogenic capacity compared to the control group. Increasing the storage time up to 24 h further decreased the mitogenicity of the cells by 22%,47%. The highest mitogenicity after 24 h of storage was found in PDLF stored in culture medium or HBSS, and the lowest in ,-MEM. PDLF stored for 2,8 h in various media had a comparable clonogenic capacity to the control group. However, after 24 h, the cells' clonogenic ability dropped by 14%,66%. A similar trend of reduction was noted in the mitogenic and clonogenic capacity, although it was statistically significant only in the clonogenic capacity. Culture medium and ViaSpan, followed by HBSS, were the most effective in preserving the clonogenic capacity of PDLF after 24 h of storage. The lowest clonogenic capacity after 24 h of storage was in the ,-MEM group (66%, P<0.0025). In conclusion, culture medium, followed by HBSS and ViaSpan, was the most effective media for preserving the viability, mitogenicity and clonogenic capacity of PDLF stored for up to 24 h at room temperature. The lowest functional abilities were found in PDLF stored in ,-MEM. [source] Synthesis of Hexagonal-Phase NaYF4:Yb,Er and NaYF4:Yb,Tm Nanocrystals with Efficient Up-Conversion Fluorescence,ADVANCED FUNCTIONAL MATERIALS, Issue 18 2006S. Yi Abstract IR-to-visible up-conversion fluorescent nanocrystals of hexagonal-phase NaYF4:20,%Yb,2,%Er and NaYF4:20,%Yb,2,%Tm have been synthesized by decomposition of multiprecursors of CF3COONa, (CF3COO)3Y, (CF3COO)3Yb, and (CF3COO)3Er/(CF3COO)3Tm in oleylamine at 330,°C. The average particle size is 10.5,±,0.7,nm (from random measurements of 200,particles from five transmission electron microscopy images) and 11.1,±,1.3,nm (from dynamic-light-scattering measurements). The up-conversion fluorescence intensity of the hexagonal nanocrystals in this work is much higher than that of other cubic-phase NaYF4:Yb,Er nanocrystals, including the ones in this work (by a factor of 7.5). Mechanisms for nucleation and growth of the hexagonal-phase nanoparticles are proposed. These nanocrystals are easily dispersed in organic solvents, producing a transparent colloidal solution. The hydrophobic surfaces of the particles are made hydrophilic using a bipolar surfactant. These nanoparticles and their dispersions in various media have potential applications in optical nanodevices and bioprobes. [source] A conceptual selenium management modelINTEGRATED ENVIRONMENTAL ASSESSMENT AND MANAGEMENT, Issue 3 2009Peter M Chapman Abstract We describe herein a conceptual selenium (Se) management model, directed toward coal mining in western Canada, but which can be applied to other coal mines and, with appropriate modification, to other industrial sources of Se to aquatic and terrestrial environments. This conceptual model provides a transparent means to integrate and synthesize existing information that can be used to provide an adaptive approach for managing ecological exposures and associated risk. It is particularly useful for visualizing and subsequently developing management interventions for Se control and risk reduction. The model provides a structured process by which critical information needs can be identified and addressed. It effectively provides the foundation for making management decisions related to Se discharges to aquatic and terrestrial environments by showing interrelationships of the various media and receptors as well as primary sources, release mechanisms, secondary sources, and exposure pathways. [source] Communication media use in the grandparent-grandchild relationshipJOURNAL OF COMMUNICATION, Issue 4 2000J Harwood This study surveyed college-aged grandchildren as to the frequency of their communication with a grandparent using various media. Face-to-face (FtF) and telephone communication were used more frequently than written media, but all were used fairly frequently. Communication using all media was more frequent when the grandparent or grandchild initiated interaction as opposed to the parent. Relationships in which the grandparent initiated contact featured more use of written media (letters, e-mail, cards). Frequency of communication using all media was positively associated with relational quality. Telephone communication best predicted relational quality when use of other media was controlled. In this paper, I discuss implications for media richness theory, the communication predicament of aging model, and future research on grandparent-grandchild relationships. [source] Future integrated learning environments with multimediaJOURNAL OF COMPUTER ASSISTED LEARNING, Issue 1 2001T. Okamoto Abstract, Recent progress in information technology hardware and the spread