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Sample records for cemented stem clinical

  1. Pre-clinical evaluation of the mechanical properties of a low-stiffness cement-injectable hip stem.

    Eldesouky, Ibrahim; Harrysson, Ola; Marcellin-Little, Denis J; West, Harvey; El-Hofy, Hassan

    2017-11-01

    In total hip arthroplasty (THA), the femoral stem can be fixed with or without bone cement. Cementless stem fixation is recommended for young and active patients as it eliminates the risk of loss of fixation at the bone-cement and cement-implant interfaces. Cementless fixation, however, suffers from a relatively high early revision rate. In the current research, a novel low-stiffness hip stem was designed, fabricated and tested. The stem design provided the option to inject biodegradable bone cement that could enhance initial stem stability. The stem was made of Ti6Al4V alloy. The proximal portion of the stem was porous, with cubic cells. The stem was fabricated using electron beam melting (EBM) technology and tested in compression and bending. Finite-element analysis was used to evaluate stem performance under a dynamic load representing a stair descending cycle and compare it to the performance of a solid stem with similar geometry. The von Mises stresses and maximum principal strains generated within the bone increased after porous stem insertion compared to solid stem insertion. The low-modulus stem tested in this study has acceptable mechanical properties and generates strain patterns in bone that appear compatible with clinical use.

  2. Surface roughness of debonded straight-tapered stems in cemented THA reduces subsidence but not cement damage

    Verdonschot, N.J.J.; Huiskes, H.W.J.

    1998-01-01

    Although stress analyses have shown that the mechanical endurance of cemented femoral THA reconstructions is served by stems that firmly bond to their cement mantles, retrieval studies suggest that this may be difficult to achieve. Clinical studies with roentgen stereophotogrammetric analyses have

  3. The effect of cement on hip stem fixation: a biomechanical study.

    Çelik, Talip; Mutlu, İbrahim; Özkan, Arif; Kişioğlu, Yasin

    2017-06-01

    This study presents the numerical analysis of stem fixation in hip surgery using with/without cement methods since the use of cement is still controversial based on the clinical studies in the literature. Many different factors such as stress shielding, aseptic loosening, material properties of the stem, surgeon experiences etc. play an important role in the failure of the stem fixations. The stem fixation methods, cemented and uncemented, were evaluated in terms of mechanical failure aspects using computerized finite element method. For the modeling processes, three dimensional (3D) femur model was generated from computerized tomography (CT) images taken from a patient using the MIMICS Software. The design of the stem was also generated as 3D CAD model using the design parameters taken from the manufacturer catalogue. These 3D CAD models were generated and combined with/without cement considering the surgical procedure using SolidWorks program and then imported into ANSYS Workbench Software. Two different material properties, CoCrMo and Ti6Al4V, for the stem model and Poly Methyl Methacrylate (PMMA) for the cement were assigned. The material properties of the femur were described according to a density calculated from the CT images. Body weight and muscle forces were applied on the femur and the distal femur was fixed for the boundary conditions. The calculations of the stress distributions of the models including cement and relative movements of the contacts examined to evaluate the effects of the cement and different stem material usage on the failure of stem fixation. According to the results, the use of cement for the stem fixation reduces the stress shielding but increases the aseptic loosening depending on the cement crack formations. Additionally, using the stiffer material for the stem reduces the cement stress but increases the stress shielding. Based on the results obtained in the study, even when taking the disadvantages into account, the cement usage

  4. Femoral component revision with use of impaction bone-grafting and a cemented polished stem.

    Schreurs, B.W.; Arts, J.J.C.; Verdonschot, N.J.J.; Buma, P.; Slooff, T.J.J.H.; Gardeniers, J.W.M.

    2005-01-01

    BACKGROUND: The purpose of this study was to evaluate the clinical and radiographic outcomes of revision of the femoral component of a hip arthroplasty with use of an impaction bone-grafting technique and a cemented polished stem. METHODS: Thirty-three consecutive femoral reconstructions that were

  5. 21 CFR 888.4210 - Cement mixer for clinical use.

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cement mixer for clinical use. 888.4210 Section... (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Surgical Devices § 888.4210 Cement mixer for clinical use. (a) Identification. A cement mixer for clinical use is a device consisting of a container intended for use in mixing...

  6. The initial instability of cemented and non-cemented femoral stems fixated with a bone grafting technique

    Schreurs, B.W.; Huiskes, H.W.J.; Slooff, T.J.J.H.

    1994-01-01

    To reconstruct intramedullary bone stock in revision surgery of failed total hip arthroplasties, a method was developed using impacted trabecular bone grafts. In an in vitro model with femora of the goat, the initial stabilities of both cemented and non-cemented hydroxylapatite-coated stems in this

  7. Crown and bridge cements: clinical applications.

    Bunek, Sabiha S; Powers, John M

    2012-12-01

    Cement selection can be confusing because factors such as substrate, the type of restoration, and patient needs must be considered. Some substrates require additional treatment before cementation. This article describes the most commonly used traditional crown and bridge cements (GI and RMGI) used for metal and metal-ceramic restorations, and resin cements used for all-ceramic restorations. Advantages, disadvantages, indications, and contraindications of cements have been reviewed. Recommended uses of cements for metal, ceramic, and laboratory composite restorations have been presented. General guidelines for surface treatment ot silica- and zirconia-based restorations when using resin cements have been discussed.

  8. Femoral component revision with use of impaction bone-grafting and a cemented polished stem. Surgical technique.

    Schreurs, B.W.; Arts, J.J.C.; Verdonschot, N.J.J.; Buma, P.; Slooff, T.J.J.H.; Gardeniers, J.W.M.

    2006-01-01

    BACKGROUND: The purpose of this study was to evaluate the clinical and radiographic outcomes of revision of the femoral component of a hip arthroplasty with use of an impaction bone-grafting technique and a cemented polished stem. METHODS: Thirty-three consecutive femoral reconstructions that were

  9. Three-dimensional shape optimization of a cemented hip stem and experimental validations.

    Higa, Masaru; Tanino, Hiromasa; Nishimura, Ikuya; Mitamura, Yoshinori; Matsuno, Takeo; Ito, Hiroshi

    2015-03-01

    This study proposes novel optimized stem geometry with low stress values in the cement using a finite element (FE) analysis combined with an optimization procedure and experimental measurements of cement stress in vitro. We first optimized an existing stem geometry using a three-dimensional FE analysis combined with a shape optimization technique. One of the most important factors in the cemented stem design is to reduce stress in the cement. Hence, in the optimization study, we minimized the largest tensile principal stress in the cement mantle under a physiological loading condition by changing the stem geometry. As the next step, the optimized stem and the existing stem were manufactured to validate the usefulness of the numerical models and the results of the optimization in vitro. In the experimental study, strain gauges were embedded in the cement mantle to measure the strain in the cement mantle adjacent to the stems. The overall trend of the experimental study was in good agreement with the results of the numerical study, and we were able to reduce the largest stress by more than 50% in both shape optimization and strain gauge measurements. Thus, we could validate the usefulness of the numerical models and the results of the optimization using the experimental models. The optimization employed in this study is a useful approach for developing new stem designs.

  10. Stability Loss of the Cemented Stem of Hip Prosthesis due to Fretting Corrosion Fatigue

    L. Capitanu

    2017-12-01

    Full Text Available Aim of this project was to study the fretting behaviour of the cemented femoral stem fixation of a total hip prosthesis, trying to capture the loss of contact between the femoral stem and polymetylmethacrilate cement fixation. To have a landmark, studies were performed compared with cementless fixation, where no fretting phenomenon occurs, on real prostheses, under biological 3D loading conditions. A fatigue test device, installed on a servo-hydraulic triaxial dynamic testing machine was used. It allowed monitoring the flexion-extension, abduction-adduction, inner-outer rotation movements, and the variation of the torsional torque, depending on normal loading. The test ends when the sample does not fail after 2000000 cycles, or when it has reached a predetermined number of cycles. Test fluid medium used was NaCl mixed with distilled water, a favourable environment for appearance of fretting corrosion. After the failure of stem fixation at 2450000 cycles, the mantle of bone cement remaining adherent on femoral stem was removed. Microscopic inspection of the femoral stem and of the inner part of the polymetylmethacrilate mantle demonstrated the existence of corrosion of the femoral stem surface beneath the cement mantle, and Fe2O3 deposits on the femoral stem surface and on the inner part of the mantle.

  11. Sr-substituted bone cements direct mesenchymal stem cells, osteoblasts and osteoclasts fate.

    Monica Montesi

    Full Text Available Strontium-substituted apatitic bone cements enriched with sodium alginate were developed as a potential modulator of bone cells fate. The biological impact of the bone cement were investigated in vitro through the study of the effect of the nanostructured apatitic composition and the doping of strontium on mesenchymal stem cells, pre-osteoblasts and osteoclasts behaviours. Up to 14 days of culture the bone cells viability, proliferation, morphology and gene expression profiles were evaluated. The results showed that different concentrations of strontium were able to evoke a cell-specific response, in fact an inductive effect on mesenchymal stem cells differentiation and pre-osteoblasts proliferation and an inhibitory effect on osteoclasts activity were observed. Moreover, the apatitic structure of the cements provided a biomimetic environment suitable for bone cells growth. Therefore, the combination of biological features of this bone cement makes it as promising biomaterials for tissue regeneration.

  12. Contact damage failure analyses of fretting wear behavior of the metal stem titanium alloy-bone cement interface.

    Zhang, Lanfeng; Ge, Shirong; Liu, Hongtao; Wang, Qingliang; Wang, Liping; Xian, Cory J

    2015-11-01

    Although cemented titanium alloy is not favored currently in the Western world for its poor clinical and radiography outcomes, its lower modulus of elasticity and good biocompatibility are instrumental for its ability supporting and transforming physical load, and it is more suitable for usage in Chinese and Japanese populations due to their lower body weights and unique femoral characteristics. Through various friction tests of different cycles, loads and conditions and by examining fretting hysteresis loops, fatigue process curves and wear surfaces, the current study investigated fretting wear characteristics and wear mechanism of titanium alloy stem-bone cement interface. It was found that the combination of loads and displacement affected the wear quantity. Friction coefficient, which was in an inverse relationship to load under the same amplitude, was proportional to amplitudes under the same load. Additionally, calf serum was found to both lubricate and erode the wear interface. Moreover, cement fatigue contact areas appeared black/oxidative in dry and gruel in 25% calf serum. Fatigue scratches were detected within contact areas, and wear scars were found on cement and titanium surfaces, which were concave-shaped and ring concave/ convex-shaped, respectively. The coupling of thermoplastic effect and minimal torque damage has been proposed to be the major reason of contact damage. These data will be important for further studies analyzing metal-cement interface failure performance and solving interface friction and wear debris production issues. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Probabilistic analysis of the influence of the bonding degree of the stem-cement interface in the performance of cemented hip prostheses.

    Pérez, M A; Grasa, J; García-Aznar, J M; Bea, J A; Doblaré, M

    2006-01-01

    The long-term behavior of the stem-cement interface is one of the most frequent topics of discussion in the design of cemented total hip replacements, especially with regards to the process of damage accumulation in the cement layer. This effect is analyzed here comparing two different situations of the interface: completely bonded and debonded with friction. This comparative analysis is performed using a probabilistic computational approach that considers the variability and uncertainty of determinant factors that directly compromise the damage accumulation in the cement mantle. This stochastic technique is based on the combination of probabilistic finite elements (PFEM) and a cumulative damage approach known as B-model. Three random variables were considered: muscle and joint contact forces at the hip (both for walking and stair climbing), cement damage and fatigue properties of the cement. The results predicted that the regions with higher failure probability in the bulk cement are completely different depending on the stem-cement interface characteristics. In a bonded interface, critical sites appeared at the distal and medial parts of the cement, while for debonded interfaces, the critical regions were found distally and proximally. In bonded interfaces, the failure probability was higher than in debonded ones. The same conclusion may be established for stair climbing in comparison with walking activity.

  14. Longevity of metal-ceramic crowns cemented with self-adhesive resin cement: a prospective clinical study

    Lucas Pradebon BRONDANI

    2017-04-01

    Full Text Available Abstract Resin cements are often used for single crown cementation due to their physical properties. Self-adhesive resin cements gained widespread due to their simplified technique compared to regular resin cement. However, there is lacking clinical evidence about the long-term behavior of this material. The aim of this prospective clinical trial was to assess the survival rates of metal-ceramic crowns cemented with self-adhesive resin cement up to six years. One hundred and twenty-nine subjects received 152 metal-ceramic crowns. The cementation procedures were standardized and performed by previously trained operators. The crowns were assessed as to primary outcome (debonding and FDI criteria. Statistical analysis was performed using Kaplan-Meier statistics and descriptive analysis. Three failures occurred (debonding, resulting in a 97.6% survival rate. FDI criteria assessment resulted in scores 1 and 2 (acceptable clinical evaluation for all surviving crowns. The use of self-adhesive resin cement is a feasible alternative for metal-ceramic crowns cementation, achieving high and adequate survival rates.

  15. Longevity of metal-ceramic crowns cemented with self-adhesive resin cement: a prospective clinical study

    Brondani, Lucas Pradebon; Pereira-Cenci, Tatiana; Wandsher, Vinicius Felipe; Pereira, Gabriel Kalil; Valandro, Luis Felipe; Bergoli, César Dalmolin

    2017-04-10

    Resin cements are often used for single crown cementation due to their physical properties. Self-adhesive resin cements gained widespread due to their simplified technique compared to regular resin cement. However, there is lacking clinical evidence about the long-term behavior of this material. The aim of this prospective clinical trial was to assess the survival rates of metal-ceramic crowns cemented with self-adhesive resin cement up to six years. One hundred and twenty-nine subjects received 152 metal-ceramic crowns. The cementation procedures were standardized and performed by previously trained operators. The crowns were assessed as to primary outcome (debonding) and FDI criteria. Statistical analysis was performed using Kaplan-Meier statistics and descriptive analysis. Three failures occurred (debonding), resulting in a 97.6% survival rate. FDI criteria assessment resulted in scores 1 and 2 (acceptable clinical evaluation) for all surviving crowns. The use of self-adhesive resin cement is a feasible alternative for metal-ceramic crowns cementation, achieving high and adequate survival rates.

  16. [Poldi-Čech cemented femoral stem in total hip arthroplasty after 25 years].

    Rozkydal, Z; Janíček, P

    2010-08-01

    The aim of the study was to evaluate the results of Poldi-Čech femoral stem implantation in primary total hip arthroplasty after 25 years. A group of 65 patients (90 hips) with Poldi-Čech total hip arthroplasty carried out between 1974 and 1984 was evaluated at the end of 2009. The mean follow-up of all patients was 28 years (25 to 35). There were seven men and 58 women. The mean age at the time of implantation was 43 years (26 to 60) and at the latest follow-up it was 72 years. In all patients the cemented UHMW PE acetabular component (RCH 1000) was used together with AKV Ultra 2 Poldi steel femoral stems (1st, 2nd and 3rd generations). The stem was a monoblock with a 32-mm head. The evaluation of the results was based on the Harris hip score and X ray with an A-P view of the pelvis and the affected hip. Statistical analysis was made using the life-table method. At the latest follow up the mean Harris score was 69.7 points (40 to 88). There were 69 hips with an original Poldi-Čech femoral component still in situ, 64 of them were stable and five with radiological evidence of aseptic loosening. Five patients had undergone Girdlestone resection arthroplasty for septic loosening. Thirteen patients (16 hips) had femoral stem revision. The cumulative proportion of clinical survivorship of the Poldi-Čech femoral stem, with revision for any reason as the endpoint, .was 0.93 at 6 years, 0.84 at 12 years, and 0.77 at 18, 24 and 30 years after the index surgery. Radiographic findings revealed 64 hips with stable stems, five hips with ;aseptic loosening (probable, 0 possible, 2, definite, 3). Six- teen hips were after revision surgery for aseptic loosening of the stem and five hips were after Girdlestone resection arthroplasty for septic failure. The cumulative proportion of radiological survivorship of the Poldi-Čech femoral stem with any reason as the endpoint was 0.92 at 6 years, 0.78 at 12 years, 0.72 at 18 years, 0.69 at 24 years and 0.69 at 30 years. The Poldi

  17. Calcium silicate-based cements: composition, properties, and clinical applications.

    Dawood, Alaa E; Parashos, Peter; Wong, Rebecca H K; Reynolds, Eric C; Manton, David J

    2017-05-01

    Mineral trioxide aggregate (MTA) is a calcium silicate-based cement (CSC) commonly used in endodontic procedures involving pulpal regeneration and hard tissue repair, such as pulp capping, pulpotomy, apexogenesis, apexification, perforation repair, and root-end filling. Despite the superior laboratory and clinical performance of MTA in comparison with previous endodontic repair cements, such as Ca(OH) 2 , MTA has poor handling properties and a long setting time. New CSC have been commercially launched and marketed to overcome the limitations of MTA. The aim of the present review was to explore the available literature on new CSC products, and to give evidence-based recommendations for the clinical use of these materials. Within the limitations of the available data in the literature regarding the properties and performance of the new CSC, the newer products could be promising alternatives to MTA; however, further research is required to support this assumption. © 2015 Wiley Publishing Asia Pty Ltd.

  18. Total Hip Arthroplasty Using a Polished Tapered Cemented Stem in Hereditary Multiple Exostosis

    Kanda, Akio; Kaneko, Kazuo; Obayashi, Osamu; Mogami, Atsuhiko

    2016-01-01

    A 61-year-old Japanese man underwent right total hip arthroplasty for hereditary multiple exostosis. At first presentation, he had suffered from coxalgia for a long time. On radiographic images, there was a gigantic femoral head, increased shaft angle, and large diameter of the femoral neck. He had also developed coxarthrosis and severe pain of the hip joint. The transformation of the proximal femur bone causes difficulty in setting a cementless total hip prosthesis. Therefore, total hip arthroplasty using a cemented polished tapered stem was performed via a direct lateral approach. Using a cemented polished tapered stem allowed us to deal with the femoral bone transformation and bone substance defectiveness due to exostosis and also minimized the invasiveness of the operation. PMID:27127668

  19. Effects of Prosthesis Stem Tapers on Stress Distribution of Cemented Hip Arthroplasty

    Abdullah, Abdul Halim; Nor, Mohd Asri Mohd; Saman, Alias Mohd; Tamin, Mohd Nasir; Kadir, Mohammed Rafiq Abdul

    2010-01-01

    Aseptic loosening effects are critical issues in encouraging long term stability of cemented hip arthroplasty. Stress shielding is believed to be an important factor that contributes to the aseptic loosening problems. The numerous changes in the prosthesis stem design are intended to minimize the stress shielding and aseptic loosening problems and to improve the long term performance of the implants. In this study, the stress distribution in cemented hip arthroplasty is established using finite element method. The taper of the prosthesis is designed to be 3 deg. at anterior/posterior, 3 deg. at medial/lateral and 10 deg. from wide lateral to narrow medial. Major muscle loads and contact forces are simulated for walking (toe-off phase) and stair climbing load cases. Effects of prosthesis stem tapers on the resulting stress distribution are investigated. Results show that compressive stress dominates in the medial plane while tensile stress in the lateral plane of the femur. The corresponding stress levels of intact femur for walking and stair-climbing load cases are 22 and 29 MPa, respectively. The magnitude of Tresca stress for the THA femur in stair-climbing load case remains higher in the region of 85 MPa while the walking load case induces around 40 MPa. The stress range in the straight and single taper stem prosthesis is lower than 260 MPa, while localized Tresca stress is in the order of the yield strength of Ti-6Al-4V alloy for double and triple taper stem design.

  20. Changes in bone mineral density (BMD) around the cemented Exeter stem: a prospective study in 18 women with 5 years follow-up

    Damborg, Frank; Nissen, Nis; Jørgensen, Hans R I

    2008-01-01

    BACKGROUND AND PURPOSE: THA changes the pattern of strain distribution in the proximal femur. We quantified the changes in BMD for 5 years after insertion of the cemented Exeter stem in women. METHODS: 18 women aged 55-79 years, undergoing unilateral THA with the cemented Exeter stem, were included...

  1. Changes in bone mineral density (BMD) around the cemented Exeter stem: a prospective study in 18 women with 5 years follow-up

    Damborg, Frank Lindhøj; Nissen, Nis; Jørgensen, Hans R I

    2008-01-01

    THA changes the pattern of strain distribution in the proximal femur. We quantified the changes in BMD for 5 years after insertion of the cemented Exeter stem in women.......THA changes the pattern of strain distribution in the proximal femur. We quantified the changes in BMD for 5 years after insertion of the cemented Exeter stem in women....

  2. A modified PMMA cement (Sub-cement) for accelerated fatigue testing of cemented implant constructs using cadaveric bone.

    Race, Amos; Miller, Mark A; Mann, Kenneth A

    2008-10-20

    Pre-clinical screening of cemented implant systems could be improved by modeling the longer-term response of the implant/cement/bone construct to cyclic loading. We formulated bone cement with degraded fatigue fracture properties (Sub-cement) such that long-term fatigue could be simulated in short-term cadaver tests. Sub-cement was made by adding a chain-transfer agent to standard polymethylmethacrylate (PMMA) cement. This reduced the molecular weight of the inter-bead matrix without changing reaction-rate or handling characteristics. Static mechanical properties were approximately equivalent to normal cement. Over a physiologically reasonable range of stress-intensity factor, fatigue crack propagation rates for Sub-cement were higher by a factor of 25+/-19. When tested in a simplified 2 1/2-D physical model of a stem-cement-bone system, crack growth from the stem was accelerated by a factor of 100. Sub-cement accelerated both crack initiation and growth rate. Sub-cement is now being evaluated in full stem/cement/femur models.

  3. Clinical trials for stem cell transplantation: when are they needed?

    Van Pham, Phuc

    2016-04-27

    In recent years, both stem cell research and the clinical application of these promising cells have increased rapidly. About 1000 clinical trials using stem cells have to date been performed globally. More importantly, more than 10 stem cell-based products have been approved in some countries. With the rapid growth of stem cell applications, some countries have used clinical trials as a tool to diminish the rate of clinical stem cell applications. However, the point at which stem cell clinical trials are essential remains unclear. This commentary discusses when stem cell clinical trials are essential for stem cell transplantation therapies.

  4. Peri-Implantitis Associated with Type of Cement: A Retrospective Analysis of Different Types of Cement and Their Clinical Correlation to the Peri-Implant Tissue.

    Korsch, Michael; Walther, Winfried

    2015-10-01

    The cementation of fixed implant-supported dental restorations involves the risk of leaving excess cement in the mouth which can promote biofilm formation in the peri-implant sulcus. As a result, an inflammation may develop. The aim of the present study was to investigate the clinical effect of two different luting cements on the peri-implant tissue. Within the scope of a retrospective clinical follow-up study, the prosthetic structures of 22 patients with 45 implants were revised. In all cases, a methacrylate cement (Premier Implant Cement [PIC], Premier® Dental Products Company, Plymouth Meeting, PA, USA) had been used for cementation. In 16 additional patients with 28 implants, the suprastructures were retained with a zinc oxide-eugenol cement (Temp Bond [TB], Kerr Sybron Dental Specialities, Glendora, CA, USA). These patients were evaluated in the course of routine treatment. In both populations, the retention time of the suprastructures was similar (TB 3.77 years, PIC 4.07 years). In the PIC cases, 62% of all implants had excess cement. In the TB cases, excess cement was not detectable on any of the implants. Bleeding on probing was significantly more frequent on implants cemented with PIC (100% with and 94% without excess cement) than on implants cemented with TB (46%). Pocket suppuration was observed on 89% of the PIC-cemented implants with excess cement (PIC without excess cement 24%), whereas implants with TB were not affected by it at all. The peri-implant bone loss was significantly greater in the PIC patients (with excess cement 1.37 mm, without excess cement 0.41 mm) than it was in the TB patients (0.07 mm). The frequency of undetected excess cement depends essentially on the type of cement used. Cements that tend to leave more undetected excess have a higher prevalence for peri-implant inflammation and cause a more severe peri-implant bone loss. © 2014 Wiley Periodicals, Inc.

  5. Can finite element models detect clinically inferior cemented hip implants?

    Stolk, J.; Maher, S.A.; Verdonschot, N.J.J.; Prendergast, P.J.; Huiskes, R.

    2003-01-01

    Rigorous preclinical testing of cemented hip prostheses against the damage accumulation failure scenario will reduce the incidence of aseptic loosening. For that purpose, a finite element simulation is proposed that predicts damage accumulation in the cement mantle and prosthetic migration. If the

  6. A computerized pre-clinical test for cemented hip prostheses based on finite element techniques

    Stolk, Jan

    2003-01-01

    Despite the success of cemented total hip replacement (THR), high failure rates are occasionally reported for cemented hip implants that are introduced on the orthopaedic market. Rigorous pre-clinical testing of hip implants could prevent these disasters, by detecting unsafe implant designs at a

  7. Clinical grade adult stem cell banking.

    Thirumala, Sreedhar; Goebel, W Scott; Woods, Erik J

    2009-07-01

    There has been a great deal of scientific interest recently generated by the potential therapeutic applications of adult stem cells in human care but there are several challenges regarding quality and safety in clinical applications and a number of these challenges relate to the processing and banking of these cells ex-vivo. As the number of clinical trials and the variety of adult cells used in regenerative therapy increases, safety remains a primary concern. This has inspired many nations to formulate guidelines and standards for the quality of stem cell collection, processing, testing, banking, packaging and distribution. Clinically applicable cryopreservation and banking of adult stem cells offers unique opportunities to advance the potential uses and widespread implementation of these cells in clinical applications. Most current cryopreservation protocols include animal serum proteins and potentially toxic cryoprotectant additives (CPAs) that prevent direct use of these cells in human therapeutic applications. Long term cryopreservation of adult stem cells under good manufacturing conditions using animal product free solutions is critical to the widespread clinical implementation of ex-vivo adult stem cell therapies. Furthermore, to avoid any potential cryoprotectant related complications, reduced CPA concentrations and efficient post-thaw washing to remove CPA are also desirable. The present review focuses on the current strategies and important aspects of adult stem cell banking for clinical applications. These include current good manufacturing practices (cGMPs), animal protein free freezing solutions, cryoprotectants, freezing & thawing protocols, viability assays, packaging and distribution. The importance and benefits of banking clinical grade adult stem cells are also discussed.

  8. Representations of stem cell clinics on Twitter.

    Kamenova, Kalina; Reshef, Amir; Caulfield, Timothy

    2014-12-01

    The practice of travelling abroad to receive unproven and unregulated stem cell treatments has become an increasingly problematic global phenomenon known as 'stem cell tourism'. In this paper, we examine representations of nine major clinics and providers of such treatments on the microblogging network Twitter. We collected and conducted a content analysis of Twitter posts (n = 363) by these establishments and by other users mentioning them, focusing specifically on marketing claims about treatment procedures and outcomes, discussions of safety and efficacy of stem cell transplants, and specific representations of patients' experiences. Our analysis has shown that there were explicit claims or suggestions of benefits associated with unproven stem cell treatments in approximately one third of the tweets and that patients' experiences, whenever referenced, were presented as invariably positive and as testimonials about the efficacy of stem cell transplants. Furthermore, the results indicated that the tone of most tweets (60.2 %) was overwhelmingly positive and there were rarely critical discussions about significant health risks associated with unproven stem cell therapies. When placed in the context of past research on the problems associated with the marketing of unproven stem cell therapies, this analysis of representations on Twitter suggests that discussions in social media have also remained largely uncritical of the stem cell tourism phenomenon, with inaccurate representations of risks and benefits for patients.

  9. Correlation between clinical performance and degree of conversion of resin cements: a literature review

    Grace DE SOUZA

    2015-08-01

    Full Text Available AbstractResin-based cements have been frequently employed in clinical practice to lute indirect restorations. However, there are numerous factors that may compromise the clinical performance of those cements. The aim of this literature review is to present and discuss some of the clinical factors that may affect the performance of current resin-based luting systems. Resin cements may have three different curing mechanisms: chemical curing, photo curing or a combination of both. Chemically cured systems are recommended to be used under opaque or thick restorations, due to the reduced access of the light. Photo-cured cements are mainly indicated for translucent veneers, due to the possibility of light transmission through the restoration. Dual-cured are more versatile systems and, theoretically, can be used in either situation, since the presence of both curing mechanisms might guarantee a high degree of conversion (DC under every condition. However, it has been demonstrated that clinical procedures and characteristics of the materials may have many different implications in the DC of currently available resin cements, affecting their mechanical properties, bond strength to the substrate and the esthetic results of the restoration. Factors such as curing mechanism, choice of adhesive system, indirect restorative material and light-curing device may affect the degree of conversion of the cement and, therefore, have an effect on the clinical performance of resin-based cements. Specific measures are to be taken to ensure a higher DC of the luting system to be used.

  10. A Review of Glass-Ionomer Cements for Clinical Dentistry

    Sharanbir K. Sidhu

    2016-06-01

    Full Text Available This article is an updated review of the published literature on glass-ionomer cements and covers their structure, properties and clinical uses within dentistry, with an emphasis on findings from the last five years or so. Glass-ionomers are shown to set by an acid-base reaction within 2–3 min and to form hard, reasonably strong materials with acceptable appearance. They release fluoride and are bioactive, so that they gradually develop a strong, durable interfacial ion-exchange layer at the interface with the tooth, which is responsible for their adhesion. Modified forms of glass-ionomers, namely resin-modified glass-ionomers and glass carbomer, are also described and their properties and applications covered. Physical properties of the resin-modified glass-ionomers are shown to be good, and comparable with those of conventional glass-ionomers, but biocompatibility is somewhat compromised by the presence of the resin component, 2 hydroxyethyl methacrylate. Properties of glass carbomer appear to be slightly inferior to those of the best modern conventional glass-ionomers, and there is not yet sufficient information to determine how their bioactivity compares, although they have been formulated to enhance this particular feature.

  11. Cytotoxic effects of glass ionomer cements on human dental pulp stem cells correlate with fluoride release.

    Kanjevac, Tatjana; Milovanovic, Marija; Volarevic, Vladislav; Lukic, Miodrag L; Arsenijevic, Nebojsa; Markovic, Dejan; Zdravkovic, Nebojsa; Tesic, Zivoslav; Lukic, Aleksandra

    2012-01-01

    Glass ionomer cements (GICs) are commonly used as restorative materials. Responses to GICs differ among cell types and it is therefore of importance to thoroughly investigate the influence of these restorative materials on pulp stem cells that are potential source for dental tissue regeneration. Eight biomaterials were tested: Fuji I, Fuji II, Fuji VIII, Fuji IX, Fuji Plus, Fuji Triage, Vitrebond and Composit. We compared their cytotoxic activity on human dental pulp stem cells (DPSC) and correlated this activity with the content of Fluoride, Aluminium and Strontium ions in their eluates. Elution samples of biomaterials were prepared in sterile tissue culture medium and the medium was tested for toxicity by an assay of cell survival/proliferation (MTT test) and apoptosis (Annexin V FITC Detection Kit). Concentrations of Fluoride, Aluminium and Strontium ions were tested by appropriate methods in the same eluates. Cell survival ranged between 79.62% (Fuji Triage) to 1.5% (Fuji Plus) and most dead DPSCs were in the stage of late apoptosis. Fluoride release correlated with cytotoxicity of GICs, while Aluminium and Strontium ions, present in significant amount in eluates of tested GICs did not. Fuji Plus, Vitrebond and Fuji VIII, which released fluoride in higher quantities than other GICs, were highly toxic to human DPSCs. Opposite, low levels of released fluoride correlated to low cytotoxic effect of Composit, Fuji I and Fuji Triage.

  12. Clinical trials for stem cell therapies

    Lomax Geoff

    2011-05-01

    Full Text Available Abstract In recent years, clinical trials with stem cells have taken the emerging field in many new directions. While numerous teams continue to refine and expand the role of bone marrow and cord blood stem cells for their vanguard uses in blood and immune disorders, many others are looking to expand the uses of the various types of stem cells found in bone marrow and cord blood, in particular mesenchymal stem cells, to uses beyond those that could be corrected by replacing cells in their own lineage. Early results from these trials have produced mixed results often showing minor or transitory improvements that may be attributed to extracellular factors. More research teams are accelerating the use of other types of adult stem cells, in particular neural stem cells for diseases where beneficial outcome could result from either in-lineage cell replacement or extracellular factors. At the same time, the first three trials using cells derived from pluripotent cells have begun.

  13. Cemented total knee replacement in 24 dogs: surgical technique, clinical results, and complications.

    Allen, Matthew J; Leone, Kendall A; Lamonte, Kimberly; Townsend, Katy L; Mann, Kenneth A

    2009-07-01

    To characterize the performance of cemented total knee replacement (TKR) in dogs. Preclinical research study. Skeletally mature, male Hounds (25-30 kg; n=24) with no preexisting joint pathology. Dogs had unilateral cemented TKR and were evaluated at 6, 12, 26, or 52 weeks (6 dogs/time point) by radiography, bone density analysis, visual gait assessment, and direct measurement of thigh circumference and stifle joint range of motion as indicators of functional recovery. At study end, the stability of the cemented tibial component was determined by destructive mechanical testing. Joint stability was excellent in 16 dogs (67%) and good in 8 dogs. None of the tibial components had evidence of migration or periprosthetic osteolysis whereas 1 femoral component was loose at 52 weeks. There was an early and significant decrease in tibial bone density, likely because of disuse of the operated limb. Dogs returned to full activity by 12 weeks. The tibial cement-bone interface maintained its strength over 52 weeks. Cement provides stable fixation of the tibial component in canine TKR. Cemented TKR yields adequate clinical function and stifle joint excursion in the dog. Clinical studies are needed to determine the long-term fate of cemented TKR implants, to assess the influence of implant design on implant fixation and wear, and to obtain objective functional data.

  14. Gold nanoparticles in injectable calcium phosphate cement enhance osteogenic differentiation of human dental pulp stem cells.

    Xia, Yang; Chen, Huimin; Zhang, Feimin; Bao, Chongyun; Weir, Michael D; Reynolds, Mark A; Ma, Junqing; Gu, Ning; Xu, Hockin H K

    2018-01-01

    In this study, a novel calcium phosphate cement containing gold nanoparticles (GNP-CPC) was developed. Its osteogenic induction ability on human dental pulp stem cells (hDPSCs) was investigated for the first time. The incorporation of GNPs improved hDPSCs behavior on CPC, including better cell adhesion (about 2-fold increase in cell spreading) and proliferation, and enhanced osteogenic differentiation (about 2-3-fold increase at 14 days). GNPs endow CPC with micro-nano-structure, thus improving surface properties for cell adhesion and subsequent behaviors. In addition, GNPs released from GNP-CPC were internalized by hDPSCs, as verified by transmission electron microscopy (TEM), thus enhancing cell functions. The culture media containing GNPs enhanced the cellular activities of hDPSCs. This result was consistent with and supported the osteogenic induction results of GNP-CPC. In conclusion, GNP-CPC significantly enhanced the osteogenic functions of hDPSCs. GNPs are promising to modify CPC with nanotopography and work as bioactive additives thus enhance bone regeneration. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Factors influencing success of cement versus screw-retained implant restorations: a clinical review

    Ahmad Manawar

    2012-10-01

    Full Text Available Aim: As more and more dental practitioners are focusing on implant-supported fixed restorations, some clinicians favor the use of cement retained restorations while others consider screw retained prosthesis to be the best choice. Discussion: In screw-retained restorations, the fastening screw provides a solid joint between the restoration and the implant abutment, while in cement-retained prostheses the restorative screw is eliminated to enhance esthetics, occlusal stability, and passive fit of the restorations. The factors that influence the type of fixation of the prostheses to the implants like passivity of the framework, ease of fabrication, occlusion, esthetics, accessibility, retention and retrievability are discussed in this article with scientific studies demonstrating superior outcomes of one technique over another. Screwretained implant restorations have an advantage of predictable retention, retrievability and lack of potentially retained subgingival cement. However, a few disadvantages exist such as precise placement of the implant for optimal and esthetic location of the screw access hole and obtaining passive fit. On the other hand, cement retained restorations eliminate unesthetic screw access holes, have passive fit of castings, reduced complexity of clinical and lab procedures, enhanced esthetics, reduced cost factors and non disrupted morphology of the occlusal table. Conclusion: This article compares the advantages, potential disadvantages and limitations of screw and cement retained restorations and their specific implications in the most common clinical situation.

  16. Low-cost glass ionomer cement as ART sealant in permanent molars: a randomized clinical trial

    Hesse, D.; Bonifácio, C.C.; Guglielmi, C. de Almeida Brandao; da Franca, C.; Mendes, F.M.; Raggio, D.P.

    2015-01-01

    Clinical trials are normally performed with well-known brands of glass ionomer cement (GIC), but the cost of these materials is high for public healthcare in less-affluent communities. Given the need to research cheaper materials, it seems pertinent to investigate the retention rate of a low-cost

  17. Bioethics of Clinical Applications of Stem Cells.

    Petrini, Carlo

    2017-04-12

    The clinical applications of stem cells pose a multitude of problems, including safety, efficacy, information and consent, the right to unproven treatments, the "right to try", costs, access, sustainability, scientific scrupulousness, patents and regulatory aspects, to name but a few. This article does not address individual issues, but rather introduces and discusses some of the possible approaches to solving the problems. The first part compares the consequentialist and deontological approaches, offering an overview of "top-down" and "bottom-up" models and proposing the principles of personalism as applied in clinical settings. The second part of the article suggests practical frameworks for organising the ethical issues, focusing in particular on the medical indications, patient preferences, quality of life, and contextual features.

  18. Human tooth germ stem cell response to calcium-silicate based endodontic cements

    Esra Pamukcu Guven

    2013-07-01

    Full Text Available OBJECTIVE: The aim of this study was to compare the cytotoxic effects of endodontic cements on human tooth germ stem cells (hTGSCs. MTA Fillapex, a mineral trioxide aggregate (MTA-based, salicylate resin containing root canal sealer, was compared with iRoot SP, a bioceramic sealer, and AH Plus Jet, an epoxy resin-based root canal sealer. MATERIAL AND METHODS: To evaluate cytotoxicity, all materials were packed into Teflon rings (4 mmµ3 mm and co-cultured with hTGSCs with the aid of 24-well Transwell permeable supports, which had a pore size of 0.4 µm. Coverslips were coated with MTA Fillapex, iRoot SP and AH Plus Jet and each coverslip was placed onto the bottom of one well of a six-well plate for scanning electron microscopy (SEM analysis. Before the cytotoxicity and SEM analysis, all samples were stored at 37ºC and at 95% humidity and 5% CO2 for 24 hours to set. The cellular viability was analyzed using MTS test (3-(4,5-dimethyl-thiazol-2-yl-5-(3-carboxy-methoxy-phenyl-2-(4-sulfo-phenyl-2H-tetrazolium. The cytotoxic effects and SEM visualization of the tested materials were analyzed at 24-hour, 72-hour, one-week and two-week periods. RESULTS: On the 1st day, only MTA Fillapex caused cytotoxicity compared to negative control (NC group (p0.05. After 14 days of incubation with the test materials, MTA Fillapex exhibited significantly higher cytotoxicity compared with iRoot SP, AH Plus Jet and the NC group (P<0.008. In the SEM analysis, the highest levels of cell attachment were observed for iRoot SP and the control group. After 24 hours, MTA Fillapex reduced the number of cells attached to the surface. CONCLUSIONS: Within the limitations of this study, sealers exerted different cytotoxic effects on hTGSCs. Although all materials have exerted cellular toxicity, iRoot SP and AH Plus Jet may promote better attachment to hTGSCs.

  19. Cement-in-cement acetabular revision with a constrained tripolar component.

    Leonidou, Andreas; Pagkalos, Joseph; Luscombe, Jonathan

    2012-02-17

    Dislocation of a total hip replacement (THR) is common following total hip arthroplasty (THA). When nonoperative management fails to maintain reduction, revision surgery is considered. The use of constrained acetabular liners has been extensively described. Complete removal of the old cement mantle during revision THA can be challenging and is associated with significant complications. Cement-in-cement revision is an established technique. However, the available clinical and experimental studies focus on femoral stem revision. The purpose of this study was to present a case of cement-in-cement acetabular revision with a constrained component for recurrent dislocations and to investigate the current best evidence for this technique. This article describes the case of a 74-year-old woman who underwent revision of a Charnley THR for recurrent low-energy dislocations. A tripolar constrained acetabular component was cemented over the primary cement mantle following removal of the original liner by reaming, roughening the surface, and thoroughly irrigating and drying the primary cement. Clinical and radiological results were good, with the Oxford Hip Score improving from 11 preoperatively to 24 at 6 months postoperatively. The good short-term results of this case and the current clinical and biomechanical data encourage the use of the cement-in-cement technique for acetabular revision. Careful irrigation, drying, and roughening of the primary surface are necessary. Copyright 2012, SLACK Incorporated.

  20. The mechanical effect of the existing cement mantle on the in-cement femoral revision.

    Keeling, Parnell

    2012-08-01

    Cement-in-cement revision hip arthroplasty is an increasingly popular technique to replace a loose femoral stem which retains much of the original cement mantle. However, some concern exists regarding the retention of the existing fatigued and aged cement in such cement-in-cement revisions. This study investigates whether leaving an existing fatigued and aged cement mantle degrades the mechanical performance of a cement-in-cement revision construct.

  1. Clinical and computed tomographic evaluation of portland cement pulpotomy in primary molar: A case report

    Kamrun Nahar

    2016-08-01

    Full Text Available The present case describes the clinical & radiographic outcome of a Portland Cement pulpotomy. The 5 years old girl presenting extensive carious exposure in her mandibular left 2nd deciduous molar and was suffering pain in her left lower jaw only on exposure to cold for last 2 days. She was ultimately diagnosed clinic-radio-graphically as a case of irreversible pulpitis. Coronal pulpotomy procedure was carried out in the responsible tooth and Portland cement (PC was applied as a medicament after pulpotomy. At the 3 & 6-months follow-up appointments, treated tooth was asymptomatic clinically and radiographic examinations revealed no sign of periradicular pathosis in the pulpotomized teeth. Additionally, the formation of a dentin bridge immediately below the PC in the treated tooth was confirmed by RVG and CBCT.

  2. CIRM Alpha Stem Cell Clinics: Collaboratively Addressing Regenerative Medicine Challenges.

    Jamieson, Catriona H M; Millan, Maria T; Creasey, Abla A; Lomax, Geoff; Donohoe, Mary E; Walters, Mark C; Abedi, Mehrdad; Bota, Daniela A; Zaia, John A; Adams, John S

    2018-06-01

    The California Institute for Regenerative Medicine (CIRM) Alpha Stem Cell Clinic (ASCC) Network was launched in 2015 to address a compelling unmet medical need for rigorous, FDA-regulated, stem cell-related clinical trials for patients with challenging, incurable diseases. Here, we describe our multi-center experiences addressing current and future challenges. Copyright © 2018 Elsevier Inc. All rights reserved.

  3. Stem cell clinics online: the direct-to-consumer portrayal of stem cell medicine.

    Lau, Darren; Ogbogu, Ubaka; Taylor, Benjamin; Stafinski, Tania; Menon, Devidas; Caulfield, Timothy

    2008-12-04

    Despite the immature state of stem cell medicine, patients are seeking and accessing putative stem cell therapies in an "early market" in which direct-to-consumer advertising via the internet likely plays an important role. We analyzed stem cell clinic websites and appraised the relevant published clinical evidence of stem cell therapies to address three questions about the direct-to-consumer portrayal of stem cell medicine in this early market: What sorts of therapies are being offered? How are they portrayed? Is there clinical evidence to support the use of these therapies? We found that the portrayal of stem cell medicine on provider websites is optimistic and unsubstantiated by peer-reviewed literature.

  4. High risk of early periprosthetic fractures after primary hip arthroplasty in elderly patients using a cemented, tapered, polished stem

    Brodén, Cyrus; Mukka, Sebastian; Muren, Olle; Eisler, Thomas; Boden, Henrik; Stark, André; Sköldenberg, Olof

    2015-01-01

    Background and purpose Postoperative periprosthetic femoral fracture (PPF) after hip arthroplasty is associated with considerable morbidity and mortality. We assessed the incidence and characteristics of periprosthetic fractures in a consecutive cohort of elderly patients treated with a cemented, collarless, polished and tapered femoral stem (CPT). Patients and methods In this single-center prospective cohort study, we included 1,403 hips in 1,357 patients (mean age 82 (range 52–102) years, 72% women) with primary osteoarthritis (OA) or a femoral neck fracture (FNF) as indication for surgery (367 hips and 1,036 hips, respectively). 64% of patients were ASA class 3 or 4. Hip-related complications and need for repeat surgery were assessed at a mean follow-up time of 4 (1–7) years. A Cox regression analysis was used to evaluate risk factors associated with PPF. Results 47 hips (3.3%) sustained a periprosthetic fracture at median 7 (2–79) months postoperatively; 41 were comminute Vancouver B2 or complex C-type fractures. The fracture rate was 3.8% for FNF patients and 2.2% for OA patients (hazard ratio (HR) = 4; 95% CI: 1.3–12). Patients > 80 years of age also had a higher risk of fracture (HR = 2; 95% CI: 1.1–4.5). Interpretation We found a high incidence of early PPF associated with the CPT stem in this old and frail patient group. A possible explanation may be that the polished tapered stem acts as a wedge, splitting the femur after a direct hip contusion. Our results should be confirmed in larger, registry-based studies, but we advise caution when using this stem for this particular patient group. PMID:25280133

  5. Ethical clinical translation of stem cell interventions for neurologic disease

    Cote, David J; Bredenoord, Annelien L; Smith, Timothy R

    2017-01-01

    The application of stem cell transplants in clinical practice has increased in frequency in recent years. Many of the stem cell transplants in neurologic diseases, including stroke, Parkinson disease, spinal cord injury, and demyelinating diseases, are unproven-they have not been tested...... in prospective, controlled clinical trials and have not become accepted therapies. Stem cell transplant procedures currently being carried out have therapeutic aims, but are frequently experimental and unregulated, and could potentially put patients at risk. In some cases, patients undergoing such operations...... are not included in a clinical trial, and do not provide genuinely informed consent. For these reasons and others, some current stem cell interventions for neurologic diseases are ethically dubious and could jeopardize progress in the field. We provide discussion points for the evaluation of new stem cell...

