bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pulsatile Flow and Atherogenesis: Results from in Vivo Studies
Authors: Grigioni M. , Daniele C. , D'Avenio G. , Formigari R. , Bernucci P. , Ballerini L. , Barbaro V. 
Published: March 2018

Compliance mismatch between prosthetic vascular replacement (possibly stented) and native artery is considered to be an important factor in implant failure due, e.g., to vascular remodeling, tissutal growth or intimal hyperplasia (IH). From an in vivo study involving altered vascular mechanics (and, consequently, compliance mismatch), carried out using the Moncada model of atherosclerosis development and smooth muscle cell (SMC) proliferation, the hemodynamic assessment was followed by means of real-time multigated ultrasound profilometry, of collared carotid artery using two different models: nonconstrictive and costrictive plastic collars, wrapped around the vessel. The experiments provided the real-time measurement of velocity profiles in vivo and the subsequent estimation of wall shear stresses, locally responsible for the altered hemodynamics. Endothelium modifications were correlated with local hemodynamic alterations by using statistical regression analysis of the development of intimal hyperplasia and the mechanical stimulus applied to the endothelium by means of the two different manipulation models. Different correlations were found between wall shear rate and IH in the two models, showing the importance of the vascular pulsatility in determining SMC proliferation. This result could be useful in minimizing the negative consequences of clinical interventions such as graft and/or stent implantation.
Two-Photon Techniques in Tissue Engineering
Authors: Schade Ronald , Weiß Thomas , Berg Albrecht , Schnabelrauch Matthias , Liefeith Klaus 
Published: March 2018

Purpose NIR radiation in the range of about 800 nm is less absorbed by biological tissues and is suited for triggering photonic effects using femtosecond pulsed Ti: Sa lasers. Especially in the life sciences, two-photon techniques are gaining greater importance. We introduce two laser applications for tissue engineering: the autofluorescent visualization of cells seeded on 3D scaffolds after two-photon excitation; and the manufacturing of 3D-structured hydrogel-like scaffolds by triggering free-radical polymerization processes within polymerizable precursors. Methods Primary bovine chondrocytes were cultivated on collagen I/III scaffolds using a flow chamber system coupled with a two-photon laser scanning microscope (2PLSM). During the incubation the cell population was hydrostatically stimulated. The selective visualization of unlabeled cells and scaffolds was achieved by spectral autofluorescence imaging. To gain some insight into scaffold-mediated effects on cell growth and cell differentiation, hydrogel-like scaffolds with well defined 3D structures were generated by two-photon polymerization (2PP) using methacrylated urethane and polyethyleneglycol diacrylate. Results We were able to show that spectral autofluorescence imaging provides spatially resolved data for the non-invasive online control of the tissue engineering process as well as the quantification of cell distribution within the scaffold. The fabrication of 3D 2PP scaffolds made from hydrogel-forming monomers and their effect on cell attachment and cell growth were also shown. Conclusions Two-photon techniques provide powerful tools for both the non-invasive online visualization of 3D cell-scaffold constructs and the structuring of 3D cultivation environments. The application of these techniques is also suitable for integration into micro-systems technology (e.g. BioMEMS, Cells-on-Chip, Lab-on-a Chip).
Combined Impedance Spectroscopy and Fourier Domain Optical Coherence Tomography to Monitor Cells in Three-Dimensional Structures
Authors: Bagnaninchi Pierre O. 
Published: March 2018

Objectives To assess non-invasively and in real time the three- dimensional organization of cells within porous matrices by combining Fourier Domain Optical Coherence Tomography (FDOCT) and Impedance Spectroscopy (IS). Materials and Methods Broadband interferences resulting from the recombination of in-depth light scattering events within the sample and light from a reference arm are measured as a modulation of the spectrum generated by a superluminescent laser diode (λo = 930nm, FWHM 90nm). Fourier transform allows in-depth localization of the scatterers, and the 3D microstructure of the sample is reconstructed by raster scanning. Simultaneously impedance spectroscopy is performed with a dielectric probe connected to an impedance analyzer to gather additional cellular information, and synchronized with FDOCT measurements. Results A combined IS-FDOCT system allowing an axial resolution of 5 micrometer in tissues and impedance measurements over the range 20MHz-1GHz has been developed. Alginate matrices have been characterized in terms of microstructure and impedance. Matrices seeded with adipose-derived stem cells have been monitored without the use of labeling agent. Conclusions We have developed a multimodality system that will be instrumental to non-invasively monitor changes in total cell volume fraction and infer cell-specific dielectric properties in 3D structure.
Intervertebral Disc Regeneration: Influence of Growth Factors on Differentiation of Human Mesenchymal Stem Cells (hMSC)
Authors: Ehlicke Franziska , Freimark Denise , Heil Birthe , Dorresteijn Adriaan , Czermak Peter 
Published: March 2018

