bluuebunny/crossref_metadata_2025 huggingface dataset:
Decellularized Native and Engineered Arterial Scaffolds for Transplantation
Authors: Dahl Shannon L. M. , Koh Jennifer , Prabhakar Vikas , Niklason Laura E.
Published: September 2014

More than 570,000 coronary artery bypass grafts are implanted each year, creating an important demand for small-diameter vascular grafts. For patients who lack adequate internal mammary artery or saphenous vein, tissue-engineered arteries may prove useful. However, the time needed to tissue engineer arteries (7 weeks or more) is too long for many patients. Decellularized cadaveric human arteries are another possible source of vascular conduit, but limited availability and the potential for disease transmission limit their widespread use. In contrast, decellularized tissue-engineered arteries could serve as grafts for immediate implantation, as scaffolds onto which patients' cells could be seeded, or as carriers for genetically engineered cells to aid cell transplantation. The goal of this study was to quantify the effects of decellularization on vascular matrix and mechanical properties. Specifically, we compared cellular elimination, extracellular matrix retention, and mechanical characteristics of porcine carotid arteries before and after treatment with three decellularization methods. In addition, for the first time, tissue-engineered arteries were decellularized. Decellularized native arteries were also used as a scaffold onto which vascular cells were seeded. These studies identified a decellularization method for native and engineered arteries that maximized cellular elimination, without greatly compromising mechanical integrity. We showed that engineered tissues could be decellularized, and demonstrated the feasibility of reseeding decellularized vessels with vascular cells.
Novel Technique for Suspension Culture of Autologous Chondrocytes Improves Cell Proliferation and Tissue Architecture
Authors: Takahashi Toshiaki , Nieda Takamasa , Miyazaki Eriko , Enzan Hideaki
Published: September 2014

We have developed a new and simple method of chondrocyte suspension culture using a spinner bottle with rotation of the matrices. We compared the characteristics of chondrocytes cultured by this method with those grown in standard monolayer cultures. We also determined the optimal nutritional medium for suspension cultures. Periosteum explants seeded with chondrocytes were grown in monolayer and suspension cultures under three conditions: in medium with no additive (control), with 10% fetal bovine serum (FBS), or with 10% autologous serum (AS). After culturing, the explants were harvested, processed for histology, and stained with hematoxylin-eosin or TUNEL, or immunostained for type I, II, and III collagen, and Ki-67 antigen. In monolayer cultures, the attachment of the chondrocytes to the periosteum was weak and the superficial layer consisted of fibrotic tissue and few nucleated cells. Collagen type II staining was strong, but types I and III were weak. Among the suspension cultures the AS group produced the thickest layer of chondrocytes with the fewest apoptotic cells. The superficial layer of cartilage in these cultures stained positive for type I and III collagen and Ki-67 antigen. Among the suspension cultures, total chondroitin and chondroitin-4 sulfate (C-4S) concentration was highest in the AS group, while prostaglandin E2(PGE2) was highest in the FBS group. In summary, our new method of suspension culture of periosteal explants using rotational matrices combined with AS nutritional media was the most effective method for maintaining the bond between the chondrocyte layer and periosteum, as well as the production of type I and III collagen in the superficial layer.
Modulation of Specific Beta Cell Gene (Re)Expression during In Vitro Expansion of Human Pancreatic Islet Cells
Authors: Bouckenooghe Thomas , Vandewalle Brigitte , Lukowiak Bruno , Kerr-Conte Julie , Beläich Sandrine , Gmyr Valéry , Dubois Mathilde , Riachy Rita , Pattou François
Published: September 2014

The need for transplantable beta cells with a stable phenotype has given rise to several strategies including the expansion of existing pancreatic islets and/or growth of new ones. In vitro studies of beta cell proliferation on extracellular matrices plus growth factors have highlighted a possible cell expansion technique; however, the technique was accompanied with loss of insulin secretion. Herein we showed that human islet cell proliferation was marked by a decreased expression of specific differentiation markers, particularly insulin, insulin promoting factor-1 (IPF-1), and glucokinase. After a 6-day expansion period, we tried to reexpress the beta cell differentiation markers with compounds known for their differentiation and/or insulin-secreting properties. Sodium butyrate was a potent factor of IPF-1, insulin, and glucokinase gene reexpression; it also clearly induced secretion of gastrin, a known neogenic factor. Other compounds, namely TGF-β, calcitriol, GLP-1, and activin A, efficiently enhanced the glucose sensor machinery, particularly Glut-1 and glucokinase, thus triggering glucose responsiveness. Our results indicate that specific beta cell gene expression may be induced after expansion and dedifferentiation. This rekindles interest in human beta cell expansion. The possible stabilization of specialized genes needed by beta cells to fulfill their role as nutrient sensors and metabolic regulators may also be of interest to ensure graft maintenance and efficiency.
Improvement of Pancreatic Islet Isolation Outcomes Using Glutamine Perfusion during Isolation Procedure
Authors: Avila J. G. , Tsujimura T. , Oberholzer J. , Churchill T. , Salehi P. , Shapiro A. M. James , Lakey J. R. T.
Published: September 2014