of the Internet have opened a variety of new ways for many fields. Although slower than the business field to catch up with these new developments, the educational field has gradually migrated towards the World-wide web, mostly under the slogan of free, accessible education, to and from anyplace, at anytime. This development triggered an important shift from the teaching paradigm to the learning paradigm. However, slow network speed hindered the first learning environments from being more than simple, electronic text-books. The latest trends making use of increased bandwidths and integrating various media to enhance learning. Moreover, for obtaining learner-oriented, customised learning environ-ments, intelligent tutoring techniques are being adapted and developed for the web. This paper presents these trends on one hand, but on the other hand, also addresses the dangers and pitfalls that such an avalanche of change can bring and stresses the task of ensuring that the real goal of enhancing and improving learning is not overlooked. [source] Chondrogenic differentiation and lubricin expression of caprine infraspinatus tendon cellsJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 6 2010Tadanao Funakoshi Abstract Reparative strategies for the treatment of injuries to tendons, including those of the rotator cuff of the shoulder, need to address the formation of the cartilage which serves as the attachment apparatus to bone and which forms at regions undergoing compressive loading. Moreover, recent work indicates that cells employed for rotator cuff repair may need to synthesize a lubricating glycoprotein, lubricin, which has recently been found to play a role in tendon tribology. The objective of the present study was to investigate the chondrogenic differentiation and lubricin expression of caprine infraspinatus tendon cells in monolayer and three-dimensional culture, and to compare the behavior with bone marrow-derived mesenchymal stem cells (MSCs). The results demonstrated that while tendon cells in various media, including chondrogenic medium, expressed lubricin, virtually none of the MSCs synthesized this important lubricating molecule. Also of interest was that the cartilage formation capacity of the tendon cells grown in pellet culture in chondrogenic medium was comparable with MSCs. These data inform the use of tendon cells for rotator cuff repair, including for fibrocartilaginous zones. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:716,725, 2010 [source] Student affairs professionals and the mediaNEW DIRECTIONS FOR STUDENT SERVICES, Issue 100 2002Ted Montgomery A good strategy for working with external media is essential to the success of student affairs professionals. Examples of practices that lead to effective engagement with the various media are examined. [source] Fibroblast Growth Factor 2 Promotes Endothelial Differentiation of Adipose Tissue-Derived Stem CellsTHE JOURNAL OF SEXUAL MEDICINE, Issue 4 2009Hongxiu Ning PhD ABSTRACT Introduction., Adipose tissue-derived stem cells (ADSC) could potentially restore endothelial function in vasculogenic erectile dysfunction (ED). The mechanism for ADSC endothelial differentiation remained unidentified. Aim., To test whether ADSC could differentiate into endothelial cells in the penis and to identify the underlying mechanism of ADSC endothelial differentiation. Methods., For in vivo endothelial differentiation, ADSC were labeled with bromodeoxyuridine (BrdU), injected into rat corpora cavernosa, and localized by immunofluorescence and phase-contrast microscopy. For in vitro endothelial differentiation, ADSC were grown in endothelial growth medium 2 (EGM2), stained for endothelial markers CD31, von Willebrand Factor (vWF), and endothelial nitric oxide synthase (eNOS), and assessed for the ability to form tube-like structures in Matrigel and to endocytose acetylated low-density lipoprotein (Ac-LDL). To identify factors that promote ADSC endothelial differentiation, ADSC were grown in various media, each of which contained a specific combination of supplemental factors and assessed for LDL-uptake. PD173074, a selective inhibitor of fibroblast growth factor 2 (FGF2) receptor, was used to confirm the importance of FGF2 signaling for ADSC endothelial differentiation. Main Outcome Measures., In vivo endothelial differentiation was assessed by immunofluorescence microscopy. In vitro endothelial differentiation was assessed by immunofluorescence, Matrigel tube formation, and Ac-LDL uptake. Results., Injected ADSC were localized to the sinusoid endothelium, some of which stained positive for both BrdU and endothelial antigen rat endothelial cell antigen. ADSC proliferated at a faster rate in EGM2 than in standard DMEM, expressed endothelial markers CD31, vWF, and eNOS, formed tube-like structures in Matrigel, and endocytosed Ac-LDL. These properties were greatly diminished when ADSC were grown in the absence of FGF2 but were unaffected when grown in the absence of vascular endothelial growth factor, insulin-like growth factor, or epidermal growth factor. Furthermore, ADSC displayed similar endothelial properties when grown in FGF2-supplemented basic medium as in EGM2. Finally, blockade of FGF2 signaling with PD173074 abrogated ADSC endothelial differentiation. Conclusions., ADSC could differentiate into endothelial cells in the penis. FGF2 signaling mediates ADSC endothelial differentiation. Ning H, Liu G, Lin G, Yang R, Lue TF, and Lin CS. FGF2 promotes endothelial differentiation of adipose tissue-derived stem cells. J Sex Med **;**:**,**. [source] Estimation of intragastric drug solubility in the fed state: comparison of various media with data in aspiratesBIOPHARMACEUTICS AND DRUG DISPOSITION, Issue 6 2009A. Diakidou Abstract The suitability of various media to forecast the solubility of ketoconazole and dipyridamole in the fed stomach at various periods after meal administration was evaluated. Solubilities were measured with the shake-flask method in gastric fluids aspirated 30, 60 and 120,min after administration of 500,ml Ensure plus® to healthy fasted adults, in three sets of simulated gastric fluids based on milk, and in simple aqueous buffered media. Simple aqueous buffered media vastly underestimated the intragastric solubility of model compounds in the fed state. When using undigested milk-based media, the solubilities of model compounds in aspirates were also underestimated by a factor of 2.5,27. Solubility in milk digested with pepsin was useful for estimating the intragastric solubility of ketoconazole (within 20%) but overestimated the intragastric values of dipyridamole by a factor of 2,19. For both drugs, the solubility in milk digested with pepsin and lipase predicted the solubility in aspirates collected 60,min after meal administration, whereas at other times it overestimated the intragastric solubility (by a factor of <5). Both the use of biorelevant media and simulation of intragastric digestion are necessary for the prediction of drug solubility in the fed stomach. Milk digested with pepsin and lipase enabled the estimation of the intragastric solubility of dipyridamole and ketoconazole at 1,h after meal intake. Simulation of vesicle/micellar structures seems to be key for the prediction of intragastric solubility in the fed stomach. Copyright © 2009 John Wiley & Sons, Ltd. [source] Amphipathic control of the 310 -/,-helix equilibrium in synthetic peptidesCHEMICAL BIOLOGY & DRUG DESIGN, Issue 2 2001L. G. J. Hammarström Abstract: A series of short, amphipathic peptides incorporating 80% C,,C, -disubstituted glycines has been prepared to investigate amphipathicity as a helix-stabilizing effect. The peptides were designed to adopt 310 - or ,-helices based on amphipathic design of the primary sequence. Characterization by circular dichroism spectroscopy in various media (1,:,1 acetonitrile/water; 9,:,1 acetonitrile/water; 9,:,1 acetonitrile/TFE; 25 mm SDS micelles in water) indicates that the peptides selectively adopt their designed conformation in micellar environments. We speculate that steric effects from ith and ith + 3 residues interactions may destabilize the 310 -helix in peptides containing amino acids with large side-chains, as with 1-aminocyclohexane-1-carboxylic acid (Ac6c). This problem may be overcome by alternating large and small amino acids in the ith and ith + 3 residues, which are staggered in the 310 -helix. [source] Aldol reaction catalyzed by a hydrophilic catalyst in aqueous micelle as an enzyme mimic systemCHIRALITY, Issue 5 2009Hefeng Zhang Abstract Chitosan-supported L -proline complex was synthesized and applied as a catalyst for the direct asymmetric aldol reaction in various organic solvents and water as well. It was found that the novel synthesized catalyst was able to efficiently catalyze the aldol reaction in various media. The catalytic capacity and stereoselectivity of the catalyst were obviously improved with the introduction of aqueous micelle, possibly because the micelle functioned as a hydrophobic pocket, like the hydrophobic portion in enzymes. Moreover, the present synthetic catalyst showed performance similar to that of enzymes and could be used as a model of enzyme catalysis to help better understand the mystic mechanism of enzymes. Chirality, 2009. © 2008 Wiley-Liss, Inc. [source] | ||||||||||||||||