Introduction One common cause of disability in modern society is low back pain. The main reason for this pain is the degeneration of the intervertebral disc (IVD), particularly of the nucleus pulposus (NP). For the early degeneration stage, a cell-based therapy could constitute a minimally invasive method of treatment. Therefore, adequate cells are needed. As the usage of NP cells is limited because of their insufficient amount or vitality, a promising alternative is the application of human mesenchymal stem cells (hMSCs). Objective To investigate the potential of various growth factors to induce the differentiation of hMSCs into NP cells and thereby to obtain an alternative cell source for the treatment of IVD degeneration. Methods hMSC-TERT were cultivated three-dimensionally in a hydrogel for 21 days to form NP cells. Cell survival and proliferation were determined using SybrGreen/propidium iodide double staining and the WST-test. To investigate the ability of several growth factors to differentiate hMSCs into NP cells, fluorescence immunostaining of NP-specific marker proteins (e.g., chondroadherin (CHAD) and the recently discovered cytokeratin 19) were performed. Results Following the procedure described above, cells are able to maintain their viability and proliferation capacity throughout the cultivation time. By using a previously established immunofluorescence protocol, we were able to indicate the ability of three different growth factors for differentiating hMSCs into NP-like cells. Conclusion The expression of several marker proteins in all differentiation experiments indicates the ability of IGF-1, FGF-2 and PDGF-BB to differentiate hMSCs into NP-like cells apart from the usually applied TGF-β3. Furthermore, our findings preclude the application of Cytokeratin 19 as a specific marker protein for NP cells. Further experiments have to be done to find real specific NP marker proteins to indisputably verify the differentiation of hMSCs into NP cells. If so, application of these three growth factors would possibly be an option to obtain sufficient NP cells for minimally invasive IVD regeneration.
Effects of Low Concentrated BMP-7 Administered by co-Cultivation or Plasmid Transfection on Human Osteoarthritic Chondrocytes
Authors: Gavenis Karsten , Schneider Ulrich , Wallich Reinhard , Mueller-Rath Ralf , Schmidt-Rohlfing Bernhard , Andereya Stefan 
Published: March 2018

Introduction While BMP-7 has proven to be one of the most potent growth factors in cartilage tissue engineering, protein concentration and route of administration remain a matter of debate. Here we investigated the effects of a low concentration of BMP-7 on human osteoarthritic chondrocytes administered by protein co-cultivation and plasmid transfection. Methods Freshly released (P0) or in vitro propagated chondrocytes (P2) were cultivated in a collagen type-I gel for 3 weeks in vitro or in nude mice. Seeded chondrocytes were treated with 50 ng/mL BMP-7 directly added to the medium or were subject to transient BMP-7 plasmid transfection prior to gel cultivation. Untreated specimens served as a control. After recovery, samples were investigated by histological and immunohistochemical staining and real-time PCR. Results In vitro, collagen type-II protein production was enhanced, and it was stored mainly pericellularly. Collagen type-II and aggrecan gene expression were enhanced in both treatment groups. After nude mouse cultivation, col-II protein production was further enhanced, but specimens of the BMP-7 transfection group revealed a clustering of col-II positive cells. Gene expression was strongly up-regulated, chondrocyte number was increased and the differentiated phenotype prevailed. In general, freshly released chondrocytes (P0) proved to be superior to chondrocytes pre-amplified in vitro (P2). Conclusions Both BMP-7 co-cultivation and plasmid transfection of human osteoarthritic chondrocytes led to improved cartilage repair tissue. Nevertheless, the col-II distribution following BMP-7 co-cultivation was homogeneous, while samples produced by transient transfection revealed a col-II clustering.
A Three-Dimensional Traction/Torsion Bioreactor System for Tissue Engineering
Authors: Scaglione Silvia , Zerega Barbara , Badano Roberto , Benatti Umberto , Fato Marco , Quarto Rodolfo 
Published: March 2018

Purpose The aim of this study was to design, develop and validate a simple, compact bioreactor system for tissue engineering. The resulting bioreactor was designed to achieve ease-of-use and low costs for automated cell-culturing procedures onto three-dimensional scaffolds under controlled torsion/traction regimes. Methods Highly porous poly-caprolactone-based scaffolds were used as substrates colonized by fibroblast cells (3T3 cell line). Constructs were placed within the cylindrical culture chamber, clumped at the ends and exposed to controlled sequences of torsional stimuli (forward/back-forward sequential cycles of 100° from neutral position at a rate of 600°/min) through a stepper-motor; working settings were defined via PC by an easy user-interface. Cell adhesion, morphology, cytoskeletal fiber orientation and gene expression of extracellular matrix proteins (collagen type I, tenascin C, collagen type III) were evaluated after three days of torsional stimulation in the bioreactor system. Results and Conclusions The 3D bioreactor system was validated in terms of sterility, experimental reproducibility and flexibility. Cells adhered well onto the polymeric scaffolds. Collagen type I, tenascin C and collagen type III gene expression were significantly up-regulated when cells were cultured under torsion in the bioreactor for three days. In conclusion, we have developed a simple, efficient and versatile 3D cell-culture system to engineer ligament grafts. This system can be used either as a model to investigate mechanisms of tissue development or as a graft manufacturing system for possible clinical use in the field of regenerative medicine.
The modified polymethyl methacrylate-silicone keratoprosthesis in rabbit model
Authors: Sun Heng , Hu Zhu-lin 
Published: March 2018

Purpose: To evaluate the safety and effectiveness of a modified polymethyl methacrylate-silicone keratoprosthesis and its operation method in alkali-burned rabbit model. Methods and materials: The polymethyl methacrylate-silicone keratoprostheses were implanted into seven alkali-burned rabbit corneas by a special operation method using autologous graft as the keratoprosthesis (Kpro) carrier. The long-term postoperative outcomes were evaluated. Results: During a postoperative study period of 16 months, except for one Kpro extruded at 3 months, all Kpros were in good position and were kept transparent without Kpro extrusion, keratolysis, infection, endophthalmitis, or retinal detachment. The postoperative complications included elevated intraocular pressure in two cases and temporary retroprosthetic membrane formation in two cases. Conclusion: The modified polymethyl methacrylate-silicone Kpro and its operation method is a relatively safe and effective choice for alkali-burned rabbit eyes. Elevated intraocular pressure is the main complication needing to be resolved.
Sterilization of Therapeutic Immunoadsorbents with Aqueous Propylene Oxide Solution
Authors: Sato H. , Kidaka T. , Hori M. 
Published: March 2018

Propylene oxide (PO), in the form of its aqueous solution, was evaluated as a chemical sterilant for therapeutic immunoadsorbent to be used in on-line plasmapheresis. Generally, PO is characterized as less toxic and less antimicrobial than ethylene oxide. PO was significant sporicidal to B. subtilis at 25°C and 10β spores/ml were killed with 1% (V/V) PO solution after storage for 3 weeks when 75% to 80% of PO decomposed; the death-rate conformed to the kinetics of a first-order reaction although PO decomposed rapidly. Thus an apparent D values were estimated to be 13 to 16 days with 0.5% PO solution and 5 to 7 days with 1% PO. An immunoadsorbent consisting of Sepharose 4B immobilizing anti-human IgE antibody was used to study the effect of PO on adsorption characteristics. PO affected the IgE removal of the immunoadsorbents depending on its concentration ranging from 0% to 4%. The IgE-adsorptions were lowered by only 17% and 30% of the intact and glutaraldehyde-treated immunoadsorbents respectively after storage for 3 months in the 2% PO solution at 25°C, and these numbers are considered to be acceptable for a clinical use. A 2% PO solution was chosen based on the results of the shelf life test of immunoadsorbents and the sporicidal test of PO.
Urinary Prostaglandin E2 Excretion after the Resumption of Renal Function Post Renal Transplantation
Authors: Zawada E.T. 
Published: March 2018