During procurement, isolation, and transplantation, islets are exposed to high levels of oxidative stress triggering a variety of signaling pathways that can ultimately lead to cell death. Glutamine is an important cellular fuel and an essential precursor for the antioxidant glutathione. The aim of this study was to examine the role of intraductal glutamine administration in facilitating recovery of isolated rat islets from pancreases subjected to a clinically relevant period of warm ischemia. Islets were isolated in Sprague-Dawley (SD) rats (n= 18 per group). Pancreata in groups 1 and 2 were procured immediately while groups 3 and 4 were subjected to 30-min warm ischemia. Groups 2 and 4 were treated intraductally with 5 mM glutamine prior to pancreatectomy. Exposure to 30-min warm ischemia significantly reduced islet yield [groups 1 & 2 (nonischemia): 503 ± 29 islets/rat vs. groups 3 & 4 (ischemia): 247 ± 26 islets/rat; p < 0.05]. Intraductal glutamine treatment significantly improved islet yield when pancreata were subjected to 30-min warm ischemia [144 ± 16 islets/rat without glutamine (group 3) vs. 343 ± 36 islets/rat with glutamine (group 4), p < 0.05]. Glutamine also significantly improved islet viability (values were 50 ± 4% in group 4 vs. 27 ± 3% in group 3, p < 0.05). Similarly, glutathione (reduced) levels were significantly elevated in both glutamine-treated groups; however, this increase was greatest in tissues exposed to ischemia (2.76 ± 0.04 nmol/mg protein in group 4 vs. 1.66 ± 0.04 nmol/mg protein in group 3, p < 0.05). Intraductal glutamine administration considerably improves the islet yield, viability, and augments endogenous glutathione levels in pancreata procured after a clinically relevant period of ischemia. Intraductal administration of glutamine at the time of digestive enzyme delivery into the harvested pancreas may represent a simple yet effective tool to improve islet yields in clinical isolations.
Development and Transplantation of a Mineralized Matrix Formed by Osteoblasts in Vitro for Bone Regeneration
Authors: Xiao Yin , Haase Helen , Young William G. , Bartold P. Mark
Published: September 2014

The use of extracellular matrix materials as scaffolds for the repair and regeneration of tissues is receiving increased attention. The current study was undertaken to test whether extracellular matrix formed by osteoblasts in vitro could be used as a scaffold for osteoblast transplantation and induce new bone formation in critical size osseous defects in vivo. Human osteoblasts derived from alveolar bone were cultured in six-well plates until confluent and then in mineralization media for a further period of 3 weeks to form an osteoblast–mineralized matrix complex. Histologically, at this time point a tissue structure with a “connective tissue”-like morphology was formed. Type I collagen was the major extracellular component present and appeared to determine the matrix macrostructure. Other bone-related proteins such as alkaline phosphatase (ALP), bone morphogenetic protein (BMP)-2 and -4, bone sialoprotein (BSP), osteopontin (OPN), and osteocalcin (OCN) also accumulated in the matrix. The osteoblasts embedded in this matrix expressed mRNAs for these bone-related proteins very strongly. Nodules of calcification were detected in the matrix and there was a correlation between calcification and the distribution of BSP and OPN. When this matrix was transplanted into a critical size bone defect in skulls of immunodeficient mice (SCID), new bone formation occurred. Furthermore, the cells inside the matrix survived and proliferated in the recipient sites, and were traceable by the human-specific Alu gene sequence using in situ hybridization. It was found that bone-forming cells differentiated from both transplanted human osteoblasts and activated endogenous mesenchymal cells. This study indicates that a mineralized matrix, formed by human osteoblasts in vitro, can be used as a scaffold for osteoblast transplantation, which subsequently can induce new bone formation.
The Origin of Biliary Ductular Cells that Appear in the Spleen after Transplantation of Hepatocytes
Authors: Fukuda Kenji , Sugihara Ayako , Nakasho Keiji , Tsujimura Tohru , Yamada Naoko , Okaya Atsuhito , Sakagami Masafumi , Terada Nobuyuki
Published: September 2014

Transplantation of rat hepatocytes into the syngeneic rat spleen results in the appearance of cytokeration (CK)-19-positive biliary cells that form ductules. The exact origin of CK-19-positive cells is not known and the possibility that they are derived from biliary cells or precursors of oval cells in transplanted hepatocyte preparations has been raised. In the present study, we found that the number of CK-19-positive biliary cells increased rapidly after transplantation of hepatocytes, reached the maximum at 4 weeks, and then gradually decreased. However, a Ki-67 labeling index of CK-19-positive biliary cells was low and showed no significant changes throughout the experimental period. In addition, no or few CK-19-positive cells appeared in the spleen after transplantation of nonparenchymal liver cells enriched with biliary cells. These results showed that biliary cells were not the source of CK-19-positive cells in the spleen. Impairment of precursors of oval cells in the liver by administration of 4,4′-diaminodiphenylmethane 24 h before transplantation of hepatocytes did not prevent the appearance of CK-19-positive biliary cells in the spleen. Moreover, transplantation of nonparenchymal cells carrying an increased number of oval cells by means of treatment with 2-acetylaminofluorene and partial hepatectomy resulted in no appearance of CK-19-positive biliary cells in the spleen. These results ruled out oval cells as the origin of CK-19-positive biliary cells in the spleen. Because CK-19-positive biliary cells appeared in the spleen only when hepatocyte fractions were transplanted, we suggest transdifferentiation of heptocytes may be the mechanism by which CK-19-positive biliary cells are generated.
Effect of the Embolization of Completely Unpurified Islets on Portal Vein Pressure and Hepatic Biochemistry in Clinical Practice
Authors: Hyon Sung Ho , Ceballos María Candela , Barbich Mariana , Groppa Rosana , Grosembacher Luis , Vieiro María Mercedes , Barcan Laura , Algranati Salomon , Litwak Leon , Argibay Pablo F.
Published: September 2014

Here we report on the impact of completely unpurified islet transplantation on the portal vein pressure (PVP) and the hepatic biochemistry in the peritransplant period and on follow-up. Type I diabetic patients underwent simultaneous kidney and islet transplantation. Islets were not purified from the acinar tissue to prevent loss of endocrine mass. Each patient received a mean 521,846 ± 201,539.4 islet equivalents (7812.1 islet equivalents/kg/recipient). Immunosuppression and peritransplant medication were given according to the Giessen protocol. The islets were injected into the left hepatic lobe through the umbilical vein. PVP was recorded at time 0 and every 5 min throughout cell infusion. Liver function was assessed daily for the first 10 days, and on follow-up. Basal, peak, and final PVP were 12 ± 3.8, 25.1 ± 7.9, and 19.5 ± 6.2 mmHg, respectively (basal vs. final, p < 0.05). Bilirubin, alkaline phosphatase, prothrombin time, and APTT stayed within normal range. Peak aspartate aminotransferase (AST), alanine aminotransferase (ALT), and serum amylase were 109.4 ± 61.2 IU/L (basal vs. peak, not significant), 79.5 ± 56.9 IU/L (basal vs. peak, not significant), and 887.5 ± 153.6 IU/L (basal vs. peak, p = 0.02), respectively. In all cases AST, ALT, and amylase normalized within 6 days posttransplant and remained so on follow-up (longest control, 33 months posttransplant). Although the intrahepatic infusion of unpurified pancreatic islets affects both the portal vein pressure and the hepatic biochemical profile, this effect is transient and does not compromise the safety of the procedure.
Assessment of Different Transfection Parameters in Efficiency Optimization
Authors: Young A. T. L. , Moore R. B. , Murray A. G. , Mullen J. C. , Lakey Jonathan R. T.
Published: September 2014

Achieving optimal transfection efficiency is the most critical step in overcoming the primary obstacle to success in nonviral-mediated gene therapy. Several transfection parameters were being examined including the effects of different types of transfection media, glucose concentration, reporter DNA concentration, and incubation time in lipotransfectant. Efficiency of transfection obtained was highest for Opti-MEM I (29 ± 2.28%; p = 0.001) followed by M199 (24 ± 1.54%; p = 0.009), both of which performed significantly better than DMEM (14 ± 0.28%) as a transfection medium. The rate of transfection was affected by glucose levels in only DMEM with higher efficiency achieved using low glucose containing DMEM (17 ± 0.38%) than its counterpart. Furthermore, transfection rate and cell viability were severely hampered by lengthened exposure to transfection complexes, leading to an overall mean efficiency of 5 ± 0.87%. However, doubling the DNA content in the transfection mixture did not significantly change the mean rate of transfection in M199 medium (24 ± 1.54% to 27 ± 1.54%; p = 0.273). The overall range of mean efficiency acquired with our protocol under different transfection conditions was between 14% and 29%. Hopefully results from this study will further potential success in nonviral-mediated gene transfer.
Factors Influencing the Loss of β-Cell Mass in Islet Transplantation
Authors: Emamaullee Juliet A. , Shapiro A. M. James
Published: September 2014

Recent advances in clinical islet transplantation have clearly demonstrated that this procedure can provide excellent glycemic control and often insulin independence in a population of patients with type 1 diabetes. A key limitation in the widespread application of clinical islet transplantation is the requirement of 10,000 islet equivalents/kg in most recipients, generally derived from two or more cadaveric donors. It has been determined that a majority of the transplanted islets fail to engraft and become fully functional. In this review article, the factors that contribute to this early loss of islets following transplantation are discussed in depth.
Functional and Phenotypic Alteration of Intrasplenic Lymphocytes Affected by Mesenchymal Stem Cells in a Murine Allosplenocyte Transfusion Model
Authors: Li Hong , Gu Zi-Kuan , Li Xiu-Sen , Hou Chun-Mei , Tang Pei-Hsien , Mao Ning
Published: September 2014

Previous data have demonstrated that mesenchymal stem cells (MSCs) can exert immunomodulatory activity in vitro, in which of the process nearly all kinds of immune cell subsets are involved. However, there is still a paucity of information about whether and why MSCs inhibit the ongoing immune responses in vivo. Working in a murine splenocyte transfusion model across the major histocompatibility barrier (C57BL/6 → BALB/c, H2b → H2d), we have found that MSC coinfusion prolongs the mean survival time (MST) of the recipient mice in a dose-dependent manner and reduces graft-versus-host-associated histopathology in comparison to the allosplenocyte transfusion controls. In vivo eGFP tracing with polymerase chain reaction analysis revealed that grafted MSCs could migrate and settle into the lungs, spleen, liver, intestine, and skin shortly after administration. Further investigations into the functional characteristics of intrasplenic lymphocytes showed that their proliferation and cytotoxic activity against P815 cells (H2d) were significantly restrained by MSC cotransfer. FACS analysis demonstrated that MSC infusion not only increased the proportion of CD4+ subset but also decreased that of CD8+ cells at the belated observation points, resulting in the increase of the ratio of CD4+/CD8+ cells. Also, in contrast to the slight increase of the proportion of CD4+CD25+ T regulatory cells (Tregs) in MSC cotransfer mice, the ratio of Tregs/CD8+ cells was dramatically elevated. Furthermore, RT-PCR analysis on the cytokine array of IL-2, IL-4, IL-12, TNF-α, and TGF-β in recipient splenocytes implied the Th1 to Th2 polarization. Therefore, it is deducible that alteration in the proportions of different T-lymphocyte subsets may be one of the main mechanisms by which grafted MSCs suppress the ongoing immune responses in vivo. The study here might provide some new clues for the design of therapeutic approaches for MSC transplantation.
The Role of Endothelial Progenitor Cells in Ischemic Cerebral and Heart Diseases
Authors: Ding Dah-Ching , Shyu Woei-Cherng , Lin Shinn-Zong , Li Hung
Published: September 2014

Ischemic heart and cerebral diseases are complex clinical syndromes. Endothelial dysfunction caused by dysfunctional endothelial progenitor cells (EPCs) is thought to play a major role in pathophysiology of both types of disease. Healthy EPCs may be able to replace the dysfunctional endothelium through endogenous repair mechanisms. EPC levels are changed in patients with ischemic cerebrovascular and cardiovascular disease and EPCs may play a role in the pathophysiology of these diseases. EPCs are also a marker for preventive and therapeutic interventions. Homing of EPCs to ischemic sites is a mechanism of ischemic tissue repair, and molecules such as stromal-derived factor-1 and integrin may play a role in EPC homing in ischemic disease. Potentiation of the function and numbers of EPCs as well as combining EPCs with other pharmaceutical agents may improve the condition of ischemia patients. However, the precise role of EPCs in ischemic heart and cerebral disease and their therapeutic potential still remain to be explored. Here, we discuss the identification, mobilization, and clinical implications of EPCs in ischemic diseases.
Cell Viability and Noninvasive In Vivo MRI Tracking of 3D Cell Encapsulating Self-Assembled Microcontainers
Authors: Gimi Barjor , Artemov Dmitri , Leong Timothy , Gracias David H. , Gilson Wesley , Stuber Matthias , Bhujwalla Zaver M.
Published: September 2014

Several molecular therapies require the implantation of cells that secrete biotherapeutic molecules and imaging the location and microenvironment of the cellular implant to ascertain its function. We demonstrate noninvasive in vivo magnetic resonance imaging (MRI) of self-assembled microcontainers that are capable of cell encapsulation. Negative contrast was obtained to discern the microcontainer with MRI; positive contrast was obtained in the complete absence of background signal. MRI on a clinical scanner highlights the translational nature of this research. The microcontainers were loaded with cells that were dispersed in an extracellular matrix, and implanted both subcutaneously and in human tumor xenografts in SCID mice. MRI was performed on the implants, and microcontainers retrieved postimplantation showed cell viability both within and proximal to the implant. The microcontainers are characterized by their small size, three dimensionality, controlled porosity, ease of parallel fabrication, chemical and mechanical stability, and noninvasive traceability in vivo.
In Vitro Exposure of Cultured Porcine Choroid Plexus Epithelial Cells to Immunosuppressant, Anti-Inflammatory, and Psychoactive Drugs
Authors: Emerich Dwaine F. , Schneider Patricia , Bintz Briannan , Hudak Jebecka , Thanos Christopher G.
Published: September 2014

Delivery of neurotrophic molecules to the CNS is a potential treatment for preventing the neuronal loss in neurological disorders such as Huntington's disease (HD). Choroid plexus (CP) epithelial cell transplants secrete several neurotrophic factors and are neuroprotective in rat and monkey animal models of HD. HD patients receiving CP transplants would likely receive a course of immunosuppressant/anti-inflammatory treatment postsurgery and would remain on psychoactive medications to treat their motor, psychiatric, and emotional symptoms. Therefore, we examined whether CP epithelial cells are impacted by incubation with cyclosporine A (CsA), dexmethasone, haloperidol, fluoxetine, and carbamezapine. In each case, DNA was quantified to determine cell number, a formazen dye-based assay was used to quantify cell metabolism, and vascular endothelial growth factor (VEGF) levels were measured as a marker of protein secretion. Except for the highest dose of fluoxetine, none of the drugs tested exerted any detrimental effect on cell number. Incubation with CsA or dexamethasone did not have any consistent significant effect on VEGF secretion or cell metabolism. Carbamazepine was without effect while only the highest dose of haloperidol tested modestly lowered cell metabolism. VEGF secretion and cell metabolism was not measurable from CP cells exposed to 100 μM fluoxetine. These data continue to support the potential use of CP transplants in HD.
An Immortalized Rat Ventral Mesencephalic Cell Line, RTC4, Is Protective in a Rodent Model of Stroke
Authors: Harvey B. K. , Chen G. J. , Schoen C. J. , Lee C. T. , Howard D. B. , Dillon-Carter O. , Coggiano M. , Freed W. J. , Wang Y. , Hoffer B. J. , Sanchez J. F.
Published: September 2014

One therapeutic approach to stroke is the transplantation of cells capable of trophic support, reinnervation, and/or regeneration. Previously, we have described the use of novel truncated isoforms of SV40 large T antigen to generate unique cell lines from several primary rodent tissue types. Here we describe the generation of two cell lines, RTC3 and RTC4, derived from primary mesencephalic tissue using a fragment of mutant T antigen, T155c (cDNA) expressed from the RSV promoter. Both lines expressed the glial markers vimentin and S100β, but not the neuronal markers NeuN, MAP2, or β-III-tubulin. A screen for secreted trophic factors revealed substantially elevated levels of platelet-derived growth factor (PDGF) in RTC4, but not RTC3 cells. When transplanted into rat cortex, RTC4 cells survived for at least 22 days and expressed PDGF. Because PDGF has been reported to reduce ischemic injury, we examined the protective functions of RTC4 cells in an animal model of stroke. RTC4 or RTC3 cells, or vehicle, were injected into rat cortex 15–20 min prior to a 60-min middle cerebral artery ligation. Forty-eight hours later, animals were sacrificed and the stroke volume was assessed by triphenyl-tetrazolium chloride (TTC) staining. Compared to vehicle or RTC3 cells, transplanted RTC4 cells significantly reduced stroke volume. Overall, we generated a cell line with glial properties that produces PDGF and reduces ischemic injury in a rat model of stroke.
Distribution of Intraportally Implanted Microspheres and Fluorescent Islets in Mice
Authors: Von Seth Erik , Nyqvist Daniel , Andersson Arne , Carlsson Per-Ola , Köhler Martin , Mattsson Göran , Nordin Astrid , Berggren Per-Olof , Jansson Leif
Published: September 2014

The aim of the study was to evaluate the distribution of intraportally transplanted islets in mice. We initially administered 2000 polystyrene microspheres with a diameter of 50 μm intraportally into normoglycemic C57BL/6 mice. In separate experiments other mice were injected similarly with 300 microspheres each with a diameter of 100 or 200 μm. One week later the animals were killed, and the lungs and livers were removed and divided into lobes. The number of microspheres in each individual liver lobe and in the lungs was counted using a stereomicroscope. In other experiments, athymic C57BL/6 mice were similarly implanted with 250 islets isolated from transgenic mice expressing the enhanced yellow fluorescent protein in the islet cells. The distribution of microspheres and islets was independent of size, and fairly homogenous within the liver, with the exception of the caudate lobe, which contained fewer microspheres and islets, respectively. Approximately one third of all microspheres and islets were present as aggregates. Eighty-five to 90% of the implanted microspheres were identified in the liver sections, whereas 60–65% of the implanted islets were recovered. Aggregates or single fluorescent cells were observed in the liver of islet-implanted mice. We conclude that islets and microspheres implanted into the liver distribute fairly homogenously and quite a few of them exist as aggregates or, with respect to islets, as fragments.
Novel Cell Seeding System into a Porous Scaffold Using a Modified Low-Pressure Method to Enhance Cell Seeding Efficiency and Bone Formation
Authors: Torigoe Ichiro , Sotome Shinichi , Tsuchiya Akio , Yoshii Toshitaka , Takahashi Makoto , Kawabata Shigenori , Shinomiya Kenichi
Published: September 2014

The efficient seeding of cells into porous scaffolds is important in bone tissue engineering techniques. To enhance efficiency, we modified the previously reported cell seeding techniques using low-pressure conditions. In this study, the effects of low pressure on bone marrow-derived stromal cells (BMSCs) of rats and the usefulness of the modified technique were assessed. There was no significant difference found in the proliferative and osteogenic capabilities among various low-pressure (50–760 mmHg, 1–10 min) conditions. To analyze the efficacies of the cell seeding techniques, BMSCs suspended in the plasma of rats were seeded into porous β-tricalcium phosphate (β-TCP) blocks by the following three procedures: 1) spontaneous penetration of cell suspension under atmospheric pressure (SP); 2) spontaneous penetration and subsequent low pressure treatment (SPSL), the conventional technique; and 3) spontaneous penetration under low pressure conditions (SPUL), the modified technique. Subsequently, these BMSCs/β-TCP composites were used for the analysis of cell seeding efficiency or in vivo bone formation capability. Both the number of BMSCs seeded into β-TCP blocks and the amount of bone formation of the SPUL group were significantly higher than those of the other groups. The SPUL method with a simple technique permits high cell seeding efficiency and is useful for bone tissue engineering using BMSCs and porous scaffolds.
Comparison of Chondral Defects Repair with In Vitro and In Vivo Differentiated Mesenchymal Stem Cells
Authors: Fan Hongbin , Liu Haifeng , Zhu Rui , Li Xusheng , Cui Yuming , Hu Yunyu , Yan Yongnian
Published: September 2014

The purpose of this study was to compare chondral defects repair with in vitro and in vivo differentiated mesenchymal stem cells (MSCs). A novel PLGA-gelatin/chondroitin/hyaluronate (PLGA-GCH) hybrid scaffold with transforming growth factor-β1 (TGF-β1)-impregnated microspheres (MS-TGF) was fabricated to mimic the extracellular matrix. MS-TGF showed an initial burst release (22.5%) and a subsequent moderate one that achieved 85.1% on day 21. MSCs seeded on PLGA-GCH/MS-TGF or PLGA-GCH were incubated in vitro and showed that PLGA-GCH/MS-TGF significantly augmented proliferation of MSCs and glycosaminoglycan synthesis compared with PLGA-GCH. Then MSCs seeded on PLGA-GCH/MS-TGF were implanted and differentiated in vivo to repair chondral defect on the right knee of rabbit (in vivo differentiation repair group), while the contralateral defect was repaired with in vitro differentiated MSCs seeded on PLGA-GCH (in vitro differentiation repair group). The histology observation demonstrated that in vivo differentiation repair showed better chondrocyte morphology, integration, and subchondral bone formation compared with in vitro differentiation repair 12 and 24 weeks postoperatively, although there was no significant difference after 6 weeks. The histology grading score comparison also demonstrated the same results. The present study implies that in vivo differentiation induced by PLGA-GCH/MS-TGF and the host microenviroment could keep chondral phenotype and enhance repair. It might serve as another way to induce and expand seed cells in cartilage tissue engineering.
Article Commentary: Stem Cell Research in Cell Transplantation: An Analysis of Geopolitical Influence by Publications
Authors: Eve David J. , Sanberg Paul R.
Published: September 2014

One of the fastest growing fields in researching treatments for neurodegenerative and other disorders is the use of stem cells. These cells are naturally occurring and can be obtained from three different stages of an organism's life: embryonic, fetal, and adult. In the US, political doctrine has restricted use of federal funds for stem cells, enhancing research towards an adult source. In order to determine how this legislation may be represented by the stem cell field, a retrospective analysis of stem cell articles published in the journal Cell Transplantation over a 2-year period was performed. Cell Transplantation is considered a translational journal from preclinical to clinical, so it was of interest to determine the publication outcome of stem cell articles 6 years after the US regulations. The distribution of the source of stem cells was found to be biased towards the adult stage, but relatively similar over the embryonic and fetal stages. The fetal stem cell reports were primarily neural in origin, whereas the adult stem cell ones were predominantly mesenchymal and used mainly in neural studies. The majority of stem cell studies published in Cell Transplantation were found to fall under the umbrella of neuroscience research. American scientists published the most articles using stem cells with a bias towards adult stem cells, supporting the effect of the legislation, whereas Europe was the leading continent with a bias towards embryonic and fetal stem cells, where research is “controlled” but not restricted. Japan was also a major player in the use of stem cells. Allogeneic transplants (where donor and recipient are the same species) were the most common transplants recorded, although the transplantation of human-derived stem cells into rodents was the most common specific transplantation performed. This demonstrates that the use of stem cells is an increasingly important field (with a doubling of papers between 2005 and 2006), which is likely to develop into a major therapeutic area over the next few decades and that funding restrictions can affect the type of research being performed.
Combination of Anti-CD4 with Anti-LFA-1 and Anti-CD154 Monoclonal Antibodies Promotes Long-Term Survival and Function of Neonatal Porcine Islet Xenografts in Spontaneously Diabetic NOD Mice
Authors: Arefanian Hossein , Tredget Eric B. , Rajotte Ray V. , Korbutt Gregory S. , Gill Ron G. , Rayat Gina R.
Published: September 2014

Type 1 diabetes mellitus (T1DM) is caused by the autoimmune destruction of pancreatic islet β-cells, which are required for the production of insulin. Islet transplantation has been shown to be an effective treatment option for T1DM; however, the current shortage of human islet donors limits the application of this treatment to patients with brittle T1DM. Xenotransplantation of pig islets is a potential solution to the shortage of human donor islets provided xenograft rejection is prevented. We demonstrated that a short-term administration of a combination of anti-LFA-1 and anti-CD154 monoclonal antibodies (mAbs) was highly effective in preventing rejection of neonatal porcine islet (NPI) xenografts in non-autoimmune-prone B6 mice. However, the efficacy of this therapy in preventing rejection of NPI xenografts in autoimmune-prone nonobese diabetic (NOD) mice is not known. Given that the current application of islet transplantation is for the treatment of T1DM, we set out to determine whether a combination of anti-LFA-1 and anti-CD154 mAbs could promote long-term survival of NPI xenografts in NOD mice. Short-term administration of a combination of anti-LFA-1 and anti-CD154 mAbs, which we found highly effective in preventing rejection of NPI xenografts in B6 mice, failed to promote long-term survival of NPI xenografts in NOD mice. However, addition of anti-CD4 mAb to short-term treatment of a combination of anti-LFA-1 and anti-CD154 mAbs resulted in xenograft function in 9/12 animals and long-term graft (>100 days) survival in 2/12 mice. Immunohistochemical analysis of islet grafts from these mice identified numerous insulin-producing β-cells. Moreover, the anti-porcine antibody as well as autoreactive antibody responses in these mice was reduced similar to those observed in naive nontransplanted mice. These data demonstrate that simultaneous targeting of LFA-1, CD154, and CD4 molecules can be effective in inducing long-term islet xenograft survival and function in autoimmune-prone NOD mice.
Chromosome behavior at the base of the angiosperm radiation: Karyology of Trithuria submersa (Hydatellaceae, Nymphaeales)
Authors: Kynast Ralf G. , Joseph Jeffrey A. , Pellicer Jaume , Ramsay Margaret M. , Rudall Paula J.
Published: September 2014

• Premise of the study: Hydatellaceae are minute annual herbs with potential as a model system for studying early angiosperm evolution, but their karyology and ploidy levels are almost unknown. We investigated these aspects of Trithuria submersa, a widespread species that we show to be amenable to extended vegetative propagation.

• Methods: We cultivated plants of T. submersa in vitro after developing and optimizing culture conditions. We estimated genome size using flow cytometry, counted chromosome numbers using root‐meristem squashes after Feulgen staining, and examined meiotic chromosome behavior using microsporocytes.

• Key results: We developed methods to reliably germinate seeds of T. submersa and to propagate them vegetatively in critical thermo‐ and photoperiod regimes on 1/2 Murashige–Skoog (MS) medium with vitamins and 2% sucrose solidified with 0.7% agar‐agar. Seedling growth requires the medium be supplemented with activated charcoal. The mean nuclear DNA content of T. submersa sporophytes is 2C = 2.74 pg (∼2.68 Gbp). The sporophytic chromosome number is 2n = 56 with a bimodal complement, which may suggest an allopolyploid origin. Some of the largest chromosomes lack a recognizable constriction, which relates to a highly unusual and irregular chromosome behavior. Microsporocytes undergo reduced and asynchronous meioses that show a modified intermediate cell division with a nucleus division by fractional postreduction, indicating partially inverted microsporogenesis.

• Conclusions: In vitro cultivation and karyological assessment of T. submersa open new opportunities for investigating early‐divergent angiosperms. The remarkably different meiotic behavior exhibits new insights into a potentially ancestral microsporogenesis.
Silica nanoparticles are less toxic to human lung cells when deposited at the air–liquid interface compared to conventional submerged exposure
Authors: Panas Alicja , Comouth Andreas , Saathoff Harald , Leisner Thomas , Al-Rawi Marco , Simon Michael , Seemann Gunnar , Dössel Olaf , Mülhopt Sonja , Paur Hanns-Rudolf , Fritsch-Decker Susanne , Weiss Carsten , Diabaté Silvia
Published: September 2014

Background: Investigations on adverse biological effects of nanoparticles (NPs) in the lung by in vitro studies are usually performed under submerged conditions where NPs are suspended in cell culture media. However, the behaviour of nanoparticles such as agglomeration and sedimentation in such complex suspensions is difficult to control and hence the deposited cellular dose often remains unknown. Moreover, the cellular responses to NPs under submerged culture conditions might differ from those observed at physiological settings at the air–liquid interface.

Results: In order to avoid problems because of an altered behaviour of the nanoparticles in cell culture medium and to mimic a more realistic situation relevant for inhalation, human A549 lung epithelial cells were exposed to aerosols at the air–liquid interphase (ALI) by using the ALI deposition apparatus (ALIDA). The application of an electrostatic field allowed for particle deposition efficiencies that were higher by a factor of more than 20 compared to the unmodified VITROCELL deposition system. We studied two different amorphous silica nanoparticles (particles produced by flame synthesis and particles produced in suspension by the Stöber method). Aerosols with well-defined particle sizes and concentrations were generated by using a commercial electrospray generator or an atomizer. Only the electrospray method allowed for the generation of an aerosol containing monodisperse NPs. However, the deposited mass and surface dose of the particles was too low to induce cellular responses. Therefore, we generated the aerosol with an atomizer which supplied agglomerates and thus allowed a particle deposition with a three orders of magnitude higher mass and of surface doses on lung cells that induced significant biological effects. The deposited dose was estimated and independently validated by measurements using either transmission electron microscopy or, in case of labelled NPs, by fluorescence analyses. Surprisingly, cells exposed at the ALI were less sensitive to silica NPs as evidenced by reduced cytotoxicity and inflammatory responses.

Conclusion: Amorphous silica NPs induced qualitatively similar cellular responses under submerged conditions and at the ALI. However, submerged exposure to NPs triggers stronger effects at much lower cellular doses. Hence, more studies are warranted to decipher whether cells at the ALI are in general less vulnerable to NPs or specific NPs show different activities dependent on the exposure method.
FACILITATING THE HOUSING BARGAINING WITH THE HELP OF THE BARGAINING DECISION SUPPORT SYSTEM
Authors: Urbanavičienė Vita , Kaklauskas Artūras , Zavadskas Edmundas Kazimieras , Šliogerienė Jūratė , Naimavičienė Jurga , Vatin Nikolay Ivanovich
Published: September 2014

More than 90 percent home buyers today rely on the Internet as one of their primary research sources and real estate related searches continually grows. Internet helps buyers to find and select bigger number of right homes for sale in a shorter time, so provides more alternatives for bargaining. The bargaining is an inseparable part of the home buying and selling process. However, housing bargaining mostly is conducted face-to face, so there is a growing need for facilitating the housing bargaining and conducting such bargaining on the Web with the help of the systems. The article describes the developed Real-Time Housing Multiple Criteria Bargaining Decision Support System, based on multiple-criteria mathematical methods, which helps to improve the efficiency of bargaining through the following functions: search for housing alternatives; formulation of the initial comparative table of alternatives; multiple criteria analysis of housing alternatives and negotiation tactics; determination of the most useful home option for buying; presentation of recommendations and real-time determination of a home's market value; e-bargaining using templates of bargaining e-mails generated by the system.
VALUE INFLUENCING MECHANISM OF GREEN CERTIFICATES IN THE DISCOUNTED CASH FLOW VALUATION
Authors: Vimpari Jussi , Junnila Seppo
Published: September 2014

The market value of green properties is already acknowledged in scientific literature, but it has still remained unclear how green certificates are incorporated into property valuation. In this study, value influencing mechanism of green certificates in property investment is studied. A widely used discounted cash flow (DCF) model for property valuation was constructed and communicated with spreadsheet to industry professionals for valuing an office property in metropolitan Finland. The goal was to understand the value influencing mechanism and even deeper to identify the differences in DCF parameters between certified properties and non-certified properties. The results show that a green certificate increases on average the property value with 9.0% in the DCF valuation model. Improved yield and net rental income were the main reasons for the higher property value. Interestingly, this is the first known study to empirically open the value influencing mechanisms of green properties presented in earlier theoretical studies.
AN INTERACTIVE DECISION SUPPORT METHOD FOR REAL ESTATE MANAGEMENT IN A MULTI-CRITERIA FRAMEWORK – REMIND
Authors: Taillandier Franck , Abi-Zeid Irène , Taillandier Patrick , Sauce Gérard , Bonetto Régis
Published: September 2014

Managing a housing stock involves complex decision making such as the design of a multiyear action plan pertaining to the maintenance and upgrading of the properties. In order to address this problem, we developed a novel interactive decision support method (REMIND) to assist a housing stock manager in the progressive design and choice of a multiyear action plan based on multiple criteria. It uses a filtering approach both at the individual action level and at the global scenario level where the housing stock manager can gradually express preferences and conduct what-if analyses. An optimization component based on Tabu search allows the decision-maker to obtain a set of good plans from which he can choose the one to implement. The quality of a plan is defined in terms of how well it meets the goals on each criterion. The application of the method was tested in a leading French property management company.
MODELLING AND FORECASTING CENTRAL HELSINKI OFFICE RENTS
Authors: Kiehelä Sami , Falkenbach Heidi
Published: September 2014

Office market modelling has attracted a mounting amount of interest among researchers and practitioners during past decades. Growing research activity in the area is not surprising considering the importance of rent on property values. Nonetheless, very little quantitative research on Finnish rental markets has been carried out. The objective of this study is to respond to that lack of research by examining office rent determination in the Helsinki central business district (CBD) in reduced form single equation context. We discover that changes in central Helsinki office rents are subject to variations in new office completions and changes in the added value of services sector. As historical fit does not necessarily translate into a satisfactory predictive fit, the forecasting adequacy of the final model is also tested by constructing out of the sample forecast over 2007-2009. We find that the model outperforms two naïve forecasting methods, but fails to perfectly trail the actual index.
Enjeux identitaires multiples chez des personnes homosexuel.les ou transgenres, issu.es de l'immigration arabo-musulmane
Authors: Monheim Myriam
Published: September 2014

Tenant compte de leurs parcours identitaires multiples, cet article aborde la spécificité des vulnérabilités vécues par les personnes lesbiennes, gays, bisexuel.les et transgenres (LGBT), issues de l’immigration arabo-musulmane vivant à Bruxelles (Belgique). Ces personnes vivent certains aspects de leur orientation sexuelle/identité de genre différemment du reste des personnes LGBT. À partir du dispositif spécifique de prise en charge thérapeutique proposé aux personnes LGBT, nous aborderons les particularités culturelles, sociales et migratoires à prendre en compte avec les personnes LGBT issues de l’immigration arabo-musulmane.
Persona non grata. Au seuil de la participation
Authors: Berger Mathieu , Charles Julien
Published: September 2014

Dans ce texte, les auteurs portent attention au trouble suscité, chez les observateurs et les acteurs de la participation, par l’absence de franges entières de la population et par l’incapacité des dispositifs à s’approprier une part importante des contributions des personnes présentes. Dans un premier temps, les auteurs problématisent les limites de l’inclusion participative en restituant la diversité des traitements que leur ont accordés les principaux théoriciens de l’espace public démocratique. Pour faciliter l’appréhension de cette question dans de futures enquêtes, les auteurs proposent ensuite un équipement empirico-conceptuel centré sur la notion de seuil . Espace-limite, celui-ci représente également un espace critique de prédilection pour les recherches sur la participation.
Mépris et répression de la prise de parole en public. Construction d'une domination symbolique profane dans une copropriété et dénonciation publique
Authors: Motta Alessio
Published: September 2014

Des copropriétaires d’une tour se mobilisent et dénoncent un « complot » du syndic et du conseil syndical pour licencier leur gardien. Parmi eux, quelques savants rétifs à ces dénonciations qui, subissant un renversement de domination symbolique, se trouvent raillés pour leur naïveté. La conquête de la parole ici réalisée par les profanes tend à valider l’hypothèse selon laquelle les exclusions au seuil des espaces publics sont essentiellement le fruit des petites humiliations que les dominants y infligent.
Retrouver la face par la participation. Ethnographie de la fragile élaboration d'une œuvre d'art par des adolescents dans un quartier populaire
Authors: Pecqueux Anthony
Published: September 2014

Cet article est une ethnographie de la réalisation par des adolescents d’un film numérique participatif en pied d’immeuble dans un quartier populaire. Il en rend compte en mettant en évidence les contraintes du dispositif ; en montrant que, malgré ces contraintes, le film se poursuit et se recommence à chaque séance, en puisant une part importante de sa dynamique dans une dimension collective, sa valuation ; enfin en analysant les conséquences « heureuses » susceptibles d’en émerger (quoique difficilement), à savoir permettre à certains adolescents de revaloriser, par le biais du film, leur face dégradée.
Réformer par l'expérimentation : la réception du budget participatif des lycées en Région Nord-Pas-de-Calais
Authors: O’Miel Julien , Mongy Aymeric
Published: September 2014

Cet article s’intéresse à l’importation du budget participatif des lycées en région Nord-Pas-de-Calais. Il entreprend d’en saisir la réappropriation à travers une analyse contextualisée des acteurs en prise avec le dispositif. Notre recherche montre que les anticipations des réformateurs conduisent à une mise en œuvre a minima du dispositif susceptible d’atténuer les résistances au changement. Pourtant, l’analyse montre que cette mise en œuvre ne se fait pas sans heurts, les acteurs administratifs et les proviseurs des lycées réinvestissant leurs intérêts et leurs pratiques contribuant ainsi à une redéfinition du dispositif.