  6. Clinical perspectives of cancer stem cell research in radiation oncology

    Bütof, Rebecca; Baumann, Michael; Dubrovska, Anna

    2013-01-01

    Radiotherapy has a proven potential to eradicate cancer stem cells which is reflected by its curative potential in many cancer types. Considerable progress has been made in identification and biological characterisation of cancer stem cells during the past years. Recent biological findings indicate significant inter- and intratumoural and functional heterogeneity of cancer stem cells and lead to more complex models which have potential implications for radiobiology and radiotherapy. Clinical evidence is emerging that biomarkers of cancer stem cells may be prognostic for the outcome of radiotherapy in some tumour entities. Perspectives of cancer stem cell based research for radiotherapy reviewed here include their radioresistance compared to the mass of non-cancer stem cells which form the bulk of all tumour cells, implications for image- and non-image based predictive bio-assays of the outcome of radiotherapy and a combination of novel systemic treatments with radiotherapy

  7. Cement augmentation in the proximal femur to prevent stem subsidence in revision hip arthroplasty with Paprosky type II/IIIa defects

    Shang-Wen Tsai

    2018-06-01

    Full Text Available Background: Subsidence remains a common complication after revision hip arthroplasty which may lead to prolonged weight-bearing restrictions, leg-length discrepancies or considerable loss of function. We evaluated the effectiveness of cement augmentation in the proximal femoral metaphysis during a revision of femoral components to prevent post-operative stem subsidence. Methods: Forty patients were enrolled. Follow-up averaged 67.7 months (range: 24–149. Twenty-seven patients had a Paprosky type II defect and 13 had a type IIIa defect. All revision hip arthroplasty used a cementless, cylindrical, non-modular cobalt–chromium stem. The defect in the metaphysis was filled with antibiotic-loaded bone cement. Thirteen patients who had undergone stem revision only was allowed to walk immediately without weight-bearing restrictions. Twenty-seven patients who had undergone revision total hip arthroplasty was allowed partial weight-bearing within 6 weeks after surgery in the consideration of acetabular reconstruction. Results: Three patients (7.5% had post-surgery stem subsidences of three mm, five mm, and 10 mm, respectively, at three, one, and 14 months. There were no acute surgical site infections. There were three femoral stem failures: two delayed infections and one periprosthetic Vancouver B2 fracture. Both five- and 10-year survivorships of the femoral implant were 90.1%. Conclusion: An adequate length of the scratch-fit segment and diaphyseal ingrowth remain of paramount importance when revising femoral components. To fill metaphyseal bone defects with antibiotic-loaded bone cement may be an alternative method in dealing with proximal femoral bone loss during a femoral revision. Keywords: Bone defect, Cement augmentation, Femur, Revision hip arthroplasty, Subsidence

  8. Human embryonic stem cell-encapsulation in alginate microbeads in macroporous calcium phosphate cement for bone tissue engineering

    Tang, Minghui; Chen, Wenchuan; Weir, Michael D.; Thein-Han, Wahwah; Xu, Hockin H. K.

    2012-01-01

    Human embryonic stem cells (hESCs) are exciting for regenerative medicine applications because of their strong proliferative ability and multilineage differentiation capability. To date there has been no report on hESC seeding with calcium phosphate cement (CPC). The objective of this study was to investigate hESC-derived mesenchymal stem cell (hESCd-MSC) encapsulation in hydrogel microbeads in macroporous CPC for bone tissue engineering. hESCs were cultured to form embryoid bodies (EBs), and the MSCs were then migrated out of the EBs. hESCd-MSCs had surface markers characteristic of MSCs, with positive alkaline phosphatase (ALP) staining when cultured in osteogenic medium. hESCd-MSCs were encapsulated in alginate at a density of 1 million cells/mL, with an average microbead size of 207 µm. CPC contained mannitol porogen to create a porosity of 64% and macropores with size of 218 µm, with 20% absorbable fibers for additional porosity when the fibers degrade. hESCd-MSCs encapsulated in microbeads in CPC had good viability from 1 to 21 d. ALP gene expression at 21 d was 25-fold that at 1 d. Osteocalcin (OC) at 21 d was two orders of magnitude of that at 1 d. ALP activity in colorimetric p-nitrophenyl phosphate assay at 21 d was 5-fold that at 1 d. Mineral synthesis by the encapsulated hESCd-MSCs at 21 d was 7-fold that at 1 d. Potential benefits of the CPC-stem cell paste include injectability, intimate adaptation to complex-shaped bone defects, ease in contouring to achieve esthetics in maxillofacial repairs, and in situ setting ability. In conclusion, hESCd-MSCs were encapsulated in alginate microbeads in macroporous CPC showing good cell viability, osteogenic differentiation and mineral synthesis for the first time. The hESCd-MSC-encapsulating macroporous CPC construct is promising for bone regeneration in a wide range of orthopedic and maxillofacial applications. PMID:22633970

  9. Hurdles to clinical translation of human induced pluripotent stem cells.

    Neofytou, Evgenios; O'Brien, Connor Galen; Couture, Larry A; Wu, Joseph C

    2015-07-01

    Human pluripotent stem cells are known to have the capacity to renew indefinitely, being intrinsically able to differentiate into many different cell types. These characteristics have generated tremendous enthusiasm about the potential applications of these cells in regenerative medicine. However, major challenges remain with the development and testing of novel experimental stem cell therapeutics in the field. In this Review, we focus on the nature of the preclinical challenges and discuss potential solutions that could help overcome them. Furthermore, we discuss the use of allogeneic versus autologous stem cell products, including a review of their respective advantages and disadvantages, major clinical requirements, quality standards, time lines, and costs of clinical grade development.

  10. Clinical and radiographic evaluation of Portland cement added to radiopacifying agents in primary molar pulpotomies.

    Lourenço Neto, N; Marques, N C T; Fernandes, A P; Hungaro Duarte, M A; Abdo, R C C; Machado, M A A M; Oliveira, T M

    2015-10-01

    This was to evaluate the clinical and radiographic outcomes of Portland cement (PC) added to radiopacifying agents in primary molar pulpotomies. Thirty primary mandibular molars of children aged between 5 and 9 years were randomly assigned to the following groups: PC; PC with iodoform (PC + CHI(3)); PC with zirconium oxide (PC + ZrO(2)) and treated by pulpotomy technique. Clinical and radiographic follow-up assessments were performed at 6, 12 and 24 months. Statistical analysis was performed by Fisher's exact test (P < 0.05). The clinical and radiographic evaluations showed 100 % success rates, and the results showed no statistically significant difference between groups. According to this study, PC added to radiopacifying agents exhibited satisfactory clinical and radiographic results in primary molar pulpotomies.

  11. Stem cells: roadmap to the clinic

    Daley, George Q.

    2010-01-01

    Over the last decade, a remarkable number of papers have been published in which the biology of stem cells is introduced with words and phrases such as “promise,” “rapid progress,” and “future therapies.” To separate myth and hype from reality, the articles in this Stem Cells Review series comprise a rich resource on the state of this fast-paced field and provide a balanced perspective on some of the major advances. They recount what the field has achieved over the past decade and where the f...

  12. Mammary Stem Cells and Breast Cancer Stem Cells: Molecular Connections and Clinical Implications.

    Celià-Terrassa, Toni

    2018-05-04

    Cancer arises from subpopulations of transformed cells with high tumor initiation and repopulation ability, known as cancer stem cells (CSCs), which share many similarities with their normal counterparts. In the mammary gland, several studies have shown common molecular regulators between adult mammary stem cells (MaSCs) and breast cancer stem cells (bCSCs). Cell plasticity and self-renewal are essential abilities for MaSCs to maintain tissue homeostasis and regenerate the gland after pregnancy. Intriguingly, these properties are similarly executed in breast cancer stem cells to drive tumor initiation, tumor heterogeneity and recurrence after chemotherapy. In addition, both stem cell phenotypes are strongly influenced by external signals from the microenvironment, immune cells and supportive specific niches. This review focuses on the intrinsic and extrinsic connections of MaSC and bCSCs with clinical implications for breast cancer progression and their possible therapeutic applications.

  13. Stem cells: roadmap to the clinic

    Daley, George Q.

    2010-01-01

    Over the last decade, a remarkable number of papers have been published in which the biology of stem cells is introduced with words and phrases such as “promise,” “rapid progress,” and “future therapies.” To separate myth and hype from reality, the articles in this Stem Cells Review series comprise a rich resource on the state of this fast-paced field and provide a balanced perspective on some of the major advances. They recount what the field has achieved over the past decade and where the field is headed. They also highlight the challenges to be faced in translating what is indeed highly promising science into proven therapies that will regenerate and repair diseased tissues. PMID:20051631

  14. Does cement mantle thickness really matter?

    Caruana, J.

    2008-01-01

    The thickness of the cement mantle around the femoral component of total hip replacements is a contributing factor to aseptic loosening and revision. Nevertheless, various designs of stems and surgical tooling lead to cement mantles of differing thicknesses. This thesis is concerned with variability in cement thickness around the Stanmore Hip, due to surgical approach, broach size and stem orientation, and its effects on stress and cracking in the cement. The extent to which cement mantle thi...

  15. Stem cells: progressions and applications in clinical medicine

    Ali Hosseini Bereshneh

    2016-05-01

    of them in transferring gene into different cells. Today, this method have had considerable progress in the treatment of many disease. In this review study, some aspect of stem cells like types and characteristic, origin, derivation techniques, storage conditions and differentiation to target tissues, current clinical usage and their therapeutic capabilities will be discussed.

  16. Evaluation of dentin hypersensitivity treatment with glass ionomer cements: A randomized clinical trial

    Marina de Matos MADRUGA

    Full Text Available Abstract A randomized, double-blind, split-mouth clinical trial was performed compared the desensitizing efficacy of the resin-modified glass ionomer cement (GIC ClinproTM XT (3M ESPE, Minnesota, USA and the conventional GIC Vidrion R (SS White, Gloucester, UK in a 6-month follow-up. Subjects were required to have at least two teeth with dentin hypersensitivity. Teeth were divided at random into 2 groups, one group received Clinpro XT and the other conventional GIC Vidrion R. Treatments were assessed by tactile and air blast tests using Visual Analogue Scale (VAS at baseline, after 20 minutes, and at 7, 15, 21, 30, 90 and 180 days post-treatment. Twenty subjects (152 teeth were included. Both tests (tactile and air blast showed a significant reduction of dentin hypersensitivity immediately after the application of Vidrion R and Clinpro XT (20 min. VAS scores obtained along the 6-month follow-up were statistically lower when compared to initial rates (p 0.05. Both cements provided satisfactory results in long-term dental sensitivity reduction.

  17. Clinical potentials of human pluripotent stem cells.

    Mora, Cristina; Serzanti, Marialaura; Consiglio, Antonella; Memo, Maurizio; Dell'Era, Patrizia

    2017-08-01

    Aging, injuries, and diseases can be considered as the result of malfunctioning or damaged cells. Regenerative medicine aims to restore tissue homeostasis by repairing or replacing cells, tissues, or damaged organs, by linking and combining different disciplines including engineering, technology, biology, and medicine. To pursue these goals, the discipline is taking advantage of pluripotent stem cells (PSCs), a peculiar type of cell possessing the ability to differentiate into every cell type of the body. Human PSCs can be isolated from the blastocysts and maintained in culture indefinitely, giving rise to the so-called embryonic stem cells (ESCs). However, since 2006, it is possible to restore in an adult cell a pluripotent ESC-like condition by forcing the expression of four transcription factors with the rejuvenating reprogramming technology invented by Yamanaka. Then the two types of PSC can be differentiated, using standardized protocols, towards the cell type necessary for the regeneration. Although the use of these derivatives for therapeutic transplantation is still in the preliminary phase of safety and efficacy studies, a lot of efforts are presently taking place to discover the biological mechanisms underlying genetic pathologies, by differentiating induced PSCs derived from patients, and new therapies by challenging PSC-derived cells in drug screening.

  18. Continuous distal migration and internal rotation of the C-stem prosthesis without any adverse clinical effects: an RSA study of 33 primary total hip arthroplasties followed for up to ten years.

    von Schewelov, T; Carlsson, A; Sanzén, L; Besjakov, J

    2014-05-01

    In 2005, we demonstrated that the polished triple-tapered C-stem at two years had migrated distally and rotated internally. From that series, 33 patients have now been followed radiologically, clinically and by radiostereometric analysis (RSA) for up to ten years. The distal migration within the cement mantle had continued and reached a mean of 2 mm (0.5 to 4.0) at ten years. Internal rotation, also within the cement mantle, was a mean 3.8° (external 1.6° to internal 6.6°) The cement mantle did not show any sign of migration or loosening in relation to the femoral bone. There were no clinical or radiological signs indicating that the migration or rotation within the cement mantle had had any adverse effects for the patients.

  19. Umbilical cord stem cells released from alginate-fibrin microbeads inside macroporous and biofunctionalized calcium phosphate cement for bone regeneration

    Chen, Wenchuan; Zhou, Hongzhi; Weir, Michael D.; Bao, Chongyun; Xu, Hockin H.K.

    2012-01-01

    The need for bone repair has increased as the population ages. The objectives of this study were to (1) develop a novel biofunctionalized and macroporous calcium phosphate cement (CPC) containing alginate-fibrin microbeads encapsulating human umbilical cord mesenchymal stem cells (hUCMSCs); and (2) investigate hUCMSC proliferation and osteogenic differentiation inside CPC for the first time. Macroporous CPC was developed using calcium phosphate powders, chitosan, and gas-foaming porogen. Five types of CPCs were fabricated: CPC control, CPC + 0.05% fibronectin (Fn), CPC + 0.1% Fn, CPC + 0.1% Arg-Gly-Asp (RGD), and CPC + 0.1% Fn + 0.1% RGD. Alginate-fibrin microbeads containing 106 hUCMSCs/mL were encapsulated in the CPC paste. After CPC had set, the degradable microbeads released hUCMSCs inside CPC. hUCMScs proliferated inside CPC, with cell density at 21 d being 4-fold that at 1 d. CPC + 0.1% RGD had the highest cell density, which was 4-fold that of CPC control. The released cells differentiated into the osteogenic lineage and synthesized bone minerals. hUCMSCs inside the CPC + 0.1% RGD construct had gene expressions of alkaline phosphatase (ALP), osteocalcin (OC) and collagen I, which were twice those of CPC control. Mineral synthesis by hUCMSCs inside the CPC + 0.1% RGD construct was 2-fold that in CPC control. RGD and Fn incorporation in CPC did not compromise the strength of CPC, which matched the reported strength of cancellous bone. In conclusion, degradable microbeads released the hUCMSCs which proliferated, differentiated and synthesized minerals inside the macroporous CPC for the first time. CPC with RGD greatly enhanced cell functions. The novel biofunctionalized and macroporous CPC-microbead-hUCMSC construct is promising for bone tissue engineering applications. PMID:22391411

  20. Adult Stromal (Skeletal, Mesenchymal) Stem Cells: Advances Towards Clinical Applications

    Kermani, Abbas Jafari; Harkness, Linda; Zaher, Walid

    2014-01-01

    Mesenchymal Stem Cells (MSC) are non-hematopoietic adult stromal cells that reside in a perivascular niche in close association with pericytes and endothelial cells and possess self-renewal and multi-lineage differentiation capacity. The origin, unique properties, and therapeutic benefits of MSC ...... the translation of MSC into clinic: Generation of MSC-like cells from human pluripotent stem cells, strategies to enhance homing of MSC to injured tissues, and targeting of MSC in vivo.......Mesenchymal Stem Cells (MSC) are non-hematopoietic adult stromal cells that reside in a perivascular niche in close association with pericytes and endothelial cells and possess self-renewal and multi-lineage differentiation capacity. The origin, unique properties, and therapeutic benefits of MSC...

  1. Mesenchymal stem cells: biological characteristics and potential clinical applications

    Kassem, Moustapha

    2004-01-01

    are among the first stem cell types to be introduced in the clinic. Several studies have demonstrated the possible use of MSC in systemic transplantation for systemic diseases, local implantation for local tissue defects, as a vehicle for genes in gene therapy protocols or to generate transplantable tissues...... and organs in tissue engineering protocols. Before their widespread use in therapy, methods allowing the generation of large number of cells without affecting their differentiation potential as well as technologies that overcome immunological rejection (in case allogenic transplantation) must be developed.......Mesenchymal stem cells (MSC) are clonogenic, non-hematpoietic stem cells present in the bone marrow and are able to differentiate into multiple mesoderm-type cell lineages, for example, osteoblasts, chondrocytes, endothelial-cells and also non-mesoderm-type lineages, for example, neuronal...

  2. Clinical performance of cements as luting agents for telescopic double crown-retained removable partial and complete overdentures.

    Behr, Michael; Kolbeck, Carola; Lang, Reinhold; Hahnel, Sebastian; Dirschl, Lisa; Handel, Gerhard

    2009-01-01

    The aim of this study was to investigate the survival rates and technical failures of removable prostheses (RPs) supported by telescopic double crown (TDC)-retained abutment teeth luted with zinc-phosphate or glass-ionomer cement. Clinical records of 577 patients (288 women, 289 men) who received 577 TDC-retained RPs supported by 1,807 abutments at the Department of Prosthodontics of the University Hospital Regensburg, Regensburg, Germany, between 1984 and 2007 were analyzed. The 577 prostheses included 200 attached to telescopic crowns with friction fit (FFs), 62 to conical crowns (CCs), and 315 to parallel-sided telescopic crowns with clearance fit (CFs). Survival probabilities were evaluated for the RPs, loss of cementation of the inner copings, secondary caries, and abutment teeth that required endodontic treatment using the Kaplan-Meier method. A Cox regression analysis determined the impact of covariates such as sex, denture location (maxilla/mandible), Eichner classification, number of abutment teeth, and the type of double crown system used. The 10-year survival probability was 98.8% +/- 0.09% for FFs, 92.9% +/- 0.41% for CCs, and 86.6% +/- 0.05% for CFs. During the observation period, loss of cementation was frequently observed (FFs: 32%, CCs: 53.2%, CFs: 21.3%). After 15 years, more than 75% of patients had experienced at least one "loss of cementation" event. In this respect, zinc-oxide phosphate and glass-ionomer cements did not show any significant difference. The long-term successful outcome of the RP experience was not compromised, although numerous clinical visits were required for maintenance. The predominant maintenance procedure was the need for recementation of the inner copings.

  3. Imaging: Guiding the Clinical Translation of Cardiac Stem Cell Therapy

    Nguyen, Patricia K.; Lan, Feng; Wang, Yongming; Wu, Joseph C.

    2011-01-01

    Stem cells have been touted as the holy grail of medical therapy with promises to regenerate cardiac tissue, but it appears the jury is still out on this novel therapy. Using advanced imaging technology, scientists have discovered that these cells do not survive nor engraft long-term. In addition, only marginal benefit has been observed in large animal studies and human trials. However, all is not lost. Further application of advanced imaging technology will help scientists unravel the mysteries of stem cell therapy and address the clinical hurdles facing its routine implementation. In this review, we will discuss how advanced imaging technology will help investigators better define the optimal delivery method, improve survival and engraftment, and evaluate efficacy and safety. Insights gained from this review may direct the development of future preclinical investigations and clinical trials. PMID:21960727

  4. A Simplified Method of Opacifying and Mixing Acrylic Cement for Percutaneous Vertebroplasty: A Clinical and In Vitro Study

    Teng Gaojun; He Shicheng; Deng Gang; Guo Jinhe; Fang Wen; Zhu Guangyu

    2005-01-01

    The objective of this study was to simplify the opacifying mixing process of the bone cement and contrast used for percutaneous vertebroplasty (PVP). We performed a biomechanical study of polymethyl methacrylate (PMMA) (Corinplast TM 3) using three different mixtures of PMMA, monomer, and contrast: group I, 2:1; group II, 3:2; group III, 3:2:1 ratio of powder/monomer/iodinated contrast (Omnipaque). In vitro biomechanical testing of ultimate compressive strength was carried out in all samples. Following the conclusion of a proper bone cement mixture regimen drawn from the in vitro study, PVP was performed in 125 patients: 58 with cancer, 12 with hemangioma, and 54 with osteoporotic fracture. The ultimate compressive strength in group III was decreased by 38% compared to groups II and I. Proper fluoroscopic visualization was achieved in all PVP procedures using this mixture. There were no major complications associated with injection of the cement mixture. Complete (CR) and partial response (PR) was obtained in 64% and 32.8%, respectively. No further vertebral collapse occurred during follow-up. The regimen using iodinated contrast for cement visualization during PVP provides a simple and convenient new method for mixing. Although the biomechanical strength is altered by the contrast medium added, it seems insignificant in clinical practice based on the authors' limited experience

  5. Research gaps identified during systematic reviews of clinical trials: glass-ionomer cements.

    Mickenautsch, Steffen

    2012-06-29

    To report the results of an audit concerning research gaps in clinical trials that were accepted for appraisal in authored and published systematic reviews regarding the application of glass-ionomer cements (GIC) in dental practice Information concerning research gaps in trial precision was extracted, following a framework that included classification of the research gap reasons: 'imprecision of information (results)', 'biased information', 'inconsistency or unknown consistency' and 'not the right information', as well as research gap characterization using PICOS elements: population (P), intervention (I), comparison (C), outcomes (O) and setting (S). Internal trial validity assessment was based on the understanding that successful control for systematic error cannot be assured on the basis of inclusion of adequate methods alone, but also requires empirical evidence about whether such attempt was successful. A comprehensive and interconnected coverage of GIC-related clinical topics was established. The most common reasons found for gaps in trial precision were lack of sufficient trials and lack of sufficient large sample size. Only a few research gaps were ascribed to 'Lack of information' caused by focus on mainly surrogate trial outcomes. According to the chosen assessment criteria, a lack of adequate randomisation, allocation concealment and blinding/masking in trials covering all reviewed GIC topics was noted (selection- and detection/performance bias risk). Trial results appear to be less affected by loss-to-follow-up (attrition bias risk). This audit represents an adjunct of the systematic review articles it has covered. Its results do not change the systematic review's conclusions but highlight existing research gaps concerning the precision and internal validity of reviewed trials in detail. These gaps should be addressed in future GIC-related clinical research.

  6. Research gaps identified during systematic reviews of clinical trials: glass-ionomer cements

    Mickenautsch Steffen

    2012-06-01

    Full Text Available Abstract Background To report the results of an audit concerning research gaps in clinical trials that were accepted for appraisal in authored and published systematic reviews regarding the application of glass-ionomer cements (GIC in dental practice Methods Information concerning research gaps in trial precision was extracted, following a framework that included classification of the research gap reasons: ‘imprecision of information (results’, ‘biased information’, ‘inconsistency or unknown consistency’ and ‘not the right information’, as well as research gap characterization using PICOS elements: population (P, intervention (I, comparison (C, outcomes (O and setting (S. Internal trial validity assessment was based on the understanding that successful control for systematic error cannot be assured on the basis of inclusion of adequate methods alone, but also requires empirical evidence about whether such attempt was successful. Results A comprehensive and interconnected coverage of GIC-related clinical topics was established. The most common reasons found for gaps in trial precision were lack of sufficient trials and lack of sufficient large sample size. Only a few research gaps were ascribed to ‘Lack of information’ caused by focus on mainly surrogate trial outcomes. According to the chosen assessment criteria, a lack of adequate randomisation, allocation concealment and blinding/masking in trials covering all reviewed GIC topics was noted (selection- and detection/performance bias risk. Trial results appear to be less affected by loss-to-follow-up (attrition bias risk. Conclusion This audit represents an adjunct of the systematic review articles it has covered. Its results do not change the systematic review’s conclusions but highlight existing research gaps concerning the precision and internal validity of reviewed trials in detail. These gaps should be addressed in future GIC-related clinical research.

  7. Low-cost glass ionomer cement as ART sealant in permanent molars: a randomized clinical trial

    Daniela HESSE

    2015-01-01

    Full Text Available Clinical trials are normally performed with well-known brands of glass ionomer cement (GIC, but the cost of these materials is high for public healthcare in less-affluent communities. Given the need to research cheaper materials, it seems pertinent to investigate the retention rate of a low-cost GIC applied as atraumatic restorative treatment (ART sealants in two centers in Brazil. Four hundred and thirty-seven 6-to-8-year-old schoolchildren were selected in two cities in Brazil. The children were randomly divided into two groups, according to the tested GIC applied in the first permanent molars. The retention rate was evaluated after 3, 6 and 12 months. Kaplan-Meier survival analysis and the log-rank test were performed. The variables were tested for association with sealant longevity, using logistic regression analyses (α = 5%. The retention rate of sealants after 12 months was 19.1%. The high-cost GIC brand presented a 2-fold-more-likely-to-survive rate than the low-cost brand (p < 0.001. Significant difference was also found between the cities where the treatments were performed, in that Barueri presented a higher sealant survival rate than Recife (p < 0.001. The retention rate of a low-cost GIC sealant brand was markedly lower than that of a well-known GIC sealant brand.

  8. The Alpha Stem Cell Clinic: a model for evaluating and delivering stem cell-based therapies.

    Trounson, Alan; DeWitt, Natalie D; Feigal, Ellen G

    2012-01-01

    Cellular therapies require the careful preparation, expansion, characterization, and delivery of cells in a clinical environment. There are major challenges associated with the delivery of cell therapies and high costs that will limit the companies available to fully evaluate their merit in clinical trials, and will handicap their application at the present financial environment. Cells will be manufactured in good manufacturing practice or near-equivalent facilities with prerequisite safety practices in place, and cell delivery systems will be specialized and require well-trained medical and nursing staff, technicians or nurses trained to handle cells once delivered, patient counselors, as well as statisticians and database managers who will oversee the monitoring of patients in relatively long-term follow-up studies. The model proposed for Alpha Stem Cell Clinics will initially use the capacities and infrastructure that exist in the most advanced tertiary medical clinics for delivery of established bone marrow stem cell therapies. As the research evolves, they will incorporate improved procedures and cell preparations. This model enables commercialization of medical devices, reagents, and other products required for cell therapies. A carefully constructed cell therapy clinical infrastructure with the requisite scientific, technical, and medical expertise and operational efficiencies will have the capabilities to address three fundamental and critical functions: 1) fostering clinical trials; 2) evaluating and establishing safe and effective therapies, and 3) developing and maintaining the delivery of therapies approved by the Food and Drug Administration, or other regulatory agencies.

  9. Potential and clinical utility of stem cells in cardiovascular disease

    Korff Krause

    2010-03-01

    Full Text Available Korff Krause, Carsten Schneider, Kai Jaquet, Karl-Heinz KuckHanseatic Heart Center Hamburg, Department of Cardiology, Asklepios Hospital St. Georg, Hamburg, GermanyAbstract: The recent identification of bone marrow-derived adult stem cells and other types of stem cells that could improve heart function after transplantation have raised high expectations. The basic mechanisms have been studied mostly in murine models. However, these experiments revealed controversial results on transdifferentiation vs transfusion of adult stem cells vs paracrine effects of these cells, which is still being debated. Moreover, the reproducibility of these results in precisely translated large animal models is still less well investigated. Despite these weaknesses results of several clinical trials including several hundreds of patients with ischemic heart disease have been published. However, there are no solid data showing that any of these approaches can regenerate human myocardium. Even the effectiveness of cell therapy in these approaches is doubtful. In future we need in this important field of regenerative medicine: i more experimental data in large animals that are closer to the anatomy and physiology of humans, including data on dose effects, comparison of different cell types and different delivery routes; ii a better understanding of the molecular mechanisms involved in the fate of transplanted cells; iii more intensive research on genuine regenerative medicine, applying genetic regulation and cell engineering.Keywords: stem cells, cardiovascular disease

  10. The long-term in vivo behavior of polymethyl methacrylate bone cement in total hip arthroplasty.

    Oonishi, Hiroyuki; Akiyama, Haruhiko; Takemoto, Mitsuru; Kawai, Toshiyuki; Yamamoto, Koji; Yamamuro, Takao; Oonishi, Hironobu; Nakamura, Takashi

    2011-10-01

    The long-term success of cemented total hip arthroplasty (THA) has been well established. Improved outcomes, both radiographically and clinically, have resulted mainly from advances in stem design and improvements in operating techniques. However, there is concern about the durability of bone cement in vivo. We evaluated the physical and chemical properties of CMW1 bone cements retrieved from patients undergoing revision THA. CMW1 cements were retrieved from 14 patients who underwent acetabular revision because of aseptic loosening. The time in vivo before revision was 7-30 years. The bending properties of the retrieved bone cement were assessed using the three-point bending method. The molecular weight and chemical structure were analyzed by gel permeation chromatography and Fourier-transform infrared spectroscopy. The porosity of the bone cements was evaluated by 3-D microcomputer tomography. The bending strength decreased with increasing time in vivo and depended on the density of the bone cement, which we assume to be determined by the porosity. There was no correlation between molecular weight and time in vivo. The infrared spectra were similar in the retrieved cements and in the control CMW1 cements. Our results indicate that polymer chain scission and significant hydrolysis do not occur in CMW1 cement after implantation in vivo, even in the long term. CMW1 cement was stable through long-term implantation and functional loading.

  11. A randomized clinical trial on the use of medical Portland cement, MTA and calcium hydroxide in indirect pulp treatment.

    Petrou, Marina Agathi; Alhamoui, Fadi Alhaddad; Welk, Alexander; Altarabulsi, Mohammed Basel; Alkilzy, Mohammed; H Splieth, Christian

    2014-01-01

    Studies on indirect pulp treatment (IPT) show varying success rates of 73 to 97 %. The necessity of re-opening the cavity and the question of the optimal capping material is still under debate. The aim of this prospective in vivo study was to compare the clinical and microbiological outcomes of mineral trioxide aggregate (MTA), medical Portland cement, and calcium hydroxide on the dentin-pulp complex of permanent and primary teeth treated with two-step IPT. In 86 regular patients (51 % men; 49 % women; age 17.2 years ±13.8), one deep carious lesion each was treated with incomplete caries removal, randomly selected capping with either calcium hydroxide (n = 31), medical Portland cement (29) or white MTA (26), and re-entry (6.3 months ±1.0). Clinical (color, humidity, and consistency of dentin) and microbiological (Lactobacilli/Mutans Strep. counts) parameters were recorded at the first and second treatment. The IPT had a high success rate of 90.3 % regardless of the material used (p = 0.72). The arrested lesions showed consistently darker, dry, and therefore, sclerotic dentine (p Portland cement. The findings of this study could promote the improvement of the IPT as a one-step treatment of deep carious lesions when the remaining demineralized dentin would be sealed with durable restorations.

  12. Femoral Component Revision with Use of Impaction Bone-Grafting and a Cemented Polished Stem: A Concise Follow-up, at Fifteen to Twenty Years, of a Previous Report*

    Te Stroet, M.A.; Gardeniers, J.W.M.; Verdonschot, N.J.; Rijnen, W.H.C.; Slooff, T.J.J.H.; Schreurs, B.W.

    2012-01-01

    We previously reported our results for thirty-three consecutive femoral component revisions with impaction bone-grafting, performed with the X-change femoral revision system and a cemented polished Exeter stem, at a minimum of eight years of follow-up. The present updated study shows the results

  13. Immunoregulation by Mesenchymal Stem Cells: Biological Aspects and Clinical Applications

    Castro-Manrreza, Marta E.; Montesinos, Juan J.

    2015-01-01

    Mesenchymal stem cells (MSCs) are multipotent cells capable of differentiation into mesenchymal lineages and that can be isolated from various tissues and easily cultivated in vitro. Currently, MSCs are of considerable interest because of the biological characteristics that confer high potential applicability in the clinical treatment of many diseases. Specifically, because of their high immunoregulatory capacity, MSCs are used as tools in cellular therapies for clinical protocols involving immune system alterations. In this review, we discuss the current knowledge about the capacity of MSCs for the immunoregulation of immunocompetent cells and emphasize the effects of MSCs on T cells, principal effectors of the immune response, and the immunosuppressive effects mediated by the secretion of soluble factors and membrane molecules. We also describe the mechanisms of MSC immunoregulatory modulation and the participation of MSCs as immune response regulators in several autoimmune diseases, and we emphasize the clinical application in graft versus host disease (GVHD). PMID:25961059

  14. Neoplastic stem cells: current concepts and clinical perspectives.

    Schulenburg, Axel; Brämswig, Kira; Herrmann, Harald; Karlic, Heidrun; Mirkina, Irina; Hubmann, Rainer; Laffer, Sylvia; Marian, Brigitte; Shehata, Medhat; Krepler, Clemens; Pehamberger, Hubert; Grunt, Thomas; Jäger, Ulrich; Zielinski, Christoph C; Valent, Peter

    2010-11-01

    Neoplastic stem cells have initially been characterized in myeloid leukemias where NOD/SCID mouse-repopulating progenitors supposedly reside within a CD34+/Lin- subset of the malignant clone. These progenitors are considered to be self-renewing cells responsible for the in vivo long-term growth of neoplastic cells in leukemic patients. Therefore, these cells represent an attractive target of therapy. In some lymphoid leukemias, NOD/SCID mouse-repopulating cells were also reported to reside within the CD34+/Lin- subfraction of the clone. More recently, several attempts have been made to transfer the cancer stem cell concept to solid tumors and other non-hematopoietic neoplasms. In several of these tumors, the cell surface antigens AC133 (CD133) and CD44 are considered to indicate the potential of a cell to initiate permanent tumor formation in vivo. However, several questions concerning the phenotype, self-renewal capacity, stroma-dependence, and other properties of cancer- or leukemia-initiating cells remain to be solved. The current article provides a summary of our current knowledge on neoplastic (cancer) stem cells, with special emphasis on clinical implications and therapeutic options as well as a discussion about conceptual and technical limitations. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  15. Stem cells in clinical trials for treatment of retinal degeneration.

    Klassen, Henry

    2016-01-01

    After decades of basic science research involving the testing of regenerative strategies in animal models of retinal degenerative diseases, a number of clinical trials are now underway, with additional trials set to begin shortly. These efforts will evaluate the safety and preliminary efficacy of cell-based products in the eyes of patients with a number of retinal conditions, notably including age-related macular degeneration, retinitis pigmentosa and Stargardt's disease. This review considers the scientific work and early trials with fetal cells and tissues that set the stage for the current clinical investigatory work, as well the trials themselves, specifically those either now completed, underway or close to initiation. The cells of interest include retinal pigment epithelial cells derived from embryonic stem or induced pluripotent stem cells, undifferentiated neural or retinal progenitors or cells from the vascular/bone marrow compartment or umbilical cord tissue. Degenerative diseases of the retina represent a popular target for emerging cell-based therapeutics and initial data from early stage clinical trials suggest that short-term safety objectives can be met in at least some cases. The question of efficacy will require additional time and testing to be adequately resolved.

  16. Ocular Stem Cell Research from Basic Science to Clinical Application: A Report from Zhongshan Ophthalmic Center Ocular Stem Cell Symposium

    Hong Ouyang

    2016-03-01

    Full Text Available Stem cells hold promise for treating a wide variety of diseases, including degenerative disorders of the eye. The eye is an ideal organ for stem cell therapy because of its relative immunological privilege, surgical accessibility, and its being a self-contained system. The eye also has many potential target diseases amenable to stem cell-based treatment, such as corneal limbal stem cell deficiency, glaucoma, age-related macular degeneration (AMD, and retinitis pigmentosa (RP. Among them, AMD and glaucoma are the two most common diseases, affecting over 200 million people worldwide. Recent results on the clinical trial of retinal pigment epithelial (RPE cells from human embryonic stem cells (hESCs and induced pluripotent stem cells (iPSCs in treating dry AMD and Stargardt’s disease in the US, Japan, England, and China have generated great excitement and hope. This marks the beginning of the ocular stem cell therapy era. The recent Zhongshan Ophthalmic Center Ocular Stem Cell Symposium discussed the potential applications of various stem cell types in stem cell-based therapies, drug discoveries and tissue engineering for treating ocular diseases.

  17. Do oxidized zirconium femoral heads reduce polyethylene wear in cemented THAs? A blinded randomized clinical trial.

    Zaoui, Amine; Hage, Samer El; Langlois, Jean; Scemama, Caroline; Courpied, Jean Pierre; Hamadouche, Moussa

    2015-12-01

    Charnley low-friction torque total hip arthroplasty (THA) remains the gold standard in THA. The main cause for failure is wear of the socket. Highly crosslinked polyethylene (HXLPE) has been associated with reduced wear rates. Also, oxidized zirconium has shown in vitro reduced wear rates. However, to our knowledge, there are no data comparing oxidized zirconium femoral heads with metal heads against HXLPE or ultrahigh-molecular-weight polyethylene (UHMWPE) when 22.25-mm bearings were used, which was the same size that performed so well in Charnley-type THAs. We hypothesized that after a minimal 4-year followup (1) use of HXLPE would result in lower radiographic wear than UHMWPE when articulating with a stainless steel head or with an oxidized zirconium head; (2) use of oxidized zirconium would result in lower radiographic wear than stainless steel when articulating with UHMWPE and HXLPE; and (3) there would be no difference in terms of Merle d'Aubigné scores between the bearing couple combinations. One hundred patients were randomized to receive cemented THA with either oxidized zirconium or a stainless steel femoral head. UHMWPE was used in the first 50 patients, whereas HXLPE was used in the next 50 patients. There were 25 patients in each of the four bearing couple combinations. All other parameters were identical in both groups. Complete followup was available in 86 of these patients. Femoral head penetration was measured using a validated computer-assisted method dedicated to all-polyethylene sockets. Clinical results were compared between the groups using the Merle d'Aubigné score. In the UHMWPE series, the median steady-state penetration rate from 1 year onward was 0.03 mm/year (range, 0.003-0.25 mm/year) in the oxidized zirconium group versus 0.11 mm/year (range, 0.03-0.29 mm/year) in the metal group (difference of medians 0.08, p zirconium group versus 0.05 mm/year (range, -0.39 to 0.11 mm/year) in the metal group (difference of medians 0.03, p

  18. Circulating mesenchymal stem cells and their clinical implications

    Liangliang Xu

    2014-01-01

    Full Text Available Circulating mesenchymal stem cells (MSCs is a new cell source for tissue regeneration and tissue engineering. The characteristics of circulating MSCs are similar to those of bone marrow-derived MSCs (BM-MSCs, but they exist at a very low level in healthy individuals. It has been demonstrated that MSCs are able to migrate to the sites of injury and that they have some distinct genetic profiles compared to BM-MSCs. The current review summaries the basic knowledge of circulating MSCs and their potential clinical applications, such as mobilizing the BM-MSCs into circulation for therapy. The application of MSCs to cure a broad spectrum of diseases is promising, such as spinal cord injury, cardiovascular repair, bone and cartilage repair. The current review also discusses the issues of using of allogeneic MSCs for clinical therapy.

  19. Cermet cements.

    McLean, J W

    1990-01-01

    Cermet ionomer cements are sintered metal/glass powders, which can be made to react with poly(acids). These new cements are significantly more resistant to abrasion than regular glass ionomer cements and are widely accepted as core build-up materials and lining cements. They can strengthen teeth and provide the clinician with an opportunity to treat early dental caries.

  20. Influence of an alloy addition on the physical and clinical behaviour of glass ionomer cement

    Abour, Mohamed Abour Bashir

    These in vitro studies compared the various properties of an experimental high powder liquid content glass ionomer cement (EXPT) with those of a metal addition GIC (Hi-Dense) and disperse phase amalgam (Dispersalloy). Bi-axial, four point flexural and compressive tests were used to evaluate strength. Six groups of ten specimens were constructed for each test for each material and allowed to set in an oven at 37°C for 60 minutes. Specimens were stored in distilled water at 37°C until testing at one day, one week, one, three, six months and year. It was found that the strength of Hi-Dense increased and then maintained over extended time, whereas the strength of EXPT showed a declined at 3 months. The bond strengths of the materials to both enamel and dentine were also evaluated. Ten groups of ten teeth, five for each surface for each glass ionomer materials, were prepared. Teeth were aligned leaving the enamel and dentine surfaces exposed. The mixed material was condensed into a cylinder placed on the appropriate surface. These specimens were also stored in distilled water at 37°C. It was found that Hi-Dense had a higher bond strength to enamel that increased with time. The bond strength to dentine was maintained over the test period. The erosion rate of the materials was evaluated using the lactic acid erosion test. Three groups of six specimens for each material were constructed and tested after one hour, one day and at six months. Each specimen was subjected to an impinging jet of lactic acid solution. The erosion rate was determined by weight loss and dimensional change. It was found that Hi-Dense had a high erosion resistance which was slightly better than the experimental material. The microleakage, around restorations prepared, using the glass ionomer materials, was evaluated after cyclical loading the restoration-tooth complex. It was found that there was less leakage around Hi-Dense than EXPT at both the cervical and occlusal margins. In a clinical

  1. Stem cell tourism--a web-based analysis of clinical services available to international travellers.

    Connolly, Ruairi; O'Brien, Timothy; Flaherty, Gerard

    2014-01-01

    Stem cell therapies are advertised through online resources which describe a range of treatments with diverse clinical indications. Stem cell tourists may not be aware of the information they should seek when consulting these clinics, or of the potential risks involved. The aim of this study was to characterise the therapies offered by online stem cell clinics. A web based search utilising five search terms was employed. The first twenty pages of each search result were screened against 340 variables. 224 out of 1091 websites advertised stem cell clinics. 68 eligible sites covering 21 countries were evaluated. The top five clinical indications for stem cell therapy were multiple sclerosis, anti-ageing, Parkinson's disease, stroke and spinal cord injury. Adult, autologous stem cells were the most commonly utilised stem cell, and these were frequently sourced from bone marrow and adipose tissue and administered intravenously. Thirty-four per cent of sites mentioned the number of patients treated while one quarter of clinics provided outcome data. Twenty-nine per cent of clinics had an internationally recognised accreditation. Fifteen per cent of clinics stated that their therapies posed no risk. Eighty-eight per cent of clinics claimed treatment effectiveness, with 16% describing their curative potential. Over 40% of sites did not specify the number or duration of treatments. Fifty-three per cent of clinics requested access to patients' medical records, and 12% recommended patients discuss the proposed therapy with their doctor. No clinic recommended that travellers consult a travel medicine specialist or receive vaccinations prior to their intended travel. One quarter of sites discussed contraindications to treatment, with 41% of sites detailing follow up patient care. There is potential for stem cell tourists to receive misleading or deficient information from online stem cell clinics. Both the stem cell tourist and travel medicine practitioner should be educated

  2. Molecular biology of breast cancer stem cells: potential clinical applications.

    Nguyen, Nam P; Almeida, Fabio S; Chi, Alex; Nguyen, Ly M; Cohen, Deirdre; Karlsson, Ulf; Vinh-Hung, Vincent

    2010-10-01

    Breast cancer stem cells (CSC) have been postulated recently as responsible for failure of breast cancer treatment. The purpose of this study is to review breast CSCs molecular biology with respect to their mechanism of resistance to conventional therapy, and to develop treatment strategies that may improve survival of breast cancer patients. A literature search has identified in vitro and in vivo studies of breast CSCs. Breast CSCs overexpress breast cancer resistance protein (BCRP) which allows cancer cells to transport actively chemotherapy agents out of the cells. Radioresistance is modulated through activation of Wnt signaling pathway and overexpression of genes coding for glutathione. Lapatinib can selectively target HER-2 positive breast CSCs and improves disease-free survival in these patients. Metformin may target basal type breast CSCs. Parthenolide and oncolytic viruses are promising targeting agents for breast CSCs. Future clinical trials for breast cancer should include anti-cancer stem cells targeting agents in addition to conventional chemotherapy. Hypofractionation radiotherapy may be indicated for residual disease post chemotherapy. 2010 Elsevier Ltd. All rights reserved.

  3. Islet and Stem Cell Encapsulation for Clinical Transplantation

    Krishnan, Rahul; Alexander, Michael; Robles, Lourdes; Foster 3rd, Clarence E.; Lakey, Jonathan R.T.

    2014-01-01

    Over the last decade, improvements in islet isolation techniques have made islet transplantation an option for a certain subset of patients with long-standing diabetes. Although islet transplants have shown improved graft function, adequate function beyond the second year has not yet been demonstrated, and patients still require immunosuppression to prevent rejection. Since allogeneic islet transplants have experienced some success, the next step is to improve graft function while eliminating the need for systemic immunosuppressive therapy. Biomaterial encapsulation offers a strategy to avoid the need for toxic immunosuppression while increasing the chances of graft function and survival. Encapsulation entails coating cells or tissue in a semipermeable biocompatible material that allows for the passage of nutrients, oxygen, and hormones while blocking immune cells and regulatory substances from recognizing and destroying the cell, thus avoiding the need for systemic immunosuppressive therapy. Despite advances in encapsulation technology, these developments have not yet been meaningfully translated into clinical islet transplantation, for which several factors are to blame, including graft hypoxia, host inflammatory response, fibrosis, improper choice of biomaterial type, lack of standard guidelines, and post-transplantation device failure. Several new approaches, such as the use of porcine islets, stem cells, development of prevascularized implants, islet nanocoating, and multilayer encapsulation, continue to generate intense scientific interest in this rapidly expanding field. This review provides a comprehensive update on islet and stem cell encapsulation as a treatment modality in type 1 diabetes, including a historical outlook as well as current and future research avenues. PMID:25148368

  4. Monitoring cancer stem cells: insights into clinical oncology

    Lin SC

    2016-02-01

    Full Text Available ShuChen Lin,1,* YingChun Xu,2,* ZhiHua Gan,1 Kun Han,1 HaiYan Hu,3 Yang Yao,3 MingZhu Huang,4 DaLiu Min1 1Department of Oncology, Shanghai Sixth People’s Hospital East Campus, Shanghai Jiao Tong University, 2Department of Oncology, Renji Hospital, Shanghai Jiao Tong University, 3Department of Oncology, The Sixth People’s Hospital, Shanghai Jiao Tong University, 4Department of Medical Oncology, Cancer Hospital of Fudan University, Shanghai, People’s Republic of China *These authors contributed equally to this work Abstract: Cancer stem cells (CSCs are a small, characteristically distinctive subset of tumor cells responsible for tumor initiation and progression. Several treatment modalities, such as surgery, glycolytic inhibition, driving CSC proliferation, immunotherapy, and hypofractionated radiotherapy, may have the potential to eradicate CSCs. We propose that monitoring CSCs is important in clinical oncology as CSC populations may reflect true treatment response and assist with managing treatment strategies, such as defining optimal chemotherapy cycles, permitting pretreatment cancer surveillance, conducting a comprehensive treatment plan, modifying radiation treatment, and deploying rechallenge chemotherapy. Then, we describe methods for monitoring CSCs. Keywords: cancer stem cells, glycolytic inhibition, watchful waiting, rechallenge, immunotherapy

  5. Clinical Applications of Mesenchymal Stem Cells in Chronic Diseases

    Andrea Farini

    2014-01-01

    Full Text Available Extraordinary progress in understanding several key features of stem cells has been made in the last ten years, including definition of the niche, and identification of signals regulating mobilization and homing as well as partial understanding of the mechanisms controlling self-renewal, commitment, and differentiation. This progress produced invaluable tools for the development of rational cell therapy protocols that have yielded positive results in preclinical models of genetic and acquired diseases and, in several cases, have entered clinical experimentation with positive outcome. Adult mesenchymal stem cells (MSCs are nonhematopoietic cells with multilineage potential to differentiate into various tissues of mesodermal origin. They can be isolated from bone marrow and other tissues and have the capacity to extensively proliferate in vitro. Moreover, MSCs have also been shown to produce anti-inflammatory molecules which can modulate humoral and cellular immune responses. Considering their regenerative potential and immunoregulatory effect, MSC therapy is a promising tool in the treatment of degenerative, inflammatory, and autoimmune diseases. It is obvious that much work remains to be done to increase our knowledge of the mechanisms regulating development, homeostasis, and tissue repair and thus to provide new tools to implement the efficacy of cell therapy trials.

  6. Clinical Application of Induced Pluripotent Stem Cells in Cardiovascular Medicine.

    Chi, Hong-jie; Gao, Song; Yang, Xin-chun; Cai, Jun; Zhao, Wen-shu; Sun, Hao; Geng, Yong-Jian

    2015-01-01

    Induced pluripotent stem cells (iPSCs) are generated by reprogramming human somatic cells through the overexpression of four transcription factors: Oct4, Sox2, Klf4 and c-Myc. iPSCs are capable of indefinite self-renewal, and they can differentiate into almost any type of cell in the body. These cells therefore offer a highly valuable therapeutic strategy for tissue repair and regeneration. Recent experimental and preclinical research has revealed their potential for cardiovascular disease diagnosis, drug screening and cellular replacement therapy. Nevertheless, significant challenges remain in terms of the development and clinical application of human iPSCs. Here, we review current progress in research related to patient-specific iPSCs for ex vivo modeling of cardiovascular disorders and drug screening, and explore the potential of human iPSCs for use in the field of cardiovascular regenerative medicine. © 2015 S. Karger AG, Basel.

  7. Clinical efficacy of bone cement injectable pedicle screw system combined with intervertebral fusion in treatment of lumbar spondylolysis and osteoporosis

    Peng-yi DAI

    2016-10-01

    Full Text Available Objective  To observe the therapeutic effect of bone cement injectable pedicle screw system combined with intervertebral fusion for lumbar spondylolysis and osteoporosis. Methods  The clinical data were analyzed retrospectively of 21 patients with lumbar spondylolysis and osteoporosis who received treatment of bone cement injectable pedicle screw system and intervertebral fusion from Aug. 2013 to Nov. 2015. The 21 patients (9 males and 12 females aged from 60 to 80 years (mean 64 years old; 6 of them presented degenerative spondylolysis, 15 with isthmic spondylolisthesis; 2 cases had I degree slippage, 13 had Ⅱdegree slippage, 6 had Ⅲdegree slippage, and all the cases were unisegmental slippage including 9 cases in L4 and 12 cases in L5. Bone mineral density of lumbar vertebrae (L2-L5 was measured with dual-energy X-ray absorptiometry, and T values conforming to the diagnostic criteria of osteoporosis were less than or equal to -2.5; All patients were operated with whole lamina resection for decompression, bone cement injectable pedicle screws system implantation, propped open reduction and fixation intervertebral fusion. The clinical outcomes were determined by the radiographic evaluation including intervertebral height, height of intervertebral foramen, slip distance, slip rate and slip angle, and Oswestry disability index (ODI on preoperative, 3 months after operation and the end of the time, and the interbody fusion were followed up. Results  Cerebrospinal fluid leakage of incision was observed in two cases after operation, compression and dressing to incision, Trendelenburg position, dehydration and other treatments were taken, and the stitches of incisions were taken out on schedule. Slips in the 21 patients were reset to different extent, and lumbar physiological curvatures were recovered. The intervertebral height and height of intervertebral foramen were obviously higher 3 months after operation than that before operation (P0

  8. A Comparative Study of the Retentive Strengths of Commercial and Indigenously Developed Luting Cements using Both Lathe-cut and Clinically Simulated Specimens.

    Mathew, Joe; Kurian, Byju P; Philip, Biju; Mohammed, Sunil; Menon, Preetha; Raj, Rajan S

    2016-08-01

    Superior adhesive strength in luting agents is of paramount significance in fixed partial denture success. In this in vitro study five cements were tested for retentive qualities, using both lathe-cut and hand-prepared specimens. A total of 104 freshly extracted tooth specimens were prepared. Seventy of them were lathe-cut and 30 specimens were hand-prepared to simulate clinical conditions. Five different cements were tested, which included a compomer, a composite, a zinc phosphate, and 2 glass-ionomer luting cements. Of the 5, 2 trial cements were indigenously developed by Sree Chitra Tirunal Institute for Medical Sciences and Technology (SCTIMST), Trivandrum, India - a glass-ionomer cement (Chitra GIC) and a chemical-cure composite (Chitra CCC). All cements were compared within each group and between groups (lathe-prepared and hand-prepared). GC Fuji 1 (GC America) exhibited superior retentive strengths in both lathe-cut and hand-prepared specimens, whereas the compomer cement displayed the lowest values when tested. In lathe-cut specimens, statistical analysis showed no significant difference between GC Fuji 1 and indigenously developed Chitra CCC. Both Chitra CCC and GC Fuji 1 have comparable strengths in lathe-cut samples, making Chitra CCC a potential luting agent. Statistical analysis reveals that all cements, except GC Fuji 1, exhibited a significant decrease in strength due to the change in design uniformity. The chemical bonding of GC Fuji 1 proves to be quite strong irrespective of shape and precision of the tooth crown. The indigenously developed Chitra GIC and Chitra CCC showed promising results to be used as a potential luting agent.

  9. Stem Cell Applications in Tendon Disorders: A Clinical Perspective

    Mark Young

    2012-01-01

    Full Text Available Tendon injuries are a common cause of morbidity and a significant health burden on society. Tendons are structural tissues connecting muscle to bone and are prone to tearing and tendinopathy, an overuse or degenerative condition that is characterized by failed healing and cellular depletion. Current treatments, for tendon tear are conservative, surgical repair or surgical scaffold reconstruction. Tendinopathy is treated by exercises, injection therapies, shock wave treatments or surgical tendon debridement. However, tendons usually heal with fibrosis and scar tissue, which has suboptimal tensile strength and is prone to reinjury, resulting in lifestyle changes with activity restriction. Preclinical studies show that cell therapies have the potential to regenerate rather than repair tendon tissue, a process termed tenogenesis. A number of different cell lines, with varying degrees of differentiation, have being evaluated including stem cells, tendon derived cells and dermal fibroblasts. Even though cellular therapies offer some potential in treating tendon disorders, there have been few published clinical trials to determine the ideal cell source, the number of cells to administer, or the optimal bioscaffold for clinical use.

  10. 10-year results of a new low-monomer cement: follow-up of a randomized RSA study.

    Söderlund, Per; Dahl, Jon; Röhrl, Stephan; Nivbrant, Bo; Nilsson, Kjell G

    2012-12-01

    The properties and performance of a new low-monomer cement were examined in this prospective randomized, controlled RSA study. 5-year data have already been published, showing no statistically significant differences compared to controls. In the present paper we present the 10-year results. 44 patients were originally randomized to receive total hip replacement with a Lubinus SPII titanium-aluminum-vanadium stem cemented either with the new Cemex Rx bone cement or with control bone cement, Palacos R. Patients were examined using RSA, Harris hip score, and conventional radiographs. At 10 years, 33 hips could be evaluated clinically and 30 hips could be evaluated with RSA (16 Cemex and 14 Palacos). 9 patients had died and 4 patients were too old or infirm to be investigated. Except for 1 hip that was revised for infection after less than 5 years, no further hips were revised before the 10-year follow-up. There were no statistically significant clinical differences between the groups. The Cemex cement had magnitudes of migration similar to or sometimes lower than those of Palacos cement. In both groups, most hips showed extensive radiolucent lines, probably due to the use of titanium alloy stems. At 10 years, the Cemex bone cement tested performed just as well as the control (Palacos bone cement).

  11. A clinical trial to evaluate the retention of a silver cermet-ionomer cement used as a fissure sealant.

    Mills, R W; Ball, I A

    1993-01-01

    A randomized clinical trial was under-taken to compare the retention of a silver cermet-ionomer cement, Ketac Silver, with a conventional, autopolymerizing BIS-GMA resin sealant, Delton, using matched pairs of fissure sites within each subject's mouth. One hundred twenty matched contralateral pairs of fissure sites in first and second permanent molars of 53 school children were sealed with the two materials. The choice of site and material was selected at random. The ages of the children ranged from five to 16 years; first permanent molars were sealed in the five- to 10-year age group, and second permanent molars in the 11- to 16-year age group. Sealants were assessed as present, partly present, or absent at 6, 12, and 24 months. The number of pairs of sites available for reassessment declined from 102 at six months to 59 at 24 months as patients were lost to the study. Retention rates were higher for the Ketac Silver sealants at all three inspection intervals (P cermet cement was better retained than conventional resin sealants in younger children.

  12. Stem Cell Research and Clinical Translation: A Roadmap about Good Clinical Practice and Patient Care

    Paola Frati

    2017-01-01

    Full Text Available The latest research achievements in the field of stem cells led in 2016 to the publication of “Guidelines for Stem Cell Research and Clinical Translation” by the International Society for Stem Cell Research (ISSCR. Updating the topics covered in previous publications, the new recommendations offer interesting ethical and scientific insights. Under the common principles of research integrity, protection of patient’s welfare, respect for the research subjects, transparency and social justice, the centrality of good clinical practice, and informed consent in research and translational medicine is supported. The guidelines implement the abovementioned publications, requiring rigor in all areas of research, promoting the validity of the scientific activity results and emphasizing the need for an accurate and efficient public communication. This paper aims to analyze the aforementioned guidelines in order to provide a valid interpretive tool for experts. In particular, a research activity focused on the bioethical, scientific, and social implications of the new recommendations is carried out in order to provide food for thought. Finally, as an emerging issue of potential impact of current guidelines, an overview on implications of compensation for egg donation is offered.

  13. The combination of ultrasound with antibiotics released from bone cement decreases the viability of planktonic and biofilm bacteria: an in vitro study with clinical strains.

    Ensing, Geert T; Neut, Daniëlle; van Horn, Jim R; van der Mei, Henny C; Busscher, Henk J

    2006-12-01

    Antibiotic-loaded bone cements are used for the permanent fixation of joint prostheses. Antibiotic-loaded cements significantly decrease the incidence of infection. The objective of this study was to investigate whether the viability of bacteria derived from patients with a prosthesis-related infection could be further decreased when antibiotic release from bone cements was combined with application of pulsed ultrasound. Escherichia coli ATCC 10798, Staphylococcus aureus 7323, coagulase-negative staphylococci (CoNS 7368 and CoNS 7391) and Pseudomonas aeruginosa 5148 were grown planktonically in suspension and as a biofilm on three different bone cements: Palacos R without gentamicin as control, gentamicin-loaded Palacos R-G and gentamicin/clindamycin-loaded Copal. The viability of planktonic and biofilm bacteria was measured in the absence and presence of pulsed ultrasound for 40 h. Ultrasound itself did not affect bacterial viability. However, application of pulsed ultrasound in combination with antibiotic release by antibiotic-loaded bone cements yielded a reduction of both planktonic and biofilm bacterial viability compared with antibiotic release without application of ultrasound. This study shows that antibiotic release in combination with ultrasound increases the antimicrobial efficacy further than antibiotic release alone against a variety of clinical isolates. Application of ultrasound in combination with antibiotic release in clinical practice could therefore lead to better prevention or treatment of prosthesis-related infections.

  14. Autologous mesenchymal stem cells: clinical applications in amyotrophic lateral sclerosis.

    Mazzini, Letizia; Mareschi, Katia; Ferrero, Ivana; Vassallo, Elena; Oliveri, Giuseppe; Boccaletti, Riccardo; Testa, Lucia; Livigni, Sergio; Fagioli, Franca

    2006-07-01

    Our study was aimed to evaluate the feasibility and safety of intraspinal cord implantation of autologous mesenchymal stem cells (MSCs) in a few well-monitored amyotrophic lateral sclerosis (ALS) patients. Seven patients affected by definite ALS were enrolled in the study and two patients were treated for compassionate use and monitored for at least 3 years. Bone marrow was collected from the posterior iliac crest according to the standard procedure and MSCs were expanded ex vivo according to Pittenger's protocol. The cells were suspended in 2 ml autologous cerebrospinal fluid and transplanted into the spinal cord by a micrometric pump injector. The in vitro expanded MSCs did not show any bacterial o fungal contamination, hemopoietic cell contamination, chromosomic alterations and early cellular senescence. No patient manifested major adverse events such as respiratory failure or death. Minor adverse events were intercostal pain irradiation and leg sensory dysesthesia, both reversible after a mean period of 6 weeks. No modification of the spinal cord volume or other signs of abnormal cell proliferation were observed. A significant slowing down of the linear decline of the forced vital capacity was evident in four patients 36 months after MSCs transplantation. Our results demonstrate that direct injection of autologous expanded MSCs into the spinal cord of ALS patients is safe, with no significant acute or late toxicity, and well tolerated. The clinical results seem to be encouraging.

  15. [Non-cemented self-locking total arthroplasty of the hip. Clinical and radiological results after three years].

    Desjardins, A L; Roy, A; Duchesne, R; Béliveau, P; Fallaha, M; Bornais, S

    1993-01-01

    We reviewed 47 patients who had fifty-one (51) primary, cementless biofit total hip arthroplasties (THA) implanted at Maisonneuve-Rosemont Hospital between 1986 and 1990. An independent observer rated the patients on the Harris Hip Score (HHS) by questionnaire, physical examination and radiological assessment. The average follow-up was 40 months. Twenty-two percent (22%) of the femoral components had been revised because of incapacitating pain, limping or a HHS inferior to 60. A little more than 20% of the unrevised prostheses had a mediocre result (HHS inferior to 70). There was no correlation between results and radiological signs of instability. The femoral component of the hip arthroplasty has a poor clinical performance which compares unfavourably with cemented prostheses.

  16. Stem cells: Biology and clinical potential | Alenzi | African Journal of ...

    Stem cell technology has developed rapidly in recent years to the point that we can now envisage its future use in a variety of therapeutic areas. This review seeks to summarize the types and sources of stem cells that may be utilized in this way, their pattern of development, their plasticity in terms of differentiation and ...

  17. Setting global standards for stem cell research and clinical translation : The 2016 ISSCR guidelines

    Daley, George Q.; Hyun, Insoo; Apperley, Jane F.; Barker, Roger A.; Benvenisty, Nissim; Bredenoord, Annelien L.; Breuer, Christopher K.; Caulfield, Timothy; Cedars, Marcelle I.; Frey-Vasconcells, Joyce; Heslop, Helen E.; Jin, Ying; Lee, Richard T.; McCabe, Christopher; Munsie, Megan; Murry, Charles E.; Piantadosi, Steven; Rao, Mahendra; Rooke, Heather M.; Sipp, Douglas; Studer, Lorenz; Sugarman, Jeremy; Takahashi, Masayo; Zimmerman, Mark; Kimmelman, Jonathan

    2016-01-01

    The International Society for Stem Cell Research (ISSCR) presents its 2016 Guidelines for Stem Cell Research and Clinical Translation (ISSCR, 2016). The 2016 guidelines reflect the revision and extension of two past sets of guidelines (ISSCR, 2006; ISSCR, 2008) to address new and emerging areas of

  18. Clinical Implications of Intestinal Stem Cell Markers in Colorectal Cancer

    Espersen, Maiken Lise Marcker; Olsen, Jesper; Linnemann, Dorte

    2015-01-01

    Colorectal cancer (CRC) still has one of the highest incidence and mortality rate among cancers. Therefore, improved differential diagnostics and personalized treatment are still needed. Several intestinal stem cell markers have been found to be associated with CRC and might have a prognostic...... and predictive significance in CRC patients. This review provides an overview of the intestinal stem cell markers leucine-rich repeat-containing G-protein-coupled receptor 5 (LGR5), B cell–specific Moloney murine leukemia virus insertion site 1 (BMI1), Musashi1 (MSI1), and sex-determining region y-box 9 (SOX9......) and their implications in human CRC. The exact roles of the intestinal stem cell markers in CRC development and progression remain unclear; however, high expression of these stem cell markers have a potential prognostic significance and might be implicated in chemotherapy resistance...

  19. Stem cells and the pancreas: from discovery to clinical approach

    Angelica Dessì

    2016-02-01

    Full Text Available The existence of stem cells within the adult pancreas is supported by the ability of this organ to regenerate its endocrine component in various conditions such as pregnancy and following partial pancreatectomy. Several studies have shown that progenitor or adult stem cells may reside within the pancreas and particularly in the pancreatic ducts, including acinar cells and islets of Langerhans. The discovery of human pluripotent stem cells in the pancreas, and the possibility of development of strategies for generating these, represented a turning point for the therapeutic interventions of type 1 diabetes.Proceedings of the 2nd International Course on Perinatal Pathology (part of the 11th International Workshop on Neonatology · October 26th-31st, 2015 · Cagliari (Italy · October 31st, 2015 · Stem cells: present and future Guest Editors: Gavino Faa, Vassilios Fanos, Antonio Giordano

  20. Hurdles to clinical translation of human induced pluripotent stem cells

    Neofytou, Evgenios; O’Brien, Connor Galen; Couture, Larry A.; Wu, Joseph C.

    2015-01-01

    Human pluripotent stem cells are known to have the capacity to renew indefinitely, being intrinsically able to differentiate into many different cell types. These characteristics have generated tremendous enthusiasm about the potential applications of these cells in regenerative medicine. However, major challenges remain with the development and testing of novel experimental stem cell therapeutics in the field. In this Review, we focus on the nature of the preclinical challenges and discuss p...

  1. The effect of tourniquet use on fixation quality in cemented total knee arthroplasty a prospective randomized clinical controlled RSA trial.

    Molt, Mats; Harsten, Andreas; Toksvig-Larsen, Sören

    2014-03-01

    A concern that arises with any change in technique is whether it affects the long-term implant stability. The objective of this study was to evaluate the early migration, measured by radiostereometric analysis (RSA), and the functional outcome of the Triathlon™ cemented knee prosthesis, operated on with or without a tourniquet. During the last decades RSA has emerged as a way to assess prosthetic fixation and long time prognosis. The method has been used extensively in both hip and knee arthroplasty. This was a single centre prospective study including 60 patients randomized into two groups operated on either with or without tourniquet. RSA investigation was done within 2-3 days postoperatively after full weight bearing, and then at 3 months, 1 year and 2 years postoperatively. There were no differences between the groups regarding the translation along or rotation around the three coordinal axes, or in maximum total point motion (MTPM). At 2 years the mean MTPM (SD) was 0.71 mm (0.64) for the tourniquet-group and 0.53 mm (0.21) for the non-tourniquet-group. The tibial tray of the Triathlon™ cemented knee prosthesis showed similar early stability whether operated on with or without tourniquet. Level I. Article focus: A safety study for total knee replacement operated on with or without perioperative tourniquet regarding the prosthetic fixation. Strengths and limitations: Strength of this study is that it is a randomized prospective trial using an objective measuring tool. The sample size of 25-30 patients is reportedly sufficient for the screening of implants using RSA (1-3). Clinical trials NCT01604382, Ethics Committee approval D-nr: 144/20085. © 2013.

  2. Clinical Trial Design for Testing the Stem Cell Model for the Prevention and Treatment of Cancer

    Reddy, Rishindra M., E-mail: reddyrm@med.umich.edu [Medical Center, University of Michigan, 1500 E. Medical Center Drive, 2120 Taubman Center, Ann Arbor, MI 48109 (United States); Kakarala, Madhuri; Wicha, Max S. [Comprehensive Cancer Center, University of Michigan, 1500 E. Medical Center Drive, Ann Arbor, MI 48109 (United States)

    2011-06-20

    The cancer stem cell model introduces new strategies for the prevention and treatment of cancers. In cancers that appear to follow the stem cell model, pathways such as Wnt, Notch and Hedgehog may be targeted with natural compounds such as curcumin or drugs to reduce the risk of initiation of new tumors. Disease progression of established tumors could also potentially be inhibited by targeting the tumorigenic stem cells alone, rather than aiming to reduce overall tumor size. These new approaches mandate a change in the design of clinical trials and biomarkers chosen for efficacy assessment for preventative, neoadjuvant, adjuvant, and palliative treatments. Cancer treatments could be evaluated by assessing stem cell markers before and after treatment. Targeted stem cell specific treatment of cancers may not result in “complete” or “partial” responses radiologically, as stem cell targeting may not reduce the tumor bulk, but eliminate further tumorigenic potential. These changes are discussed using breast, pancreatic, and lung cancer as examples.

  3. Clinical Trial Design for Testing the Stem Cell Model for the Prevention and Treatment of Cancer

    Reddy, Rishindra M.; Kakarala, Madhuri; Wicha, Max S.

    2011-01-01

    The cancer stem cell model introduces new strategies for the prevention and treatment of cancers. In cancers that appear to follow the stem cell model, pathways such as Wnt, Notch and Hedgehog may be targeted with natural compounds such as curcumin or drugs to reduce the risk of initiation of new tumors. Disease progression of established tumors could also potentially be inhibited by targeting the tumorigenic stem cells alone, rather than aiming to reduce overall tumor size. These new approaches mandate a change in the design of clinical trials and biomarkers chosen for efficacy assessment for preventative, neoadjuvant, adjuvant, and palliative treatments. Cancer treatments could be evaluated by assessing stem cell markers before and after treatment. Targeted stem cell specific treatment of cancers may not result in “complete” or “partial” responses radiologically, as stem cell targeting may not reduce the tumor bulk, but eliminate further tumorigenic potential. These changes are discussed using breast, pancreatic, and lung cancer as examples

  4. Cytotoxicity of accelerated white MTA and Malaysian white Portland cement on stem cells from human exfoliated deciduous teeth (SHED): An in vitro study.

    Ong, Ren Ming; Luddin, Norhayati; Ahmed, Hany Mohamed Aly; Omar, Nor Shamsuria

    2012-12-01

    The aim of this study was to compare the cytotoxicity of accelerated-set white MTA (AWMTA) and accelerated-set Malaysian white PC (AMWPC) on stem cells from human exfoliated deciduous teeth (SHED). The test materials were introduced into paraffin wax moulds after mixing with calcium chloride dihydrate and sterile distilled water. Subsequently, the set cement specimens were sterilized, incubated in a prepared Dulbecco's modified Eagle medium (DMEM) for seven days. The biomarker CD166 was used for characterization of SHED using flow cytometry. The material extracts were diluted at five different concentrations and incubated for 72h with SHED. The cell viability was evaluated using Dimethylthiazol diphenyltetrazolium bromide (MTT) assay, and the data was analysed using Mann-Whitney test (P<0.05). The results showed that AWMTA revealed significantly greater cell viability at 25 and 12.5mg/ml concentrations (P<0.05). Concomitantly, AMWPC exhibited greater cell viability at concentrations <12.5mg/ml and the results were significant at 1.563mg/ml (P<0.05). Both materials demonstrated moderate cytotoxicity at 25mg/ml and slight cytotoxicity at 6.25 and 3.125mg/ml. At 1.563mg/ml, no cytotoxic activity was merely observed with AMWPC. In conclusion, AMWPC exhibited favourable and comparable cell viability to that of AWMTA, and has the potential to be used as an alternative and less costly material in dental applications. Copyright © 2012. Published by Elsevier B.V.

  5. Cement Formation

    Telschow, Samira; Jappe Frandsen, Flemming; Theisen, Kirsten

    2012-01-01

    Cement production has been subject to several technological changes, each of which requires detailed knowledge about the high multiplicity of processes, especially the high temperature process involved in the rotary kiln. This article gives an introduction to the topic of cement, including...... an overview of cement production, selected cement properties, and clinker phase relations. An extended summary of laboratory-scale investigations on clinkerization reactions, the most important reactions in cement production, is provided. Clinker formations by solid state reactions, solid−liquid and liquid......−liquid reactions are discussed, as are the influences of particles sizes on clinker phase formation. Furthermore, a mechanism for clinker phase formation in an industrial rotary kiln reactor is outlined....

  6. Satisfactory Results of the Exeter Revision Femoral Stem Used for Primary Total Hip Arthroplasty.

    Desy, Nicholas M; Johnson, Joshua D; Sierra, Rafael J

    2017-02-01

    The Exeter cemented femoral stem has demonstrated excellent clinical and radiographic outcomes as well as long-term survivorship free from aseptic loosening. A shorter revision stem (125 mm) with a 44 offset became available for the purpose of cement-in-cement revision situations. In certain cases, this shorter revision stem may be used for various primary total hip arthroplasties (THAs) where the standard length stem would require distally reaming the femoral canal. We sought to report on the early to midterm results of this specific stem when used for primary THA regarding (1) clinical and radiographic outcomes, (2) complications, and (3) survivorship. Twenty-nine patients (33 hips) underwent a hybrid THA using the smaller revision Exeter cemented femoral stem. Twenty-five patients (28 hips) had at least 2 years of follow-up and were assessed for clinical and radiographic outcomes. All 33 hips were included in the analysis of complications and survivorship. The Kaplan-Meier survivorship was performed using revision for all causes and for aseptic loosening as the end points. The average clinical follow-up was 4 years (range, 2-7). Harris Hip Scores improved from a mean preoperative value of 56 (range, 23-96) to 90 (range, 51-100) at the latest follow-up. All patients demonstrated superior cement mantles with no signs of loosening. One patient suffered a B2 periprosthetic fracture and 1 patient experienced 2 episodes of instability. The 5-year Kaplan-Meier survivorship was 96.7% for all causes of revision and was 100% using aseptic loosening as the end point. The shorter Exeter revision cemented femoral stem has favorable early to midterm clinical and radiographic outcomes when used for primary THA with a low complication rate and is a viable option in patients with narrow femoral canals where uncemented stem fixation is not desired. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Migration characteristics and early clinical results of the NANOS® short-stem hip arthroplasty.

    Kaipel, Martin; Grabowiecki, Phillip; Sinz, Katrina; Farr, Sebastian; Sinz, Günter

    2015-05-01

    Femoral short stems promise essential advantages in total hip arthroplasty. Up to now, only short- and midterm clinical studies exist. Data on early stem migration that could predict later aseptic loosening at an early stage are rare. The purpose of this study was to assess migration patterns and clinical outcome 2 years after hip replacement by a metaphyseal anchored cementless short stem. Migration data and clinical results were prospectively assessed in 49 patients. Clinical outcome was measured using the Harris Hip Score (HHS). Migration analyses were performed using the computer-assisted Einzel-Bild-Roentgen-Analyse (EBRA) system. At 2 years after surgery, none of the implants needed revision, and HHS increased from 47.9 up to 98.1. Of 49 patients, 5 (10%) showed increased vertical stem migration (1.5 mm/2a) that might predict late aseptic loosening. Of 49 stems, 44 (90%) showed stable migration patterns indicating a beneficial long-term outcome. Results of this study confirm the excellent clinical data of previous works. Migration patterns strongly suggest that short-stem arthroplasty is not only an innovative but also a reliable strategy in total hip replacement.

  8. Clinical and Radiographic Evaluation of the Effectiveness of Formocresol, Mineral Trioxide Aggregate, Portland Cement, and Enamel Matrix Derivative in Primary Teeth Pulpotomies: A Two Year Follow-Up.

    Yildirim, Ceren; Basak, Feridun; Akgun, Ozlem Marti; Polat, Gunseli Guven; Altun, Ceyhan

    2016-01-01

    The aim of this study was to evaluate and to compare clinical and radiographic outcomes of 4 materials (formocresol, mineral trioxide aggregate (MTA), Portland cement and enamel matrix derivative) using in primary teeth pulpotomies. Sixty-five patients aged 5-9 years (32 female, 33 male) were included in this study. A total of 140 primary first and second molars with deep caries were treated with pulpotomy. All teeth were then restored with stainless steel crowns. The treated teeth were evaluated clinically and radiographically at 3, 6, 12, 18 and 24 months. At 24 months, the clinical success rates of formocresol, MTA, Portland cement, and enamel matrix derivative were 96.9%, 100%, 93.9%, and 93.3%, respectively. The corresponding radiographic success rates were 84.4%, 93.9%, 86.7% and 78.1%, respectively. Although there were no statistically significant differences in clinical and radiographic success rates among the 4 groups, MTA appears to be superior to formocresol, Portland cement, and enamel matrix derivative as a pulpotomy agent in primary teeth.

  9. The mechanical effect of the existing cement mantle on the in-cement femoral revision.

    Keeling, Parnell; Lennon, Alexander B; Kenny, Patrick J; O'Reilly, Peter; Prendergast, Patrick J

    2012-08-01

    Cement-in-cement revision hip arthroplasty is an increasingly popular technique to replace a loose femoral stem which retains much of the original cement mantle. However, some concern exists regarding the retention of the existing fatigued and aged cement in such cement-in-cement revisions. This study investigates whether leaving an existing fatigued and aged cement mantle degrades the mechanical performance of a cement-in-cement revision construct. Primary cement mantles were formed by cementing a polished stem into sections of tubular steel. If in the test group, the mantle underwent conditioning in saline to simulate ageing and was subject to a fatigue of 1 million cycles. If in the control group no such conditioning or fatigue was carried out. The cement-in-cement procedure was then undertaken. Both groups underwent a fatigue of 1 million cycles subsequent to the revision procedure. Application of a Mann-Whitney test on the recorded subsidence (means: 0.51, 0.46, n=10+10, P=0.496) and inducible displacement (means: 0.38, 0.36, P=0.96) revealed that there was no statistical difference between the groups. This study represents further biomechanical investigation of the mechanical behaviour of cement-in-cement revision constructs. Results suggest that pre-revision fatigue and ageing of the cement may not be deleterious to the mechanical performance of the revision construct. Thus, this study provides biomechanical evidence to back-up recent successes with this useful revision technique. Copyright © 2012 Elsevier Ltd. All rights reserved.

  10. Adipose Derived Mesenchymal Stem Cells In Wound Healing: A Clinical Review

    Gunalp Uzun

    2014-08-01

    Full Text Available The aim of this article is to review clinical studies on the use of adipose derived mesenchymal stem cells in the treatment of chronic wounds. A search on PubMed was performed on April 30th, 2014 to identify the relevant clinical studies. We reviewed 13 articles that reported the use adipose derived stem cells in the treatment of different types of wounds. Adipose derived stem cells have the potential to be used in the treatment of chronic wounds. However, standard methods for isolation, storage and application of these cells are needed. New materials to transfer these stem cells to injured tissues should be investigated. [Dis Mol Med 2014; 2(4.000: 57-64

  11. Setting Global Standards for Stem Cell Research and Clinical Translation: The 2016 ISSCR Guidelines

    George Q. Daley

    2016-06-01

    Full Text Available The International Society for Stem Cell Research (ISSCR presents its 2016 Guidelines for Stem Cell Research and Clinical Translation (ISSCR, 2016. The 2016 guidelines reflect the revision and extension of two past sets of guidelines (ISSCR, 2006; ISSCR, 2008 to address new and emerging areas of stem cell discovery and application and evolving ethical, social, and policy challenges. These guidelines provide an integrated set of principles and best practices to drive progress in basic, translational, and clinical research. The guidelines demand rigor, oversight, and transparency in all aspects of practice, providing confidence to practitioners and public alike that stem cell science can proceed efficiently and remain responsive to public and patient interests. Here, we highlight key elements and recommendations in the guidelines and summarize the recommendations and deliberations behind them.

  12. Feasibility of mesenchymal stem cell culture expansion for a phase I clinical trial in multiple sclerosis.

    Planchon, Sarah M; Lingas, Karen T; Reese Koç, Jane; Hooper, Brittney M; Maitra, Basabi; Fox, Robert M; Imrey, Peter B; Drake, Kylie M; Aldred, Micheala A; Lazarus, Hillard M; Cohen, Jeffrey A

    2018-01-01

    Multiple sclerosis is an inflammatory, neurodegenerative disease of the central nervous system for which therapeutic mesenchymal stem cell transplantation is under study. Published experience of culture-expanding multiple sclerosis patients' mesenchymal stem cells for clinical trials is limited. To determine the feasibility of culture-expanding multiple sclerosis patients' mesenchymal stem cells for clinical use. In a phase I trial, autologous, bone marrow-derived mesenchymal stem cells were isolated from 25 trial participants with multiple sclerosis and eight matched controls, and culture-expanded to a target single dose of 1-2 × 10 6 cells/kg. Viability, cell product identity and sterility were assessed prior to infusion. Cytogenetic stability was assessed by single nucleotide polymorphism analysis of mesenchymal stem cells from 18 multiple sclerosis patients and five controls. One patient failed screening. Mesenchymal stem cell culture expansion was successful for 24 of 25 multiple sclerosis patients and six of eight controls. The target dose was achieved in 16-62 days, requiring two to three cell passages. Growth rate and culture success did not correlate with demographic or multiple sclerosis disease characteristics. Cytogenetic studies identified changes on one chromosome of one control (4.3%) after extended time in culture. Culture expansion of mesenchymal stem cells from multiple sclerosis patients as donors is feasible. However, culture time should be minimized for cell products designated for therapeutic administration.

  13. Concepts for the clinical use of stem cells in equine medicine

    Koch, Thomas Gadegaard; Berg, Lise Charlotte; Betts, Dean H.

    2008-01-01

    experimental and empirical commercial use. A better understanding of equine stem cell biology and concepts is needed in order to develop and evaluate rational clinical applications in the horse. Controlled, well-designed studies of the basic biologic characteristics and properties of these cells are needed......Stem cells from various tissues hold great promise for their therapeutic use in horses, but so far efficacy or proof-of-principle has not been established. The basic characteristics and properties of various equine stem cells remain largely unknown, despite their increasingly widespread...

  14. The clinical application of mesenchymal stromal cells in hematopoietic stem cell transplantation

    Ke Zhao

    2016-05-01

    Full Text Available Abstract Mesenchymal stromal cells (MSCs are multipotent stem cells well known for repairing tissue, supporting hematopoiesis, and modulating immune and inflammation response. These outstanding properties make MSCs as an attractive candidate for cellular therapy in immune-based disorders, especially hematopoietic stem cell transplantation (HSCT. In this review, we outline the progress of MSCs in preventing and treating engraftment failure (EF, graft-versus-host disease (GVHD following HSCT and critically discuss unsolved issues in clinical applications.

  15. Stem cell technology using bioceramics: hard tissue regeneration towards clinical application

    Hiroe Ohnishi, Yasuaki Oda and Hajime Ohgushi

    2010-01-01

    Full Text Available Mesenchymal stem cells (MSCs are adult stem cells which show differentiation capabilities toward various cell lineages. We have already used MSCs for treatments of osteoarthritis, bone necrosis and bone tumor. For this purpose, culture expanded MSCs were combined with various ceramics and then implanted. Because of rejection response to allogeneic MSC implantation, we have utilized patients' own MSCs for the treatment. Bone marrow is a good cell source of MSCs, although the MSCs also exist in adipose tissue. When comparing osteogenic differentiation of these MSCs, bone marrow MSCs show more extensive bone forming capability than adipose MSCs. Thus, the bone marrow MSCs are useful for bone tissue regeneration. However, the MSCs show limited proliferation and differentiation capabilities that hindered clinical applications in some cases. Recent advances reveal that transduction of plural transcription factors into human adult cells results in generation of new type of stem cells called induced pluripotent stem cells (iPS cells. A drawback of the iPS cells for clinical applications is tumor formation after their in vivo implantation; therefore it is difficult to use iPS cells for the treatment. To circumvent the problem, we transduced a single factor of either SOX2 or NANOG into the MSCs and found high proliferation as well as osteogenic differentiation capabilities of the MSCs. The stem cells could be combined with bioceramics for clinical applications. Here, we summarize our recent technologies using adult stem cells in viewpoints of bone tissue regeneration.

  16. Ambivalent journeys of hope: embryonic stem cell therapy in a clinic in India.

    Prasad, Amit

    2015-03-01

    Stem cell therapy in non-Western countries such as India has received a lot of attention. Apart from media reports, there are a number of social science analyses of stem cell policy, therapy, and research, their ethical implications, and impact of advertising on patients. Nevertheless, in the media reports as well as in academic studies, experiences of patients, who undertake overseas journeys for stem cell therapy, have largely been either ignored or presented reductively, often as a "false hope." In this article, I analyze the experiences of patients and their "journeys of hope" to NuTech Mediworld, an embryonic stem cell therapy clinic in New Delhi, India. My analysis, which draws on my observations in the clinic and patients' experiences, instead of seeking to adjudicate whether embryonic stem cell therapy in clinics such as NuTech is right or wrong, true or false, focuses on how patients navigate and contest these concerns. I utilize Gilles Deleuze and Felix Guattari's "concepts," lines of flight and deterritorialization, to highlight how embryonic stem cell therapy's "political economy of hope" embodies deterritorialization of several "regimes of truth" and how these deterritorializations impact patients' experiences. © The Author(s) 2014.

  17. TOPICAL REVIEW: Stem cell technology using bioceramics: hard tissue regeneration towards clinical application

    Ohnishi, Hiroe; Oda, Yasuaki; Ohgushi, Hajime

    2010-02-01

    Mesenchymal stem cells (MSCs) are adult stem cells which show differentiation capabilities toward various cell lineages. We have already used MSCs for treatments of osteoarthritis, bone necrosis and bone tumor. For this purpose, culture expanded MSCs were combined with various ceramics and then implanted. Because of rejection response to allogeneic MSC implantation, we have utilized patients' own MSCs for the treatment. Bone marrow is a good cell source of MSCs, although the MSCs also exist in adipose tissue. When comparing osteogenic differentiation of these MSCs, bone marrow MSCs show more extensive bone forming capability than adipose MSCs. Thus, the bone marrow MSCs are useful for bone tissue regeneration. However, the MSCs show limited proliferation and differentiation capabilities that hindered clinical applications in some cases. Recent advances reveal that transduction of plural transcription factors into human adult cells results in generation of new type of stem cells called induced pluripotent stem cells (iPS cells). A drawback of the iPS cells for clinical applications is tumor formation after their in vivo implantation; therefore it is difficult to use iPS cells for the treatment. To circumvent the problem, we transduced a single factor of either SOX2 or NANOG into the MSCs and found high proliferation as well as osteogenic differentiation capabilities of the MSCs. The stem cells could be combined with bioceramics for clinical applications. Here, we summarize our recent technologies using adult stem cells in viewpoints of bone tissue regeneration.

  18. Global regulatory developments for clinical stem cell research: diversification and challenges to collaborations.

    Rosemann, Achim; Bortz, Gabriela; Vasen, Federico; Sleeboom-Faulkner, Margaret

    2016-10-01

    In this article, we explore regulatory developments in stem cell medicine in seven jurisdictions: Japan, China, India, Argentina, Brazil, the USA and the EU. We will show that the research methods, ethical standards and approval procedures for the market use of clinical stem cell interventions are undergoing an important process of global diversification. We will discuss the implications of this process for international harmonization and the conduct of multicountry clinical research collaborations. It will become clear that the increasing heterogeneity of research standards and regulations in the stem cell field presents a significant challenge to international clinical trial partnerships, especially with countries that diverge from the regulatory models that have been developed in the USA and the EU.

  19. A prospective clinical trial on the influence of a triamcinolone/demeclocycline and a calcium hydroxide based temporary cement on pain perception

    Willershausen Brita

    2012-03-01

    Full Text Available Abstract Introduction The aim of this clinical trial was to compare the degree of short term post-operative irritation after application of a triamcinolone/demeclocycyline based or a calcium hydroxide based provisional cement. Methods A total of 109 patients (55 female and 54 male; mean age: 51 ± 14 years with primary or secondary dentinal caries were randomly assigned to the two treatment groups of this biomedical clinical trial (phase III. Selection criteria were good systemic health and treated teeth, which were vital and showed no symptoms of pulpitis. Up to three teeth were prepared for indirect metallic restorations, and the provisional restorations were cemented with a triamcinolone/demeclocycyline (Ledermix or a calcium hydroxide (Provicol based material. The intensity of post-operative pain experienced was documented according to the VAS (4, 12, 20, 24, and 82 h and compared to VAS baseline. Results A total of 159 teeth were treated (Ledermix: 83 teeth, Provicol: 76 teeth. The minor irritation of the teeth, experienced prior to treatment, was similar in both groups; however, 4 h after treatment this value was significantly higher in the Provicol group than in the Ledermix group (p Conclusions The patients had no long term post-operative pain experience in both groups. However, within the first hours after cementation the sensation of pain was considerably higher in the Provicol group than in the Ledermix group.

  20. Resolving ethical issues in stem cell clinical trials: the example of Parkinson disease.

    Lo, Bernard; Parham, Lindsay

    2010-01-01

    Clinical trials of stem cell transplantation raise ethical issues that are intertwined with scientific and design issues, including choice of control group and intervention, background interventions, endpoints, and selection of subjects. We recommend that the review and IRB oversight of stem cell clinical trials should be strengthened. Scientific and ethics review should be integrated in order to better assess risks and potential benefits. Informed consent should be enhanced by assuring that participants comprehend key aspects of the trial. For the trial to yield generalizable knowledge, negative findings and serious adverse events must be reported.

  1. IPS Empress onlays luted with two dual-cured resin cements for endodontically treated teeth: a 3-year clinical evaluation.

    Atali, Pinar Yilmaz; Cakmakcioglu, Ozcan; Topbasi, Bulent; Turkmen, Cafer; Suslen, Ozlem

    2011-01-01

    The aim of this study was to evaluate the performance of IPS Empress ceramic onlays luted with two dual-cured adhesive resin cements for endodontically treated teeth. Twenty molar teeth were restored with all-ceramic restorations luted randomly with Maxcem or Clearfil Esthetic Cement and DC Bond Kit luting systems (n = 10 each) in 20 patients. The restorations were assessed using modified US Public Health Service criteria at baseline, 6 months, and 1, 2, and 3 years. A statistically significant deterioration was found for the criteria marginal integrity, anatomical form, and surface roughness. For luting of ceramic onlays, no difference between the two luting systems was detected.

  2. Challenges of stem cell-based pulp and dentin regeneration: a clinical perspective.

    Huang, George T-J; Al-Habib, Mey; Gauthier, Philippe

    2013-03-01

    There are two types of approaches to regenerate tissues: cell-based and cell-free. The former approach is to introduce exogenous cells into the host to regenerate tissues, and the latter is to use materials other than cells in an attempt to regenerate tissues. There has been a significant advancement in stem cell-based pulp and dentin regeneration research in the past few years. Studies in small and large animals have demonstrated that pulp/dentin-like tissues can be regenerated partially or completely in the root canal space with apical openings of 0.7-3.0 mm using dental pulp stem cells, including stem cells from apical papilla (SCAP) and subpopulations of pulp stem cells. Bone marrow mesenchymal stem cells (BMMSCs) and adipose tissue-derived MSCs (ADMSCs) have also been shown to regenerate pulp-like tissue. In contrast, the cell-free approach has not produced convincing evidence on pulp regeneration. However, one crucial concept has not been considered nor defined in the field of pulp/dentin regeneration and that is the critical size defect of dentin and pulp. Without such consideration and definition, it is difficult to predict or anticipate the extent of cell-free pulp regeneration that would occur. By reasoning, cell-free therapy is unlikely to regenerate an organ/tissue after total loss. Similarly, after a total loss of pulp, it is unlikely to regenerate without using exogenously introduced cells. A cell homing approach may provide a limited amount of tissue regeneration. Although stem cell-based pulp/dentin regeneration has shown great promise, clinical trials are difficult to launch at present. This article will address several issues that challenge and hinder the clinical applications of pulp/dentin regeneration which need to be overcome before stem cell-based pulp/dentin regeneration can occur in the clinic.

  3. Single-visit endodontic treatment of mature teeth with chronic apical abscesses using mineral trioxide aggregate cement: a randomized clinical trial.

    Alsulaimani, Reem Siraj

    2016-08-23

    Mature teeth with chronic apical abscesses characterized by intermittent discharge of pus through an associated sinus tract. This communication between oral mucosa and periapical inflammation is challenging for the sealing ability of root canal obturation material. Therefore, the study aim was to compare the outcomes of endodontic treatment using mineral trioxide aggregate (MTA) cement to the conventional gutta-percha cone and root canal sealer as an obturation material in mature teeth with chronic apical abscesses. Mature teeth with chronic apical abscesses referred to our clinic for root canal treatment between 2010 and 2012 were treated in a single visit and distributed among treatment (T) and control (C) groups using a predetermined randomization block (TCTC). After chemo-mechanical preparation, teeth in group T received MTA cement mixed in a 0.26 water to powder ratio, and teeth group C received gutta-percha and root canal sealer using the warm vertical technique. The treatment outcomes were defined as obturation length, periapical healing, resorption of extruded material, and survival rate at least 2.5 years after treatment. Three endodontists blinded to the type of obturation material documented treatment outcomes. Statistical analysis at P chronic apical abscesses using MTA cement were better, but not statistically significant, compared to conventional treatment. ISRCTN15285974 . Registered retrospectively 23 June 2015.

  4. Informed consent in clinical trials using stem cells: Sugges tions and ...

    2015-08-01

    Aug 1, 2015 ... research. The correlated results showed the need for continuous training and education of elucidators in order to make sure that they acquire and maintain ... in the recommendations show that improving IC related to stem cell research is a .... of this clinical trial. • Contact information and consultation service.

  5. Stem cell therapy for joint problems using the horse as a clinically relevant animal model

    Koch, Thomas Gadegaard; Betts, Dean H.

    2007-01-01

    of experimentally induced lesions. The horse lends itself as a good animal model of spontaneous joint disorders that are clinically relevant to similar human disorders. Equine stem cell and tissue engineering studies may be financially feasible to principal investigators and small biotechnology companies...

  6. Mesenchymal Stem Cells from Adipose Tissue in Clinical Applications for Dermatological Indications and Skin Aging

    Meenakshi Gaur

    2017-01-01

    Full Text Available Operating at multiple levels of control, mesenchymal stem cells from adipose tissue (ADSCs communicate with organ systems to adjust immune response, provide signals for differentiation, migration, enzymatic reactions, and to equilibrate the regenerative demands of balanced tissue homeostasis. The identification of the mechanisms by which ADSCs accomplish these functions for dermatological rejuvenation and wound healing has great potential to identify novel targets for the treatment of disorders and combat aging. Herein, we review new insights into the role of adipose-derived stem cells in the maintenance of dermal and epidermal homeostasis, and recent advances in clinical applications of ADSCs related to dermatology.

  7. Stem Cells of Dental Origin: Current Research Trends and Key Milestones towards Clinical Application

    Athina Bakopoulou

    2016-01-01

    Full Text Available Dental Mesenchymal Stem Cells (MSCs, including Dental Pulp Stem Cells (DPSCs, Stem Cells from Human Exfoliated Deciduous teeth (SHED, and Stem Cells From Apical Papilla (SCAP, have been extensively studied using highly sophisticated in vitro and in vivo systems, yielding substantially improved understanding of their intriguing biological properties. Their capacity to reconstitute various dental and nondental tissues and the inherent angiogenic, neurogenic, and immunomodulatory properties of their secretome have been a subject of meticulous and costly research by various groups over the past decade. Key milestone achievements have exemplified their clinical utility in Regenerative Dentistry, as surrogate therapeutic modules for conventional biomaterial-based approaches, offering regeneration of damaged oral tissues instead of simply “filling the gaps.” Thus, the essential next step to validate these immense advances is the implementation of well-designed clinical trials paving the way for exploiting these fascinating research achievements for patient well-being: the ultimate aim of this ground breaking technology. This review paper presents a concise overview of the major biological properties of the human dental MSCs, critical for the translational pathway “from bench to clinic.”

  8. The effect of a nano-filled resin coating on the 3-year clinical performance of a conventional high-viscosity glass-ionomer cement.

    Diem, Vu Thi Kieu; Tyas, Martin J; Ngo, Hien C; Phuong, Lam Hoai; Khanh, Ngo Dong

    2014-04-01

    The main aim of the study was to compare the clinical performance of the conventional high-powder/liquid ratio glass-ionomer cement (GIC) Fuji IX GP Extra (F IX), Fuji IX GP Extra with a low-viscosity nano-filled resin coating, G-Coat Plus (F IX+GCP), and a resin composite, Solare (S), as a comparison material. Moderate-depth occlusal cavities in the first permanent molars of 91 11-12-year-old children (1-4 restorations per child) were restored with either F IX (87 restorations), F IX+GCP (84 restorations) or S (83 restorations). Direct clinical assessment, photographic assessment and assessment of stone casts of the restorations were carried out at 6 months, 1 year, 2 years and 3 years. The colour match with the tooth of the GIC restorations improved over the 3 years of the study. Marginal staining and marginal adaptation were minimal for all restorations; three restorations exhibited secondary caries at 3 years. From the assessment of the casts, at 2 years, there was significantly less wear of the F IX GP Extra+GCP restorations than the F IX GP Extra restorations (P G-Coat Plus showed acceptable clinical performance in occlusal cavities in children, the application of G-Coat Plus gave some protection against wear. The application of G-Coat Plus to Fuji IX GP Extra glass-ionomer cement may be beneficial in reducing wear in occlusal cavities.

  9. CEMENT SLURRIES FOR GEOTHERMAL WELLS CEMENTING

    Nediljka Gaurina-Međimurec

    1994-12-01

    Full Text Available During a well cementing special place belongs to the cement slurry design. To ensure the best quality of cementing, a thorough understanding of well parameters is essential, as well as behaviour of cement slurry (especially at high temperatures and application of proven cementing techniques. Many cement jobs fail because of bad job planning. Well cementing without regarding what should be accomplished, can lead to well problems (channels in the cement, unwanted water, gas or fluid production, pipe corrosion and expensive well repairs. Cementing temperature conditions are important because bot-tomhole circulating temperatures affect slurry thickening time, arheology, set time and compressive strength development. Knowing the actual temperature which cement encounters during placement allows the selection of proper cementing materials for a specific application. Slurry design is affected by well depth, bottom hole circulating temperature and static temperature, type or drilling fluid, slurry density, pumping time, quality of mix water, fluid loss control, flow regime, settling and free water, quality of cement, dry or liquid additives, strength development, and quality of the lab cement testing and equipment. Most Portland cements and Class J cement have shown suitable performances in geot-hermal wells. Cement system designs for geothermal wells differ from those for conventional high temperature oil and gas wells in the exclusive use of silica flour instead of silica sand, and the avoidance of fly ash as an extender. In this paper, Portland cement behaviour at high temperatures is described. Cement slurry and set cement properties are also described. Published in literature, the composition of cement slurries which were tested in geothermal conditions and which obtained required compressive strength and water permeability are listed. As a case of our practice geothermal wells Velika Ciglena-1 and Velika Ciglena-la are described.

  10. Stem cell therapy clinical research: A regulatory conundrum for academia.

    Nagpal, Anjali; Juttner, Chris; Hamilton-Bruce, Monica Anne; Rolan, Paul; Koblar, Simon A

    2017-12-01

    The encouraging pace of discovery and development in the field of regenerative medicine holds tremendous potential for bringing therapies to the clinic that may offer meaningful benefit to patients, particularly in diseases with no or suboptimal therapeutic options. Academic researchers will continue to play a critical role in developing concepts and therapies, thus determining whether regenerative medicine will be able to live up to this potential that clearly excites clinicians, researchers and patients alike. This review summarises recent developments in regulatory frameworks across different countries that aim to ensure adequate oversight of the development of regenerative medicine products, which are unique in structural and functional complexity when compared to traditional chemical drugs and fully characterised biological drugs. It discusses the implications of these developments for researchers aiming to make the challenging transition from laboratory to clinical development of these therapies and considers possible pragmatic solutions that could accelerate this process that is essential to maintain research credibility and ensure patient safety. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. A Clinical Indications Prediction Scale Based on TWIST1 for Human Mesenchymal Stem Cells

    Siddaraju V. Boregowda

    2016-02-01

    Full Text Available In addition to their stem/progenitor properties, mesenchymal stem cells (MSCs also exhibit potent effector (angiogenic, antiinflammatory, immuno-modulatory functions that are largely paracrine in nature. It is widely believed that effector functions underlie most of the therapeutic potential of MSCs and are independent of their stem/progenitor properties. Here we demonstrate that stem/progenitor and effector functions are coordinately regulated at the cellular level by the transcription factor Twist1 and specified within populations according to a hierarchical model. We further show that manipulation of Twist1 levels by genetic approaches or by exposure to widely used culture supplements including fibroblast growth factor 2 (Ffg2 and interferon gamma (IFN-gamma alters MSC efficacy in cell-based and in vivo assays in a predictable manner. Thus, by mechanistically linking stem/progenitor and effector functions our studies provide a unifying framework in the form of an MSC hierarchy that models the functional complexity of populations. Using this framework, we developed a CLinical Indications Prediction (CLIP scale that predicts how donor-to-donor heterogeneity and culture conditions impact the therapeutic efficacy of MSC populations for different disease indications.

  12. Deriving multipotent stem cells from mouse spermatogonial stem cells: a new tool for developmental and clinical research

    de Rooij, Dirk G.; Mizrak, S. Canan

    2008-01-01

    In recent years, embryonic stem (ES) cell-like cells have been obtained from cultured mouse spermatogonial stem cells (SSCs). These advances have shown that SSCs can transition from being the stem cell-producing cells of spermatogenesis to being multipotent cells that can differentiate into

  13. Controlled, prospective, randomized, clinical split-mouth evaluation of partial ceramic crowns luted with a new, universal adhesive system/resin cement: results after 18 months.

    Vogl, Vanessa; Hiller, Karl-Anton; Buchalla, Wolfgang; Federlin, Marianne; Schmalz, Gottfried

    2016-12-01

    A new universal adhesive with corresponding luting composite was recently marketed which can be used both, in a self-etch or in an etch-and-rinse mode. In this study, the clinical performance of partial ceramic crowns (PCCs) inserted with this adhesive and the corresponding luting material used in a self-etch or selective etch approach was compared with a self-adhesive universal luting material. Three PCCs were placed in a split-mouth design in 50 patients. Two PCCs were luted with a combination of a universal adhesive/resin cement (Scotchbond Universal/RelyX Ultimate, 3M ESPE) with (SB+E)/without (SB-E) selective enamel etching. Another PCC was luted with a self-adhesive resin cement (RelyX Unicem 2, 3M ESPE). Forty-eight patients were evaluated clinically according to FDI criteria at baseline and 6, 12 and 18 months. For statistical analyses, the chi-square test (α = 0.05) and Kaplan-Meier analysis were applied. Clinically, no statistically significant differences between groups were detected over time. Within groups, clinically significant increase for criterion "marginal staining" was detected for SB-E over 18 months. Kaplan-Meier analysis revealed significantly higher retention rates for SB+E (97.8 %) and SB-E (95.6 %) in comparison to RXU2 (75.6 %). The 18-month clinical performance of a new universal adhesive/composite combination showed no differences with respect to bonding strategy and may be recommended for luting PCCs. Longer-term evaluation is needed to confirm superiority of SB+E over SB-E. At 18 months, the new multi-mode adhesive, Scotchbond Universal, showed clinically reliable results when used for luting PCCs.

  14. Lunar cement

    Agosto, William N.

    1992-01-01

    With the exception of water, the major oxide constituents of terrestrial cements are present at all nine lunar sites from which samples have been returned. However, with the exception of relatively rare cristobalite, the lunar oxides are not present as individual phases but are combined in silicates and in mixed oxides. Lime (CaO) is most abundant on the Moon in the plagioclase (CaAl2Si2O8) of highland anorthosites. It may be possible to enrich the lime content of anorthite to levels like those of Portland cement by pyrolyzing it with lunar-derived phosphate. The phosphate consumed in such a reaction can be regenerated by reacting the phosphorus product with lunar augite pyroxenes at elevated temperatures. Other possible sources of lunar phosphate and other oxides are discussed.

  15. Pre-Clinical Cell-Based Therapy for Limbal Stem Cell Deficiency.

    Sehic, Amer; Utheim, Øygunn Aass; Ommundsen, Kristoffer; Utheim, Tor Paaske

    2015-08-28

    The cornea is essential for normal vision by maintaining transparency for light transmission. Limbal stem cells, which reside in the corneal periphery, contribute to the homeostasis of the corneal epithelium. Any damage or disease affecting the function of these cells may result in limbal stem cell deficiency (LSCD). The condition may result in both severe pain and blindness. Transplantation of ex vivo cultured cells onto the cornea is most often an effective therapeutic strategy for LSCD. The use of ex vivo cultured limbal epithelial cells (LEC), oral mucosal epithelial cells, and conjunctival epithelial cells to treat LSCD has been explored in humans. The present review focuses on the current state of knowledge of the many other cell-based therapies of LSCD that have so far exclusively been explored in animal models as there is currently no consensus on the best cell type for treating LSCD. Major findings of all these studies with special emphasis on substrates for culture and transplantation are systematically presented and discussed. Among the many potential cell types that still have not been used clinically, we conclude that two easily accessible autologous sources, epidermal stem cells and hair follicle-derived stem cells, are particularly strong candidates for future clinical trials.

  16. Ethics of international clinical research collaboration - the experience of AlloStem.

    Chaplin, C

    2006-02-01

    This paper examines the ethics of international clinical collaboration in stem cell research by focusing on the AlloStem project. AlloStem is an international research programme, financed by the European Union under the Sixth Framework Programme, with the aim of advancing the use of stem cells in treating leukaemia and other haematological diseases. Several areas of ethical importance are explored. Research justification and the need to consider both deontological and teleological aspects are examined. Ethical sensitivity in research and the requirement to respond to areas of ethical concern identified by the European Commission, such as the involvement of human beings, the use of human tissue, and the use of animals are also explored. Ethical issues around project structure and management, such as ethical standardization in international research, and achieving set targets are discussed. The ethical importance of dissemination of findings and teaching in clinical research is also considered. Finally, the distribution of benefits is addressed and the importance of distributive justice is emphasized.

  17. Recent technological updates and clinical applications of induced pluripotent stem cells.

    Diecke, Sebastian; Jung, Seung Min; Lee, Jaecheol; Ju, Ji Hyeon

    2014-09-01

    Induced pluripotent stem cells (iPSCs) were first described in 2006 and have since emerged as a promising cell source for clinical applications. The rapid progression in iPSC technology is still ongoing and directed toward increasing the efficacy of iPSC production and reducing the immunogenic and tumorigenic potential of these cells. Enormous efforts have been made to apply iPSC-based technology in the clinic, for drug screening approaches and cell replacement therapy. Moreover, disease modeling using patient-specific iPSCs continues to expand our knowledge regarding the pathophysiology and prospective treatment of rare disorders. Furthermore, autologous stem cell therapy with patient-specific iPSCs shows great propensity for the minimization of immune reactions and the provision of a limitless supply of cells for transplantation. In this review, we discuss the recent updates in iPSC technology and the use of iPSCs in disease modeling and regenerative medicine.

  18. Progressing a human embryonic stem-cell-based regenerative medicine therapy towards the clinic.

    Whiting, Paul; Kerby, Julie; Coffey, Peter; da Cruz, Lyndon; McKernan, Ruth

    2015-10-19

    Since the first publication of the derivation of human embryonic stem cells in 1998, there has been hope and expectation that this technology will lead to a wave of regenerative medicine therapies with the potential to revolutionize our approach to managing certain diseases. Despite significant resources in this direction, the path to the clinic for an embryonic stem-cell-based regenerative medicine therapy has not proven straightforward, though in the past few years progress has been made. Here, with a focus upon retinal disease, we discuss the current status of the development of such therapies. We also highlight some of our own experiences of progressing a retinal pigment epithelium cell replacement therapy towards the clinic. © 2015 The Author(s).

  19. Enhancement of human adipose-derived stem cell expansion and stability for clinical use

    Krähenbühl, S. M.

    2016-01-01

    Co-culture techniques associating both dermal fibroblasts and epidermal keratinocytes have shown to have better clinical outcome than keratinocyte culture alone for the treatment of severe burns. Since fat grafting has been shown to improve scar remodelling, new techniques such as cell-therapy-assisted surgical reconstruction with isolated and expanded autologous adipose-derived stem cells (ASCs) would be of benefit to increase graft acceptation. Therefore, integrating ASCs into s...

  20. Equally good fixation of cemented and uncemented cups in total trapeziometacarpal joint prostheses. A randomized clinical RSA study with 2-year follow-up.

    Hansen, Torben Baek; Stilling, Maiken

    2013-02-01

    Cup failure is a recognized problem in total trapeziometacarpal (TM) joint prostheses; it may be related to poor fixation, which can be revealed by radiostereometric analysis (RSA). We compared the early implant migration of cemented trapezium cups to that of uncemented screw cups. In a prospective, parallel-group, randomized patient-blinded clinical trial, we included 32 hands in 28 patients (5 males) with a mean age of 58 (40-77) years and with Eaton stage-2 or -3 osteoarthritis of the trapeziometacarpal joint. Patients were randomized to surgery with a cemented DLC all-polyethylene cup (C) (n = 16) or an uncemented hydroxyapatite-coated chrome-cobalt Elektra screw cup (UC) (n = 16). Uncemented cups were inserted without threading of the bone. Stereoradiographs for evaluation of cup migration (primary effect size) and DASH and pain scores were obtained during 2 years of follow-up. The 2-year total translation (TT) was similar (p = 0.2): 0.24 mm (SD 0.10) for the C (n = 11) and 0.19 mm (SD 0.16) for the UC (n = 11). Variances were similar (p = 0.4). Judged by RSA, 2 UC cups and 1 C cup became loose (TT > 1 mm). Both UC cups were found to be loose at revision. Grip strength, pain, and DASH scores were similar between groups at all measurement points. Early implant fixation and clinical outcome were equally good with both cup designs. This is the first clinical RSA study on trapezium cups, and the method appears to be clinically useful for detection of loose implants.

  1. Characterisation of the surface topography, tomography and chemistry of fretting corrosion product found on retrieved polished femoral stems.

    Bryant, M; Ward, M; Farrar, R; Freeman, R; Brummitt, K; Nolan, J; Neville, A

    2014-04-01

    This study presents the characterisation of the surface topography, tomography and chemistry of fretting corrosion product found on retrieved polished femoral stems. Scanning Electron Microscopy (SEM), X-ray Photoelectron Spectroscopy (XPS), Transmission Electron Microscopy (TEM) and Fourier Transform Infrared Spectroscopy (FI-IR) were utilised in order to assess the surface morphology of retrieved Metal-on-Metal Total Hip Replacements and surface chemistry of the films found on the surface. Gross slip, plastic deformation and directionality of the surface were extensively seen on the proximal surfaces of the retrievals. A more corrosive phenomenon was observed in the distal regions of the stem, demonstrating a seemingly intergranular attack. Tribochemical reactions were seen to occur within the stem-cement interfaces with tribofilms being observed on the femoral stem and counterpart PMMA bone cement. XPS, TEM-EDX and FT-IR analyses demonstrated that the films present in the stem surfaces were a complex mixture of chromium oxide and amorphous organic material. A comparison between current experimental and clinical literature has been conducted and findings from this study demonstrate that the formation and chemistry of films are drastically influenced by the type of wear or degradation mechanism. Films formed in the stem-cement interface are thought to further influence the biological environment outside the stem-cement interface due to the formation of Cr and O rich films within the interface whilst Co is free to migrate away. © 2013 Elsevier Ltd. All rights reserved.

  2. Pyruvate dehydrogenase expression is negatively associated with cell stemness and worse clinical outcome in prostate cancers

    Zhong, Yali; Li, Xiaoli; Ji, Yasai; Li, Xiaoran; Li, Yaqing; Yu, Dandan; Yuan, Yuan; Liu, Jian; Li, Huixiang; Zhang, Mingzhi; Ji, Zhenyu; Fan, Dandan; Wen, Jianguo; Goscinski, Mariusz Adam; Yuan, Long; Hao, Bin; Nesland, Jahn M; Suo, Zhenhe

    2017-01-01

    Cells generate adenosine-5′-triphosphate (ATP), the major currency for energy-consuming reactions, through mitochondrial oxidative phosphorylation (OXPHOS) and glycolysis. One of the remarkable features of cancer cells is aerobic glycolysis, also known as the “Warburg Effect”, in which cancer cells rely preferentially on glycolysis instead of mitochondrial OXPHOS as the main energy source even in the presence of high oxygen tension. One of the main players in controlling OXPHOS is the mitochondrial gatekeeperpyruvate dehydrogenase complex (PDHc) and its major subunit is E1α (PDHA1). To further analyze the function of PDHA1 in cancer cells, it was knock out (KO) in the human prostate cancer cell line LnCap and a stable KO cell line was established. We demonstrated that PDHA1 gene KO significantly decreased mitochondrial OXPHOS and promoted anaerobic glycolysis, accompanied with higher stemness phenotype including resistance to chemotherapy, enhanced migration ability and increased expression of cancer stem cell markers. We also examined PDHA1 protein expression in prostate cancer tissues by immunohistochemistry and observed that reduced PDHA1 protein expression in clinical prostate carcinomas was significantly correlated with poor prognosis. Collectively, our results show that negative PDHA1 gene expressionis associated with significantly higher cell stemness in prostate cancer cells and reduced protein expression of this gene is associated with shorter clinical outcome in prostate cancers. PMID:28076853

  3. Stem Cell Basics

    ... Tips Info Center Research Topics Federal Policy Glossary Stem Cell Information General Information Clinical Trials Funding Information Current ... Basics » Stem Cell Basics I. Back to top Stem Cell Basics I. Introduction: What are stem cells, and ...

  4. Nonmyeloablative and reduced-intensity conditioning for allogeneic hematopoietic stem cell transplantation: a clinical review.

    Pollack, Seth M; O'Connor, Thomas P; Hashash, Jana; Tabbara, Imad A

    2009-12-01

    Allogeneic hematopoietic stem cell transplantation provides many patients, with hematological and malignant diseases, hope of remission and in some cases cure. Because the toxicities of this approach are severe, its use has been limited to younger healthier patients. Nonmyeloablative and reduced intensity conditioning regimens depend more on donor cellular immune effects and less on the cytotoxic effects of the conditioning regimen to eradicate the underlying disease. This approach is based on the induction of host tolerance to donor cells followed by the administration of scheduled donor T-lymphocytes infusions. Accumulated clinical data have been encouraging, and prospective studies are underway to compare this approach to conventional myeloablative allogeneic stem cell transplantation with regard to outcome, durability of responses, effects on the immune system, and the consequences of late complications such as chronic graft-versus-host disease.

  5. Skin Stem Cells: At the Frontier Between the Laboratory and Clinical Practice. Part 1: Epidermal Stem Cells.

    Pastushenko, I; Prieto-Torres, L; Gilaberte, Y; Blanpain, C

    2015-11-01

    Stem cells are characterized by their ability to self-renew and differentiate into the different cell lineages of their tissue of origin. The discovery of stem cells in adult tissues, together with the description of specific markers for their isolation, has opened up new lines of investigation, expanding the horizons of biomedical research and raising new hope in the treatment of many diseases. In this article, we review in detail the main characteristics of the stem cells that produce the specialized cells of the skin (epidermal, mesenchymal, and melanocyte stem cells) and their potential implications and applications in diseases affecting the skin. Part I deals with the principal characteristics and potential applications of epidermal stem cells in dermatology. Copyright © 2015 Elsevier España, S.L.U. and AEDV. All rights reserved.

  6. Cement pulmonary embolism after vertebroplasty.

    Sifuentes Giraldo, Walter Alberto; Lamúa Riazuelo, José Ramón; Gallego Rivera, José Ignacio; Vázquez Díaz, Mónica

    2013-01-01

    In recent years, the use of vertebral cementing techniques for vertebroplasty and kyphoplasty has spread for the treatment of pain associated with osteoporotic vertebral compression fractures. This is also associated with the increased incidence of complications related with these procedures, the most frequent being originated by leakage of cementation material. Cement can escape into the vertebral venous system and reach the pulmonary circulation through the azygous system and cava vein, producing a cement embolism. This is a frequent complication, occurring in up to 26% of patients undergoing vertebroplasty but, since most patients have no clinical or hemodynamical repercussion, this event usually goes unnoticed. However, some serious, and even fatal cases, have been reported. We report the case of a 74-year-old male patient who underwent vertebroplasty for persistent pain associated with osteoporotic L3 vertebral fracture and who developed a cement leak into the cava vein and right pulmonary artery during the procedure. Although he developed a pulmonary cement embolism, the patient remained asymptomatic and did not present complications during follow-up. Copyright © 2012 Elsevier España, S.L. All rights reserved.

  7. Low pH Cements

    Savage, David; Benbow, Steven

    2007-05-01

    The development of low-pH cements for use in geological repositories for radioactive waste stems from concerns over the potential for deleterious effects upon the host rock and other EBS materials (notably bentonite) under the hyperalkaline conditions (pH > 12) of cement pore fluids. Low pH cement (also known as low heat cement) was developed by the cement industry for use where large masses of cement (e.g. dams) could cause problems regarding heat generated during curing. In low pH cements, the amount of cement is reduced by substitution of materials such as fly ash, blast furnace slag, silica fume, and/or non-pozzolanic silica flour. SKB and Posiva have ruled out the use of blast furnace slag and fly-ash and are focusing on silica fume as a blending agent. Currently, no preferred composition has been identified by these agencies. SKB and Posiva have defined a pH limit ≤ 11 for cement grout leachates. To attain this pH, blending agents must comprise at least 50 wt % of dry materials. Because low pH cement has little, or no free portlandite, the cement consists predominantly of calcium silicate hydrate (CSH) gel with a Ca/Si ratio ≤ 0.8. Although there are potential implications for the performance of the spent fuel and cladding due to the presence of hyperalkaline fluids from cement, the principal focus for safety assessment lies with the behaviour of bentonite. There are a number of potential constraints on the interaction of hyperalkaline cement pore fluids with bentonite, including mass balance, thermodynamic issues, mass transport, and kinetics, but none of these is likely to be limiting if conventional OPC cements are employed in repository construction. Nevertheless: Low-pH cements may supply approximately 50 % less hydroxyl ions than conventional OPC for a given volume of cement, but mass balance constraints are complicated by the uncertainty concerning the type of secondary minerals produced during cement-bentonite interaction. The change of aqueous

  8. Low pH Cements

    Savage, David; Benbow, Steven [Quintessa Ltd., Henley-on-Thames (United Kingdom)

    2007-05-15

    The development of low-pH cements for use in geological repositories for radioactive waste stems from concerns over the potential for deleterious effects upon the host rock and other EBS materials (notably bentonite) under the hyperalkaline conditions (pH > 12) of cement pore fluids. Low pH cement (also known as low heat cement) was developed by the cement industry for use where large masses of cement (e.g. dams) could cause problems regarding heat generated during curing. In low pH cements, the amount of cement is reduced by substitution of materials such as fly ash, blast furnace slag, silica fume, and/or non-pozzolanic silica flour. SKB and Posiva have ruled out the use of blast furnace slag and fly-ash and are focusing on silica fume as a blending agent. Currently, no preferred composition has been identified by these agencies. SKB and Posiva have defined a pH limit {<=} 11 for cement grout leachates. To attain this pH, blending agents must comprise at least 50 wt % of dry materials. Because low pH cement has little, or no free portlandite, the cement consists predominantly of calcium silicate hydrate (CSH) gel with a Ca/Si ratio {<=} 0.8. Although there are potential implications for the performance of the spent fuel and cladding due to the presence of hyperalkaline fluids from cement, the principal focus for safety assessment lies with the behaviour of bentonite. There are a number of potential constraints on the interaction of hyperalkaline cement pore fluids with bentonite, including mass balance, thermodynamic issues, mass transport, and kinetics, but none of these is likely to be limiting if conventional OPC cements are employed in repository construction. Nevertheless: Low-pH cements may supply approximately 50 % less hydroxyl ions than conventional OPC for a given volume of cement, but mass balance constraints are complicated by the uncertainty concerning the type of secondary minerals produced during cement-bentonite interaction. The change of aqueous

  9. Catching moving targets: cancer stem cell hierarchies, therapy-resistance & considerations for clinical intervention.

    Gasch, Claudia

    2017-01-01

    It is widely believed that targeting the tumour-initiating cancer stem cell (CSC) component of malignancy has great therapeutic potential, particularly in therapy-resistant disease. However, despite concerted efforts, CSC-targeting strategies have not been efficiently translated to the clinic. This is partly due to our incomplete understanding of the mechanisms underlying CSC therapy-resistance. In particular, the relationship between therapy-resistance and the organisation of CSCs as Stem-Progenitor-Differentiated cell hierarchies has not been widely studied. In this review we argue that modern clinical strategies should appreciate that the CSC hierarchy is a dynamic target that contains sensitive and resistant components and expresses a collection of therapy-resisting mechanisms. We propose that the CSC hierarchy at primary presentation changes in response to clinical intervention, resulting in a recurrent malignancy that should be targeted differently. As such, addressing the hierarchical organisation of CSCs into our bench-side theory should expedite translation of CSC-targeting to bed-side practice. In conclusion, we discuss strategies through which we can catch these moving clinical targets to specifically compromise therapy-resistant disease.

  10. [Early aseptic loosening of the CF 30 femoral stem].

    Kovanda, M; Havlícek, V; Hudec, J

    2007-02-01

    The CF 30 stem in combination with a cementless acetabulum was used at the First Department of Orthopedic Surgery in Brno in the years 1994 to 1995. From the second year following implantation, aseptic stem loosening was recorded. In order to find explanation of this early loosening, the authors, in cooperation with the Institute of Solid Mechanics, Mechatronics and Biomechanics, carried out the stress-strain analysis in a model system. Eighty patients (31 men and 49 women) received a cemented CF30 femoral component in 1994. Of them, 16 patients underwent revision arthroplasty, three died of causes unrelated to the surgery, and four were lost to follow-up. The final clinical and radiographic check-up was carried out in 2001. The results of a comprehensive examination were available in 57 patients with a CF30 stem. The patients were evaluated on the basis of the Harris hip score and anteroposterior radiographs of the hip. X-ray films obtained immediately after surgery and those taken at regular intervals during follow-up were compared. The following characteristics were noted: translucent lines in individual zones along the stem at the cement-bone interface; osteolysis, i. e., non-linear translucent areas, at least 5 mm long, at the cement-bone interface; and subsidence of the femoral component, i. e., migration of the stem distal to the tip of the greater trochanter. The CF 30 stem survival curve showed that aseptic stem loosening occurred from post-implantation year 2, and increased during the following years. At 6 years and 6 months, a total of 16 patients underwent revision surgery, involving reimplantation in 14 and implant removal in 2 patients. Potential causes of aseptic loosening: Polyethylene wear.However, no acetabular loosening was found in this group, although acetabular components are reported to become loose more often than femoral components. By comparison of the stem survival curves for Poldi and CF 30 stems it appeared that, at 6 years and 6 months

  11. Clinical efficacy of gene-modified stem cells in adenosine deaminase-deficient immunodeficiency.

    Shaw, Kit L; Garabedian, Elizabeth; Mishra, Suparna; Barman, Provaboti; Davila, Alejandra; Carbonaro, Denise; Shupien, Sally; Silvin, Christopher; Geiger, Sabine; Nowicki, Barbara; Smogorzewska, E Monika; Brown, Berkley; Wang, Xiaoyan; de Oliveira, Satiro; Choi, Yeong; Ikeda, Alan; Terrazas, Dayna; Fu, Pei-Yu; Yu, Allen; Fernandez, Beatriz Campo; Cooper, Aaron R; Engel, Barbara; Podsakoff, Greg; Balamurugan, Arumugam; Anderson, Stacie; Muul, Linda; Jagadeesh, G Jayashree; Kapoor, Neena; Tse, John; Moore, Theodore B; Purdy, Ken; Rishi, Radha; Mohan, Kathey; Skoda-Smith, Suzanne; Buchbinder, David; Abraham, Roshini S; Scharenberg, Andrew; Yang, Otto O; Cornetta, Kenneth; Gjertson, David; Hershfield, Michael; Sokolic, Rob; Candotti, Fabio; Kohn, Donald B

    2017-05-01

    Autologous hematopoietic stem cell transplantation (HSCT) of gene-modified cells is an alternative to enzyme replacement therapy (ERT) and allogeneic HSCT that has shown clinical benefit for adenosine deaminase-deficient (ADA-deficient) SCID when combined with reduced intensity conditioning (RIC) and ERT cessation. Clinical safety and therapeutic efficacy were evaluated in a phase II study. Ten subjects with confirmed ADA-deficient SCID and no available matched sibling or family donor were enrolled between 2009 and 2012 and received transplantation with autologous hematopoietic CD34+ cells that were modified with the human ADA cDNA (MND-ADA) γ-retroviral vector after conditioning with busulfan (90 mg/m2) and ERT cessation. Subjects were followed from 33 to 84 months at the time of data analysis. Safety of the procedure was assessed by recording the number of adverse events. Efficacy was assessed by measuring engraftment of gene-modified hematopoietic stem/progenitor cells, ADA gene expression, and immune reconstitution. With the exception of the oldest subject (15 years old at enrollment), all subjects remained off ERT with normalized peripheral blood mononuclear cell (PBMC) ADA activity, improved lymphocyte numbers, and normal proliferative responses to mitogens. Three of nine subjects were able to discontinue intravenous immunoglobulin replacement therapy. The MND-ADA vector was persistently detected in PBMCs (vector copy number [VCN] = 0.1-2.6) and granulocytes (VCN = 0.01-0.3) through the most recent visits at the time of this writing. No patient has developed a leukoproliferative disorder or other vector-related clinical complication since transplant. These results demonstrate clinical therapeutic efficacy from gene therapy for ADA-deficient SCID, with an excellent clinical safety profile. ClinicalTrials.gov NCT00794508. Food and Drug Administration Office of Orphan Product Development award, RO1 FD003005; NHLBI awards, PO1 HL73104 and Z01 HG000122; UCLA

  12. Application of MultiStem® allogeneic cells for immunomodulatory therapy: clinical progress and pre-clinical challenges in prophylaxis for graft vs host disease

    Bart eVaes

    2012-11-01

    Full Text Available The last decade has seen much progress in adjunctive cell therapy for immune disorders. Both corporate and institutional Phase III studies have been run using mesenchymal stromal cells (MSC for treatment of Graft vs Host Disease (GvHD, and product approval has been achieved for treatment of pediatric GvHD in Canada and New Zealand (Prochymal®; Osiris Therapeutics. This effectiveness has prompted the prophylactic use of adherent stem cells at the time of allogeneic hematopoietic stem cell transplantation (HSCT to prevent occurrence of GvHD and possibly provide stromal support for hematopoietic recovery. The MultiStem® product is an adult adherent stem cell product derived from bone marrow which has significant clinical exposure. MultiStem cells are currently in phase II clinical studies for treatment of ischemic stroke and ulcerative colitis, with Phase I studies completed in acute myocardial infarction and for GvHD prophylaxis in allogeneic HSCT, demonstrating that MultiStem administration was well tolerated while the incidence and severity of GvHD was reduced. In advancing this clinical approach, it is important to recognize that alternate models exist based on clinical manufacturing strategies. Corporate sponsors exploit the universal donor properties of adherent stem cells and manufacture at large scale, with many products obtained from one or limited donors and used across many patients. In Europe, institutional sponsors often produce allogeneic product in a patient designated context. For this approach, disposable bioreactors producing <10 products per donor in a closed system manner are very well suited. In this review, the use of adherent stem cells for GvHD prophylaxis is summarized and the suitability of disposable bioreactors for MultiStem production is presented, with an emphasis on quality control parameters, which are critical with a multiple donor approach for manufacturing.

  13. Stem cell therapy for type 1 diabetes mellitus: a review of recent clinical trials

    Couri Carlos

    2009-10-01

    Full Text Available Abstract Stem cell therapy is one of the most promising treatments for the near future. It is expected that this kind of therapy can ameliorate or even reverse some diseases. With regard to type 1 diabetes, studies analyzing the therapeutic effects of stem cells in humans began in 2003 in the Hospital das Clínicas of the Faculty of Medicine of Ribeirão Preto - SP USP, Brazil, and since then other centers in different countries started to randomize patients in their clinical trials. Herein we summarize recent data about beta cell regeneration, different ways of immune intervention and what is being employed in type 1 diabetic patients with regard to stem cell repertoire to promote regeneration and/or preservation of beta cell mass. The Diabetes Control and Complications Trial (DCCT was a 7-year longitudinal study that demonstrated the importance of the intensive insulin therapy when compared to conventional treatment in the development of chronic complications in patients with type 1 diabetes mellitus (T1DM. This study also demonstrated another important issue: there is a reverse relationship between C-peptide levels (endogenous indicator of insulin secretion chronic complications - that is, the higher the C-peptide levels, the lower the incidence of nephropathy, retinopathy and hypoglycemia. From such data, beta cell preservation has become an additional target in the management of T1DM 1.

  14. A Twofold Comparison between Dual Cure Resin Modified Cement and Glass Ionomer Cement for Orthodontic Band Cementation.

    Attar, Hanaa El; Elhiny, Omnia; Salem, Ghada; Abdelrahman, Ahmed; Attia, Mazen

    2016-12-15

    To test the solubility of dual cure resin modified resin cement in a food simulating solution and the shear bond strength compared to conventional Glass ionomer cement. The materials tested were self-adhesive dual cure resin modified cement and Glass Ionomer (GIC). Twenty Teflon moulds were divided into two groups of tens. The first group was injected and packed with the modified resin cement, the second group was packed with GIC. To test the solubility, each mould was weighed before and after being placed in an analytical reagent for 30 days. The solubility was measured as the difference between the initial and final drying mass. To measure the Shear bond strength, 20 freshly extracted wisdom teeth were equally divided into two groups and embedded in self-cure acrylic resin. Four mm sections of stainless steel bands were cemented to the exposed buccal surfaces of teeth under a constant load of 500 g. Shear bond strength was measured using a computer controlled materials testing machine and the load required to deband the samples was recorded in Newtons. GIC showed significantly higher mean weight loss and an insignificant lower Shear bond strength, compared to dual cure resin Cement. It was found that dual cure resin modified cement was less soluble than glass ionomer cement and of comparable bond strength rendering it more useful clinically for orthodontic band cementation.

  15. Biomedical and Clinical Promises of Human Pluripotent Stem Cells for Neurological Disorders

    Nopporn Jongkamonwiwat

    2013-01-01

    Full Text Available Neurological disorders are characterized by the chronic and progressive loss of neuronal structures and functions. There is a variability of the onsets and causes of clinical manifestations. Cell therapy has brought a new concept to overcome brain diseases, but the advancement of this therapy is limited by the demands of specialized neurons. Human pluripotent stem cells (hPSCs have been promised as a renewable resource for generating human neurons for both laboratory and clinical purposes. By the modulations of appropriate signalling pathways, desired neuron subtypes can be obtained, and induced pluripotent stem cells (iPSCs provide genetically matched neurons for treating patients. These hPSC-derived neurons can also be used for disease modeling and drug screening. Since the most urgent problem today in transplantation is the lack of suitable donor organs and tissues, the derivation of neural progenitor cells from hPSCs has opened a new avenue for regenerative medicine. In this review, we summarize the recent reports that show how to generate neural derivatives from hPSCs, and discuss the current evidence of using these cells in animal studies. We also highlight the possibilities and concerns of translating these hPSC-derived neurons for biomedical and clinical uses in order to fight against neurological disorders.

  16. High purity of human oligodendrocyte progenitor cells obtained from neural stem cells: suitable for clinical application.

    Wang, Caiying; Luan, Zuo; Yang, Yinxiang; Wang, Zhaoyan; Wang, Qian; Lu, Yabin; Du, Qingan

    2015-01-30

    Recent studies have suggested that the transplantation of oligodendrocyte progenitor cells (OPCs) may be a promising potential therapeutic strategy for a broad range of diseases affecting myelin, such as multiple sclerosis, periventricular leukomalacia, and spinal cord injury. Clinical interest arose from the potential of human stem cells to be directed to OPCs for the clinical application of treating these diseases since large quantities of high quality OPCs are needed. However, to date, there have been precious few studies about OPC induction from human neural stem cells (NSCs). Here we successfully directed human fetal NSCs into highly pure OPCs using a cocktail of basic fibroblast growth factor, platelet-derived growth factor, and neurotrophic factor-3. These cells had typical morphology of OPCs, and 80-90% of them expressed specific OPC markers such as A2B5, O4, Sox10 and PDGF-αR. When exposed to differentiation medium, 90% of the cells differentiated into oligodendrocytes. The OPCs could be amplified in our culture medium and passaged at least 10 times. Compared to a recent published method, this protocol had much higher stability and repeatability, and OPCs could be obtained from NSCs from passage 5 to 38. It also obtained more highly pure OPCs (80-90%) via simpler and more convenient manipulation. This study provided an easy and efficient method to obtain large quantities of high-quality human OPCs to meet clinical demand. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Stem cell transplantation for amyotrophic lateral sclerosis: therapeutic potential and perspectives on clinical translation.

    Faravelli, Irene; Riboldi, Giulietta; Nizzardo, Monica; Simone, Chiara; Zanetta, Chiara; Bresolin, Nereo; Comi, Giacomo P; Corti, Stefania

    2014-09-01

    Amyotrophic lateral sclerosis (ALS) is a fatal neurological disease characterized by degeneration of upper and lower motor neurons. There are currently no clinically impactful treatments for this disorder. Death occurs 3-5 years after diagnosis, usually due to respiratory failure. ALS pathogenesis seems to involve several pathological mechanisms (i.e., oxidative stress, inflammation, and loss of the glial neurotrophic support, glutamate toxicity) with different contributions from environmental and genetic factors. This multifaceted combination highlights the concept that an effective therapeutic approach should counteract simultaneously different aspects: stem cell therapies are able to maintain or rescue motor neuron function and modulate toxicity in the central nervous system (CNS) at the same time, eventually representing the most comprehensive therapeutic approach for ALS. To achieve an effective cell-mediated therapy suitable for clinical applications, several issues must be addressed, including the identification of the most performing cell source, a feasible administration protocol, and the definition of therapeutic mechanisms. The method of cell delivery represents a major issue in developing cell-mediated approaches since the cells, to be effective, need to be spread across the CNS, targeting both lower and upper motor neurons. On the other hand, there is the need to define a strategy that could provide a whole distribution without being too invasive or burdened by side effects. Here, we review the recent advances regarding the therapeutic potential of stem cells for ALS with a focus on the minimally invasive strategies that could facilitate an extensive translation to their clinical application.

  18. Sources of Hematopoietic Stem and Progenitor Cells and Methods to Optimize Yields for Clinical Cell Therapy.

    Panch, Sandhya R; Szymanski, James; Savani, Bipin N; Stroncek, David F

    2017-08-01

    Bone marrow (BM) aspirates, mobilized peripheral blood, and umbilical cord blood (UCB) have developed as graft sources for hematopoietic stem and progenitor cells (HSPCs) for stem cell transplantation and other cellular therapeutics. Individualized techniques are necessary to enhance graft HSPC yields and cell quality from each graft source. BM aspirates yield adequate CD34 + cells but can result in relative delays in engraftment. Granulocyte colony-stimulating factor (G-CSF)-primed BM HSPCs may facilitate faster engraftment while minimizing graft-versus-host disease in certain patient subsets. The levels of circulating HSPCs are enhanced using mobilizing agents, such as G-CSF and/or plerixafor, which act via the stromal cell-derived factor 1/C-X-C chemokine receptor type 4 axis. Alternate niche pathway mediators, including very late antigen-4/vascular cell adhesion molecule-1, heparan sulfate proteoglycans, parathyroid hormone, and coagulation cascade intermediates, may offer promising alternatives for graft enhancement. UCB grafts have been expanded ex vivo with cytokines, notch-ligand, or mesenchymal stromal cells, and most studies demonstrated greater quantities of CD34 + cells ex vivo and improved short-term engraftment. No significant changes were observed in long-term repopulating potential or in patient survival. Early phase clinical trials using nicotinamide and StemReginin1 may offer improved short- and long-term repopulating ability. Breakthroughs in genome editing and stem cell reprogramming technologies may hasten the generation of pooled, third-party HSPC grafts. This review elucidates past, present, and potential future approaches to HSPC graft optimization. Published by Elsevier Inc.

  19. Antimicrobial potential of Dialium guineense (Wild.) stem bark on some clinical isolates in Nigeria.

    Olajubu, Fa; Akpan, I; Ojo, DA; Oluwalana, Sa

    2012-01-01

    The persistent increase in the number of antibiotic-resistant strains of microorganisms has led to the development of more potent but also more expensive antibiotics. In most developing countries of the world these antibiotics are not readily affordable, thus making compliance difficult. This calls for research into alternative sources of antimicrobials. Dialium guineense is a shrub of the family Leguminosae. Its stem bark is used for the treatment of cough, toothache, and bronchitis. Despite the acclaimed efficacy of D guineense, there is no scientific evidence in its support. This work was carried out to assess the antimicrobial activity of D guineense in vitro against some clinical isolates. D guineense stem bark was collected and 50 gm of air-dried and powdered stem bark of the plant was soaked for 72 hours in 1 l of each of the six solvents used in this study. Each mixture was refluxed, agitated at 200 rpm for 1 hour, filtered using Whatman No. 1 filter paper and, finally, freeze dried. The extracts were then tested for antimicrobial activity using the agar diffusion method. The highest percentage yield of 23.2% was obtained with ethanol. Phytochemical screening showed that D guineense contains anthraquinone, alkaloids, flavonoids, tannins, and saponins. The antimicrobial activity of the extracts revealed a broad spectrum of activity, with Salmonella typhi and Staphylococcus aureusa showing the greatest zones of inhibition (18.0 mm). Only Candida albicans among the fungi tested was inhibited by the extract. The greatest zone of inhibition among the fractions was 16.0 mm. D guineense exhibited bactericidal activity at the 7th and 9th hours against Streptococcus pneumoniae and S. aureus 25923 while the 10th hour against S. typhi and C. albicans. The greatest activity was noted against S pneumoniae, where there was reduced viable cell count after 6 hours of exposure. Stem bark extract of D guineense (Wild.) has the potential to be developed into an antimicrobial

  20. Cartilage Repair With Autologous Bone Marrow Mesenchymal Stem Cell Transplantation: Review of Preclinical and Clinical Studies.

    Yamasaki, Shinya; Mera, Hisashi; Itokazu, Maki; Hashimoto, Yusuke; Wakitani, Shigeyuki

    2014-10-01

    Clinical trials of various procedures, including bone marrow stimulation, mosaicplasty, and autologous chondrocyte implantation, have been explored to treat articular cartilage defects. However, all of them have some demerits. We focused on autologous culture-expanded bone marrow mesenchymal stem cells (BMSC), which can proliferate without losing their capacity for differentiation. First, we transplanted BMSC into the defective articular cartilage of rabbit and succeeded in regenerating osteochondral tissue. We then applied this transplantation in humans. Our previous reports showed that treatment with BMSC relieves the clinical symptoms of chondral defects in the knee and elbow joint. We investigated the efficacy of BMSC for osteoarthritic knee treated with high tibial osteotomy, by comparing 12 BMSC-transplanted patients with 12 cell-free patients. At 16-month follow-up, although the difference in clinical improvement between both groups was not significant, the arthroscopic and histological grading score was better in the cell-transplanted group. At the over 10-year follow-up, Hospital for Special Surgery knee scores improved to 76 and 73 in the BMSC-transplanted and cell-free groups, respectively, which were better than preoperative scores. Additionally, neither tumors nor infections were observed in all patients, and in the clinical study, we have never observed hypertrophy of repaired tissue, thereby guaranteeing the clinical safety of this therapy. Although we have never observed calcification above the tidemark in rabbit model and human histologically, the repair cartilage was not completely hyaline cartilage. To elucidate the optimum conditions for cell therapy, other stem cells, culture conditions, growth factors, and gene transfection methods should be explored.

  1. The use of stem cells in aesthetic dermatology and plastic surgery procedures. A compact review of experimental and clinical applications.

    Nowacki, Maciej; Kloskowski, Tomasz; Pietkun, Katarzyna; Zegarski, Maciej; Pokrywczyńska, Marta; Habib, Samy L; Drewa, Tomasz; Zegarska, Barbara

    2017-12-01

    The aim of this paper was to collect currently available data related to the use of stem cells in aesthetic dermatology and plastic surgery based on a systemic review of experimental and clinical applications. We found that the use of stem cells is very promising but the current state of art is still not effective. This situation is connected with not fully known mechanisms of cell interactions, possible risks and side effects. We think that there is a big need to create and conduct different studies which could resolve problems of stem cells use for implementation into aesthetic dermatology and plastic surgery.

  2. Exploiting science? A systematic analysis of complementary and alternative medicine clinic websites' marketing of stem cell therapies.

    Murdoch, Blake; Zarzeczny, Amy; Caulfield, Timothy

    2018-02-28

    To identify the frequency and qualitative characteristics of stem cell-related marketing claims made on websites of clinics featuring common types of complementary and alternative medicine practitioners. The involvement of complementary and alternative medicine practitioners in the marketing of stem cell therapies and stem cell-related interventions is understudied. This research explores the extent to which they are involved and collaborate with medical professionals. This knowledge will help with identifying and evaluating potential policy responses to this growing market. Systematic website analysis. Global. US and English-language bias due to methodology. Representations made on clinic websites in relation to practitioner types, stem cell therapies and their targets, stem cell-related interventions. Statements about stem cell therapies relating to evidence of inefficacy, limited evidence of efficacy, general procedural risks, risks specific to the mode of therapy, regulatory status, experimental or unproven nature of therapy. Use of hype language (eg, language that exaggerates potential benefits). 243 websites offered stem cell therapies. Many websites advertised stem cell transplantation from multiple sources, such as adipose-derived (112), bone marrow-derived (100), blood-derived (28), umbilical cord-derived (26) and others. Plant stem cell-based treatments and products (20) were also advertised. Purposes for and targets of treatment included pain, physical injury, a wide range of diseases and illnesses, cosmetic concerns, non-cosmetic ageing, sexual enhancement and others. Medical doctors (130), chiropractors (53) and naturopaths (44) commonly work in the clinics we found to be offering stem cell therapies. Few clinic websites advertising stem cell therapies included important additional information, including statements about evidence of inefficacy (present on only 12.76% of websites), statements about limited evidence of efficacy (18.93%), statements of

  3. Clinical Evaluation of Decellularized Nerve Allograft with Autologous Bone Marrow Stem Cells to Improve Peripheral Nerve Repair and Functional Outcomes

    2017-07-01

    with autologous mesenchymal stem cells . Exp Neurol. 2007 Apr; 204(2):658-66. 19. Dezawa M., et al., Sciatic nerve regeneration in rats induced by...36 23. Mimura T., et al., Peripheral nerve regeneration by transplantation of bone marrow stromal cell -derived Schwann cells in adult rats. J...AWARD NUMBER: W81XWH-15-2-0026 TITLE: Clinical Evaluation of Decellularized Nerve Allograft with Autologous Bone Marrow Stem Cells to Improve

  4. Stem cell transplantation as a dynamical system: are clinical outcomes deterministic?

    Toor, Amir A; Kobulnicky, Jared D; Salman, Salman; Roberts, Catherine H; Jameson-Lee, Max; Meier, Jeremy; Scalora, Allison; Sheth, Nihar; Koparde, Vishal; Serrano, Myrna; Buck, Gregory A; Clark, William B; McCarty, John M; Chung, Harold M; Manjili, Masoud H; Sabo, Roy T; Neale, Michael C

    2014-01-01

    Outcomes in stem cell transplantation (SCT) are modeled using probability theory. However, the clinical course following SCT appears to demonstrate many characteristics of dynamical systems, especially when outcomes are considered in the context of immune reconstitution. Dynamical systems tend to evolve over time according to mathematically determined rules. Characteristically, the future states of the system are predicated on the states preceding them, and there is sensitivity to initial conditions. In SCT, the interaction between donor T cells and the recipient may be considered as such a system in which, graft source, conditioning, and early immunosuppression profoundly influence immune reconstitution over time. This eventually determines clinical outcomes, either the emergence of tolerance or the development of graft versus host disease. In this paper, parallels between SCT and dynamical systems are explored and a conceptual framework for developing mathematical models to understand disparate transplant outcomes is proposed.

  5. Producing cement

    Stone, E G

    1923-09-12

    A process and apparatus are described for producing Portland cement in which pulverized shale is successively heated in a series of inclined rotary retorts having internal stirrers and oil gas outlets, which are connected to condensers. The partially treated shale is removed from the lowermost retort by a conveyor, then fed separately or conjointly into pipes and thence into a number of vertically disposed retorts. Each of these retorts may be fitted interiorly with vertical arranged conveyors which elevate the shale and discharge it over a lip, from whence it falls to the bottom of the retorts. The lower end of each casing is furnished with an adjustable discharge door through which the spent shale is fed to a hopper, thence into separate trucks. The oil gases generated in the retorts are exhausted through pipes to condensers. The spent shale is conveyed to a bin and mixed while hot with ground limestone. The admixed materials are then ground and fed to a rotary kiln which is fired by the incondensible gases derived from the oil gases obtained in the previous retorting of the shale. The calcined materials are then delivered from the rotary kiln to rotary coolers. The waste gases from the kiln are utilized for heating the retorts in which the ground shale is heated for the purpose of extracting therefrom the contained hydrocarbon oils and gases.

  6. The combination of ultrasound with antibiotics released from bone cement decreases the viability of planktonic and biofilm bacteria : an in vitro study with clinical strains

    Ensing, Geert T.; Neut, Danielle; Horn, Jim R. van; van der Mei, Henny C.; Busscher, Henk J.

    2006-01-01

    Objectives: Antibiotic-loaded bone cements are used for the permanent fixation of joint prostheses. Antibiotic-loaded cements significantly decrease the incidence of infection. The objective of this study was to investigate whether the viability of bacteria derived from patients with a

  7. Stem cell biobanks.

    Bardelli, Silvana

    2010-04-01

    Stem cells contribute to innate healing and harbor a promising role for regenerative medicine. Stem cell banking through long-term storage of different stem cell platforms represents a fundamental source to preserve original features of stem cells for patient-specific clinical applications. Stem cell research and clinical translation constitute fundamental and indivisible modules catalyzed through biobanking activity, generating a return of investment.

  8. Clinical efficacy of gene-modified stem cells in adenosine deaminase–deficient immunodeficiency

    Shaw, Kit L.; Garabedian, Elizabeth; Mishra, Suparna; Barman, Provaboti; Davila, Alejandra; Carbonaro, Denise; Shupien, Sally; Silvin, Christopher; Geiger, Sabine; Nowicki, Barbara; Smogorzewska, E. Monika; Brown, Berkley; Wang, Xiaoyan; de Oliveira, Satiro; Choi, Yeong; Ikeda, Alan; Terrazas, Dayna; Fu, Pei-Yu; Yu, Allen; Fernandez, Beatriz Campo; Cooper, Aaron R.; Engel, Barbara; Podsakoff, Greg; Balamurugan, Arumugam; Anderson, Stacie; Muul, Linda; Jagadeesh, G. Jayashree; Kapoor, Neena; Tse, John; Moore, Theodore B.; Purdy, Ken; Rishi, Radha; Mohan, Kathey; Skoda-Smith, Suzanne; Buchbinder, David; Abraham, Roshini S.; Scharenberg, Andrew; Yang, Otto O.; Cornetta, Kenneth; Gjertson, David; Hershfield, Michael; Sokolic, Rob; Candotti, Fabio

    2017-01-01

    BACKGROUND. Autologous hematopoietic stem cell transplantation (HSCT) of gene-modified cells is an alternative to enzyme replacement therapy (ERT) and allogeneic HSCT that has shown clinical benefit for adenosine deaminase–deficient (ADA-deficient) SCID when combined with reduced intensity conditioning (RIC) and ERT cessation. Clinical safety and therapeutic efficacy were evaluated in a phase II study. METHODS. Ten subjects with confirmed ADA-deficient SCID and no available matched sibling or family donor were enrolled between 2009 and 2012 and received transplantation with autologous hematopoietic CD34+ cells that were modified with the human ADA cDNA (MND-ADA) γ-retroviral vector after conditioning with busulfan (90 mg/m2) and ERT cessation. Subjects were followed from 33 to 84 months at the time of data analysis. Safety of the procedure was assessed by recording the number of adverse events. Efficacy was assessed by measuring engraftment of gene-modified hematopoietic stem/progenitor cells, ADA gene expression, and immune reconstitution. RESULTS. With the exception of the oldest subject (15 years old at enrollment), all subjects remained off ERT with normalized peripheral blood mononuclear cell (PBMC) ADA activity, improved lymphocyte numbers, and normal proliferative responses to mitogens. Three of nine subjects were able to discontinue intravenous immunoglobulin replacement therapy. The MND-ADA vector was persistently detected in PBMCs (vector copy number [VCN] = 0.1–2.6) and granulocytes (VCN = 0.01–0.3) through the most recent visits at the time of this writing. No patient has developed a leukoproliferative disorder or other vector-related clinical complication since transplant. CONCLUSION. These results demonstrate clinical therapeutic efficacy from gene therapy for ADA-deficient SCID, with an excellent clinical safety profile. TRIAL REGISTRATION. ClinicalTrials.gov NCT00794508. FUNDING. Food and Drug Administration Office of Orphan Product

  9. Asphalt cement poisoning

    ... petroleum material that hardens when it cools. Asphalt cement poisoning occurs when someone swallows asphalt. If hot ... found in: Road paving materials Roofing materials Tile cements Asphalt may also be used for other purposes.

  10. Radioactivity of bone cement

    Scherer, M.A.; Winkler, R.; Ascherl, R.; Lenz, E.

    1993-01-01

    A total of 14 samples of different types of bone cement from five different manufacturers were examined for their radioactivity. Each of the investigated bone cements showed a low radioactivity level, i.e. between [de

  11. Ultrafine portland cement performance

    C. Argiz

    2018-04-01

    Full Text Available By mixing several binder materials and additions with different degrees of fineness, the packing density of the final product may be improved. In this work, ultrafine cement and silica fume mixes were studied to optimize the properties of cement-based materials. This research was performed in mortars made of two types of cement (ultrafine Portland cement and common Portland cement and two types of silica fume with different particle-size distributions. Two Portland cement replacement ratios of 4% and 10% of silica fume were selected and added by means of a mechanical blending method. The results revealed that the effect of the finer silica fume mixed with the coarse cement enhances the mechanical properties and pore structure refinement at a later age. This improvement is somewhat lower in the case of ultrafine cement with silica fume.

  12. Diagnosis for the localization of cemented intramedullar stem protheses and ICLH-protheses of the hip by means of stereo X-ray prints

    Probst, K.J.; Herp, A.; Leidel, W.

    1978-01-01

    It is known that the loosening of artificial hip joints leads to their shift relative to the carrying bone structure. For a quantitative radiological detection of even minimal dislocations fix-points both in the carrying bone structure as well as in the prostheses have to be defined. While for the stem prostheses and cups such points can be defined directly from their geometrical structure, they have to be generated artificially for the carrying bone structure by implanted metal pins, which can easily be detected in the X-ray print. Having defined in this way a complete and appropriate set of fix-points, the position of the prosthesis relative to the bone structure is uniquely defined by the distance vectors between the different fix-points. The main biometrical steps of such a concept as well as their computational formulation and realization are derived; the main advantages and the accuracy of the technique are elucidated and critically discussed. (orig.) [de

  13. Bone regeneration: stem cell therapies and clinical studies in orthopaedics and traumatology.

    Gómez-Barrena, Enrique; Rosset, Philippe; Müller, Ingo; Giordano, Rosaria; Bunu, Carmen; Layrolle, Pierre; Konttinen, Yrjö T; Luyten, Frank P

    2011-06-01

    Regenerative medicine seeks to repair or replace damaged tissues or organs, with the goal to fully restore structure and function without the formation of scar tissue. Cell based therapies are promising new therapeutic approaches in regenerative medicine. By using mesenchymal stem cells, good results have been reported for bone engineering in a number of clinical studies, most of them investigator initiated trials with limited scope with respect to controls and outcome. With the implementation of a new regulatory framework for advanced therapeutic medicinal products, the stage is set to improve both the characterization of the cells and combination products, and pave the way for improved controlled and well-designed clinical trials. The incorporation of more personalized medicine approaches, including the use of biomarkers to identify the proper patients and the responders to treatment, will be contributing to progress in the field. Both translational and clinical research will move the boundaries in the field of regenerative medicine, and a coordinated effort will provide the clinical breakthroughs, particularly in the many applications of bone engineering. © 2011 The Authors Journal of Cellular and Molecular Medicine © 2011 Foundation for Cellular and Molecular Medicine/Blackwell Publishing Ltd.

  14. Premise and promise of mesenchymal stem cell-based therapies in clinical vascularized composite allotransplantation.

    Schweizer, Riccardo; Gorantla, Vijay S; Plock, Jan A

    2015-12-01

    Over the past decade, clinical vascularized composite allotransplantation (VCA) has enabled functional and quality of life restoration in a wide range of indications secondary to devastating tissue loss. However, the spectre of toxicity and long-term complications of chronic immunosuppression has curtailed the momentum of VCA. This study summarizes the literature evidence behind successful mesenchymal stem cell (MSC)-based cell therapies highlighting their multipronged immunomodulatory, restorative and regenerative characteristics with special emphasis towards VCA applications. Experimental and clinical studies in solid organs and VCA have confirmed that MSCs facilitate immunosuppression-free allograft survival or tolerance, stimulate peripheral nerve regeneration, attenuate ischaemia-reperfusion injury, and improve tissue healing after surgery. It has been hypothesized that MSC-induced long-term operational tolerance in experimental VCA is mediated by induction of mixed donor-specific chimerism and regulatory T-cell mechanisms. All these characteristics of MSCs could thus help expand the scope and clinical feasibility of VCA. Cellular therapies, especially those focusing on MSCs, are emerging in solid organ transplantation including VCA. Although some clinical trials have begun to assess the effects of MSCs in solid organ transplantation, much scientific domain remains uncharted, especially for VCA.

  15. Basic Science and Clinical Application of Stem Cells in Veterinary Medicine

    Ribitsch, I.; Burk, J.; Delling, U.; Geißler, C.; Gittel, C.; Jülke, H.; Brehm, W.

    Stem cells play an important role in veterinary medicine in different ways. Currently several stem cell therapies for animal patients are being developed and some, like the treatment of equine tendinopathies with mesenchymal stem cells (MSCs), have already successfully entered the market. Moreover, animal models are widely used to study the properties and potential of stem cells for possible future applications in human medicine. Therefore, in the young and emerging field of stem cell research, human and veterinary medicine are intrinsically tied to one another. Many of the pioneering innovations in the field of stem cell research are achieved by cooperating teams of human and veterinary medical scientists.

  16. Donor Selection for Allogenic Hemopoietic Stem Cell Transplantation: Clinical and Ethical Considerations

    Irene Riezzo

    2017-01-01

    Full Text Available Allogenic hematopoietic progenitor cell transplantation (allo-HSCT is an established treatment for many diseases. Stem cells may be obtained from different sources: mobilized peripheral blood stem cells, bone marrow, and umbilical cord blood. The progress in transplantation procedures, the establishment of experienced transplant centres, and the creation of unrelated adult donor registries and cord blood banks gave those without an human leucocyte antigen- (HLA- identical sibling donor the opportunity to find a donor and cord blood units worldwide. HSCT imposes operative cautions so that the entire donation/transplantation procedure is safe for both donors and recipients; it carries with it significant clinical, moral, and ethical concerns, mostly when donors are minors. The following points have been stressed: the donation should be excluded when excessive risks for the donor are reasonable, donors must receive an accurate information regarding eventual adverse events and health burden for the donors themselves, a valid consent is required, and the recipient’s risks must be outweighed by the expected benefits. The issue of conflict of interest, when the same physician has the responsibility for both donor selection and recipient care, is highlighted as well as the need of an adequate insurance protection for all the parties involved.

  17. From embryonic stem cells to functioning germ cells: science, clinical and ethical perspectives.

    Kiatpongsan, Sorapop

    2007-10-01

    Embryonic stem cells have been well recognized as cells having a versatile potential to differentiate into all types of cells in the body including germ cells. There are many research studies focusing on the differentiation processes and protocols to derive various types of somatic cells from embryonic stem cells. However, germ cells have unique differentiation process and developmental pathway compared with somatic cells. Consequently, they will require different differentiation protocols and special culture techniques. More understanding and established in vitro systems for gametogenesis will greatly contribute to further progression of knowledge and technology in germ cell biology, reproductive biology and reproductive medicine. Moreover if oocytes can be efficiently produced in vitro, this will play an important role on progression in nuclear transfer and nuclear reprogramming technology. The present article will provide concise review on past important discoveries, current ongoing studies and future views of this challenging research area. An ethical perspective has also been proposed to give comprehensive summary and viewpoint for future clinical application.

  18. The developing cancer stem-cell model: clinical challenges and opportunities.

    Vermeulen, Louis; de Sousa e Melo, Felipe; Richel, Dick J; Medema, Jan Paul

    2012-02-01

    During the past decade, a stem-cell-like subset of cancer cells has been identified in many malignancies. These cells, referred to as cancer stem cells (CSCs), are of particular interest because they are believed to be the clonogenic core of the tumour and therefore represent the cell population that drives growth and progression. Many efforts have been made to design therapies that specifically target the CSC population, since this was predicted to be the crucial population to eliminate. However, recent insights have complicated the initial elegant model, by showing a dominant role for the tumour microenvironment in determining CSC characteristics within a malignancy. This is particularly important since dedifferentiation of non-tumorigenic tumour cells towards CSCs can occur, and therefore the CSC population in a neoplasm is expected to vary over time. Moreover, evidence suggests that not all tumours are driven by rare CSCs, but might instead contain a large population of tumorigenic cells. Even though these results suggest that specific targeting of the CSC population might not be a useful therapeutic strategy, research into the hierarchical cellular organisation of malignancies has provided many important new insights in the biology of tumours. In this Personal View, we highlight how the CSC concept is developing and influences our thinking on future treatment for solid tumours, and recommend ways to design clinical trials to assess drugs that target malignant disease in a rational fashion. Copyright © 2012 Elsevier Ltd. All rights reserved.

  19. Sulfur polymer cement concrete

    Weber, H.H.; McBee, W.C.

    1990-01-01

    Sulfur-based composite materials formulated using sulfur polymer cement (SPC) and mineral aggregates are described and compared with conventional portland cement based materials. Materials characteristics presented include mechanical strength, chemical resistance, impact resistance, moisture permeation, and linear shrinkage during placement and curing. Examples of preparation and placement of sulfur polymer cement concrete (SC) are described using commercial scale equipment. SC applications presented are focused into hostile chemical environments where severe portland cement concrete (PCC) failure has occurred

  20. Contact dermatitis in cement workers in Isfahan

    Iraji Fariba

    2006-01-01

    Full Text Available BACKGROUND: Due to recent industrialization and inadequately protected workers or in other words poor supervision on constructive workers habits in our large city of Isfahan cement contact dermatitis is relatively high especially among cement factory workers and constructive personnel. PURPOSES: To investigate the prevalence rate of cement contact dermatitis in cement factory workers in Isfahan. METHODS: A case-control clinical study was carried out by randomly selecing 150 factory workders and 150 official clerks in a cement factory in Isfahan in 2001. After a complete physical examination, data was recorded in observational checklists. FINDINGS: The percentages of contact dermatitis prevalences in the first and the second groups were 22% and 5.3% respectively. About 60% of cement workers with contact dermatitis were between 30-40 years of age. There was a direct relationship with age in both groups of the workers. In the high-exposure group, the hand eczema along was 70% but in the other group the percentage of involvement was the same in exposed and unexposed anatomical areas. CONCLUSIONS: There was a direct relationship between occurrence and the severity of involvement and duration of contact in the first group. Cent percent of cement workers had contact dermatitis after 10 or less years, but the percentage among the other group was 35%. LIMITATION: Irritant contact dermatitis to cement has not been detected.

  1. Stem cell-based treatments against stroke: observations from human proof-of-concept studies and considerations regarding clinical applicability

    Thorsten Roland Doeppner

    2014-10-01

    Full Text Available Ischemic stroke remains a heavy burden for industrialized countries. The only causal therapy is the recanalization of occluded vessels via thrombolysis, which due to a narrow time window still can be offered only to a minority of patients. Since the majority of patients continues to exhibit neurological deficits even following successful thrombolysis, restorative therapies are urgently needed that promote brain remodeling and repair once stroke injury has occurred. Due to their unique properties of action, stem cell-based strategies gained increasing interest during recent years. Using various stroke models in both rodents and primates, the transplantation of stem cells, namely of bone marrow derived mesenchymal stem cells (MSCs or neural progenitor cells (NPCs, has been shown to promote neurological recovery most likely via indirect bystander actions. In view of promising observations, clinical proof-of-concept studies are currently under way, in which effects of stem and precursor cells are evaluated in human stroke patients. In this review we summarize already published studies, which due to the broad experience in other medical contexts mostly employed bone marrow-derived MSCs by means of intravenous transplantation. With the overall number of clinical trials limited in number, only a fraction of these studies used non-treated control groups, and only single studies were adequately blinded. Despite these limitations, first promising results justify the need for more elaborate clinical trials in order to make stem cell transplantation a success for stroke treatment in the future.

  2. Manufacturing human mesenchymal stem cells at clinical scale: process and regulatory challenges.

    Jossen, Valentin; van den Bos, Christian; Eibl, Regine; Eibl, Dieter

    2018-05-01

    Human mesenchymal stem cell (hMSC)-based therapies are of increasing interest in the field of regenerative medicine. As economic considerations have shown, allogeneic therapy seems to be the most cost-effective method. Standardized procedures based on instrumented single-use bioreactors have been shown to provide billion of cells with consistent product quality and to be superior to traditional expansions in planar cultivation systems. Furthermore, under consideration of the complex nature and requirements of allogeneic hMSC-therapeutics, a new equipment for downstream processing (DSP) was successfully evaluated. This mini-review summarizes both the current state of the hMSC production process and the challenges which have to be taken into account when efficiently producing hMSCs for the clinical scale. Special emphasis is placed on the upstream processing (USP) and DSP operations which cover expansion, harvesting, detachment, separation, washing and concentration steps, and the regulatory demands.

  3. Mesenchymal stem cells for cardiac repair: are the actors ready for the clinical scenario?

    Santiago Roura

    2017-10-01

    Full Text Available Abstract For years, sufficient progress has been made in treating heart failure following myocardial infarction; however, the social and economic burdens and the costs to world health systems remain high. Moreover, treatment advances have not resolved the underlying problem of functional heart tissue loss. In this field of research, for years we have actively explored innovative biotherapies for cardiac repair. Here, we present a general, critical overview of our experience in using mesenchymal stem cells, derived from cardiac adipose tissue and umbilical cord blood, in a variety of cell therapy and tissue engineering approaches. We also include the latest advances and future challenges, including good manufacturing practice and regulatory issues. Finally, we evaluate whether recent approaches hold potential for reliable translation to clinical trials.

  4. Development of a surrogate angiogenic potency assay for clinical-grade stem cell production.

    Lehman, Nicholas; Cutrone, Rochelle; Raber, Amy; Perry, Robert; Van't Hof, Wouter; Deans, Robert; Ting, Anthony E; Woda, Juliana

    2012-09-01

    Clinical results from acute myocardial infarction (AMI) patients treated with MultiStem®, a large-scale expanded adherent multipotent progenitor cell population (MAPC), have demonstrated a strong safety and benefit profile for these cells. The mechanism of benefit with MAPC treatment is a result, in part, of its ability to induce neovascularization through trophic support. Production of clinical-grade stem cell products requires the development of lot-release criteria based on potency assays that directly reflect the fundamental mechanistic pathway underlying the therapeutic response to verify manufacturing process consistency and product potency. Using an in vitro endothelial tube formation assay, a potency assay has been developed that reflects MAPC pro-angiogenic activity. Serum-free conditioned media collected from MAPC culture induced endothelial tube formation. A proteomic survey of angiogenic factors produced by the cells in vitro revealed candidate factors linked to angiogenic potency. Three cytokines, chemokine (C-X-C motif) ligand 5 (CXCL5), interleukin 8 (IL-8) and vascular endothelial growth factor (VEGF), were required for this angiogenic activity. Depletion of any of these factors from the media prevented tube formation, while adding back increasing amounts of these cytokines into the depleted serum-free conditioned media established the lower limits of each of the cytokines required to induce angiogenesis. A necessary threshold of angiogenic factor expression was established using an in vitro angiogenesis assay. By correlating the levels of the cytokines required to induce tube formation in vitro with levels of the factors found in the spent media from manufacturing production runs, detection of these factors was identified as a surrogate potency assay with defined pass/fail criteria.

  5. Concise review: preleukemic stem cells: molecular biology and clinical implications of the precursors to leukemia stem cells.

    Pandolfi, Ashley; Barreyro, Laura; Steidl, Ulrich

    2013-02-01

    Recent experimental evidence has shown that acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS) arise from transformed immature hematopoietic cells following the accumulation of multiple stepwise genetic and epigenetic changes in hematopoietic stem cells and committed progenitors. The series of transforming events initially gives rise to preleukemic stem cells (pre-LSC), preceding the formation of fully transformed leukemia stem cells (LSC). Despite the established use of poly-chemotherapy, relapse continues to be the most common cause of death in AML and MDS. The therapeutic elimination of all LSC, as well as pre-LSC, which provide a silent reservoir for the re-formation of LSC, will be essential for achieving lasting cures. Conventional sequencing and next-generation genome sequencing have allowed us to describe many of the recurrent mutations in the bulk cell populations in AML and MDS, and recent work has also focused on identifying the initial molecular changes contributing to leukemogenesis. Here we review recent and ongoing advances in understanding the roles of pre-LSC, and the aberrations that lead to pre-LSC formation and subsequent LSC transformation.

  6. Generation of clinical-grade human induced pluripotent stem cells in Xeno-free conditions.

    Wang, Juan; Hao, Jie; Bai, Donghui; Gu, Qi; Han, Weifang; Wang, Lei; Tan, Yuanqing; Li, Xia; Xue, Ke; Han, Pencheng; Liu, Zhengxin; Jia, Yundan; Wu, Jun; Liu, Lei; Wang, Liu; Li, Wei; Liu, Zhonghua; Zhou, Qi

    2015-11-12

    Human induced pluripotent stem cells (hiPSCs) are considered as one of the most promising seed cell sources in regenerative medicine. Now hiPSC-based clinical trials are underway. To ensure clinical safety, cells used in clinical trials or therapies should be generated under GMP conditions, and with Xeno-free culture media to avoid possible side effects like immune rejection that induced by the Xeno reagents. However, up to now there are no reports for hiPSC lines developed completely under GMP conditions using Xeno-free reagents. Clinical-grade human foreskin fibroblast (HFF) cells used as feeder cells and parental cells of the clinical-grade hiPSCs were isolated from human foreskin tissues and cultured in Xeno-free media. Clinical-grade hiPSCs were derived by integration-free Sendai virus-based reprogramming kit in Xeno-free pluriton™ reprogramming medium or X medium. Neural cells and cardiomyocytes differentiation were conducted following a series of spatial and temporal specific signals induction according to the corresponding lineage development signals. Biological safety evaluation of the clinical-grade HFF cells and hiPSCs were conducted following the guidance of the "Pharmacopoeia of the People's Republic of China, Edition 2010, Volume III". We have successfully derived several integration-free clinical-grade hiPSC lines under GMP-controlled conditions and with Xeno-free reagents culture media in line with the current guidance of international and national evaluation criteria. As for the source of hiPSCs and feeder cells, biological safety evaluation of the HFF cells have been strictly reviewed by the National Institutes for Food and Drug Control (NIFDC). The hiPSC lines are pluripotent and have passed the safety evaluation. Moreover, one of the randomly selected hiPSC lines was capable of differentiating into functional neural cells and cardiomyocytes in Xeno-free culture media. The clinical-grade hiPSC lines therefore could be valuable sources for

  7. Potential Strategies to Address the Major Clinical Barriers Facing Stem Cell Regenerative Therapy for Cardiovascular Disease: A Review.

    Nguyen, Patricia K; Neofytou, Evgenios; Rhee, June-Wha; Wu, Joseph C

    2016-11-01

    Although progress continues to be made in the field of stem cell regenerative medicine for the treatment of cardiovascular disease, significant barriers to clinical implementation still exist. To summarize the current barriers to the clinical implementation of stem cell therapy in patients with cardiovascular disease and to discuss potential strategies to overcome them. Information for this review was obtained through a search of PubMed and the Cochrane database for English-language studies published between January 1, 2000, and July 25, 2016. Ten randomized clinical trials and 8 systematic reviews were included. One of the major clinical barriers facing the routine implementation of stem cell therapy in patients with cardiovascular disease is the limited and inconsistent benefit observed thus far. Reasons for this finding are unclear but may be owing to poor cell retention and survival, as suggested by numerous preclinical studies and a small number of human studies incorporating imaging to determine cell fate. Additional studies in humans using imaging to determine cell fate are needed to understand how these factors contribute to the limited efficacy of stem cell therapy. Treatment strategies to address poor cell retention and survival are under investigation and include the following: coadministration of immunosuppressive and prosurvival agents, delivery of cardioprotective factors packaged in exosomes rather than the cells themselves, and use of tissue-engineering strategies to provide structural support for cells. If larger grafts are achieved using these strategies, it will be imperative to carefully monitor for the potential risks of tumorigenicity, immunogenicity, and arrhythmogenicity. Despite important achievements to date, stem cell therapy is not yet ready for routine clinical implementation. Significant research is still needed to address the clinical barriers outlined herein before the next wave of large clinical trials is under way.

  8. A clinical trial of Empress II porcelain inlays luted to vital teeth with a dual-curing adhesive system and a self-curing resin cement.

    Fabianelli, Andrea; Goracci, Cecilia; Bertelli, Egidio; Davidson, Carel L; Ferrari, Marco

    2006-12-01

    The aim of the study was to clinically evaluate Empress II inlays cemented with a dual-curing bonding agent and a self-curing luting system. Forty patients were selected to receive one Empress II inlay. Empress II is a heat-pressed glass ceramic containing lithium disilicate and lithium orthophosphate crystals, purported to provide higher stress resistance and improved strength. The restorations were placed between March and May 2000. Recalls were performed after 6, 12, 24, and 36 months. At the 3-year recall, 7 patients were lost to follow-up. Inlays were evaluated for postoperative sensitivity, marginal integrity, marginal leakage, color stability, surface staining, retention, and surface crazing (microcracks). At the 3-year recall, all the restorations were in place and only one showed postoperative sensitivity (at the first recall, 1 week after placement). Only 3 inlays showed slight marginal staining, and 4 inlays showed gaps, with little surface staining or microcracks. No inlay debonded or fractured during theobservation period. All the evaluated inlays were in place and acceptable.

  9. Radiopacity of portland cement associated with different radiopacifying agents.

    Húngaro Duarte, Marco Antonio; de Oliveira El Kadre, Guâniara D'arc; Vivan, Rodrigo Ricci; Guerreiro Tanomaru, Juliane Maria; Tanomaru Filho, Mário; de Moraes, Ivaldo Gomes

    2009-05-01

    This study evaluated the radiopacity of Portland cement associated with the following radiopacifying agents: bismuth oxide, zinc oxide, lead oxide, bismuth subnitrate, bismuth carbonate, barium sulfate, iodoform, calcium tungstate, and zirconium oxide. A ratio of 20% radiopacifier and 80% white Portland cement by weight was used for analysis. Pure Portland cement and dentin served as controls. Cement/radiopacifier and dentin disc-shaped specimens were fabricated, and radiopacity testing was performed according to the ISO 6876/2001 standard for dental root sealing materials. Using Insight occlusal films, the specimens were radiographed near to a graduated aluminum stepwedge varying from 2 to 16 mm in thickness. The radiographs were digitized and radiopacity compared with the aluminum stepwedge using Digora software (Orion Corporation Soredex, Helsinki, Finland). The radiographic density data were converted into mmAl and analyzed statistically by analysis of variance and Tukey-Kramer test (alpha = 0.05). The radiopacity of pure Portland cement was significantly lower (p cement/radiopacifier mixtures were significantly more radiopaque than dentin and Portland cement alone (p cement/bismuth oxide and Portland cement/lead oxide presented the highest radiopacity values and differed significantly from the other materials (p cement/zinc oxide presented the lowest radiopacity values of all mixtures (p cement as radiopacifying agents. However, the possible interference of the radiopacifiers with the setting chemistry, biocompatibility, and physical properties of the Portland cement should be further investigated before any clinical recommendation can be done.

  10. Pulp regeneration by transplantation of dental pulp stem cells in pulpitis: a pilot clinical study.

    Nakashima, Misako; Iohara, Koichiro; Murakami, Masashi; Nakamura, Hiroshi; Sato, Yayoi; Ariji, Yoshiko; Matsushita, Kenji

    2017-03-09

    Experiments have previously demonstrated the therapeutic potential of mobilized dental pulp stem cells (MDPSCs) for complete pulp regeneration. The aim of the present pilot clinical study is to assess the safety, potential efficacy, and feasibility of autologous transplantation of MDPSCs in pulpectomized teeth. Five patients with irreversible pulpitis were enrolled and monitored for up to 24 weeks following MDPSC transplantation. The MDPSCs were isolated from discarded teeth and expanded based on good manufacturing practice (GMP). The quality of the MDPSCs at passages 9 or 10 was ascertained by karyotype analyses. The MDPSCs were transplanted with granulocyte colony-stimulating factor (G-CSF) in atelocollagen into pulpectomized teeth. The clinical and laboratory evaluations demonstrated no adverse events or toxicity. The electric pulp test (EPT) of the pulp at 4 weeks demonstrated a robust positive response. The signal intensity of magnetic resonance imaging (MRI) of the regenerated tissue in the root canal after 24 weeks was similar to that of normal dental pulp in the untreated control. Finally, cone beam computed tomography demonstrated functional dentin formation in three of the five patients. Human MDPSCs are safe and efficacious for complete pulp regeneration in humans in this pilot clinical study.

  11. Clinical evaluation of glass-ionomer cement restorations Avaliação clínica de restaurações de cimento de ionômero de vidro

    Martin John Tyas

    2006-01-01

    Full Text Available This article mentions the general structure, properties and clinical performance of conventional and resin-modified glass-ionomer cements, focusing on adhesion, caries inhibition effect and recommendations of their use.Este artigo menciona a estrutura geral, propriedades e performance clínica de cimentos de ionômero de vidro convencionais e modificados por resina, enfocando propriedades como adesão, efeito anti-cariogênico e recomendações de uso.

  12. Dental Cements for Luting and Bonding Restorations: Self-Adhesive Resin Cements.

    Manso, Adriana P; Carvalho, Ricardo M

    2017-10-01

    Self-adhesive resin cements combine easy application of conventional luting materials with improved mechanical properties and bonding capability of resin cements. The presence of functional acidic monomers, dual cure setting mechanism, and fillers capable of neutralizing the initial low pH of the cement are essential elements of the material and should be understood when selecting the ideal luting material for each clinical situation. This article addresses the most relevant aspects of self-adhesive resin cements and their potential impact on clinical performance. Although few clinical studies are available to establish solid clinical evidence, the information presented provides clinical guidance in the dynamic environment of material development. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Aseptic loosening of the femoral implant after cemented total hip arthroplasty in dogs: 11 cases in 10 dogs (1991-1995)

    Edwards, M.R.; Egger, E.L.; Schwarz, P.D.

    1997-01-01

    Objective-To determine clinical signs, radiographic findings, results of surgical management, and potential causes of aseptic loosening of the femoral implant (ALFI) in dogs that have undergone cemented total hip arthroplasty (THA). Design-Retrospective study. Animals-11 cases of ALFI in 10 dogs. Procedure-Medical records of all dogs undergoing THA revision surgery were reviewed. Only dogs with ALFI were included. The prosthesis and cement were removed by creating a longitudinal osteotomy of the cranial femoral cortex. Postoperative radiographs of all dogs that underwent THA during the study period were reviewed. Results-The most common clinical sign was intermittent, subtle. or non-weight-bearing lameness. On radiographs obtained after THA, contact of the distal stem tip with cortical endosteum was evident in all dogs. Radiographic changes at the time of diagnosis of ALFI included asymmetric periosteal reaction along the femoral diaphysis, radiolucent lines between the prosthesis and cement, altered implant position, and femoral fracture. Surgical revision yielded good or excellent results in 9 cases. In 1 dog. the implant became infected; in another, aseptic loosening recurred. Aseptic loosening was significantly more common in dogs in which there was contact between the distal stem tip and cortical endosteum than in dogs in which there was no contact. Clinical Implications-ALFI is an uncommon, but important, complication of THA, and radiography is warranted in dogs with clinical signs of ALFI. Initial centering of the prosthetic stem within the femoral shaft may reduce the incidence of ALFI

  14. ULTRA-LIGHTWEIGHT CEMENT

    Fred Sabins

    2001-01-01

    The objective of this project is to develop an improved ultra-lightweight cement using ultralight hollow glass spheres (ULHS). Work reported herein addresses Task 1: Assess Ultra-Lightweight Cementing Problems and Task 3: Test Ultra-Lightweight Cements. Results reported this quarter include a review and summary of Halliburton Energy Services (HES) and BJ Services historical performance data for lightweight cement applications. These data are analyzed and compared to ULHS cement and foamed cement performances. Similar data is expected from Schlumberger, and an analysis of this data will be completed in the following phases of the project. Quality control testing of materials used to formulate ULHS cements in the laboratory was completed to establish baseline material performance standards. A testing protocol was developed employing standard procedures as well as procedures tailored to evaluate ULHS and foamed cement. This protocol is presented and discussed. Results of further testing of ULHS cements are presented along with an analysis to establish cement performance design criteria to be used during the remainder of the project. Finally, a list of relevant literature on lightweight cement performance is compiled for review during the next quarter

  15. Nano-regenerative medicine towards clinical outcome of stem cell and tissue engineering in humans

    Arora, Pooja; Sindhu, Annu; Dilbaghi, Neeraj; Chaudhury, Ashok; Rajakumar, Govindasamy; Rahuman, Abdul Abdul

    2012-01-01

    Nanotechnology is a fast growing area of research that aims to create nanomaterials or nanostructures development in stem cell and tissue-based therapies. Concepts and discoveries from the fields of bio nano research provide exciting opportunities of using stem cells for regeneration of tissues and organs. The application of nanotechnology to stem-cell biology would be able to address the challenges of disease therapeutics. This review covers the potential of nanotechnology approaches towards regenerative medicine. Furthermore, it focuses on current aspects of stem- and tissue-cell engineering. The magnetic nanoparticles-based applications in stem-cell research open new frontiers in cell and tissue engineering. PMID:22260258

  16. ULTRA-LIGHTWEIGHT CEMENT

    Fred Sabins

    2001-01-01

    The objective of this project is to develop an improved ultra-lightweight cement using ultra-lightweight hollow glass spheres (ULHS). Work reported herein addresses Task 1: Assess Ultra-Lightweight Cementing Issues, Task 2: Review Russian Ultra-Lightweight Cement Literature, Task 3: Test Ultra-Lightweight Cements, and Task 8: Develop Field ULHS Cement Blending and Mixing Techniques. Results reported this quarter include: preliminary findings from a literature review focusing on problems associated with ultra-lightweight cements; summary of pertinent information from Russian ultra-lightweight cement literature review; laboratory tests comparing ULHS slurries to foamed slurries and sodium silicate slurries for two different applications; and initial laboratory studies with ULHS in preparation for a field job

  17. Safety and function of a new clinical intracerebral microinjection instrument for stem cells and therapeutics examined in the Göttingen minipig

    Bjarkam, Carsten R; GLUD, AN; Margolin, Lee

    2010-01-01

    Safety and function of a new clinical intracerebral microinjection instrument for stem cells and therapeutics examined in the Göttingen minipig......Safety and function of a new clinical intracerebral microinjection instrument for stem cells and therapeutics examined in the Göttingen minipig...

  18. Stem cells from foetal adnexa and fluid in domestic animals: an update on their features and clinical application.

    Iacono, E; Rossi, B; Merlo, B

    2015-06-01

    Over the past decade, stem cell research has emerged as an area of major interest for its potential in regenerative medicine applications. This is in constant need of new cell sources to conceive regenerative medicine approaches for diseases that are still without therapy. Scientists drew the attention towards alternative sources such as foetal adnexa and fluid, as these sources possess many advantages: first of all, cells can be extracted from discarded foetal material and it is non-invasive and inexpensive for the patient; secondly, abundant stem cells can be obtained; and finally, these stem cell sources are free from ethical considerations. Cells derived from foetal adnexa and fluid preserve some of the characteristics of the primitive embryonic layers from which they originate. Many studies have demonstrated the differentiation potential in vitro and in vivo towards mesenchymal and non-mesenchymal cell types; in addition, the immune-modulatory properties make these cells a good candidate for allo- and xenotransplantation. Naturally occurring diseases in domestic animals can be more ideal as disease model of human genetic and acquired diseases and could help to define the potential therapeutic use efficiency and safety of stem cells therapies. This review offers an update on the state of the art of characterization of domestic animals' MSCs derived from foetal adnexa and fluid and on the latest findings in pre-clinical or clinical setting of the stem cell populations isolated from these sources. © 2015 Blackwell Verlag GmbH.

  19. Exogenous stem cells pioneer a biobridge to the advantage of host brain cells following stroke: New insights for clinical applications

    Marci G Crowley

    2017-01-01

    Full Text Available Stroke continues to maintain its status as one of the top causes of mortality within the United States. Currently, the only Food and Drug Administration (FDA-approved drug in place for stroke patients, tissue plasminogen activator (tPA, has a rigid therapeutic window, closing at approximately 4.5 h after stroke onset. Due to this short time frame and other restrictions, such as any condition that increases a patient's risk for hemorrhaging, it has been predicted that <5% of ischemic stroke patients benefit from tPA. Given that rehabilitation therapy remains the only other option for stroke victims, there is a clear unmet clinical need for treatment available for the remaining 95%. While still considered an experimental treatment, the utilization of stem cell therapies for stroke holds consistent promise. Copious preclinical studies report the capacity for transplanted stem cells to rescue the brain parenchyma surrounding the stroke-induced infarct core. At present, the exact mechanisms in which stem cells contribute a robust therapeutic benefit remains unclear. Following stem cell administration, researchers have observed cell replacement, an increase in growth factors, and a reduction in inflammation. With a deeper understanding of the precise mechanism of stem cells, these therapies can be optimized in the clinic to afford the greatest therapeutic benefit. Recent studies have depicted a unique method of endogenous stem cell activation as a result of stem cell therapy. In both traumatic brain injury and stroke models, transplanted mesenchymal stromal cells (MSCs facilitated a pathway between the neurogenic niches of the brain and the damaged area through extracellular matrix remodeling. The biobridge pioneered by the MSCs was utilized by the endogenous stem cells, and these cells were able to travel to the damaged areas distal to the neurogenic niches, a feat unachievable without prior remodeling. These studies broaden our understanding of stem

  20. Markers of stem cells in human ovarian granulosa cells: is there a clinical significance in ART?

    Varras Michail

    2012-11-01

    Full Text Available Abstract Background The purpose of the study was to determine the incidence of gene expression of Oct-4 and DAZL, which are typical markers for stem cells, in human granulosa cells during ovarian stimulation in women with normal FSH levels undergoing IVF or ICSI and to discover any clinical significance of such expression in ART. Methods Twenty one women underwent ovulation induction for IVF or ICSI and ET with standard GnRH analogue-recombinant FSH protocol. Infertility causes were male and tubal factor. Cumulus–mature oocyte complexes were denuded separately and granulosa cells were analyzed for each patient separately using quantitative reverse-transcription–polymerase chain reaction analysis for Oct-4 and DAZL gene expression with G6PD gene as internal standard. Results G6PD and Oct-4 mRNA was detected in the granulosa cells in 47.6% (10/21. The median of Oct-4 mRNA/G6PD mRNA was 1.75 with intra-quarteral range from 0.10 to 98.21. The OCT-4 mRNA expression was statistically significantly correlated with the number of oocytes retrieved; when the Oct-4 mRNA expression was higher, then more than six oocytes were retrieved (p=0.037, Wilcoxon rank-sum. No detection of DAZL mRNA was found in granulosa cells. There was no additional statistically significant correlation between the levels of Oct-4 expression and FSH basal levels or estradiol peak levels or dosage of FSH for ovulation induction. No association was found between the presence or absence of Oct-4 mRNA expression in granulosa cells and ovarian response to gonadotropin stimulation. Also, no influence on pregnancy was observed between the presence or absence of Oct-4 mRNA expression in granulosa cells or to its expression levels accordingly. Conclusions Expression of OCT-4 mRNA, which is a typical stem cell marker and absence of expression of DAZL mRNA, which is a typical germ cell marker, suggest that a subpopulation of luteinized granulosa cells in healthy ovarian follicles (47

  1. Role of Mesenchymal Derived Stem Cells in Stimulating Dormant Tumor Cells to Proliferate and Form Clinical Metastases

    2017-07-01

    Clinical Metastases PRINCIPAL INVESTIGATOR: Jeffrey Green CONTRACTING ORGANIZATION: The Geneva Foundation Tacoma, WA 98402 REPORT DATE: July 2017 TYPE...2016 - 14 June 2017 4. TITLE AND SUBTITLE Role of Mesenchymal-Derived Stem Cells in Stimulating Dormant Tumor Cells to Proliferate and Form Clinical ...and/or select agents. Nothing to report. 6. PRODUCTS: • publications, conference papers, and presentations ; Jennifer Zhu submitted an abstract and will

  2. Role of Mesenchymal-Derived Stem Cells in Stimulating Dormant Tumor Cells to Proliferate and Form Clinical Metastases

    2017-07-01

    Clinical Metastases PRINCIPAL INVESTIGATOR: Rosandra Kaplan CONTRACTING ORGANIZATION: The Geneva Foundation Tacoma, WA 98402 REPORT DATE: July 2017...2017 4. TITLE AND SUBTITLE Role of Mesenchymal-Derived Stem Cells in Stimulating Dormant Tumor Cells to Proliferate and Form Clinical Metastases 5a...PRODUCTS:  publications, conference papers, and presentations ; Jennifer Zhu submitted an abstract and will present this work at the Annual

  3. Human Induced Pluripotent Stem Cells from Basic Research to Potential Clinical Applications in Cancer

    Teresa de Souza Fernandez

    2013-01-01

    Full Text Available The human induced pluripotent stem cells (hiPSCs are derived from a direct reprogramming of human somatic cells to a pluripotent stage through ectopic expression of specific transcription factors. These cells have two important properties, which are the self-renewal capacity and the ability to differentiate into any cell type of the human body. So, the discovery of hiPSCs opens new opportunities in biomedical sciences, since these cells may be useful for understanding the mechanisms of diseases in the production of new diseases models, in drug development/drug toxicity tests, gene therapies, and cell replacement therapies. However, the hiPSCs technology has limitations including the potential for the development of genetic and epigenetic abnormalities leading to tumorigenicity. Nowadays, basic research in the hiPSCs field has made progress in the application of new strategies with the aim to enable an efficient production of high-quality of hiPSCs for safety and efficacy, necessary to the future application for clinical practice. In this review, we show the recent advances in hiPSCs’ basic research and some potential clinical applications focusing on cancer. We also present the importance of the use of statistical methods to evaluate the possible validation for the hiPSCs for future therapeutic use toward personalized cell therapies.

  4. Clinical outcome in children with chronic granulomatous disease managed conservatively or with hematopoietic stem cell transplantation.

    Cole, Theresa; Pearce, Mark S; Cant, Andrew J; Cale, Catherine M; Goldblatt, David; Gennery, Andrew R

    2013-11-01

    Chronic granulomatous disease (CGD) is a primary immunodeficiency characterized by serious infections and inflammation. It can be managed conservatively with prophylactic antimicrobial agents or curatively with hematopoietic stem cell transplantation (HSCT). In the United Kingdom and Ireland there are cohorts of children managed both conservatively and curatively. This study aimed to compare clinical outcomes (mortality and morbidity) in children managed conservatively and curatively. Children were identified from specialist centers and advertising through special interest groups. Clinical data were collected from medical records regarding infections, inflammatory complications and growth, other admissions, and curative treatment. Comparisons were made for patients not undergoing HSCT and patients after HSCT. Seventy-three living children were identified, 59 (80%) of whom were recruited. Five deceased children were also identified. Clinical information was available for 62 children (4 deceased). Thirty (48%) children had undergone HSCT. Children who did not undergo transplantation had 0.71 episodes of infection/admission/surgery per CGD life year (95% CI, 0.69-0.75 events per year). Post-HSCT children had 0.15 episodes of infection/admission/surgery per transplant year (95% CI, 0.09-0.21 events per year). The mean z score for height and body mass index (BMI) for age was significantly better in post-HSCT children. Survival in the non-HSCT group was 90% at age 15 years. Survival in the post-HSCT group was 90%. Children with CGD not undergoing transplantation have more serious infections, episodes of surgery, and admissions compared with post-HSCT children. Children undergoing transplantation have better height for age. Survival is good at the end of the pediatric age range and also after HSCT. Copyright © 2013 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.

  5. The Use of a Modular Titanium Baseplate with a Press-Fit Keel Implanted with a Surface Cementing Technique for Primary Total Knee Arthroplasty

    Christopher E. Pelt

    2014-01-01

    Full Text Available Little data exists regarding outcomes following TKA performed with surface-cementation for the fixation of modular tibial baseplates with press-fit keels. Thus, we retrospectively reviewed the clinical and radiographic outcomes of 439 consecutive primary TKAs performed with surface cemented tibial components. There were 290 female patients and 149 male patients with average age of 62 years (range 30–84. Two tibial components were revised for aseptic loosening (0.5% and four tibial components (0.9% were removed to improve instability (n=2 or malalignment (n=2. Complications included 13 deep infections treated with 2-stage revision (12 and fusion (1. These results support the surface cement technique with a modular grit-blasted titanium surface and cruciform stem during primary TKA.

  6. Evaluation of stainless steel crowns cemented with glass-ionomer and resin-modified glass-ionomer luting cements.

    Yilmaz, Yucel; Simsek, Sera; Dalmis, Anya; Gurbuz, Taskin; Kocogullari, M Elcin

    2006-04-01

    To evaluate in vitro and in vivo conditions of stainless steel crowns (SSC) cemented using one luting glass-ionomer cement (Aqua Meron) and one luting resin-modified glass-ionomer cement (Vitremer). In the in vitro part of this study, retentive properties of SSCs cemented using Aqua Meron and Vitremer on extracted primary first molars were tested. In addition, two specimens of each group were used to evaluate the tooth hard tissue-cement, within the cement itself, cement-SSC, and tooth hard tissue-cement-SSC under scanning electron microscope (SEM). In the in vivo part of this study, 152 SSCs were placed on the first or second primary molars of 86 children, and cemented using either Aqua Meron or Vitremer. The crowns were examined for retention. In addition, the clinical views of the crowns were recorded with an intraoral camera. No significant difference was found between the mean retentive forces of Aqua Meron and Vitremer (P> 0.05). SSCs cemented with Aqua Meron and Vitremer had an average lifespan of 26.44 and 24.07 months respectively. Only one (0.66%) of 152 SSCs was lost from the Aqua Meron group during post-cementation periods. Nineteen of the 152 SSCs (12.5%) had dents or perforations.

  7. Retentive [correction of Preventive] efficacy of glass ionomer, zinc phosphate and zinc polycarboxylate luting cements in preformed stainless steel crowns: a comparative clinical study.

    Khinda, V I S; Grewal, N

    2002-06-01

    This study was undertaken to assess the efficacy of three luting cements, namely, glass ionomer, zinc phosphate and zinc polycarboxylate in retainng the preformed stainless steel crowns in-vivo. Twenty subjects, with an indication for restoration of three primary molars with stainless steel crowns, were selected. Sixty teeth were taken up for the study, and twenty crowns were cemented with each of the three luting cements. After an eight month follow up the crowns were assessed for their presence/ absence or "rocking". Statistical analysis was done using Chi-square test. The results have shown no significant difference in retentivity of stainless steel crowns with the use of either of the three luting agents.

  8. Chemical and physical properties of bone cement for vertebroplasty

    Po-Liang Lai

    2013-08-01

    Full Text Available Vertebral compression fracture is the most common complication of osteoporosis. It may result in persistent severe pain and limited mobility, and significantly impacts the quality of life. Vertebroplasty involves a percutaneous injection of bone cement into the collapsed vertebrae by fluorescent guide. The most commonly used bone cement in percutaneous vertebroplasty is based on the polymerization of methylmethacrylate monomers to polymethylmethacrylate (PMMA polymers. However, information on the properties of bone cement is mostly published in the biomaterial sciences literature, a source with which the clinical community is generally unfamiliar. This review focuses on the chemistry of bone cement polymerization and the physical properties of PMMA. The effects of altering the portions and contents of monomer liquid and polymer powders on the setting time, polymerization temperature, and compressive strength of the cement are also discussed. This information will allow spine surgeons to manipulate bone cement characteristics for specific clinical applications and improve safety.

  9. Doxorubicin, mesenchymal stem cell toxicity and antitumour activity: implications for clinical use.

    Baxter-Holland, Mia; Dass, Crispin R

    2018-03-01

    The use of doxorubicin, an antineoplastic medication used for the treatment of cancers via mechanisms that prevent replication of cells or lead to their death, can result in damage to healthy cells as well as malignant. Among the affected cells are mesenchymal stem cells (MSCs), which are involved in the maintenance and repair of tissues in the body. This review explores the mechanisms of biological effects and damage attributed to doxorubicin on MSCs. The PubMed database was used as a source of literature for this review. Doxorubicin has the potential to lead to significant and irreversible damage to the human bone marrow environment, including MSCs. The primary known mechanism of these changes is through free radical damage and activation of apoptotic pathways. The presence of MSCs in culture or in vivo appears to either suppress or promote tumour growth. Interactions between doxorubicin and MSCs have the potential to increase chemotherapy resistance. Doxorubicin-induced damage to MSCs is of concern clinically. However, MSCs also have been associated with resistance of tumour cells to drugs including doxorubicin. Further studies, particularly in vivo, are needed to provide consistent results of how the doxorubicin-induced changes to MSCs affect treatment and patient health. © 2018 Royal Pharmaceutical Society.

  10. Chronic inflammation-elicited liver progenitor cell conversion to liver cancer stem cell with clinical significance.

    Li, Xiao-Feng; Chen, Cheng; Xiang, Dai-Min; Qu, Le; Sun, Wen; Lu, Xin-Yuan; Zhou, Teng-Fei; Chen, Shu-Zhen; Ning, Bei-Fang; Cheng, Zhuo; Xia, Ming-Yang; Shen, Wei-Feng; Yang, Wen; Wen, Wen; Lee, Terence Kin Wah; Cong, Wen-Ming; Wang, Hong-Yang; Ding, Jin

    2017-12-01

    The substantial heterogeneity and hierarchical organization in liver cancer support the theory of liver cancer stem cells (LCSCs). However, the relationship between chronic hepatic inflammation and LCSC generation remains obscure. Here, we observed a close correlation between aggravated inflammation and liver progenitor cell (LPC) propagation in the cirrhotic liver of rats exposed to diethylnitrosamine. LPCs isolated from the rat cirrhotic liver initiated subcutaneous liver cancers in nonobese diabetic/severe combined immunodeficient mice, suggesting the malignant transformation of LPCs toward LCSCs. Interestingly, depletion of Kupffer cells in vivo attenuated the LCSC properties of transformed LPCs and suppressed cytokeratin 19/Oval cell 6-positive tumor occurrence. Conversely, LPCs cocultured with macrophages exhibited enhanced LCSC properties. We further demonstrated that macrophage-secreted tumor necrosis factor-α triggered chromosomal instability in LPCs through the deregulation of ubiquitin D and checkpoint kinase 2 and enhanced the self-renewal of LPCs through the tumor necrosis factor receptor 1/Src/signal transducer and activator of transcription 3 pathway, which synergistically contributed to the conversion of LPCs to LCSCs. Clinical investigation revealed that cytokeratin 19/Oval cell 6-positive liver cancer patients displayed a worse prognosis and exhibited superior response to sorafenib treatment. Our results not only clarify the cellular and molecular mechanisms underlying the inflammation-mediated LCSC generation but also provide a molecular classification for the individualized treatment of liver cancer. (Hepatology 2017;66:1934-1951). © 2017 by the American Association for the Study of Liver Diseases.

  11. In search of an improved injection technique for the clinical application of spermatogonial stem cell transplantation.

    Faes, Katrien; Lahoutte, Tony; Hoorens, Anne; Tournaye, Herman; Goossens, Ellen

    2017-03-01

    When fertility is impaired by anticancer treatment, spermatogonial stem cell transplantation (SSCT) could be used as a fertility restoration technique later on in life. Previously, we have demonstrated that a testicular cell suspension could be injected into a human cadaver testis, however, leakage to the interstitium was observed. In this study, injection of mouse testicular cells at an injection height of 50 cm (hydrostatic pressure) or via an automated injection pump (1400 µl, 2600 µl and 3000 µl) was evaluated. Significant difference in the filled radioactive volume was reached between the group in which 1400 µl was injected with an infusion pump and the groups in which 2600 µl (P = 0.019) or 3000 µl (P = 0.010) was injected. In all experimental groups green fluorescent protein positive (GFP + ) cells were observed in the seminiferous tubules. In conclusion, a lower injection height did not resolve the leakage of the injected cells to the interstitium. Using the infusion pump resulted in more efficient filling of the seminiferous tubules with lower interexperimental variability. Although leakage to the interstitium was still observed, with further optimisation, the use of an infusion pump for clinical application is advantageous. Copyright © 2016 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.

  12. Clinical and immunologic outcome of patients with cartilage hair hypoplasia after hematopoietic stem cell transplantation.

    Bordon, Victoria; Gennery, Andrew R; Slatter, Mary A; Vandecruys, Els; Laureys, Genevieve; Veys, Paul; Qasim, Waseem; Waseem, Qasim; Friedrich, Wilhelm; Wulfraat, Nico M; Scherer, Franziska; Cant, Andrew J; Fischer, Alain; Cavazzana-Calvo, Marina; Cavazanna-Calvo, Marina; Bredius, Robbert G M; Notarangelo, Luigi D; Mazzolari, Evelina; Neven, Benedicte; Güngör, Tayfun; Tayfun, Güngör

    2010-07-08

    Cartilage-hair hypoplasia (CHH) is a rare autosomal recessive disease caused by mutations in the RMRP gene. Beside dwarfism, CHH has a wide spectrum of clinical manifestations including variable grades of combined immunodeficiency, autoimmune complications, and malignancies. Previous reports in single CHH patients with significant immunodeficiencies have demonstrated that allogeneic hematopoietic stem cell transplantation (HSCT) is an effective treatment for the severe immunodeficiency, while growth failure remains unaffected. Because long-term experience in larger cohorts of CHH patients after HSCT is currently unreported, we performed a European collaborative survey reporting on 16 patients with CHH and immunodeficiency who underwent HSCT. Immune dysregulation, lymphoid malignancy, and autoimmunity were important features in this cohort. Thirteen patients were transplanted in early childhood ( approximately 2.5 years). The other 3 patients were transplanted at adolescent age. Of 16 patients, 10 (62.5%) were long-term survivors, with a median follow-up of 7 years. T-lymphocyte numbers and function have normalized, and autoimmunity has resolved in all survivors. HSCT should be considered in CHH patients with severe immunodeficiency/autoimmunity, before the development of severe infections, major organ damage, or malignancy might jeopardize the outcome of HSCT and the quality of life in these patients.

  13. The developing cancer stem-cell model: clinical challenges and opportunities

    Vermeulen, Louis; de Sousa E Melo, Felipe; Richel, Dick J.; Medema, Jan Paul

    2012-01-01

    During the past decade, a stem-cell-like subset of cancer cells has been identified in many malignancies. These cells, referred to as cancer stem cells (CSCs), are of particular interest because they are believed to be the clonogenic core of the tumour and therefore represent the cell population

  14. Cancer Stem Cell Hypothesis for Therapeutic Innovation in Clinical Oncology? Taking the Root Out, Not Chopping the Leaf.

    Dzobo, Kevin; Senthebane, Dimakatso Alice; Rowe, Arielle; Thomford, Nicholas Ekow; Mwapagha, Lamech M; Al-Awwad, Nasir; Dandara, Collet; Parker, M Iqbal

    2016-12-01

    Clinical oncology is in need of therapeutic innovation. New hypotheses and concepts for translation of basic research to novel diagnostics and therapeutics are called for. In this context, the cancer stem cell (CSC) hypothesis rests on the premise that tumors comprise tumor cells and a subset of tumor-initiating cells, CSCs, in a quiescent state characterized by slow cell cycling and expression of specific stem cell surface markers with the capability to maintain a tumor in vivo. The CSCs have unlimited self-renewal abilities and propagate tumors through division into asymmetric daughter cells. This differentiation is induced by both genetic and environmental factors. Another characteristic of CSCs is their therapeutic resistance, which is due to their quiescent state and slow dividing. Notably, the CSC phenotype differs greatly between patients and different cancer types. The CSCs may differ genetically and phenotypically and may include primary CSCs and metastatic stem cells circulating within the blood system. Targeting CSCs will require the knowledge of distinct stem cells within the tumor. CSCs can differentiate into nontumorigenic cells and this has been touted as the source of heterogeneity observed in many solid tumors. The latter cannot be fully explained by epigenetic regulation or by the clonal evolution theory. This heterogeneity markedly influences how tumors respond to therapy and prognosis. The present expert review offers an analysis and synthesis of the latest research and concepts on CSCs, with a view to truly disruptive innovation for future diagnostics and therapeutics in clinical oncology.

  15. Clinical performance of stem cell therapy in patients with acute-on-chronic liver failure: a systematic review and meta-analysis.

    Xue, Ran; Meng, Qinghua; Dong, Jinling; Li, Juan; Yao, Qinwei; Zhu, Yueke; Yu, Hongwei

    2018-05-10

    Stem cell therapy has been applied in the treatment of acute-on-chronic liver failure (ACLF). However, its clinical efficiency is still debatable. The aim of this systematic review and meta-analysis is to evaluate the clinical efficiency of stem cell therapy in the treatment of ACLF. The Cochrane Library, OVID, EMBASE, and PUBMED were searched to December 2017. Both randomized and non-randomized studies, assessing stem cell therapy in patients with ACLF, were included. The outcome measures were total bilirubin (TBIL), alanine transaminase (ALT), international normalized ratio (INR), albumin (ALB), and the model for end-stage liver disease (MELD) score. The quality of evidence was assessed by GRADEpro. Four randomized controlled trials and six non-randomized controlled trials were included. The TBIL levels significantly decreased at 1-, 3-, 12-month after the stem cell therapy (p = 0.0008; p = 0.04; p = 0.007). The ALT levels decreased significantly compared with the control group in the short-term (p stem cell therapy and control groups (p = 0.008). Further subgroup analysis for 3-month clinical performance according to the stem cell types have also been performed. This study suggests that the clinical outcomes of stem cell therapy were satisfied in patients with ACLF in the short-term. MSCs may be better than BM-MNCs in the stem cells transplantation of ACLF. However, more attention should focus on clinical trials in large-volume centers.

  16. Clinical translation of stem cell therapy in traumatic brain injury: the potential of encapsulated mesenchymal cell biodelivery of glucagon-like peptide-1

    Heile, Anna; Brinker, Thomas

    2011-01-01

    Traumatic brain injury remains a major cause of death and disability; it is estimated that annually 10 million people are affected. Preclinical studies have shown the potential therapeutic value of stem cell therapies. Neuroprotective as well as regenerative properties of stem cells have been suggested to be the mechanism of action in preclinical studies. However, up to now stem cell therapy has not been studied extensively in clinical trials. This article summarizes the current experimental ...

  17. The stem-cell application in ischemic heart disease: Basic principles, specifics and practical experience from clinical studies

    Banović Marko

    2015-01-01

    Full Text Available Longer life duration, different clinical presentations of coronary disease, as well as high incidence of comorbidity in patients with ischemic heart disease have led to an increase in the incidence of ischemic heart failure. Despite numerous and new treatment methods that act on different pathophysiological mechanisms that cause heart failure, and whose aim is to slowdown or stop the progression of this devastating disease, morbidity and mortality in these patients remain high. These facts have firstly led to the introduction of the experimental, and then clinical studies with the application of stem cells in patients with ischemic heart disease. Previous studies have shown that the application of stem cells is a feasible and safe method in patients with acute coronary syndrome, as well as in patients with chronic ischemic cardiomyopathy, but the efficacy of these methods in both of the abovementioned clinical syndromes has yet to be established. This review paper outlines the basic principles of treatment of ischemic heart disease with stem cells, as well as the experience and knowledge gained in previous clinical studies.

  18. Cell-based Therapy for Acute Organ Injury: Preclinical Evidence and On-going Clinical Trials Using Mesenchymal Stem Cells

    Monsel, Antoine; Zhu, Ying-gang; Gennai, Stephane; Hao, Qi; Liu, Jia; Lee, Jae W.

    2014-01-01

    Critically ill patients often suffer from multiple organ failures involving lung, kidney, liver or brain. Genomic, proteomic and metabolomic approaches highlight common injury mechanisms leading to acute organ failure. This underlines the need to focus on therapeutic strategies affecting multiple injury pathways. The use of adult stem cells such as mesenchymal stem or stromal cells (MSC) may represent a promising new therapeutic approach as increasing evidence shows that MSC can exert protective effects following injury through the release of pro-mitotic, anti-apoptotic, anti-inflammatory and immunomodulatory soluble factors. Furthermore, they can mitigate metabolomic and oxidative stress imbalance. In this work, we review the biological capabilities of MSC and the results of clinical trials using MSC as therapy in acute organ injuries. Although preliminary results are encouraging, more studies concerning safety and efficacy of MSC therapy are needed to determine their optimal clinical use. PMID:25211170

  19. The effects of equine peripheral blood stem cells on cutaneous wound healing: a clinical evaluation in four horses.

    Spaas, J H; Broeckx, S; Van de Walle, G R; Polettini, M

    2013-04-01

    Stem-cell therapy represents a promising strategy for the treatment of challenging pathologies, such as large, infected wounds that are unresponsive to conventional therapies. The present study describes the clinical application of peripheral blood stem cells (PBSCs) for the treatment of four adult Warmblood horses with naturally occurring wounds, which were unresponsive to conventional therapies for at least 3 months. A visual assessment was performed, and a number of wound-healing parameters (granulation tissue, crust formation and scar formation) were evaluated. In all cases, tissue overgrowth was visible within 4 weeks after PBSC injection, followed by the formation of crusts and small scars in the centre of the wound, with hair regeneration at the edges. In conclusion, this is the first report of PBSC therapy of skin wounds in horses, and it produced a positive visual and clinical outcome. © The Author(s) CED © 2013 British Association of Dermatologists.

  20. A preliminary clinical trial using flowable glass-ionomer cement as a liner in proximal-ART restorations: the operator effect

    Bonifácio, C.C.; Hesse, D.; Bönecker, M.; van Loveren, C.; van Amerongen, W.E.; Raggio, D.P.

    2013-01-01

    .Objectives: This in vivo study was carried out to assess the influence of the operator experience on the survival rate of proximal-ART restorations using a two-layer technique to insert the glass-ionomer cement (GIC). Study Design: Forty five proximal cavities in primary molars were restored in a

  1. Creep and fatigue behavior of a novel 2-component paste-like formulation of acrylic bone cements.

    Köster, Ulrike; Jaeger, Raimund; Bardts, Mareike; Wahnes, Christian; Büchner, Hubert; Kühn, Klaus-Dieter; Vogt, Sebastian

    2013-06-01

    The fatigue and creep performance of two novel acrylic bone cement formulations (one bone cement without antibiotics, one with antibiotics) was compared to the performance of clinically used bone cements (Osteopal V, Palacos R, Simplex P, SmartSet GHV, Palacos R+G and CMW1 with Gentamicin). The preparation of the novel bone cement formulations involves the mixing of two paste-like substances in a static mixer integrated into the cartridge which is used to apply the bone cement. The fatigue performance of the two novel bone cement formulations is comparable to the performance of the reference bone cements. The creep compliance of the bone cements is significantly influenced by the effects of physical ageing. The model parameters of Struik's creep law are used to compare the creep behavior of different bone cements. The novel 2-component paste-like bone cement formulations are in the group of bone cements which exhibit a higher creep resistance.

  2. Stem Cells in Skin Regeneration, Wound Healing, and Their Clinical Applications.

    Ojeh, Nkemcho; Pastar, Irena; Tomic-Canic, Marjana; Stojadinovic, Olivera

    2015-10-23

    The skin is the largest organ of the body and has an array of functions. Skin compartments, epidermis, and hair follicles house stem cells that are indispensable for skin homeostasis and regeneration. These stem cells also contribute to wound repair, resulting in restoration of tissue integrity and function of damaged tissue. Unsuccessful wound healing processes often lead to non-healing wounds. Chronic wounds are caused by depletion of stem cells and a variety of other cellular and molecular mechanisms, many of which are still poorly understood. Current chronic wound therapies are limited, so the search to develop better therapeutic strategies is ongoing. Adult stem cells are gaining recognition as potential candidates for numerous skin pathologies. In this review, we will discuss epidermal and other stem cells present in the skin, and highlight some of the therapeutic applications of epidermal stem cells and other adult stem cells as tools for cell/scaffold-based therapies for non-healing wounds and other skin disorders. We will also discuss emerging concepts and offer some perspectives on how skin tissue-engineered products can be optimized to provide efficacious therapy in cutaneous repair and regeneration.

  3. Advanced cementation concepts

    Howard, C.G.

    1989-10-01

    The purpose of this programme of work was to investigate whether improvements could be made to existing formulations for cement suitable for the immobilization of intermediate level radioactive waste. Two additives were selected, microsilica and limestone flour. Improvements to the cement were only slight. (author)

  4. Preparation of hydraulic cement

    1921-08-28

    A process for the preparation of hydraulic cement by the use of oil-shale residues is characterized in that the oil-shale refuse is mixed with granular basic blast-furnace slag and a small amount of portland cement and ground together.

  5. Low force cementation.

    Wilson, P R

    1996-07-01

    The marginal adaptation of full coverage restorations is adversely affected by the introduction of luting agents of various minimum film thicknesses during the cementation process. The increase in the marginal opening may have long-term detrimental effects on the health of both pulpal and periodontal tissues. The purpose of this study was to determine the effects of varying seating forces (2.5, 12.5, 25 N), venting, and cement types on post-cementation marginal elevation in cast crowns. A standardized cement space of 40 microns was provided between a machined gold crown and a stainless steel die. An occlusal vent was placed that could be opened or closed. The post-cementation crown elevation was measured, following the use of two commercially available capsulated dental cements (Phosphacap, and Ketac-cem Applicap). The results indicate that only the combination of Ketac-Cem Applicap and crown venting produced post-cementation crown elevation of less than 20 microns when 12.5 N seating force was used. Higher forces (25 N) and venting were required for comparable seating when using Phosphacap (19 microns). The amount of force required to allow maximum seating of cast crowns appears to be cement specific, and is reduced by effective venting procedures.

  6. Cementation process study

    Park, H.H.; Han, K.W.; Ahn, S.J.; Choi, K.S.; Lee, M.W.; Ryu, Y.K.

    1985-01-01

    In the cementation process study, in 1984, design of the waste treatment simulator was finished for the first step. We can experience not only the operation of solidification system but the design and construction of comming large scale plant through the design of cementation process. (Author)

  7. Stair climbing is more detrimental to the cement in hip replacement than walking

    Stolk, J.; Verdonschot, N.J.J.; Huiskes, H.W.J.

    2002-01-01

    Stair climbing may be detrimental to cemented total hip arthroplasties, because it subjects the reconstruction to high torsional loads. The current study investigated how stair climbing contributes to damage accumulation in the cement around a femoral stem compared with walking, taking into account

  8. Towards the responsible clinical implementation of stem cell-based fertility treatments

    Hendriks, S.

    2017-01-01

    Reproductive medicine has been criticized for introducing innovative techniques without sufficient consideration of their effectiveness, safety and broader societal consequences. Researchers are currently creating oocytes or spermatozoa by manipulating stem cells with the aim of curing fertility

  9. Prospective assessment of bone turnover and clinical bone diseases after allogeneic hematopoietic stem-cell transplantation.

    Petropoulou, Anna D; Porcher, Raphael; Herr, Andrée-Laure; Devergie, Agnès; Brentano, Thomas Funck; Ribaud, Patricia; Pinto, Fernando O; Rocha, Vanderson; Peffault de Latour, Régis; Orcel, Philippe; Socié, Gérard; Robin, Marie

    2010-06-15

    Bone complications after hematopoietic stem-cell transplantation (HSCT) are relatively frequent. Evaluation of biomarkers of bone turnover and dual energy x-ray absorptiometry (DEXA) are not known in this context. We prospectively evaluated bone mineral density, biomarkers of bone turnover, and the cumulative incidence of bone complications after allogeneic HSCT. One hundred forty-six patients were included. Bone mineral density was measured by DEXA 2-month and 1-year post-HSCT. The markers of bone turnover were serum C-telopeptide (C-TP), 5 tartrate-resistant acid phosphatase (bone resorption), and osteocalcin (bone formation) determined pre-HSCT and 2 months and 1 year thereafter. Potential association between osteoporosis at 2 months, osteoporotic fracture or avascular necrosis and, individual patient's characteristics and biologic markers were tested. C-TP was high before and 2 months after transplant. At 2 months, DEXA detected osteoporosis in more than half the patients tested. Male sex, median age less than or equal to 15 years, and abnormal C-TP before HSCT were risk factors significantly associated with osteoporosis. Three-year cumulative incidences of fractures and avascular necrosis were 8% and 11%, respectively. Children were at higher risk of fracture, whereas corticosteroid treatment duration was a significant risk factor for developing a clinical bone complication post-HSCT. Bone complications and osteoporosis are frequent after HSCT. Bone biologic markers and DEXA showed that subclinical bone abnormalities appeared early post-HSCT. The risk factors, age, gender, and C-TP easily available at the time of transplantation were identified. Biphosphonates should probably be given to patients with those risk factors.

  10. Durability of cermet ionomer cement conditioned in different media.

    el-Din, I M

    1992-01-01

    The glass ionomer cement has exhibited significant adhesion to hard tooth structures, and good cariostatic properties. The sintering of the silver alloy powder and glass ionomer cement "cermet cement" has provided additional improvement in the physical properties of the restorative material. These were flexural resistance, wear resistance, increased radio-opacity, hardness and porosity. The improvement in the physical properties of the cermet glass cements has provided an extension in their clinical use as core build up, lining for inlays, amalgam and composite restoratives, fissure filling, restoration of primary teeth, class II tunnel preparation, treatment of root caries and repair of defective metal margins in crown and inlays.

  11. Adipose-derived adult stem cells: available technologies for potential clinical regenerative applications in dentistry.

    Catalano, Enrico; Cochis, Andrea; Varoni, Elena; Rimondini, Lia; Carrassi, Antonio; Azzimonti, Barbara

    2013-01-01

    Tissue homeostasis depends closely on the activity and welfare of adult stem cells. These cells represent a promising tool for biomedical research since they can aid in treatment and promote the regeneration of damaged organs in many human disorders. Adult stem cells indefinitely preserve their ability to self-renew and differentiate into various phenotypes; this capacity could be promoted in vitro by particular culture conditions (differentiation media) or spontaneously induced in vivo by exploiting the biochemical and mechanical properties of the tissue in which the stem cells are implanted. Among the different sources of adult stem cells, adipose tissue is an attractive possibility thanks to its ready availability and the standard extraction techniques at our disposal today. This review discusses the isolation, characterization, and differentiation of human adipose-derived adult stem cells, as well as regeneration strategies, therapeutic uses, and adverse effects of their delivery. In particular, since oral disorders (e.g., trauma, erosion, and chronic periodontitis) often cause the loss of dental tissue along with functional, phonetic, and aesthetic impairment, this review focuses on the application of human adipose-derived adult stem cells, alone or in combination with biomaterials, in treating oral diseases.

  12. The Challenges of First-in-Human Stem Cell Clinical Trials: What Does This Mean for Ethics and Institutional Review Boards?

    Barker, Roger A; Carpenter, Melissa K; Forbes, Stuart; Goldman, Steven A; Jamieson, Catriona; Murry, Charles E; Takahashi, Jun; Weir, Gordon

    2018-05-08

    Stem cell-based clinical interventions are increasingly advancing through preclinical testing and approaching clinical trials. The complexity and diversity of these approaches, and the confusion created by unproven and untested stem cell-based "therapies," create a growing need for a more comprehensive review of these early-stage human trials to ensure they place the patients at minimal risk of adverse events but are also based on solid evidence of preclinical efficacy with a clear scientific rationale for that effect. To address this issue and supplement the independent review process, especially that of the ethics and institutional review boards who may not be experts in stem cell biology, the International Society for Stem Cell Research (ISSCR) has developed a set of practical questions to cover the major issues for which clear evidence-based answers need to be obtained before approving a stem cell-based trial. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

  13. Safety Profile of Good Manufacturing Practice Manufactured Interferon γ-Primed Mesenchymal Stem/Stromal Cells for Clinical Trials.

    Guess, Adam J; Daneault, Beth; Wang, Rongzhang; Bradbury, Hillary; La Perle, Krista M D; Fitch, James; Hedrick, Sheri L; Hamelberg, Elizabeth; Astbury, Caroline; White, Peter; Overolt, Kathleen; Rangarajan, Hemalatha; Abu-Arja, Rolla; Devine, Steven M; Otsuru, Satoru; Dominici, Massimo; O'Donnell, Lynn; Horwitz, Edwin M

    2017-10-01

    Mesenchymal stem/stromal cells (MSCs) are widely studied by both academia and industry for a broad array of clinical indications. The collective body of data provides compelling evidence of the clinical safety of MSC therapy. However, generally accepted proof of therapeutic efficacy has not yet been reported. In an effort to generate a more effective therapeutic cell product, investigators are focused on modifying MSC processing protocols to enhance the intrinsic biologic activity. Here, we report a Good Manufacturing Practice-compliant two-step MSC manufacturing protocol to generate MSCs or interferon γ (IFNγ) primed MSCs which allows freshly expanded cells to be infused in patients on a predetermined schedule. This protocol eliminates the need to infuse cryopreserved, just thawed cells which may reduce the immune modulatory activity. Moreover, using (IFNγ) as a prototypic cytokine, we demonstrate the feasibility of priming the cells with any biologic agent. We then characterized MSCs and IFNγ primed MSCs prepared with our protocol, by karyotype, in vitro potential for malignant transformation, biodistribution, effect on engraftment of transplanted hematopoietic cells, and in vivo toxicity in immune deficient mice including a complete post-mortem examination. We found no evidence of toxicity attributable to the MSC or IFNγ primed MSCs. Our data suggest that the clinical risk of infusing MSCs or IFNγ primed MSCs produced by our two-step protocol is not greater than MSCs currently in practice. While actual proof of safety requires phase I clinical trials, our data support the use of either cell product in new clinical studies. Stem Cells Translational Medicine 2017;6:1868-1879. © 2017 The Authors Stem Cells Translational Medicine published by Wiley Periodicals, Inc. on behalf of AlphaMed Press.

  14. Advances toward regenerative medicine in the central nervous system: challenges in making stem cell therapy a viable clinical strategy.

    Stoll, Elizabeth A

    2014-01-01

    Over recent years, there has been a great deal of interest in the prospects of stem cell-based therapies for the treatment of nervous system disorders. The eagerness of scientists, clinicians, and spin-out companies to develop new therapies led to premature clinical trials in human patients, and now the initial excitement has largely turned to skepticism. Rather than embracing a defeatist attitude or pressing blindly ahead, I argue it is time to evaluate the challenges encountered by regenerative medicine in the central nervous system and the progress that is being made to solve these problems. In the twenty years since the adult brain was discovered to have an endogenous regenerative capacity, much basic research has been done to elucidate mechanisms controlling proliferation and cellular identity; how stem cells may be directed into neuronal lineages; genetic, pharmacological, and behavioral interventions that modulate neurogenic activity; and the exact nature of limitations to regeneration in the adult, aged, diseased and injured CNS. These findings should prove valuable in designing realistic clinical strategies to improve the prospects of stem cell-based therapies. In this review, I discuss how basic research continues to play a critical role in identifying both barriers and potential routes to regenerative therapy in the CNS.

  15. A randomized study on migration of the Spectron EF and the Charnley flanged 40 cemented femoral components using radiostereometric analysis at 2 years.

    Kadar, Thomas; Hallan, Geir; Aamodt, Arild; Indrekvam, Kari; Badawy, Mona; Havelin, Leif Ivar; Stokke, Terje; Haugan, Kristin; Espehaug, Birgitte; Furnes, Ove

    2011-10-01

    We performed a randomized study to determine the migration patterns of the Spectron EF femoral stem and to compare them with those of the Charnley stem, which is regarded by many as the gold standard for comparison of implants due to its extensive documentation. 150 patients with a mean age of 70 years were randomized, single-blinded, to receive either a cemented Charnley flanged 40 monoblock, stainless steel, vaquasheen surface femoral stem with a 22.2-mm head (n = 30) or a cemented Spectron EF modular, matte, straight, collared, cobalt-chrome femoral stem with a 28-mm femoral head and a roughened proximal third of the stem (n = 120). The patients were followed with repeated radiostereometric analysis for 2 years to assess migration. At 2 years, stem retroversion was 2.3° and 0.7° (p < 0.001) and posterior translation was 0.44 mm and 0.17 mm (p = 0.002) for the Charnley group (n = 26) and the Spectron EF group (n = 74), respectively. Subsidence was 0.26 mm for the Charnley and 0.20 mm for the Spectron EF (p = 0.5). The Spectron EF femoral stem was more stable than the Charnley flanged 40 stem in our study when evaluated at 2 years. In a report from the Norwegian arthroplasty register, the Spectron EF stem had a higher revision rate due to aseptic loosening beyond 5 years than the Charnley. Initial stability is not invariably related to good long-term results. Our results emphasize the importance of prospective long-term follow-up of prosthetic implants in clinical trials and national registries and a stepwise introduction of implants.

  16. Modified pavement cement concrete

    Botsman, L. N.; Ageeva, M. S.; Botsman, A. N.; Shapovalov, S. M.

    2018-03-01

    The paper suggests design principles of pavement cement concrete, which covers optimization of compositions and structures at the stage of mixture components selection due to the use of plasticizing agents and air-retaining substances that increase the viability of a concrete mixture. It also demonstrates advisability of using plasticizing agents together with air-retaining substances when developing pavement concrete compositions, which provides for the improvement of physical and mechanical properties of concrete and the reduction of cement binding agent consumption thus preserving strength indicators. The paper shows dependences of the main physical-mechanical parameters of concrete on cement consumption, a type and amount of additives.

  17. Radioactive waste cementation

    Soriano B, A.

    1996-01-01

    This research was carried out to develop the most adequate technique to immobilize low and medium-activity radioactive waste. different brands of national cement were used, portland and pozzolanic cement. Prismatic and cylindrical test tubes were prepared with different water/cement (W/C) relationship. Additives such a as clay and bentonite were added in some other cases. Later, the properties of these test tubes were evaluated. Properties such as: mechanical resistance, immersion resistance, lixiviation and porosity resistance. Cement with the highest mechanical resistance values, 62,29 MPa was pozzolanic cement for a W/C relationship of 0,35. It must be mentioned that the other types of cements reached a mechanical resistance over 10 MPa, a value indicated by the international standards for transportation and storage of low and medium-activity radioactive waste at a superficial level. However, in the case of immersion resistance, Sol cement (portland type I) with a W/C relationship of 0,35 reached a compression resistance over 61,92 MPa; as in the previous cases, the other cements reached a mechanical resistance > 10 MPa. Regarding porosity, working with W/C relationships = 0,35 0,40 and 0,45, without additives and with additives, the percentage of porosity found for all cements is lower than 40% percentage indicated by international standards. With regard to the lixiviation test, pozzolanic cement best retained Cesium-137 and Cobalt-60, and increased its advantages when bentonite was added, obtaining a lixiviation rate of 2,02 x E-6 cm/day. Sol cement also improved its properties when bentonite was added and obtained a lixiviation rate of 2,84 x E-6 cm/day for Cesium-137. However, Cobalt-60 is almost completely retained with the 3 types of cement with or without additives, reaching the limits indicated by the international standards for the lixiviation rate of beta-gamma emitter < 5,00E-4 cm/day. Characterizing the final product involves the knowledge of its

  18. Tympanoplasty with ionomeric cement

    Kjeldsen, A D; Grøntved, A M

    2000-01-01

    with isolated erosion of the long incus process have been treated with a new surgical technique in which the ossicular chain was rebuilt with ionomeric cement. The results in hearing performance (mean pure-tone average (PTA) 0.5, 1 and 2 kHz) were evaluated pre- and post-surgery, and compared to those...... of > 10 dB, in 4 there was a slight improvement and in 2 a decline. The difference was not statistically significant. Hearing improvement using ionomeric cement in type II tympanoplasty was satisfactory. Reconstruction of the ossicular chain with ionomeric cement is recommended, as the procedure is easy...

  19. Translation of Human-Induced Pluripotent Stem Cells: From Clinical Trial in a Dish to Precision Medicine.

    Sayed, Nazish; Liu, Chun; Wu, Joseph C

    2016-05-10

    The prospect of changing the plasticity of terminally differentiated cells toward pluripotency has completely altered the outlook for biomedical research. Human-induced pluripotent stem cells (iPSCs) provide a new source of therapeutic cells free from the ethical issues or immune barriers of human embryonic stem cells. iPSCs also confer considerable advantages over conventional methods of studying human diseases. Since its advent, iPSC technology has expanded with 3 major applications: disease modeling, regenerative therapy, and drug discovery. Here we discuss, in a comprehensive manner, the recent advances in iPSC technology in relation to basic, clinical, and population health. Copyright © 2016 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  20. BoneSource hydroxyapatite cement: a novel biomaterial for craniofacial skeletal tissue engineering and reconstruction.

    Friedman, C D; Costantino, P D; Takagi, S; Chow, L C

    1998-01-01

    BoneSource-hydroxyapatite cement is a new self-setting calcium phosphate cement biomaterial. Its unique and innovative physical chemistry coupled with enhanced biocompatibility make it useful for craniofacial skeletal reconstruction. The general properties and clinical use guidelines are reviewed. The biomaterial and surgical applications offer insight into improved outcomes and potential new uses for hydroxyapatite cement systems.

  1. Arthroscopic Transplantation of Synovial Stem Cells Improves Clinical Outcomes in Knees With Cartilage Defects.

    Sekiya, Ichiro; Muneta, Takeshi; Horie, Masafumi; Koga, Hideyuki

    2015-07-01

    Transplantation of mesenchymal stem cells (MSCs) is one possible strategy to achieve articular cartilage repair. We previously reported that synovial MSCs were highly proliferative and able to undergo chondrogenesis. We also found that placing a suspension of synovial MSCs on a cartilage defect for 10 minutes promoted cartilage repair in rabbit and pig models. However, the in vivo efficacy of this approach has not been tested clinically. We asked whether transplantation of synovial MSCs improves (1) MRI features, (2) histologic features, and (3) clinical evaluation scores in patients with cartilage defects in the knee? Patients with a symptomatic single cartilage lesion of the femoral condyle were indicated for inclusion in our study, and between April 2008 and April 2011, 10 patients were enrolled in this study. All patients completed followups of 3 years or more. The average followup period was 52 months (range, 37-80 months). Synovial MSCs were expanded with 10% autologous human serum for 14 days after digestion. For transplantation, the patient was positioned so that the cartilage defect was facing upward, and synovial MSC suspension was placed on the cartilage defect with a syringe under arthroscopic control. The defect with the applied suspension then was held in the upward position for 10 minutes. Five patients underwent concomitant ACL reconstructions, among whom two had meniscus suturing performed simultaneously. For MRI quantification, the cartilage defect was scored from 0 to 5. Second-look arthroscopy was performed for four patients and biopsy specimens were evaluated histologically. Clinical outcome was assessed using the Lysholm score and Tegner Activity Level Scale at final followup. Comparisons of MRI and Lysholm scores before and after treatment for each patient were analyzed using the Wilcoxon signed-rank test. MRI score (median ± 95% CI) was 1.0 ± 0.3 before and 5.0 ± 0.7 after, and increased after treatment in each patient (p = 0.005). Second

  2. Autologous Stem Cell Injection for Spinal Cord Injury - A Clinical Study from India.

    Ravikumar R

    2007-01-01

    Full Text Available We studied 100 patients with Spinal Cord injury (SCI after Autologous Stem cell Injection in the Spinal fluid with a Follow up of 6 months post Stem cell injection. There were 69 males and 31 females; age ranging from 8 years to 55 years.? Time after Spinal Injury ranged from 11 years - 3 months (Average: 4.5 years. The Level of Injury ranged from Upper Thoracic (T1-T7 - 34 pts, Lower thoracic (T7-T12 -45 pts, Lumbar -12, Cervical-9 pts. All patients had an MRI Scan, urodynamic study and SSEP (somatosensory Evoked Potential tests before and 3 months after Stem cell Injection.80% of patients had Grade 0 power in the Lower limbs and rest had grade 1-2 power before stem cell injections. 70% of cases had complete lack of Bladder control and 95% had reduced detrusor function.We Extracted CD34 and CD 133 marked Stem cells from 100 ml of Bone marrow Aspirate using Ficoll Gradient method with Cell counting done using flowcytometry.15 ml of the Stem cell concentrate was injected into the Lumbar spinal fluid in aseptic conditions. The CD 34/CD45 counts ranged from 120-400 million cells in the total volume.6 months after Injection, 8 patients had more than 2 grades of Motor power improvement, 3 are able to walk with support. 1 patient with T12/L1 injury was able to walk without support. 12 had sensory tactile and Pain perception improvement and 8 had objective improvement in bladder control and Bladder Muscle contractility. A total of 18 patients had reported or observed improvement in Neurological status. 85% of patients who had motor Improvement had Lesions below T8. MRI, SSEP and Urodynamic Study data are gathered at regular intervals. Conclusion: This study shows that Quantitative and qualitative Improvement in the Neurological status of paralyzed patients after Spinal cord injury is possible after autologous bone marrow Stem cell Injections in select patients. There was no report of Allodynia indicating the safety of the procedure. Further studies to

  3. Retention of metal-ceramic crowns with contemporary dental cements.

    Johnson, Glen H; Lepe, Xavier; Zhang, Hai; Wataha, John C

    2009-09-01

    New types of crown and bridge cement are in use by practitioners, and independent studies are needed to assess their effectiveness. The authors conducted a study in three parts (study A, study B, and study C) and to determine how well these new cements retain metal-ceramic crowns. The authors prepared teeth with a 20-degree taper and a 4-millimeter length. They cast high-noble metal-ceramic copings, then fitted and cemented them with a force of 196 newtons. The types of cements they used were zinc phosphate, resin-modified glass ionomer, conventional resin and self-adhesive modified resin. They thermally cycled the cemented copings, then removed them. They recorded the removal force and calculated the stress of dislodgment by using the surface area of each preparation. They used a single-factor analysis of variance to analyze the data (alpha = .05). The mean stresses necessary to remove crowns, in megapascals, were 8.0 for RelyX Luting (3M ESPE, St. Paul, Minn.), 7.3 for RelyX Unicem (3M ESPE), 5.7 for Panavia F (Kuraray America, New York) and 4.0 for Fuji Plus (GC America, Alsip, Ill.) in study A; 8.1 for RelyX Luting, 2.6 for RelyX Luting Plus (3M ESPE) and 2.8 for Fuji CEM (GC America) in study B; and 4.9 for Maxcem (Kerr, Orange, Calif.), 4.0 for BisCem (Bisco, Schaumburg, Ill.), 3.7 for RelyX Unicem Clicker (3M ESPE), 2.9 for iCEM (Heraeus Kulzer, Armonk, N.Y.) and 2.3 for Fleck's Zinc Cement (Keystone Industries, Cherry Hill, N.J.) in study C. Powder-liquid versions of new cements were significantly more retentive than were paste-paste versions of the same cements. The mean value of crown removal stress for the new self-adhesive modified-resin cements varied appreciably among the four cements tested. All cements retained castings as well as or better than did zinc phosphate cement. Powder-liquid versions of cements, although less convenient to mix, may be a better clinical choice when crown retention is an issue. All cements tested will retain castings

  4. Safety and effectiveness of stem cell therapies in early-phase clinical trials in stroke: a systematic review and meta-analysis.

    Nagpal, Anjali; Choy, Fong Chan; Howell, Stuart; Hillier, Susan; Chan, Fiona; Hamilton-Bruce, Monica A; Koblar, Simon A

    2017-08-30

    Stem cells have demonstrated encouraging potential as reparative therapy for patients suffering from post-stroke disability. Reperfusion interventions in the acute phase of stroke have shown significant benefit but are limited by a narrow window of opportunity in which they are beneficial. Thereafter, rehabilitation is the only intervention available. The current review summarises the current evidence for use of stem cell therapies in stroke from early-phase clinical trials. The safety and feasibility of administering different types of stem cell therapies in stroke seem to be reasonably proven. However, the effectiveness needs still to be established through bigger clinical trials with more pragmatic clinical trial designs that address the challenges raised by the heterogeneous nature of stroke per se, as well those due to unique characteristics of stem cells as therapeutic agents.

  5. A New Biphasic Dicalcium Silicate Bone Cement Implant

    Fausto Zuleta

    2017-07-01

    Full Text Available This study aimed to investigate the processing parameters and biocompatibility of a novel biphasic dicalcium silicate (C2S cement. Biphasic α´L + β-C2Sss was synthesized by solid-state processing, and was used as a raw material to prepare the cement. In vitro bioactivity and biocompatibility studies were assessed by soaking the cement samples in simulated body fluid (SBF and human adipose stem cell cultures. Two critical-sized defects of 6 mm Ø were created in 15 NZ tibias. A porous cement made of the high temperature forms of C2S, with a low phosphorous substitution level, was produced. An apatite-like layer covered the cement’s surface after soaking in SBF. The cell attachment test showed that α´L + β-C2Sss supported cells sticking and spreading after 24 h of culture. The cement paste (55.86 ± 0.23 obtained higher bone-to-implant contact (BIC percentage values (better quality, closer contact in the histomorphometric analysis, and defect closure was significant compared to the control group (plastic. The residual material volume of the porous cement was 35.42 ± 2.08% of the initial value. The highest BIC and bone formation percentages were obtained on day 60. These results suggest that the cement paste is advantageous for initial bone regeneration.

  6. the Danish cement industry

    la Cour, Lisbeth Funding; Møllgård, Peter

    2001-01-01

    We test econometrically whether the sole Danish producer of cement holds a dominant position in the Danish market for (grey) cement. In import penetration tests, we find that its pricing and quantity decisions are independent of import price and quantity, implying that it can act to a considerable extent independently of its competitors. We also test whether it can act independently of its customers and find that its demand is inelastic with respect to its price. It thus holds a dominant posi...

  7. Nanoparticulate fillers improve the mechanical strength of bone cement.

    Gomoll, Andreas H; Fitz, Wolfgang; Scott, Richard D; Thornhill, Thomas S; Bellare, Anuj

    2008-06-01

    Polymethylmethacrylate (PMMA-) based bone cement contains micrometer-size barium sulfate or zirconium oxide particles to radiopacify the cement for radiographic monitoring during follow-up. Considerable effort has been expended to improve the mechanical qualities of cements, largely through substitution of PMMA with new chemical structures. The introduction of these materials into clinical practice has been complicated by concerns over the unknown long-term risk profile of these new structures in vivo. We investigated a new composite with the well characterized chemical composition of current cements, but with nanoparticles instead of the conventional, micrometer-size barium sulfate radiopacifier. In this study, we replaced the barium sulfate microparticles that are usually present in commercial PMMA cements with barium sulfate nanoparticles. The resultant "microcomposite" and "nanocomposite" cements were then characterized through morphological investigations such as ultra-small angle X-ray scattering (USAXS) and scanning electron microscopy (SEM). Mechanical characterization included compression, tensile, compact tension, and fatigue testing. SEM and USAXS showed excellent dispersion of nanoparticles. Substitution of nanoparticles for microparticles resulted in a 41% increase in tensile strain-to-failure (p = 0.002) and a 70% increase in tensile work-of-fracture (p = 0.005). The nanocomposite cement also showed a two-fold increase in fatigue life compared to the conventional, microcomposite cement. In summary, nanoparticulate substitution of radiopacifiers substantially improved the in vitro mechanical properties of PMMA bone cement without changing the known chemical composition.

  8. Mesenchymal and induced pluripotent stem cells: general insights and clinical perspectives

    Zomer HD

    2015-09-01

    Full Text Available Helena D Zomer,1 Atanásio S Vidane,1 Natalia N Gonçalves,1 Carlos E Ambrósio2 1Department of Surgery, Faculty of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo, SP, Brazil; 2Department of Veterinary Medicine, Faculty of Animal Sciences and Food Engineering, University of São Paulo, Pirassununga, SP, Brazil Abstract: Mesenchymal stem cells have awakened a great deal of interest in regenerative medicine due to their plasticity, and immunomodulatory and anti-inflammatory properties. They are high-yield and can be acquired through noninvasive methods from adult tissues. Moreover, they are nontumorigenic and are the most widely studied. On the other hand, induced pluripotent stem (iPS cells can be derived directly from adult cells through gene reprogramming. The new iPS technology avoids the embryo destruction or manipulation to generate pluripotent cells, therefore, are exempt from ethical implication surrounding embryonic stem cell use. The pre-differentiation of iPS cells ensures the safety of future approaches. Both mesenchymal stem cells and iPS cells can be used for autologous cell transplantations without the risk of immune rejection and represent a great opportunity for future alternative therapies. In this review we discussed the therapeutic perspectives using mesenchymal and iPS cells. Keywords: cell transplantation, cell therapy, iPS, MSC

  9. Guidelines for defining and implementing standard episode of care for hematopoietic stem cell transplantation within the context of clinical trials.

    Majhail, Navneet S; Giralt, Sergio; Bonagura, Anthony; Crawford, Stephen; Farnia, Stephanie; Omel, James L; Pasquini, Marcelo; Saber, Wael; LeMaistre, Charles F

    2015-04-01

    The Patient Protection and Affordable Care Act requires that health care insurers cover routine patient costs associated with participating in clinical trials for cancer and other life-threatening diseases. There is a need to better define routine costs within the context of hematopoietic stem cell transplantation (HSCT) clinical trials. This white paper presents guidance on behalf of the American Society for Blood and Marrow Transplantation for defining a standard HSCT episode and delineates components that may be considered as routine patient costs versus research costs. The guidelines will assist investigators, trial sponsors, and transplantation centers in planning for clinical trials that are conducted as a part of the HSCT episode and will inform payers who provide coverage for transplantation. Copyright © 2015 American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.

  10. Towards a clinically relevant lentiviral transduction protocol for primary human CD34 hematopoietic stem/progenitor cells.

    Michelle Millington

    2009-07-01

    Full Text Available Hematopoietic stem cells (HSC, in particular mobilized peripheral blood stem cells, represent an attractive target for cell and gene therapy. Efficient gene delivery into these target cells without compromising self-renewal and multi-potency is crucial for the success of gene therapy. We investigated factors involved in the ex vivo transduction of CD34(+ HSCs in order to develop a clinically relevant transduction protocol for gene delivery. Specifically sought was a protocol that allows for efficient transduction with minimal ex vivo manipulation without serum or other reagents of animal origin.Using commercially available G-CSF mobilized peripheral blood (PB CD34(+ cells as the most clinically relevant target, we systematically examined factors including the use of serum, cytokine combinations, pre-stimulation time, multiplicity of infection (MOI, transduction duration and the use of spinoculation and/or retronectin. A self-inactivating lentiviral vector (SIN-LV carrying enhanced green fluorescent protein (GFP was used as the gene delivery vehicle. HSCs were monitored for transduction efficiency, surface marker expression and cellular function. We were able to demonstrate that efficient gene transduction can be achieved with minimal ex vivo manipulation while maintaining the cellular function of transduced HSCs without serum or other reagents of animal origin.This study helps to better define factors relevant towards developing a standard clinical protocol for the delivery of SIN-LV into CD34(+ cells.

  11. 2-year follow-up report on micromotion of a short tibia stem. A prospective, randomized RSA study of 59 patients.

    Molt, Mats; Toksvig-Larsen, Sören

    2015-01-01

    A shortened tibial stem could influence the early prosthetic fixation. We therefore compared the short stem to the standard-length stem using radiostereometric analysis (RSA) as primary outcome measure. 60 patients were randomized to receive a cemented Triathlon total knee arthroplasty (TKA) with a tibial tray of either standard or short stem length. The patients were blinded regarding treatment allocation. The micromotion of the tibial component was measured by RSA postoperatively, at 3 months, and after 1 and 2 years; clinical outcome was measured with the American Knee Society score (AKSS) and the knee osteoarthritis and injury outcome score (KOOS). The maximum total point motion (MTPM) for the standard stem was 0.36 (SD 0.16) mm at 3 months, 0.51 (SD 0.27) mm at 1 year, and 0.54 (SD 0.28) mm at 2 years. For the short stem, it was 0.42 (0.24) mm, 0.59 (0.43) mm, and 0.61 (0.39) mm. 4 short-stemmed components and 2 standard-stemmed components had more than 0.2 mm of migration between the first- and second-year follow-up, and were classified as continuously migrating. The short-stemmed cemented tibial prosthesis showed an early prosthetic migratory pattern similar to that of the standard-stemmed cemented Triathlon knee prosthesis. The number of continuously migrating tibial plates in each group is predictive of a lower revision rate than 5% at 10 years.

  12. Systematic review of induced pluripotent stem cell technology as a potential clinical therapy for spinal cord injury.

    Kramer, Anne S; Harvey, Alan R; Plant, Giles W; Hodgetts, Stuart I

    2013-01-01

    Transplantation therapies aimed at repairing neurodegenerative and neuropathological conditions of the central nervous system (CNS) have utilized and tested a variety of cell candidates, each with its own unique set of advantages and disadvantages. The use and popularity of each cell type is guided by a number of factors including the nature of the experimental model, neuroprotection capacity, the ability to promote plasticity and guided axonal growth, and the cells' myelination capability. The promise of stem cells, with their reported ability to give rise to neuronal lineages to replace lost endogenous cells and myelin, integrate into host tissue, restore functional connectivity, and provide trophic support to enhance and direct intrinsic regenerative ability, has been seen as a most encouraging step forward. The advent of the induced pluripotent stem cell (iPSC), which represents the ability to "reprogram" somatic cells into a pluripotent state, hails the arrival of a new cell transplantation candidate for potential clinical application in therapies designed to promote repair and/or regeneration of the CNS. Since the initial development of iPSC technology, these cells have been extensively characterized in vitro and in a number of pathological conditions and were originally reported to be equivalent to embryonic stem cells (ESCs). This review highlights emerging evidence that suggests iPSCs are not necessarily indistinguishable from ESCs and may occupy a different "state" of pluripotency with differences in gene expression, methylation patterns, and genomic aberrations, which may reflect incomplete reprogramming and may therefore impact on the regenerative potential of these donor cells in therapies. It also highlights the limitations of current technologies used to generate these cells. Moreover, we provide a systematic review of the state of play with regard to the use of iPSCs in the treatment of neurodegenerative and neuropathological conditions. The

  13. Mechanical aspects of degree of cement bonding and implant wedge effect.

    Yoon, Yong-San; Oxland, Thomas R; Hodgson, Antony J; Duncan, Clive P; Masri, Bassam A; Choi, Donok

    2008-11-01

    The degree of bonding between the femoral stem and cement in total hip replacement remains controversial. Our objective was to determine the wedge effect by debonding and stem taper angle on the structural behavior of axisymmetric stem-cement-bone cylinder models. Stainless steel tapered plugs with a rough (i.e. bonded) or smooth (i.e. debonded) surface finish were used to emulate the femoral stem. Three different stem taper angles (5 degrees , 7.5 degrees , 10 degrees ) were used for the debonded constructs. Non-tapered and tapered (7.5 degrees ) aluminum cylindrical shells were used to emulate the diaphyseal and metaphyseal segments of the femur. The cement-aluminum cylinder interface was designed to have a shear strength that simulated bone-cement interfaces ( approximately 8MPa). The test involved applying axial compression at a rate of 0.02mm/s until failure. Six specimens were tested for each combination of the variables. Finite element analysis was used to enhance the understanding of the wedge effect. The debonded stems sustained about twice as much load as the bonded stem, regardless of taper angle. The metaphyseal model carried 35-50% greater loads than the diaphyseal models and the stem taper produced significant differences. Based on the finite element analysis, failure was most probably by shear at the cement-bone interface. Our results in this simplified model suggest that smooth (i.e. debonded) stems have greater failure loads and will incur less slippage or shear failure at the cement-bone interface than rough (i.e. bonded) stems.

  14. Seepage/Cement Interactions

    Carpenter, D.

    2000-01-01

    The Development Plan (CRWMS M andO 1999a) pertaining to this task defines the work scopes and objectives for development of various submodels for the Physical and Chemical Environment Abstraction Model for TSPA-LA. The Development Plan (CRWMS M andO 1999a) for this specific task establishes that an evaluation be performed of the chemical reactions between seepage that has entered the drift and concrete which might be used in the repository emplacement drifts. The Development Plan (CRWMS M andO 1999a) then states that the potential effects of these water/grout reactions on chemical conditions in the drift be assessed factoring in the influence of carbonation and the relatively small amount of grout. This task is also directed at: (1) developing a conceptualization of important cement/seepage interactions and potential impacts on EBS performance, (2) performing a screening analysis to assess the importance of cement/seepage interactions. As the work progresses and evolves on other studies, specifically the Engineered Barrier System: Physical and Chemical Environment (P andCE) Model (in progress), many of the issues associated with items 1 and 2, above, will be assessed. Such issues include: (1) Describing the mineralogy of the specified cementitious grout and its evolution over time. (2) Describing the composition of the water before contacting the grout. (3) Developing reasonable upper-bound estimates for the composition of water contacting grout, emphasizing pH and concentrations for anions such as sulfate. (4) Evaluating the equilibration of cement-influenced water with backfill and gas-phase CO 2 . (5) Developing reasonable-bound estimates for flow rate of affected water into the drift. The concept of estimating an ''upper-bound'' range for reaction between the grout and the seepage, particularly in terms of pH is based on equilibrium being established between the seepage and the grout. For example, this analysis can be based on equilibrium being established as

  15. Cement-Induced Chromate Occupational Allergic Contact Dermatitis.

    Kridin, Khalaf; Bergman, Reuven; Khamaisi, Mogher; Zelber-Sagi, Shira; Weltfriend, Sara

    2016-01-01

    Hexavalent chromium in cement is a common cause of occupational allergic contact dermatitis (OACD). Analysis of patch test data during 1999 to 2013 was done. Patients with cement-induced chromate OACD filled the Dermatology Life Quality Index, graded 1 to 5. Of 4846 consecutive patients who were patch tested, 146 (3%) were chromate-sensitive. Of 46 (31.5%) who presented with chromate OACD, 27 (59%) had cement-induced chromate OACD. The proportion of chromate-sensitive patients with clinically relevant cement exposure increased from 7.7% in 2002 to 2004 to 28.7% in 2011 to 2013 (P = 0.04). The median age of presentation was younger than for other chromate-sensitive patients (32 vs 42 years). Hand eczema (88.9%) was the most frequent clinical presentation. Of the 27 with cement-induced chromate OACD, 21 (77.8%) had ongoing dermatitis at the time of the review. Although 14/27 (51.9%) changed their occupation to avoid exposure to cement, symptoms persisted in 9/14 (64.3%). Prolonged exposure to cement before development of symptoms was associated with chronicity. All the symptomatic patients experienced at least a moderate effect on their quality of life (grade 3 or higher on the Dermatology Life Quality Index). We recommend the adoption of the European legislation in Israel, to reduce the prevalence of chromate OACD from cement.

  16. Immune ablation and stem-cell therapy in autoimmune disease: Clinical experience

    Tyndall, Alan; Gratwohl, Alois

    2000-01-01

    In the past 5 years, around 350 patients have received haematopoietic stem cell (HSC) transplantation for an autoimmune disease, with 275 of these registered in an international data base in Basel under the auspices of the European League Against Rheumatism (EULAR) and the European Group for Blood and Marrow Transplantation(EBMT). Most patients had either a progressive form of multiple sclerosis (MS; n = 88) or scleroderma (now called systemic sclerosis; n = 55). Other diseases were rheumatoi...

  17. Antimicrobial potential of Dialium guineense (Wild.) stem bark on some clinical isolates in Nigeria

    Olajubu, FA; Akpan, I; Ojo, DA; Oluwalana, SA

    2012-01-01

    Context: The persistent increase in the number of antibiotic-resistant strains of microorganisms has led to the development of more potent but also more expensive antibiotics. In most developing countries of the world these antibiotics are not readily affordable, thus making compliance difficult. This calls for research into alternative sources of antimicrobials. Dialium guineense is a shrub of the family Leguminosae. Its stem bark is used for the treatment of cough, toothache, and bronchitis...

  18. Cemental tear: To know what we have neglected in dental practice

    Po-Yuan Jeng

    2018-04-01

    Full Text Available Cemental tear is a special kind of root surface fracture, contributing to periodontal and periapical breakdown. However, it is a challenge for doctors to diagnose, resulting in delayed or improper treatment. We reviewed the predisposing factors, location, radiographic/clinical characteristics, diagnosis and treatments of cemental tears. From the literature, patients with cemental tear were mainly males, over 60 year-old. Possible predisposing factors include gender, age, tooth type, traumatic occlusal force and vital teeth. Cemental tears were common in upper and lower anterior teeth, single or multiple, and can be present in cervical, middle and apical third of roots. Morphology of cemental tears can be either piece-shaped or U-shaped. Clinically, cemental tear shows a unitary periodontal pocket and signs/symptoms mimicking localized periodontitis, apical periodontitis and vertical root fractures. Treatment of cemental tears include scaling, root planning, root canal treatment, periodontal/periapical surgery, guided tissue regeneration, bone grafting, and intentional replantation. Recurrence of cemental tear is possible especially when the fracture involves root apex. Extraction is recommended for teeth with poor prognosis. In conclusion, cemental tears can involve both periodontal and periapical area. Dentists should understand the predisposing factors and clinical features of cemental tears for early diagnosis/treatment to prevent bone loss/tooth extraction. Keywords: Cemental tear, Clinical characteristics, Surface root fracture, Periodontal/periapical breakdown, Recurrence, Predisposing factors

  19. Cement for Oil Well Cementing Operations in Ghana

    Michael

    For Portland cement to qualify as oil well cement, the chemical and physical properties must meet ..... Reservoir Engineering, Stanford University,. Stanford, California, pp. ... Construction”, PhD Thesis, Kwame Nkrumah. University of Science ...

  20. Stem Cell Information: Glossary

    ... Tips Info Center Research Topics Federal Policy Glossary Stem Cell Information General Information Clinical Trials Funding Information Current ... here Home » Glossary Back to top Glossary Adult stem cell Astrocyte Blastocoel Blastocyst Bone marrow stromal cells Bone ...

  1. ULTRA-LIGHTWEIGHT CEMENT

    Fred Sabins

    2001-10-23

    The objective of this project is to develop an improved ultra-lightweight cement using ultra-lightweight hollow glass spheres (ULHS). Work reported herein addresses tasks performed in the fourth quarter as well as the other three quarters of the past year. The subjects that were covered in previous reports and that are also discussed in this report include: Analysis of field laboratory data of active cement applications from three oil-well service companies; Preliminary findings from a literature review focusing on problems associated with ultra-lightweight cements; Summary of pertinent information from Russian ultra-lightweight cement literature review; and Comparison of compressive strengths of ULHS systems using ultrasonic and crush methods Results reported from the fourth quarter include laboratory testing of ULHS systems along with other lightweight cement systems--foamed and sodium silicate slurries. These comparison studies were completed for two different densities (10.0 and 11.5 lb/gal) and three different field application scenarios. Additional testing included the mechanical properties of ULHS systems and other lightweight systems. Studies were also performed to examine the effect that circulation by centrifugal pump during mixing has on breakage of ULHS.

  2. The Challenges of First-in-Human Stem Cell Clinical Trials: What Does This Mean for Ethics and Institutional Review Boards?

    Roger A. Barker

    2018-05-01

    Full Text Available Stem cell-based clinical interventions are increasingly advancing through preclinical testing and approaching clinical trials. The complexity and diversity of these approaches, and the confusion created by unproven and untested stem cell-based “therapies,” create a growing need for a more comprehensive review of these early-stage human trials to ensure they place the patients at minimal risk of adverse events but are also based on solid evidence of preclinical efficacy with a clear scientific rationale for that effect. To address this issue and supplement the independent review process, especially that of the ethics and institutional review boards who may not be experts in stem cell biology, the International Society for Stem Cell Research (ISSCR has developed a set of practical questions to cover the major issues for which clear evidence-based answers need to be obtained before approving a stem cell-based trial. Keywords: human stem cell-derived interventions, early phase clinical trials, institutional review and ethics boards, review process, guidelines

  3. Neck Rhabdoid Tumors: Clinical Features and Consideration of Autologous Stem Cell Transplant.

    Wolfe, Adam D; Capitini, Christian M; Salamat, Shahriar M; DeSantes, Kenneth; Bradley, Kristin A; Kennedy, Tabassum; Dehner, Louis P; Patel, Neha J

    2018-01-01

    Extrarenal malignant rhabdoid tumors (MRT) have a poor prognosis despite aggressive therapy. Adding high-dose chemotherapy with autologous stem cell rescue (HDC-ASCR) as consolidative therapy for MRT is controversial. We describe 2 patients, age 13 years and 19 months, with unresectable neck MRT. After chemotherapy and radiotherapy, both underwent HDC-ASCR and remain in remission over 4 years later. We reviewed all published cases of neck MRT, and found poorer outcomes and more variable age of presentation and time to progression than MRT at other sites. Neck MRT may represent a higher-risk subset of MRT, and addition of HDC-ASCR merits consideration.

  4. Derivation of the clinical grade human embryonic stem cell line RCe016-A (RC-12

    P.A. De Sousa

    2016-05-01

    Full Text Available The human embryonic stem cell line RCe016-A (RC-12 was derived under quality assured compliance with UK regulations, EU Directives and International guidance for tissue procurement, processing and storage according to good manufacturing practice (GMP standards. The cell line was derived from a cryopreserved blastocyst stage embryo voluntarily donated as surplus to fertility requirements following informed consent. RCe016-A (RC-12 shows normal pluripotency marker expression and differentiation to three germ layers in vitro. Karyology revealed a mixed male karyotype at early passage (P15, which resolved as normal 46XY by passage 33. Microsatellite PCR identity, HLA and blood group typing data is available.

  5. Experimental study with domestic bone cement in the percutaneous vertebroplasty

    Ni Caifang; Liu Xisheng; Chen Long; Yang Huilin; Tang Tiansi; Ding Yi

    2004-01-01

    Objective: To study the feasibility of injecting domestic bone cement in the process of the percutaneous vertebroplasty. Methods: (1) Various types cement were disposed with domestic PMMA. The concretionary phases of cement were observed according to the stages and holding time. Then the most ideal ratio of the mixed cement was selected and ten cement columns were made with this ratio, which was taken as the trial group. The other ten referring to was taken as the contrast one. The biological mechanics was measured with a load and the data of the results were compared. (2) Twenty thoracic and lumbar adjacent bodies were removed intact from five human corpses. These bodies were divided into two groups, in one group PMMA were injected, the other was severed as the contrast one. Then in these twenty vertebral bodies the biological mechanics was measured and the treatment effect was evaluated. (3) In 12 healthy dogs PVP in lumber was tried so as to observe the operational difficulty during the process of injected this bone cement and CT was used to evaluate the result of PMMA, diffusion and the complications caused by it. Results: The most ideal ratio was 4:2.6:1 (g, ml, ml) between powder, monome and contrast. After injecting this kind of cement, the loading strength of these vertebral bodies was increased remarkably (P<0.01). Conclusion: Injecting domestic bone cement provides the theoretical foundations for the clinical application of PVP. (author)

  6. Concrete = aggregate, cement, water?

    Jelinek, J.

    1990-01-01

    Concrete for the Temelin nuclear power plant is produced to about 70 different formulae. For quality production, homogeneous properties of aggregates, accurate proportioning devices, technological discipline and systematic inspections and tests should be assured. The results are reported of measuring compression strength after 28 days for different concrete samples. The results of such tests allow reducing the proportion of cement, which brings about considerable savings. Reduction in cement quantities can also be achieved by adding ash to the concrete mixes. Ligoplast, a plasticizer addition is used for improving workability. (M.D). 8 figs

  7. Technology Roadmaps: Cement

    NONE

    2009-07-01

    To support its roadmap work focusing on key technologies for emissions reductions, the International Energy Agency (IEA) also investigated one particular industry: cement. Cement production includes technologies that are both specific to this industry and those that are shared with other industries (e.g., grinding, fuel preparation, combustion, crushing, transport). An industry specific roadmap provides an effective mechanism to bring together several technology options. It outlines the potential for technological advancement for emissions reductions in one industry, as well as potential cross-industry collaboration.

  8. Reducing cement's CO2 footprint

    van Oss, Hendrik G.

    2011-01-01

    The manufacturing process for Portland cement causes high levels of greenhouse gas emissions. However, environmental impacts can be reduced by using more energy-efficient kilns and replacing fossil energy with alternative fuels. Although carbon capture and new cements with less CO2 emission are still in the experimental phase, all these innovations can help develop a cleaner cement industry.

  9. Cement Mason's Curriculum. Instructional Units.

    Hendirx, Laborn J.; Patton, Bob

    To assist cement mason instructors in providing comprehensive instruction to their students, this curriculum guide treats both the skills and information necessary for cement masons in commercial and industrial construction. Ten sections are included, as follow: related information, covering orientation, safety, the history of cement, and applying…

  10. Cementation of liquid radioactive waste

    Efremenkov, V.

    2004-01-01

    The cementation methods for immobilisation of radioactive wastes are discussed in terms of methodology, chemistry and properties of the different types of cements as well as the worldwide experience in this field. Two facilities for cementation - DEWA and MOWA - are described in details

  11. Cementing a wellbore using cementing material encapsulated in a shell

    Aines, Roger D.; Bourcier, William L.; Duoss, Eric B.; Spadaccini, Christopher M.; Cowan, Kenneth Michael

    2016-08-16

    A system for cementing a wellbore penetrating an earth formation into which a pipe extends. A cement material is positioned in the space between the wellbore and the pipe by circulated capsules containing the cement material through the pipe into the space between the wellbore and the pipe. The capsules contain the cementing material encapsulated in a shell. The capsules are added to a fluid and the fluid with capsules is circulated through the pipe into the space between the wellbore and the pipe. The shell is breached once the capsules contain the cementing material are in position in the space between the wellbore and the pipe.

  12. Cementing a wellbore using cementing material encapsulated in a shell

    Aines, Roger D.; Bourcier, William L.; Duoss, Eric B.; Floyd, III, William C.; Spadaccini, Christopher M.; Vericella, John J.; Cowan, Kenneth Michael

    2017-03-14

    A system for cementing a wellbore penetrating an earth formation into which a pipe extends. A cement material is positioned in the space between the wellbore and the pipe by circulated capsules containing the cement material through the pipe into the space between the wellbore and the pipe. The capsules contain the cementing material encapsulated in a shell. The capsules are added to a fluid and the fluid with capsules is circulated through the pipe into the space between the wellbore and the pipe. The shell is breached once the capsules contain the cementing material are in position in the space between the wellbore and the pipe.

  13. Umbilical Cord Mesenchymal Stem Cell Treatment for Crohn’s Disease: A Randomized Controlled Clinical Trial

    Zhang, Jian; Lv, Samei; Liu, Xiaojing; Song, Bin; Shi, Liping

    2018-01-01

    Background/Aims Stem cell therapy has been applied to treat a variety of autoimmune diseases, including Crohn’s disease (CD), but few studies have examined the use of umbilical cord mesenchymal stem cells (UC-MSCs). This trial sought to investigate the efficacy and safety of UC-MSCs for the treatment of CD. Methods Eighty-two patients who had been diagnosed with CD and had received steroid maintenance therapy for more than 6 months were included in this study. Forty-one patients were randomly selected to receive a total of four peripheral intravenous infusions of 1×106 UC-MSCs/kg, with one infusion per week. Patients were followed up for 12 months. The Crohn’s disease activity index (CDAI), Harvey-Bradshaw index (HBI), and corticosteroid dosage were assessed. Results Twelve months after treatment, the CDAI, HBI, and corticosteroid dosage had decreased by 62.5±23.2, 3.4±1.2, and 4.2±0.84 mg/day, respectively, in the UC-MSC group and by 23.6±12.4, 1.2±0.58, and 1.2±0.35 mg/day, respectively, in the control group (pUC-MSC vs control, respectively). Four patients developed a fever after cell infusion. No serious adverse events were observed. Conclusions UC-MSCs were effective in the treatment of CD and produced mild side effects. PMID:28873511

  14. Human-Induced Pluripotent Stem Cell Technology and Cardiomyocyte Generation: Progress and Clinical Applications

    Angela Di Baldassarre

    2018-05-01

    Full Text Available Human-induced pluripotent stem cells (hiPSCs are reprogrammed cells that have hallmarks similar to embryonic stem cells including the capacity of self-renewal and differentiation into cardiac myocytes. The improvements in reprogramming and differentiating methods achieved in the past 10 years widened the use of hiPSCs, especially in cardiac research. hiPSC-derived cardiac myocytes (CMs recapitulate phenotypic differences caused by genetic variations, making them attractive human disease models and useful tools for drug discovery and toxicology testing. In addition, hiPSCs can be used as sources of cells for cardiac regeneration in animal models. Here, we review the advances in the genetic and epigenetic control of cardiomyogenesis that underlies the significant improvement of the induced reprogramming of somatic cells to CMs; the methods used to improve scalability of throughput assays for functional screening and drug testing in vitro; the phenotypic characteristics of hiPSCs-derived CMs and their ability to rescue injured CMs through paracrine effects; we also cover the novel approaches in tissue engineering for hiPSC-derived cardiac tissue generation, and finally, their immunological features and the potential use in biomedical applications.

  15. Human-Induced Pluripotent Stem Cell Technology and Cardiomyocyte Generation: Progress and Clinical Applications.

    Di Baldassarre, Angela; Cimetta, Elisa; Bollini, Sveva; Gaggi, Giulia; Ghinassi, Barbara

    2018-05-25

    Human-induced pluripotent stem cells (hiPSCs) are reprogrammed cells that have hallmarks similar to embryonic stem cells including the capacity of self-renewal and differentiation into cardiac myocytes. The improvements in reprogramming and differentiating methods achieved in the past 10 years widened the use of hiPSCs, especially in cardiac research. hiPSC-derived cardiac myocytes (CMs) recapitulate phenotypic differences caused by genetic variations, making them attractive human disease models and useful tools for drug discovery and toxicology testing. In addition, hiPSCs can be used as sources of cells for cardiac regeneration in animal models. Here, we review the advances in the genetic and epigenetic control of cardiomyogenesis that underlies the significant improvement of the induced reprogramming of somatic cells to CMs; the methods used to improve scalability of throughput assays for functional screening and drug testing in vitro; the phenotypic characteristics of hiPSCs-derived CMs and their ability to rescue injured CMs through paracrine effects; we also cover the novel approaches in tissue engineering for hiPSC-derived cardiac tissue generation, and finally, their immunological features and the potential use in biomedical applications.

  16. Clinical Response of 277 Patients with Spinal Cord Injury to Stem Cell Therapy in Iraq

    Hammadi, Abdulmajeed Alwan; Marino, Andolina; Farhan, Saad

    2012-01-01

    Background and Objectives: Spinal cord injury is a common neurological problem secondary to car accidents, war injuries and other causes, it may lead to varying degrees of neurological disablement, and apart from physiotherapy there is no available treatment to regain neurological function loss. Our aim is to find a new method using autologous hematopoietic stem cells to gain some of the neurologic functions lost after spinal cord injury. Methods and Results: 277 patients suffering from spinal cord injury were submitted to an intrathecally treatment with peripheral stem cells. The cells were harvested from the peripheral blood after a treatment with G-CSF and then concentrated to 4∼ 6 ml. 43% of the patients improved; ASIA score shifted from A to B in 88 and from A to C in 32. The best results were achieved in patients treated within one year from the injury. Conclusions: Since mesenchymal cells increase in the peripheral blood after G-CSF stimulation, a peripheral blood harvest seems easier and cheaper than mesenchymal cell cultivation prior to injection. It seems reasonable treatment for spinal cord injury. PMID:24298358

  17. Chemical constitution, physical properties, and biocompatibility of experimentally manufactured Portland cement.

    Hwang, Yun-Chan; Kim, Do-Hee; Hwang, In-Nam; Song, Sun-Ju; Park, Yeong-Joon; Koh, Jeong-Tae; Son, Ho-Hyun; Oh, Won-Mann

    2011-01-01

    An experimental Portland cement was manufactured with pure raw materials under controlled laboratory conditions. The aim of this study was to compare the chemical constitution, physical properties, and biocompatibility of experimentally manufactured Portland cement with those of mineral trioxide aggregate (MTA) and Portland cement. The composition of the cements was determined by scanning electron microscopy (SEM) and energy-dispersive x-ray analysis (EDAX). The setting time and compressive strength were tested. The biocompatibility was evaluated by using SEM and XTT assay. SEM and EDAX revealed the experimental Portland cement to have a similar composition to Portland cement. The setting time of the experimental Portland cement was significantly shorter than that of MTA and Portland cement. The compressive strength of the experimental Portland cement was lower than that of MTA and Portland cement. The experimental Portland cement showed a similar biocompatibility to MTA. The experimental Portland cement might be considered as a possible substitute for MTA in clinical usage after further testing. Copyright © 2011 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  18. Combining Induced Pluripotent Stem Cells and Genome Editing Technologies for Clinical Applications.

    Chang, Chia-Yu; Ting, Hsiao-Chien; Su, Hong-Lin; Jeng, Jing-Ren

    2018-01-01

    In this review, we introduce current developments in induced pluripotent stem cells (iPSCs), site-specific nuclease (SSN)-mediated genome editing tools, and the combined application of these two novel technologies in biomedical research and therapeutic trials. The sustainable pluripotent property of iPSCs in vitro not only provides unlimited cell sources for basic research but also benefits precision medicines for human diseases. In addition, rapidly evolving SSN tools efficiently tailor genetic manipulations for exploring gene functions and can be utilized to correct genetic defects of congenital diseases in the near future. Combining iPSC and SSN technologies will create new reliable human disease models with isogenic backgrounds in vitro and provide new solutions for cell replacement and precise therapies.

  19. Advancing Stem Cell Biology toward Stem Cell Therapeutics

    Scadden, David; Srivastava, Alok

    2012-01-01

    Here, the International Society for Stem Cell Research (ISSCR) Clinical Translation Committee introduces a series of articles outlining the current status, opportunities, and challenges surrounding the clinical translation of stem cell therapeutics for specific medical conditions.

  20. Porous surface modified bioactive bone cement for enhanced bone bonding.

    Qiang He

    Full Text Available Polymethylmethacrylate bone cement cannot provide an adhesive chemical bonding to form a stable cement-bone interface. Bioactive bone cements show bone bonding ability, but their clinical application is limited because bone resorption is observed after implantation. Porous polymethylmethacrylate can be achieved with the addition of carboxymethylcellulose, alginate and gelatin microparticles to promote bone ingrowth, but the mechanical properties are too low to be used in orthopedic applications. Bone ingrowth into cement could decrease the possibility of bone resorption and promote the formation of a stable interface. However, scarce literature is reported on bioactive bone cements that allow bone ingrowth. In this paper, we reported a porous surface modified bioactive bone cement with desired mechanical properties, which could allow for bone ingrowth.The porous surface modified bioactive bone cement was evaluated to determine its handling characteristics, mechanical properties and behavior in a simulated body fluid. The in vitro cellular responses of the samples were also investigated in terms of cell attachment, proliferation, and osteoblastic differentiation. Furthermore, bone ingrowth was examined in a rabbit femoral condyle defect model by using micro-CT imaging and histological analysis. The strength of the implant-bone interface was also investigated by push-out tests.The modified bone cement with a low content of bioactive fillers resulted in proper handling characteristics and adequate mechanical properties, but slightly affected its bioactivity. Moreover, the degree of attachment, proliferation and osteogenic differentiation of preosteoblast cells was also increased. The results of the push-out test revealed that higher interfacial bonding strength was achieved with the modified bone cement because of the formation of the apatite layer and the osseointegration after implantation in the bony defect.Our findings suggested a new bioactive

  1. Towards the standardization of stem cell therapy studies for ischemic heart diseases: Bridging the gap between animal models and the clinical setting.

    Trindade, Fábio; Leite-Moreira, Adelino; Ferreira-Martins, João; Ferreira, Rita; Falcão-Pires, Inês; Vitorino, Rui

    2017-02-01

    Today there is an increasing demand for heart transplantations for patients diagnosed with heart failure. Though, shortage of donors as well as the large number of ineligible patients hurdle such treatment option. This, in addition to the considerable number of transplant rejections, has driven the clinical research towards the field of regenerative medicine. Nonetheless, to date, several stem cell therapies tested in animal models fall by the wayside and when they meet the criteria to clinical trials, subjects often exhibit modest improvements. A main issue slowing down the admission of such therapies in the domain of human trials is the lack of protocol standardization between research groups, which hampers comparison between different approaches as well as the lack of thought regarding the clinical translation. In this sense, given the large amount of reports on stem cell therapy studies in animal models reported in the last 3years, we sought to evaluate their advantages and limitations towards the clinical setting and provide some suggestions for the forthcoming investigations. We expect, with this review, to start a new paradigm on regenerative medicine, by evoking the debate on how to plan novel stem cell therapy studies with animal models in order to achieve more consistent scientific production and accelerate the admission of stem cell therapies in the clinical setting. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  2. Human serum and platelet lysate are appropriate xeno-free alternatives for clinical-grade production of human MuStem cell batches.

    Saury, Charlotte; Lardenois, Aurélie; Schleder, Cindy; Leroux, Isabelle; Lieubeau, Blandine; David, Laurent; Charrier, Marine; Guével, Laëtitia; Viau, Sabrina; Delorme, Bruno; Rouger, Karl

    2018-05-02

    Canine MuStem cells have demonstrated regenerative efficacy in a dog model of muscular dystrophy, and the recent characterization of human counterparts (hMuStem) has highlighted the therapeutic potential of this muscle-derived stem cell population. To date, these cells have only been generated in research-grade conditions. However, evaluation of the clinical efficacy of any such therapy will require the production of hMuStem cells in compliance with good manufacturing practices (GMPs). Because the current use of fetal bovine serum (FBS) to isolate and expand hMuStem cells raises several ethical, safety, and supply concerns, we assessed the use of two alternative xeno-free blood derivatives: human serum (HS) and a human platelet lysate (hPL). hMuStem cells were isolated and expanded in vitro in either HS-supplemented or hPL-supplemented media and the proliferation rate, clonogenicity, myogenic commitment potential, and oligopotency compared with that observed in FBS-supplemented medium. Flow cytometry and high-throughput 3'-digital gene expression RNA sequencing were used to characterize the phenotype and global gene expression pattern of hMuStem cells cultured with HS or hPL. HS-supplemented and hPL-supplemented media both supported the isolation and long-term proliferation of hMuStem cells. Compared with FBS-based medium, both supplements enhanced clonogenicity and allowed for a reduction in growth factor supplementation. Neither supplement altered the cell lineage pattern of hMuStem cells. In vitro differentiation assays revealed a decrease in myogenic commitment and in the fusion ability of hMuStem cells when cultured with hPL. In return, this reduction of myogenic potential in hPL-supplemented cultures was rapidly reversed by substitution of hPL with HS or fibrinogen-depleted hPL. Moreover, culture of hMuStem cells in hPL hydrogel and fibrinogen-depleted hPL demonstrated that myogenic differentiation potential is maintained in heparin-free hPL derivatives. Our

  3. Putative stem cell markers in cervical squamous cell carcinoma are correlated with poor clinical outcome

    Hou, Teng; Zhang, Weijing; Tong, Chongjie; Kazobinka, Gallina; Huang, Xin; Huang, Yongwen; Zhang, Yanna

    2015-01-01

    The aim of this study was to elucidate the value of putative cancer stem cell markers Musashi-1, ALDH1, Sox2, and CD49f in predicting the prognosis in cervical squamous cell carcinoma (CSCC). Real-time PCR and immunohistochemistry staining was performed to examine Musashi-1, ALDH1, Sox2, and CD49f expression in archived specimens of CSCC patients with postoperative chemotherapy. Kaplan–Meier analysis and Cox proportional hazards model were used to assess the prognostic impact of CSC markers for overall survival (OS) and recurrent-free survival (RFS). The Real-time PCR data showed that the expression of all markers were increased in CSCC tissues compared with in paired normal cervical tissues (P < 0.05). The IHC result showed that high expression of Msi1, ALDH1, Sox2, and CD49f was found in 25.7 %, 43.0 %, 62.0 % and 29.0 % CSCC samples, respectively. Moreover, high expression of Msi1 (P = 0.033 and P = 0.003, respectively), ALDH1 (P = 0.015 and P = 0.002, respectively), and Sox2 (P = 0.005 and P = 0.003, respectively), and low expression of CD49f (P = 0.027 and P = 0.025, respectively) were correlated with poor OS and PFS in CSCC patients. Interestingly, tumors with Msi1 high /CD49f low expression had the poorest prognosis according to Msi1/CD49f stratification. In multivariate Cox regression analysis, Sox2 expression (P = 0.047 and P = 0.018, respectively), ALDH1 expression (P = 0.013 and P = 0.003, respectively), and CD49f expression (P = 0.008 and P = 0.003, respectively) were independent prognostic markers for both OS and RFS. Our results suggest that cancer stem cell markers are linked with poor prognosis of CSCC patients. The online version of this article (doi:10.1186/s12885-015-1826-4) contains supplementary material, which is available to authorized users

  4. Simplified cementation of lithium disilicate crowns: Retention with various adhesive resin cement combinations.

    Johnson, Glen H; Lepe, Xavier; Patterson, Amanda; Schäfer, Oliver

    2017-09-27

    A composite resin cement and matching self-etch adhesive was developed to simplify the dependable retention of lithium disilicate crowns. The efficacy of this new system is unknown. The purpose of this in vitro study was to determine whether lithium disilicate crowns cemented with a new composite resin and adhesive system and 2 other popular systems provide clinically acceptable crown retention after long-term aging with monthly thermocycling. Extracted human molars were prepared with a flat occlusal surface, 20-degree convergence, and 4 mm axial length. The axio-occlusal line angle was slightly rounded. The preparation surface area was determined by optical scanning and the analysis of the standard tessellation language (STL) files. The specimens were distributed into 3 cement groups (n=12) to obtain equal mean surface areas. Lithium disilicate crowns (IPS e.max Press) were fabricated for each preparation, etched with 9.5% hydrofluoric acid for 15 seconds, and cleaned. Cement systems were RelyX Ultimate with Scotch Bond Universal (3M Dental Products); Monobond S, Multilink Automix with Multilink Primer A and B (Ivoclar Vivadent AG); and NX3 Nexus with OptiBond XTR (Kerr Corp). Each adhesive provided self-etching of the dentin. Before cementation, the prepared specimens were stored in 35°C water. A force of 196 N was used to cement the crowns, and the specimens were polymerized in a 35°C oven at 100% humidity. After 24 hours of storage at 100% humidity, the cemented crowns were thermocycled (5°C to 55°C) for 5000 cycles each month for 6 months. The crowns were removed axially at 0.5 mm/min. The removal force was recorded and the dislodgement stress calculated using the preparation surface area. The type of cement failure was recorded, and the data were analyzed by 1-way ANOVA and the chi-square test (α=.05) after the equality of variances had been assessed with the Levene test. The Levene test was nonsignificant (P=.936). The ANOVA revealed the mean removal

  5. Modulation of Autoimmune T-Cell Memory by Stem Cell Educator Therapy: Phase 1/2 Clinical Trial.

    Delgado, Elias; Perez-Basterrechea, Marcos; Suarez-Alvarez, Beatriz; Zhou, Huimin; Revuelta, Eva Martinez; Garcia-Gala, Jose Maria; Perez, Silvia; Alvarez-Viejo, Maria; Menendez, Edelmiro; Lopez-Larrea, Carlos; Tang, Ruifeng; Zhu, Zhenlong; Hu, Wei; Moss, Thomas; Guindi, Edward; Otero, Jesus; Zhao, Yong

    2015-12-01

    Type 1 diabetes (T1D) is a T cell-mediated autoimmune disease that causes a deficit of pancreatic islet β cells. The complexities of overcoming autoimmunity in T1D have contributed to the challenges the research community faces when devising successful treatments with conventional immune therapies. Overcoming autoimmune T cell memory represents one of the key hurdles. In this open-label, phase 1/phase 2 study, Caucasian T1D patients (N = 15) received two treatments with the Stem Cell Educator (SCE) therapy, an approach that uses human multipotent cord blood-derived multipotent stem cells (CB-SCs). SCE therapy involves a closed-loop system that briefly treats the patient's lymphocytes with CB-SCs in vitro and returns the "educated" lymphocytes (but not the CB-SCs) into the patient's blood circulation. This study is registered with ClinicalTrials.gov, NCT01350219. Clinical data demonstrated that SCE therapy was well tolerated in all subjects. The percentage of naïve CD4(+) T cells was significantly increased at 26 weeks and maintained through the final follow-up at 56 weeks. The percentage of CD4(+) central memory T cells (TCM) was markedly and constantly increased at 18 weeks. Both CD4(+) effector memory T cells (TEM) and CD8(+) TEM cells were considerably decreased at 18 weeks and 26 weeks respectively. Additional clinical data demonstrated the modulation of C-C chemokine receptor 7 (CCR7) expressions on naïve T, TCM, and TEM cells. Following two treatments with SCE therapy, islet β-cell function was improved and maintained in individuals with residual β-cell function, but not in those without residual β-cell function. Current clinical data demonstrated the safety and efficacy of SCE therapy in immune modulation. SCE therapy provides lasting reversal of autoimmune memory that could improve islet β-cell function in Caucasian subjects. Obra Social "La Caixa", Instituto de Salud Carlos III, Red de Investigación Renal, European Union FEDER Funds, Principado de

  6. Clinical Observation of Employment of Umbilical Cord Derived Mesenchymal Stem Cell for Juvenile Idiopathic Arthritis Therapy

    Liming Wang

    2016-01-01

    Full Text Available Juvenile idiopathic arthritis (JIA, known as Juvenile rheumatoid arthritis, is the most common type of arthritis in children aged under 17. It may cause sequelae due to lack of effective treatment. The goal of this study is to explore the therapeutic effect of umbilical cord mesenchymal stem cells (UC-MSCs for JIA. Ten JIA patients were treated with UC-MSCs and received second infusion three months later. Some key values such as 28-joint disease activity score (DAS28, TNF-α, IL-6, and regulatory T cells (Tregs were evaluated. Data were collected at 3 months and 6 months after first treatment. DAS28 score of 10 patients was between 2.6 and 3.2 at three months after infusion. WBC, ESR, and CRP were significantly decreased while Tregs were remarkably increased and IL-6 and TNF-α were declined. Similar changes of above values were found after 6 months. At the same time, the amount of NSAIDS and steroid usage in patients was reduced. However, no significant changes were found comparing the data from 3 and 6 months. These results suggest that UC-MSCs can reduce inflammatory cytokines, improve immune network effects, adjust immune tolerance, and effectively alleviate the symptoms and they might provide a safe and novel approach for JIA treatment.

  7. Clinical characteristics and computed tomography findings of pulmonary toxoplasmosis after hematopoietic stem cell transplantation.

    Sumi, Masahiko; Norose, Kazumi; Hikosaka, Kenji; Kaiume, Hiroko; Takeda, Wataru; Kirihara, Takehiko; Kurihara, Taro; Sato, Keijiro; Ueki, Toshimitsu; Hiroshima, Yuki; Kuraishi, Hiroshi; Watanabe, Masahide; Kobayashi, Hikaru

    2016-12-01

    The prognosis of pulmonary toxoplasmosis, including disseminated toxoplasmosis involving the lungs, following hematopoietic stem cell transplantation (HSCT) is extremely poor due to the difficulties associated with early diagnosis and the rapidly progressive deterioration of multiorgan function. In our institution, we identified nine cases of toxoplasmosis, representing incidences of 2.2 and 19.6 % among all HSCT recipients and seropositive HSCT recipients, respectively. Of the patients with toxoplasmosis, six had pulmonary toxoplasmosis. Chest computed tomography (CT) findings revealed centrilobular, patchy ground-glass opacities (n = 3), diffuse ground-glass opacities (n = 2), ground-glass opacities with septal thickening (n = 1), and marked pleural effusion (n = 1). All cases died, except for one with suspected pulmonary toxoplasmosis who was diagnosed by a polymerase chain reaction assay 2 days after the onset of symptoms. In pulmonary toxoplasmosis, CT findings are non-specific and may mimic pulmonary congestion, atypical pneumonia, viral pneumonitis, and bronchopneumonia. Early diagnosis and treatment is crucial for overcoming this serious infectious complication. Pulmonary toxoplasmosis should be considered during differential diagnosis in a recipient with otherwise unexplained signs of infection and CT findings with ground-glass opacities, regardless of the distribution.

  8. Immune ablation and stem-cell therapy in autoimmune disease. Clinical experience.

    Tyndall, A; Gratwohl, A

    2000-01-01

    In the past 5 years, around 350 patients have received haematopoietic stem cell (HSC) transplantation for an autoimmune disease, with 275 of these registered in an international data base in Basel under the auspices of the European League Against Rheumatism (EULAR) and the European Group for Blood and Marrow Transplantation(EBMT). Most patients had either a progressive form of multiple sclerosis (MS; n = 88) or scleroderma (now called systemic sclerosis; n = 55). Other diseases were rheumatoid arthritis (Ra n = 40), juvenile idiopathic arthritis (JIA; n = 30), systemic lupus erythematosus (SLE; n = 20), idiopathic thrombocytopenic purpura (ITP; n = 7) and others. The procedure-related mortality was around 9%, with between-disease differences, being higher in systemic sclerosis and JIA and lower in RA (one death only). Benefit has been seen in around two-thirds of cases. No one regimen was clearly superior to another, with a trend toward more infectious complications with more intense regimens. Prospective, controlled randomized trials are indicated and being planned.

  9. Amniotic membrane-derived stem cells: immunomodulatory properties and potential clinical application

    Insausti CL

    2014-03-01

    Full Text Available Carmen L Insausti,1 Miguel Blanquer,1 Ana M García-Hernández,1 Gregorio Castellanos,2 José M Moraleda11Unidad de Trasplante Hematopoyético y Terapia Celular, 2Servicio de Cirugía, Hospital Clínico Universitario Virgen de la Arrixaca, IMIB, Campus Mare Nostrum, Universidad de Murcia, El Palmar, Murcia, SpainAbstract: Epithelial and mesenchymal cells isolated from the amniotic membrane (AM possess stem cell characteristics, differentiation potential toward lineages of different germ layers, and immunomodulatory properties. While their expansion and differentiation potential have been well studied and characterized, knowledge about their immunomodulatory properties and the mechanisms involved is still incomplete. These mechanisms have been evaluated on various target cells of the innate and the adaptive system and in animal models of different inflammatory diseases. Some results have evidenced that the immunomodulatory effect of AM-derived cells is dependent on cell-cell contact, but many of them have demonstrated that these properties are mediated through the secretion of suppressive molecules. In this review, we present an update on the described immunomodulatory properties of the derived amniotic cells and some of the proposed involved mechanisms. Furthermore, we describe some assays in animal models of different inflammatory diseases which reveal the potential use of these cells to treat such diseases.Keywords: epithelial cells, mesenchymal cells, cell therapy, immunomodulation

  10. Mineral resource of the month: hydraulic cement

    van Oss, Hendrik G.

    2012-01-01

    Hydraulic cements are the binders in concrete and most mortars and stuccos. Concrete, particularly the reinforced variety, is the most versatile of all construction materials, and most of the hydraulic cement produced worldwide is portland cement or similar cements that have portland cement as a basis, such as blended cements and masonry cements. Cement typically makes up less than 15 percent of the concrete mix; most of the rest is aggregates. Not counting the weight of reinforcing media, 1 ton of cement will typically yield about 8 tons of concrete.

  11. The effect of cup outer sizes on the contact mechanics and cement fixation of cemented total hip replacements.

    Hua, Xijin; Li, Junyan; Wang, Ling; Wilcox, Ruth; Fisher, John; Jin, Zhongmin

    2015-10-01

    One important loosening mechanism of the cemented total hip arthroplasty is the mechanical overload at the bone-cement interface and consequent failure of the cement fixation. Clinical studies have revealed that the outer diameter of the acetabular component is a key factor in influencing aseptic loosening of the hip arthroplasty. The aim of the present study was to investigate the influence of the cup outer diameter on the contact mechanics and cement fixation of a cemented total hip replacement (THR) with different wear penetration depths and under different cup inclination angles using finite element (FE) method. A three-dimensional FE model was developed based on a typical Charnley hip prosthesis. Two acetabular cup designs with outer diameters of 40 and 43 mm were modelled and the effect of cup outer diameter, penetration depth and cup inclination angle on the contact mechanics and cement fixation stresses in the cemented THR were studied. The results showed that for all penetration depths and cup inclination angles considered, the contact mechanics in terms of peak von Mises stress in the acetabular cup and peak contact pressure at the bearing surface for the two cup designs were similar (within 5%). However, the peak von Mises stress, the peak maximum principal stress and peak shear stress in the cement mantle at the bone-cement interface for the 43 mm diameter cup design were predicted to be lower compared to those for the 40 mm diameter cup design. The differences were predicted to be 15-19%, 15-22% and 18-20% respectively for different cup penetration depths and inclination angles, which compares to the clinical difference of aseptic loosening incidence of about 20% between the two cup designs. Copyright © 2015 IPEM. Published by Elsevier Ltd. All rights reserved.

  12. Stem Cells

    Stem cells are cells with the potential to develop into many different types of cells in the body. ... the body. There are two main types of stem cells: embryonic stem cells and adult stem cells. Stem ...

  13. Cement-latex grouting mortar for cementing boreholes

    Kateev, I S; Golyshkina, L A; Gorbunova, I V; Kurochkin, B M; Vakula, Ya V

    1980-01-01

    The need for the development of cement-latex grouting mortar for the purpose of separating strata when reinforcing boreholes at deposits in the Tatar Associated SSR is evaluated. Results of studies of the physical and mechanical properties of cement-latex grouting mortar systems (mortar plus brick) are presented. Formulas for preparing cement-latex grouting mortor are evaluated and results of industrial tests of such mortars shown.

  14. US cement industry

    Nisbet, M.A.

    1997-12-31

    This paper describes the cement and concrete industry, and provides data on energy use and carbon dioxide emissions. The potential impact of an energy tax on the industry is briefly assessed. Opportunities identified for reducing carbon dioxide emissions include improved energy efficiency, alternative fuels, and alternative materials. The key factor in determining CO{sub 2} emissions is the level of domestic production. The projected improvement in energy efficiency and the relatively slow growth in domestic shipments indicate that CO{sub 2} emissions in 2000 should be about 5% above the 1990 target. However, due to the cyclical nature of cement demand, emissions will probably be above target levels during peak demand and below target levels during demand troughs. 7 figs., 2 tabs.

  15. Chemical environment in cements

    Glasser, F.B.; Angus, M.J.; McCulloch, C.E.; Macphee, D.; Rahman, A.A.

    1984-01-01

    The alkalinity of Portland cements is responsible for precipitation and low solubility of many radwastes species. The sources of alkalinity are evaluated and two chemical models, based on experimental and theoretical data presented enabling the effect of blending agents (PFA, silica fume, etc.) to be evaluated and the alkalinity of the system at longer ages predicted. The data take the form of a solubility model which is applicable to non-heat generating wastes. 7 refs., 10 figs

  16. Development of a degradable cement of calcium phosphate and calcium sulfate composite for bone reconstruction

    Guo, H; Wei, J; Liu, C S

    2006-01-01

    A new type of composite bone cement was prepared and investigated by adding calcium sulfate (CS) to calcium phosphate cement (CPC). This composite cement can be handled as a paste and easily shaped into any contour, which can set within 5-20 min, the setting time largely depending on the liquid-solid (L/S) ratio; adding CS to CPC had little effect on the setting time of the composite cements. No obvious temperature increase and pH change were observed during setting and immersion in simulated body fluid (SBF). The compressive strength of the cement decreased with an increase in the content of CS. The degradation rate of the composite cements increased with time when the CS content was more than 20 wt%. Calcium deficient apatite could form on the surface of the composite cement because the release of calcium into SBF from the dissolution of CS and the apatite of the cement induced the new apatite formation; increasing the content of CS in the composite could improve the bioactivity of the composite cements. The results suggested that composite cement has a reasonable setting time, excellent degradability and suitable mechanical strength and bioactivity, which shows promising prospects for development as a clinical cement

  17. Performance of Cement Containing Laterite as Supplementary Cementing Material

    Abbas Bukhari, Z. S.

    2013-03-01

    Full Text Available The utilization of different industrial waste, by-products or other materials such as ground granulated blast furnace slag, silica fume, fly ash, limestone, and kiln dust, etc. as supplemen- tary cementing materials has received considerable attention in recent years. A study has been conducted to look into the performance of laterite as Supplementary Cementing Materials (SCM. The study focuses on compressive strength performance of blended cement containing different percentage of laterite. The cement is replaced accordingly with percentage of 2 %, 5 %, 7 % and 10 % by weight. In addition, the effect of use of three chemically different laterites have been studied on physical performance of cement as in setting time, Le-Chatlier expansion, loss on ignition, insoluble residue, free lime and specifically compressive strength of cement cubes tested at the age of 3, 7, and 28 days. The results show that the strength of cement blended with laterite as SCM is enhanced. Key words: Portland cement, supplementary cementing materials (SCM, laterite, compressive strength KUI – 6/2013 Received January 4, 2012 Accepted February 11, 2013

  18. The prognostic value of clinical factors and cancer stem cell-related markers in gliomas

    Dahlrot, Rikke Hedegaard

    2014-01-01

    are already used in clinical decision making, and they can be used in prognostic counselling of the patients and to guide clinicians regarding the potential benefit from standard treatment in specific patients. Musashi-1 was a predictor of poor survival in WHO grade III tumours, but in patients with GBMs...

  19. Cartilage repair by mesenchymal stem cells: Clinical trial update and perspectives

    Wayne Yuk-wai Lee

    2017-04-01

    The translational potential of this article: This review summarises recent MSC-related clinical research that focuses on cartilage repair. We also propose a novel possible translational direction for hyaline cartilage formation and a new paradigm making use of extra-cellular signalling and epigenetic regulation in the application of MSCs for cartilage repair.

  20. Clinical and CT features of benign pneumatosis intestinalis in pediatric hematopoietic stem cell transplant and oncology patients

    McCarville, M.B.; Goodin, Geoffrey S.; Whittle, Sarah B.; Li, Chin-Shang; Smeltzer, Matthew P.; Hale, Gregory A.; Kaufman, Robert A.

    2008-01-01

    Pneumatosis intestinalis in children is associated with a wide variety of underlying conditions and often has a benign course. The CT features of this condition have not been systematically investigated. Defining benign pneumatosis intestinalis as pneumatosis intestinalis that resolved with medical management alone, we sought to: (1) determine whether the incidence of benign pneumatosis intestinalis had increased at our pediatric cancer hospital; (2) characterize CT features of benign pneumatosis intestinalis; and (3) determine the relationship between imaging features and clinical course of benign pneumatosis intestinalis in this cohort. Radiology reports from November 1994 to December 2006 were searched for ''pneumatosis intestinalis,'' ''free intraperitoneal air,'' and ''portal venous air or gas.'' Corresponding imaging was reviewed by two radiologists who confirmed pneumatosis intestinalis and recorded the presence of extraluminal free air, degree of intramural gaseous distension, number of involved bowel segments, and time to pneumatosis resolution. The search revealed 12 boys and 4 girls with pneumatosis intestinalis; 11 were hematopoietic stem cell transplant recipients. The annual incidences of benign pneumatosis have not changed at our institution. Increases in intramural distension marginally correlated with the number of bowel segments involved (P=0.08). Three patients had free air and longer times to resolution of pneumatosis (P=0.03). Male children may be at increased risk of benign pneumatosis intestinalis. The incidence of benign pneumatosis at our institution is proportional to the number of hematopoietic stem cell transplants. The degree of intramural distension may correlate with the number of bowel segments involved. Patients with free air have a longer time to resolution of benign pneumatosis. (orig.)

  1. Barium aluminate cement: its application

    Drozdz, M.; Wolek, W.

    1975-01-01

    The technology of manufacturing barium aluminate cement from barium sulfate and alumina, using a rotary kiln for firing the clinker is described. The method of granulation of the homogenized charge was used. Conditions of using the ''to mud'' method in industry were indicated. The physical and chemical properties of barium aluminate cement are determined and the quality of several batches of cement prepared on a semi-industrial scale and their suitability for making highly refractory concretes are tested. The optimal composition of the concretes is determined as a function of the mixing water and barium aluminate cement contents. Several experimental batches of concretes were used in the linings of furnaces in the steel industry. The suitability of these cements for use in fields other than steelmaking is examined. It is established that calcium aluminate cement has certain limited applications [fr

  2. Derivation of xeno-free and GMP-grade human embryonic stem cells--platforms for future clinical applications.

    Shelly E Tannenbaum

    Full Text Available Clinically compliant human embryonic stem cells (hESCs should be developed in adherence to ethical standards, without risk of contamination by adventitious agents. Here we developed for the first time animal-component free and good manufacturing practice (GMP-compliant hESCs. After vendor and raw material qualification, we derived xeno-free, GMP-grade feeders from umbilical cord tissue, and utilized them within a novel, xeno-free hESC culture system. We derived and characterized three hESC lines in adherence to regulations for embryo procurement, and good tissue, manufacturing and laboratory practices. To minimize freezing and thawing, we continuously expanded the lines from initial outgrowths and samples were cryopreserved as early stocks and banks. Batch release criteria included DNA-fingerprinting and HLA-typing for identity, characterization of pluripotency-associated marker expression, proliferation, karyotyping and differentiation in-vitro and in-vivo. These hESCs may be valuable for regenerative therapy. The ethical, scientific and regulatory methodology presented here may serve for development of additional clinical-grade hESCs.

  3. Febrile neutropenia in paediatric peripheral blood stem cell transplantation, in vitro sensitivity data and clinical response to empirical antibiotic therapy

    Ansari, S.H.; Nasim, S.; Ahmed, A.; Irfan, M.; Ishaque, A.; Farzana, T.; Panjwani, V.K.; Taj, M.; Shamsi, T.S.

    2006-01-01

    To find the in-vitro sensitivity data and clinical response in order to determine the changes required in empiric antibiotic therapy for management of febrile neutropenia in paediatric patients undergoing peripheral blood stem cell transplantation. All patients were treated according to institutional protocol for febrile neutropenia. Empirical antibiotics include Ceftriaxone and Amikacin. In non-responders, changes made included Imipenem and Amikacin, Piperacillin Tazobactum/Tiecoplanin or Vancomycin/Cloxacilin/Ceftazidime. In non-responders, amphotaracin was added until recovery. Out of 52 patients, 5 did not develop any fever; in the remaining 47 patients there were 57 episodes of febrile neutropenia. The mean days of febrile episodes were 4.71 (range 3-8). Fever of unknown origin (FUO) occurred in 31 (54.3%) episodes. Microbiologically documented infection (MDI) occurred in 17 (29.8%) episodes of fever. Clinically documented infection (CDI) occurred in 9 (15.7%) episodes. Gram-negative organisms were isolated in 10 while gram-positive organisms in 7. Klebseilla, S. aureus were the most common isolates. Empirical therapy was effective in 12 of the 33 (36%) episodes. Out of 28, 26 (92%) responded to Imipenem/Amikacin as second line therapy while those who received any other second line combination, only 11 out of 22 (50%) showed response. Systemic Amphotericin was used in 4 patients, 2 responded. Infection related mortality rate was 4%. (author)

  4. Processes and Equipment for the Cementation of Radioactive Waste

    Schaefer, S.; Studenski, J.

    2012-01-01

    In this article a short selection of different cement mixer types provided by NUKEM Technologies is given. The variety stems on one hand from historical development, but more especially from specific customer demands to meet their local and technical requirements. The Slant Batch Mixer is successfully installed in several Waste Treatment Centers (WTC). NUKEM Technologies set up these mixers with necessary auxiliary systems to facilitate all the cementation tasks of a WTC. By the slant design of the mixer a homogeneous intermixing and a rapid and comprehensive emptying is achieved. The High Shear Mixer is a batch mixer producing a thixotropic, fast flowing colloidal cement slurry. NUKEM Technologies uses this cement slurry to bubble-free/ empty space-free grouting of pre-packed solid waste items in container. The High Throughput Continuous Mixer is a continuously operating screw mixer that provides a high throughput. One or more dry components are continuously fed to the mixer where liquid waste or water is added. The High Performance In-Drum Mixer is a combination of planetary mixer with double helical mixer. NUKEM Technologies recently has developed a new High Capacity Mixer (HCM) based on a well proven conventional concrete mixer. The HCM is the successor of the slant mixer and will expend NUKEM Technologies' portfolio of cementation units. (A.C.)

  5. Comparison of different culture conditions for human mesenchymal stromal cells for clinical stem cell therapy

    Haack-Sorensen, M.; Friis, T.; Bindslev, L.

    2008-01-01

    OBJECTIVE: Mesenchymal stromal cells (MSCs) from adult bone marrow (BM) are considered potential candidates for therapeutic neovascularization in cardiovascular disease. When implementing results from animal trials in clinical treatment, it is essential to isolate and expand the MSCs under...... conditions following good manufacturing practice (GMP). The aims of the study were first to establish culture conditions following GMP quality demands for human MSC expansion and differentiation for use in clinical trials, and second to compare these MSCs with MSCs derived from culture in four media commonly...... analysis showed that the plastic-adherent MSCs cultured in EMEA medium or in the other four media were identically negative for the haematopoietic surface markers CD45 and CD34 and positive for CD105, CD73, CD90, CD166 and CD13, which in combined expression is characteristic of MSCs. MSC stimulation...

  6. Silver-Doped Calcium Phosphate Bone Cements with Antibacterial Properties

    J. V. Rau

    2016-04-01

    Full Text Available Calcium phosphate bone cements (CPCs with antibacterial properties are demanded for clinical applications. In this study, we demonstrated the use of a relatively simple processing route based on preparation of silver-doped CPCs (CPCs-Ag through the preparation of solid dispersed active powder phase. Real-time monitoring of structural transformations and kinetics of several CPCs-Ag formulations (Ag = 0 wt %, 0.6 wt % and 1.0 wt % was performed by the Energy Dispersive X-ray Diffraction technique. The partial conversion of β-tricalcium phosphate (TCP phase into the dicalcium phosphate dihydrate (DCPD took place in all the investigated cement systems. In the pristine cement powders, Ag in its metallic form was found, whereas for CPC-Ag 0.6 wt % and CPC-Ag 1.0 wt % cements, CaAg(PO33 was detected and Ag (met. was no longer present. The CPC-Ag 0 wt % cement exhibited a compressive strength of 6.5 ± 1.0 MPa, whereas for the doped cements (CPC-Ag 0.6 wt % and CPC-Ag 1.0 wt % the reduced values of the compressive strength 4.0 ± 1.0 and 1.5 ± 1.0 MPa, respectively, were detected. Silver-ion release from CPC-Ag 0.6 wt % and CPC-Ag 1.0 wt % cements, measured by the Atomic Emission Spectroscopy, corresponds to the average values of 25 µg/L and 43 µg/L, respectively, rising a plateau after 15 days. The results of the antibacterial test proved the inhibitory effect towards pathogenic Escherichia coli for both CPC-Ag 0.6 wt % and CPC-Ag 1.0 wt % cements, better performances being observed for the cement with a higher Ag-content.

  7. Stability of reinforced cemented backfills

    Mitchell, R.J.; Stone, D.M.

    1987-01-01

    Mining with backfill has been the subject of several international meetings in recent years and a considerable research effort is being applied to improve both mining economics and ore recovery by using backfill for ground support. Classified mill tailings sands are the most commonly used backfill material but these fine sands must be stabilized before full ore pillar recovery can be achieved. Normal portland cement is generally used for stabilization but the high cost of cement prohibits high cement usage. This paper considers the use of reinforcements in cemented fill to reduce the cement usage. It is concluded that strong cemented layers at typical spacings of about 3 meters in a low cement content bulk fill can reinforce the fill and reduce the overall cement usage. Fibre reinforcements introduced into strong layers or into bulk fills are also known to be effective in reducing cement usage. Some development work is needed to produce the ideal type of anchored fibre in order to realize economic gains from fibre-reinforced fills

  8. Modified cementless total coxofemoral prosthesis: development, implantation and clinical evaluation

    S.A. Arias

    2013-12-01

    Full Text Available The aim of this study was to modify canine coxofemoral prostheses and the clinical evaluation of the implantation. Fifteen canine hips and femora of cadavers were used in order to study the surface points of modification in prostheses and develop a perforation guide. Femoral stems and acetabular components were perforated and coated with biphasic calcium phosphate layer. Twelve young adult male mongrel dogs were implanted with coxofemoral prostheses. Six were operated upon and implanted with cemented canine modular hip prostheses, establishing the control group. The remaining six were implanted with a novel design of cementless porous tricalcic phosphate-hydroxyapatite coated hip prostheses. Clinical and orthopedic performance, complications, and thigh muscular hypotrophy were assessed up to the 120th post-operatory day. After 120 days, animals with cementless prostheses had similar clinical and orthopedic performance compared to the cemented group despite the increased pain thigh hypotrophy. Animals that underwent cementless hip prosthesis evidenced more pain, compared to animals with cemented hip prosthesis that required longer recuperation time. No luxations, two fractures and two isquiatic neurapraxies were identified in the course of the study. Using both the cemented and the bioactive coated cementless model were suitable to dogs, showing clinical satisfactory results. Osseointegration and biological fixation were observed in the animals with the modified cementless hip prosthesis.

  9. Composition and function of macroencapsulated human embryonic stem cell-derived implants: comparison with clinical human islet cell grafts.

    Motté, Evi; Szepessy, Edit; Suenens, Krista; Stangé, Geert; Bomans, Myriam; Jacobs-Tulleneers-Thevissen, Daniel; Ling, Zhidong; Kroon, Evert; Pipeleers, Daniel

    2014-11-01

    β-Cells generated from large-scale sources can overcome current shortages in clinical islet cell grafts provided that they adequately respond to metabolic variations. Pancreatic (non)endocrine cells can develop from human embryonic stem (huES) cells following in vitro derivation to pancreatic endoderm (PE) that is subsequently implanted in immune-incompetent mice for further differentiation. Encapsulation of PE increases the proportion of endocrine cells in subcutaneous implants, with enrichment in β-cells when they are placed in TheraCyte-macrodevices and predominantly α-cells when they are alginate-microencapsulated. At posttransplant (PT) weeks 20-30, macroencapsulated huES implants presented higher glucose-responsive plasma C-peptide levels and a lower proinsulin-over-C-peptide ratio than human islet cell implants under the kidney capsule. Their ex vivo analysis showed the presence of single-hormone-positive α- and β-cells that exhibited rapid secretory responses to increasing and decreasing glucose concentrations, similar to isolated human islet cells. However, their insulin secretory amplitude was lower, which was attributed in part to a lower cellular hormone content; it was associated with a lower glucose-induced insulin biosynthesis, but not with lower glucagon-induced stimulation, which together is compatible with an immature functional state of the huES-derived β-cells at PT weeks 20-30. These data support the therapeutic potential of macroencapsulated huES implants but indicate the need for further functional analysis. Their comparison with clinical-grade human islet cell grafts sets references for future development and clinical translation. Copyright © 2014 the American Physiological Society.

  10. Targeting insulin resistance in type 2 diabetes via immune modulation of cord blood-derived multipotent stem cells (CB-SCs) in stem cell educator therapy: phase I/II clinical trial.

    Zhao, Yong; Jiang, Zhaoshun; Zhao, Tingbao; Ye, Mingliang; Hu, Chengjin; Zhou, Huimin; Yin, Zhaohui; Chen, Yana; Zhang, Ye; Wang, Shanfeng; Shen, Jie; Thaker, Hatim; Jain, Summit; Li, Yunxiang; Diao, Yalin; Chen, Yingjian; Sun, Xiaoming; Fisk, Mary Beth; Li, Heng

    2013-07-09

    The prevalence of type 2 diabetes (T2D) is increasing worldwide and creating a significant burden on health systems, highlighting the need for the development of innovative therapeutic approaches to overcome immune dysfunction, which is likely a key factor in the development of insulin resistance in T2D. It suggests that immune modulation may be a useful tool in treating the disease. In an open-label, phase 1/phase 2 study, patients (N=36) with long-standing T2D were divided into three groups (Group A, oral medications, n=18; Group B, oral medications+insulin injections, n=11; Group C having impaired β-cell function with oral medications+insulin injections, n=7). All patients received one treatment with the Stem Cell Educator therapy in which a patient's blood is circulated through a closed-loop system that separates mononuclear cells from the whole blood, briefly co-cultures them with adherent cord blood-derived multipotent stem cells (CB-SCs), and returns the educated autologous cells to the patient's circulation. Clinical findings indicate that T2D patients achieve improved metabolic control and reduced inflammation markers after receiving Stem Cell Educator therapy. Median glycated hemoglobin (HbA1C) in Group A and B was significantly reduced from 8.61%±1.12 at baseline to 7.25%±0.58 at 12 weeks (P=2.62E-06), and 7.33%±1.02 at one year post-treatment (P=0.0002). Homeostasis model assessment (HOMA) of insulin resistance (HOMA-IR) demonstrated that insulin sensitivity was improved post-treatment. Notably, the islet beta-cell function in Group C subjects was markedly recovered, as demonstrated by the restoration of C-peptide levels. Mechanistic studies revealed that Stem Cell Educator therapy reverses immune dysfunctions through immune modulation on monocytes and balancing Th1/Th2/Th3 cytokine production. Clinical data from the current phase 1/phase 2 study demonstrate that Stem Cell Educator therapy is a safe approach that produces lasting improvement in

  11. Using dehydrated cement paste as new type of cement additive

    Yu, R.; Shui, Z.H.; Dong, J

    2013-01-01

    This paper presents an experimental study, including evaluation and modification, on using dehydrated cement paste (DCP) as a new type of cement additive. After a series of processes, normal DCP (N-DCP) was produced as before and a modified form of DCP (M-DCP) was produced as well. The cementitious

  12. Improvement of in vitro physicochemical properties and osteogenic activity of calcium sulfate cement for bone repair by dicalcium silicate

    Chen, Chun-Cheng; Wang, Chien-Wen; Hsueh, Nai-Shuo; Ding, Shinn-Jyh

    2014-01-01

    Highlights: • Dicalcium silicate can improve osteogenic activity of calcium sulfate cement. • The higher the calcium sulfate content, the shorter the setting time in the composite cement. • The results were useful for designing calcium-based cement with optimal properties. -- Abstract: An ideal bone graft substitute should have the same speed of degradation as formation of new bone tissue. To improve the properties of calcium sulfate hemihydrate (CSH) featured for its rapid resorption, a low degradation material of dicalcium silicate (DCS) was added to the CSH cement. This study examined the effect of DCS (20, 40, 60 and 80 wt%) on the in vitro physicochemical properties and osteogenic activities of the calcium-based composite cements. The diametral tensile strength, porosity and weight loss of the composite cements were evaluated before and after soaking in a simulated body fluid (SBF). The osteogenic activities, such as proliferation, differentiation and mineralization, of human mesenchymal stem cells (hMSCs) seeded on cement surfaces were also examined. As a result, the greater the DCS amount, the higher the setting time was in the cement. Before soaking in SBF, the diametral tensile strength of the composite cements was decreased due to the introduction of DCS. On 180-day soaking, the composite cements containing 20, 40, 60 and 80 wt% DCS lost 80%, 69%, 61% and 44% in strength, respectively. Regarding in vitro bioactivity, the DCS-rich cements were covered with clusters of apatite spherulites after soaking for 7 days, while there was no formation of apatite spherulites on the CSH-rich cement surfaces. The presence of DCS could reduce the degradation of the CSH cements, as evidenced in the results of weight loss and porosity. More importantly, DCS may promote effectively the cell proliferation, proliferation and mineralization. The combination of osteogenesis of DCS and degradation of CSH made the calcium-based composite cements an attractive choice for

  13. Adipose-Derived Stem Cells in Aesthetic Surgery: A Mixed Methods Evaluation of the Current Clinical Trial, Intellectual Property, and Regulatory Landscape.

    Arshad, Zeeshaan; Halioua-Haubold, Celine-Lea; Roberts, Mackenna; Urso-Baiarda, Fulvio; Branford, Oliver A; Brindley, David A; Davies, Benjamin M; Pettitt, David

    2018-02-17

    Adipose tissue, which can be readily harvested via a number of liposuction techniques, offers an easily accessible and abundant source of adipose-derived stem cells (ASCs). Consequently, ASCs have become an increasingly popular reconstructive option and a novel means of aesthetic soft tissue augmentation. This paper examines recent advances in the aesthetic surgery field, extending beyond traditional review formats to incorporate a comprehensive analysis of current clinical trials, adoption status, and the commercialization pathway. Keyword searches were carried out on clinical trial databases to search for trials using ASCs for aesthetic indications. An intellectual property landscape was created using commercial software (Thomson Reuters Thomson Innovation, New York, NY). Analysis of who is claiming what in respect of ASC use in aesthetic surgery for commercial purposes was analyzed by reviewing the patent landscape in relation to these techniques. Key international regulatory guidelines were also summarized. Completed clinical trials lacked robust controls, employed small sample sizes, and lacked long-term follow-up data. Ongoing clinical trials still do not address such issues. In recent years, claims to intellectual property ownership have increased in the "aesthetic stem cell" domain, reflecting commercial interest in the area. However, significant translational barriers remain including regulatory challenges and ethical considerations. Further rigorous randomized controlled trials are required to delineate long-term clinical efficacy and safety. Providers should consider the introduction of patient reported outcome metrics to facilitate clinical adoption. Robust regulatory and ethical policies concerning stem cells and aesthetic surgery should be devised to discourage further growth of "stem cell tourism." © 2017 The American Society for Aesthetic Plastic Surgery, Inc. Reprints and permission: journals.permissions@oup.com

  14. Effect of bioglass 45S5 addition on properties, microstructure and cellular response of tetracalcium phosphate/monetite cements

    Stulajterova, R., E-mail: rstulajterova@saske.sk; Medvecky, L.; Giretova, M.; Sopcak, T.; Kovalcikova, A.

    2017-04-15

    Tetracalcium phosphate/nanomonetite (TTCPMH) cement composites with 7.5 and 15 wt% addition of melt-derived 45S5 bioactive glass were prepared by mechanical homogenization of powder components and 2% NaH{sub 2}PO{sub 4} solution was used as a hardening liquid. The properties of composites with the acidic (Ca/P ratio equal 1.5) or basic (Ca/P ratio equal 1.67) TTCPMH component were compared. Addition of glass component caused rapid rise in pH of composites up to 10. In microstructure of basic cement composite, the large bioglass particles weakly bounded to surrounding cement matrix were found contrary to a more compact microstructure of acidic cement composites with the high number of spherical silica particles. Both the significant refinement of hydroxyapatite particles and the change to needle-like morphology with rise in the content of bioglass were identified in hydroxyapatite coatings created during soaking of composites in phosphate buffered saline. In acidic cement mixtures, the increase of compressive strength with an amount of bioglass was found whereas the opposite tendency was revealed in the case of basic cement mixtures. The higher concentrations of ions were verified in solutions after immersion of acidic cement composites. The severe cytotoxicity of extracts and composite cement substrates containing 15 wt% of bioglass demonstrated adverse effects of both the ionic concentrations and unappropriate surface texture on proliferation of mesenchymal stem cells. The enhanced ALP activities of cells cultured on composite cements confirmed the positive effect of bioactive glass addition on differentiation of mesenchymal stem cells. - Highlights: • Novel B45S5 bioglass/tetracalcium phosphate/nanomonetite cement composites • Cement basicity negatively affected their microstructure. • Acid composite cements had higher compressive strengths than basic composites. • Fast differentiation of MSC to osteoblast line on composite with 7.5 wt% of bioglass

  15. Vascular Wall-Resident Multipotent Stem Cells of Mesenchymal Nature within the Process of Vascular Remodeling: Cellular Basis, Clinical Relevance, and Implications for Stem Cell Therapy.

    Klein, Diana

    2016-01-01

    Until some years ago, the bone marrow and the endothelial cell compartment lining the vessel lumen (subendothelial space) were thought to be the only sources providing vascular progenitor cells. Now, the vessel wall, in particular, the vascular adventitia, has been established as a niche for different types of stem and progenitor cells with the capacity to differentiate into both vascular and nonvascular cells. Herein, vascular wall-resident multipotent stem cells of mesenchymal nature (VW-MPSCs) have gained importance because of their large range of differentiation in combination with their distribution throughout the postnatal organism which is related to their existence in the adventitial niche, respectively. In general, mesenchymal stem cells, also designated as mesenchymal stromal cells (MSCs), contribute to the maintenance of organ integrity by their ability to replace defunct cells or secrete cytokines locally and thus support repair and healing processes of the affected tissues. This review will focus on the central role of VW-MPSCs within vascular reconstructing processes (vascular remodeling) which are absolute prerequisite to preserve the sensitive relationship between resilience and stability of the vessel wall. Further, a particular advantage for the therapeutic application of VW-MPSCs for improving vascular function or preventing vascular damage will be discussed.

  16. Physicochemical properties of newly developed bioactive glass cement and its effects on various cells.

    Washio, Ayako; Nakagawa, Aika; Nishihara, Tatsuji; Maeda, Hidefumi; Kitamura, Chiaki

    2015-02-01

    Biomaterials used in dental treatments are expected to have favorable properties such as biocompatibility and an ability to induce tissue formation in dental pulp and periapical tissue, as well as sealing to block external stimuli. Bioactive glasses have been applied in bone engineering, but rarely applied in the field of dentistry. In the present study, bioactive glass cement for dental treatment was developed, and then its physicochemical properties and effects on cell responses were analyzed. To clarify the physicochemical attributes of the cement, field emission scanning electron microscopy, X-ray diffraction, and pH measurement were carried out. Cell attachment, morphology, and viability to the cement were also examined to clarify the effects of the cement on odontoblast-like cells (KN-3 cells), osteoblastic cells (MC3T3-E1 cells), human periodontal ligament stem/progenitor cells and neuro-differentiative cells (PC-12 cells). Hydroxyapatite-like precipitation was formed on the surface of the hardened cement and the pH level changed from pH10 to pH9, then stabilized in simulate body fluid. The cement had no cytotxic effects on these cells, and particulary induced process elongation of PC-12 cells. Our results suggest that the newly developed bioactive glass cement have capability of the application in dental procedures as bioactive cement. © 2014 Wiley Periodicals, Inc.

  17. Biomass for green cement

    Cumming, R. [Lafarge Canada Inc., Calgary, AB (Canada)

    2006-07-01

    Lafarge examined the use of waste biomass products in its building materials and provided background information on its operations. Cement kiln infrastructure was described in terms of providing access to shipping, rail and highways; conveying and off-loading equipment; having large storage facilities; and, offering continuous monitoring and stack testing. The presentation identified the advantages and disadvantages of a few different biomass cases such as coal; scrap tires; non-recyclable household waste; and processed biomass. A chart representing landfill diversion rates was presented and the presentation concluded with a discussion of energy recovery and recycling. 1 tab., figs.

  18. Informed Consent in Clinical Trials Using Stem Cells: Suggestions and Points of Attention from Informed Consent Training Workshops in Japan

    M Kusunose

    2015-09-01

    Full Text Available Informed consent (IC is an essential requirement of ethical research involving human participants, and usually is achieved by providing prospective research participants (PRPs with a document that explains the study and its procedures. However, results of a series of IC workshops held in Tokyo during 2014 indicate that consent forms alone are not enough to achieve full IC in regenerative medicine research due to the necessity of long-term patient-safety observations to meet the ethical challenges of such research. Adequate training of the people who are responsible for obtaining IC (elucidators is also necessary to ensure full IC. Elucidators must be able to provide PRPs with sufficient information to assure adequate comprehension of the study and its potential aftereffects; judge PRPs’ voluntariness and eligibility; and establish/maintain partnerships with PRPs. The workshops used role-playing simulations to demonstrate how to effectively obtain fuller IC to members of several Japanese research groups preparing for clinical stem cell trials. Workshop results were correlated with the results of a 2013 workshop on what information is patients want when considering participation in iPSC research. The correlated results showed the need for continuous training and education of elucidators in order to have them acquire and maintain IC competency. 

  19. The Critical, Clinical Role of Interferon-Beta in Regulating Cancer Stem Cell Properties in Triple-Negative Breast Cancer.

    Doherty, Mary R; Jackson, Mark W

    2018-05-11

    Triple-negative breast cancer (TNBC) the deadliest form of this disease currently lacks a targeted therapy and is characterized by increased risk of metastasis and presence of therapeutically resistant cancer stem cells (CSC). Recent evidence has demonstrated that the presence of an interferon (IFN)/signal transducer of activated transcription 1 (STAT1) gene signature correlates with improved therapeutic response and overall survival in TNBC patients. In agreement with these clinical observations, our recent work has demonstrated, in a cell model of TNBC that CSC have intrinsically repressed IFN signaling. Administration of IFN-β represses CSC properties, inducing a less aggressive non-CSC state. Moreover, an elevated IFN-β gene signature correlated with repressed CSC-related genes and an increased presence of tumor-infiltrating lymphocytes in TNBC specimens. We therefore propose that IFN-β be considered as a potential therapeutic option in the treatment of TNBC, to repress the CSC properties responsible for therapy failure. Future studies aim to improve methods to target delivery of IFN-β to tumors, to maximize therapeutic efficacy while minimizing systemic side effects.

  20. Clinical impact of pre-transplant gut microbial diversity on outcomes of allogeneic hematopoietic stem cell transplantation.

    Doki, Noriko; Suyama, