Conditioned Medium of Demineralized Freeze-Dried Bone Activates Gene Expression in Periodontal Fibroblasts in Vitro.

BACKGROUND: Demineralized bone matrix (DBM) is used for the treatment of osseous defects. Conditioned medium from native bone chips can activate transforming growth factor (TGF)-β signaling in mesenchymal cells. The aim of the study was to determine whether processing of native bone into DBM affects the activity of the conditioned medium. METHODS: Porcine cortical bone blocks were subjected to defatting, different concentrations of hydrochloric acid and various temperatures. DBM was lyophilized, ground, and placed into culture medium. Human gingiva and periodontal fibroblasts were exposed to the respective conditioned medium (DBCM). Changes in the expression of TGF-β target genes were determined. RESULTS: DBCM altered the expression of TGF-β target genes, e.g., adrenomedullin, pentraxin 3, KN Motif And Ankyrin Repeat Domains 4, interleukin 11, NADPH oxidase 4, and BTB (POZ) Domain Containing 11, by at least five-fold. The response was observed in fibroblasts from both sources. Defatting lowered the activity of DBCM. The TGF-β receptor type I kinase inhibitor SB431542, but not the inhibitor of bone morphogenetic protein receptor dorsomorphin, blocked the effects of DBCM on gene expression. Moreover, conditioned medium obtained from commercial human DBM modulated the expression of TGF-β target genes. CONCLUSION: The findings suggest that the conditioned medium from demineralized bone matrix can activate TGF-β signaling in oral fibroblasts. KEYWORDS: TGF-beta superfamily proteins; bone; bone substitutes; bone transplantation; conditioned media; freeze drying

Same same but different: Locational policies in small and medium-sized European cities

Globalized interurban competition is affecting cities of various sizes and locations. Small and medium-sized cities have to find ways to position themselves in global markets by formulating locational policies. This paper outlines an analytical framework of locational policies that cities adopt in order to increase their competitiveness. By comparing two European small and mediumsized cities (Lucerne and Ulm), we examine manifestations of locational policies and compare if these policies are being diverse or resemble each other. We found that strategies of both cities are sharing the intentions to be competitive, but their policy choices differ because the economic and political context is enabling or restricting certain kinds of locational policies. Furthermore, the findings point to the high explanatory power of municipal tax autonomy when studying locational policies.

Bone Conditioned Medium: Preparation and Bioassay.

Autologous bone grafts are widely used in oral and maxillofacial surgery, orthopedics, and traumatology. Autologous bone grafts not only replace missing bone, they also support the complex process of bone regeneration. This favorable behavior of autografts is attributed to the three characteristics: osteoconductivity, osteogenicity, and osteoinductivity. However, there is another aspect: Bone grafts release a myriad of molecules, including growth factors, which can target mesenchymal cells involved in bone regeneration. The paracrine properties of bone grafts can be studied in vitro by the use of bone-conditioned medium (BCM). Here we present a protocol on how to prepare bone-conditioned medium from native pig cortical bone, and bone that underwent thermal processing or demineralization. Cells can be directly exposed to BCM or seeded onto biomaterials, such as collagen membranes, previously soaked with BCM. We give examples for in vitro bioassays with mesenchymal cells on the expression of TGF-β regulated genes. The presented protocols should encourage to further reveal the paracrine effects of bone grafts during bone regeneration and open a path for translational research in the broad field of reconstructive surgery.

Bone-Conditioned Medium Changes Gene Expression in Bone-Derived Fibroblasts.

PURPOSE Autologous bone is used for augmentation in the course of oral implant placement. Bone grafts release paracrine signals that can modulate mesenchymal cell differentiation in vitro. The detailed genetic response of the bone-derived fibroblasts to these paracrine signals has remained elusive. Paracrine signals accumulate in bone-conditioned medium (BCM) prepared from porcine cortical bone chips. MATERIALS AND METHODS In this study, bone-derived fibroblasts were exposed to BCM followed by a whole genome expression profiling and downstream quantitative reverse transciptase polymerase chain reaction of the most strongly regulated genes. RESULTS The data show that ADM, IL11, IL33, NOX4, PRG4, and PTX3 were differentially expressed in response to BCM in bone-derived fibroblasts. The transforming growth factor beta (TGF-β) receptor 1 antagonist SB431542 blocked the effect of BCM on the expression of the gene panel, except for IL33. CONCLUSION These in vitro results extend existing evidence that cortical bone chips release paracrine signals that provoke a robust genetic response in mesenchymal cells that is not exclusively mediated via the TGF-β receptor. The present data provide further insights into the process of graft consolidation.

The in vitro impact of toothpaste extracts on cell viability.

Toothpastes contain three main components: detergents, abrasives, and fluoride. Detergents, particularly sodium lauryl sulfate, have been proposed as components that enable toothpastes to produce cytotoxic effects in vitro. However, not all toothpastes contain sodium lauryl sulfate, and almost no studies have found an association between detergents and the in vitro cytotoxicity of toothpastes. The present study examined the in vitro cytotoxicity of nine commercially available toothpastes containing four different detergents. Toothpastes were diluted in serum-free medium, centrifuged, and filter sterilized. The half-lethal concentration of the toothpaste-conditioned medium (TCM) was calculated based on the formation of formazan by gingival fibroblasts, oral squamous cell carcinoma HSC-2 cells, and L929 cells. Cell proliferation was analyzed, and live-dead staining was performed, after exposure of cells to conditioned medium prepared with 1% toothpaste (1% TCM). It was found that toothpastes containing sodium lauryl sulfate and amine fluoride strongly inhibited cell viability with the half-lethal concentration being obtained with conditioned medium prepared with approximately 1% toothpaste (1% TCM). Toothpastes containing cocamidopropyl betaine and Steareth-20 showed higher half-lethal concentration values, with the half-lethal concentration being obtained with conditioned medium prepared with 10% (10% TCM) and 70% (70% TCM) toothpaste, respectively. Proliferation and live-dead data were consistent with the cell-viability analyses. These results demonstrate that the type of detergent in toothpastes can be associated with changes in in vitro cell toxicity.

Raum – Perspektive – Medium 2: Wahrnehmung im Blick. reflex: Tübinger Kunstgeschichte zum Bildwissen

Im zweiten Workshop zum Thema „Raum – Perspektive – Medium“, der im Februar 2009 am Kunsthistorischen Institut der Universität Tübingen stattfand, kristallisierten sich zwei zentrale Thesen heraus, die im nun folgenden Band aus interdisziplinärer Perspektive beleuchtet werden: Erstens die Frage nach dem Anteil des Betrachters am Bildprozess und zweitens eine damit einhergehende Bewertung des Medienbegriffs. In reflex 2 sind nun die Texte versammelt, die aus dem Workshop „Raum – Perspektive – Medium 2“ hervorgegangen sind.

Conditioned medium from fresh and demineralized bone enhances osteoclastogenesis in murine bone marrow cultures

OBJECTIVES Osteoclasts rapidly form on the surface of bone chips at augmentation sites. The underlying molecular mechanism, however, is unclear. Soluble factors released from bone chips in vitro have a robust impact on mesenchymal cell differentiation. Whether these soluble factors change the differentiation of hematopoietic cells into osteoclasts remains unknown. METHODS Osteoclastogenesis, the formation of tartrate-resistant acid phosphatase-positive multinucleated cells, was studied with murine bone marrow cultures exposed to RANKL and M-CSF, and conditioned medium from fresh (BCM) and demineralized bone matrix (DCM). Histochemical staining, gene and protein expression, as well as viability assays were performed. RESULTS This study shows that BCM had no impact on osteoclastogenesis. However, when BCM was heated to 85°C (BCMh), the number of tartrate-resistant acid phosphatase-positive multinucleated cells that developed in the presence of RANKL and M-CSF approximately doubled. In line with the histochemical observations, there was a trend that BCMh increased expression of osteoclast marker genes, in particular the transcription factor c-fos. The expression of c-fos was significantly reduced by the TGF-β receptor I antagonist SB431542. DCM significantly stimulated osteoclastogenesis, independent of thermal processing. CONCLUSIONS These data demonstrate that activated BCM by heat and DBM are able to stimulate osteoclastogenesis in vitro. These in vitro results support the notion that the resorption of autografts may be supported by as yet less defined paracrine mechanisms.

Human lung-derived mesenchymal stem cell-conditioned medium exerts in vitro antitumor effects in malignant pleural mesothelioma cell lines.

BACKGROUND The soluble factors secreted by mesenchymal stem cells are thought to either support or inhibit tumor growth. Herein, we investigated whether the human lung-derived mesenchymal stem cell-conditioned medium (hlMSC-CM) exerts antitumor activity in malignant pleural mesothelioma cell lines H28, H2052 and Meso4. METHODS hlMSC-CM was collected from the human lung-derived mesenchymal stem cells. Inhibition of tumor cell growth was based on the reduction of cell viability and inhibition of cell proliferation using the XTT and BrdU assays, respectively. Elimination of tumor spheroids was assessed by the anchorage-independent sphere formation assay. The cytokine profile of hlMSC-CM was determined by a chemiluminescence-based cytokine array. RESULTS Our data showed that hlMSC-CM contains a broad range of soluble factors which include: cytokines, chemokines, hormones, growth and angiogenic factors, matrix metalloproteinases, metalloproteinase inhibitors and cell-cell mediator proteins. The 48- and 72-hour hlMSC-CM treatments of H28, H2052 and Meso4 cell lines elicited significant decreases in cell viability and inhibited cell proliferation. The 72-hour hlMSC-CM incubation of H28 cells completely eliminated the drug-resistant sphere-forming cells, which is more potent than twice the half maximal inhibitory concentration of cisplatin. CONCLUSIONS Our findings indicate that the cell-free hlMSC-CM confers in vitro antitumor activities via soluble factors in the tested mesothelioma cells and, hence, may serve as a therapeutic tool to augment the current treatment strategies in malignant pleural mesothelioma.

Tattoo: a multifaceted medium of communication

This article suggests the systems theoretical distinction of form/medium as a useful tool for distinguishing social phenomena that might look as if they stem from the same process. This is shown to be the case for the tattoo and tattooing. The tattoo is conceived as a medium of communication through which different forms of communication emerge. Tattooing is one of these forms of communication that shapes the medium in a particular way. The current article sheds a special light on its intricate, communicational constellation, for which the concept of parallax is suggested. Law, medicine and cosmetics as other forms of communication use the medium of tattoo in their own way as well. The form/medium distinction allows us to grasp these different forms of communication, while it shows that they share the tattoo as medium. The article’s ultimate goal is to illustrate that the tattoo figures as a multifaceted medium of communication.

Local Interstellar Medium: Six Years of Direct Sampling by IBEX

The Interstellar Boundary Explorer (IBEX) has been directly observing neutral atoms from the local interstellar medium for the last six years (2009–2014). This paper ties together the 14 studies in this Astrophysical Journal Supplement Series Special Issue, which collectively describe the IBEX interstellar neutral results from this epoch and provide a number of other relevant theoretical and observational results. Interstellar neutrals interact with each other and with the ionized portion of the interstellar population in the “pristine” interstellar medium ahead of the heliosphere. Then, in the heliosphereʼs close vicinity, the interstellar medium begins to interact with escaping heliospheric neutrals. In this study, we compare the results from two major analysis approaches led by IBEX groups in New Hampshire and Warsaw. We also directly address the question of the distance upstream to the pristine interstellar medium and adjust both sets of results to a common distance of ~1000 AU. The two analysis approaches are quite different, but yield fully consistent measurements of the interstellar He flow properties, further validating our findings. While detailed error bars are given for both approaches, we recommend that for most purposes, the community use “working values” of ~25.4 km s⁻¹, ~75°7 ecliptic inflow longitude, ~−5°1 ecliptic inflow latitude, and ~7500 K temperature at ~1000 AU upstream. Finally, we briefly address future opportunities for even better interstellar neutral observations to be provided by the Interstellar Mapping and Acceleration Probe mission, which was recommended as the next major Heliophysics mission by the NRCʼs 2013 Decadal Survey.