Previous studies have demonstrated that the renal prostaglandin system participate in the recovery from ischemic events, in diuresis and in natriuresis. This study was undertaken to probe renal prostaglandin E2 synthesis during the first and second weeks after renal transplantation Urinary prostaglandin E2 excretion was greatly elevated immediately after transplantation, compared to the second week, and differences in urine PGE2 concentration were also significant. This suggests that enhanced prostaglandin synthesis accompanies the resumption of renal function after transplantation.
Studies of Complement Activation in ARDS Patients Treated by Long-Term Extracorporeal CO2 Removal
Authors: Cicardi M. Gardinali M. , Frangi D. , Bergamaschini L. , Gallazzi M. , Gattinoni L. , Agostoni A. 
Published: March 2018

To investigate the role of complement activation in the adult respiratory distress syndrome (ARDS) and in the complications of extracorporeal circulation (ECC), several parameters (CH50, C3 split products, C3a, C5a, PMN aggregating activity, carboxypeptidase activity) of the complement profiles of 23 ARDS patients were measured. Twenty patients were treated by long-term extracorporeal support. Before connection to ECC, marked leukocytosis (18,250 ± 5,950) and significantly high plasma C3a levels (p < 0.005) were observed. After connection, C3a levels increased further, up to values eight times higher than the basal ones. The WBC count transiently decreased to 41% of prebypass levels after 15 minutes of ECC. At the same time C3 split products appeared and PMN aggregating activity was shown in 52% of the patients. C5a levels remained normal during bypass, even in two samples in which PMN aggregating activity was detected. Later decreases in CH50 titers (p < 0.001) and carboxypeptidase activity (p < 0.005) were observed. Complement activation was no longer evident after the 24th hour of bypass. We conclude that there is a low-degree complement activation in ARDS, and ECC is a further strong stimulus for complement activation. This phenomenon appears, however, to be self-limited.
Lymphocytapheresis in the Treatment of Rheumatoid Arthritis: Clinical and Immunological Studies
Authors: Indiveri F. , Rogna S. , Viglione D. , Pierri I. , Scudeletti M. , Grifoni V. 
Published: March 2018

Six patients with Rheumatoid Arthritis (RA) have been treated with lymphocytapheresis after their disease proved unresponsive to conventional therapy. Clinical improvement, measured evaluating articular swelling, morning stiffness, and muscle weakness, was observed in four of the six patients. From the cellular point of view lymphocytapheresis induced (1) T cell depletion without modification of lymphocyte subsets in the peripheral blood, (2) improvement of lymphocyte responsiveness to lectins, autoantigens and alloantigens. All together these data suggest that therapeutic leukapheresis modifies the immune responsiveness in humans, possibly facilitating the process of cell to cell cooperation.
Efficacy of a Combined Treatment with Plasma Exchange and Cytostatics in Macroglobulinemia
Authors: Busnach G. , dal Col A. , Brando B. , Perrino M.L. , Brunatti C. , Minetti L. 
Published: March 2018

Monthly plasma exchange (PE) sessions have been carried out in 3 patients with advanced Waldenström macroglobulinemia, in order to reduce electrophoretic M band under 2g/100 ml. When PE was combined to low doses of cytostatics (n=1 8), 3 procedures per session were required to obtain a mean 57.4±12.3% IgM reduction, from 4.2±1.2 to 1.7±0.5 g/100 ml. A mean 61.5±13.1% IgM reduction, from 5.5±1.3 to 2.1±1 g/100 ml, was obtained in 64 procedures carried out as the only therapy in 12 sessions, with 5.3 procedures requirement per monthly session. IgM percent reduction 24 hours after PE was greater with combined treatment (45±9.7 vs. 28.9±1 5.4%; p=0.001). The advantage of a combined treatment is therefore either a lowered PE requirement or a tapered maintenence cytostatic dosage.
Successful Treatment of Experimental Neonatal Respiratory Failure Using Extracorporeal Membrane Lung Assist
Authors: Fumagalli R. , Kolobow T. , Arosio P. , Chen V. , Buckhold D.K. , Pierce J.E. 
Published: March 2018

A total of 44 preterm fetal lambs at great risk of developing respiratory failure were delivered by Cesarean section, and were then managed on conventional mechanical pulmonary ventilation. Fifteen animals initially fared well, and 14 of these were long term survivors. Twenty-nine other lambs showed a progressive deterioration in arterial blood gases within 30 minutes of delivery, of which 10 lambs were continued on mechanical pulmonary ventilation (20% survival), while the remaining 19 lambs were placed on an extracorporeal membrane lung respiratory assist (79% survival). Extracorporeal membrane lung bypass rapidly corrected arterial blood gas values, and permitted the use of high levels of CPAP instead of the continuation of mechanical pulmonary ventilation at high peak airway pressures. Improvement in lung function was gradual, and predictable. Early institution of extracorporeal respiratory assist using a membrane artificial lung rapidly corrected arterial blood gas values and significantly improved on neonate survival.
Trace Elements and Plasmapheresis
Authors: Hosokawa S. , Oyamaguchi A. , Yoshida O. 
Published: March 2018

The relationship between serum aluminum (Al), zinc (Zn), copper (Cu), and iron (Fe) and plasmapheresis (PP) treatment was examined. Three patients with rheumatoid arthritis, six with myasthenia gravis, and 6 with multiple sclerosis were studied. Serum Al, Zn, Cu, and Fe were measured before and after PP. Plasma was separated by first filtration; a second filtration separated the plasma components. Three liters of plasma were treated in each PP session. With each PP treatment, total protein (TP) removed was 20 ± 5% and serum albumin removed was ± 6%. Serum Al rose significantly (p < 0.01 from 1.1 ± 0.2 μgl dl pre-PP to 2.8 ± 0.4 μg/dl post-PP. Serum Zn, Cu, and Fe decreased significantly (p < 0.01) from 86.2 ± 7.4 μg/dl, 126 ± 18 μg/dl, and 108 ± 14 μg/dl pre-PP to 58.4 ± 10.2 μg/dl, 104 ± 6 μg/dl, and 82 ± 16 μg/dI post-PP, respectively. Two days after the end of the six-month PP treatment, serum Al levels rose significantly (p < 0.01), from 1.1 ± 0.2 μg/dl to 3.6 ± 0.8 μg/dl. However, serum TP, serum albumin, and serum Zn, Cu, and Fe did not change significantly. It thus appears essential in PP treated patients, to remove Al from the blood to protect against aluminum intoxication
Cellular Mechanisms of Artificial Peptides Binding to HLA
Authors: Frumento G. , Pernis B. , Fais F. , Vitale M. , Chersi A. , Ferrara G.B. 
Published: March 2018

On the basis of the consideration that cell-free models cannot precisely mimic the complexity of the intracellular environment, we used a system to investigate the mechanisms that enable antigen-presenting cells (APC) to bind exogenous peptides through their human leukocyte antigen (HLA) molecules. We evaluated the uptake of the radiolabeled peptide 17-29-Tyr of influenza virus matrix protein by B-EBV cell lines, under various conditions. The results can be summarized as follows: a) the kinetics of peptide binding and release are very fast in living, fully competent cells; b) the peptide-HLA complexes are short-living and the DR molecules continuously undergo peptidic exchange; c) using glutaraldehyde-fixed cells, the kinetics of the two phenomena are slow, closely resembling those observed with the same peptide and purified, immobilized DR molecules. The data suggest that in APC, cellular mechanisms are operative that increase the efficiency of both loading and unloading of Class II HLA with exogenous peptides. This is likely to be related to the recycling of Class II molecules to intracellular compartments, were binding takes place. The observation that the HLA-peptide complex is a dynamic structure, suggests the possibility of replacing natural peptides with synthetic ones at this level, in order to regulate the immune response.
Importance of Purification on Transfusional Efficacy of Hemoglobin Solutions
Authors: Menu P. , Labrude P. , Grandgeorge M. , Vigneron C. 
Published: March 2018

It has only been realized quite recently how important is the purification of hemoglobin solution for use in transfusion and several techniques have been published. We used ion exchange chromatography with which the main “contaminants” (glycoproteins, enzymes, phospholipids) are absorbed by the gel, whereas hemoglobin is not retained. The solutions studied here are non-modified hemoglobin and its homologue pyridoxylated hemoglobin (PLP-Hb). Physico-chemical analyses, usually undertaken to characterize hemoglobin solutions, show no difference before and after purification, except that the enzymatic activity almost disappears. In order to appreciate the benefits of purification, total exchange transfusions were carried out on rats. Without reperfusion, purification of the hemoglobin solution allowed a significantly longer survival time which was even more significant with PLP-Hb solution. Urinary loss did not seem to be affected by purification. With reperfusion in order to compensate these renal losses, PLP-Hb solutions gave survival times up to three days. However, the inevitable death of the animals poses the problem of instability of these purified solutions following enzyme loss.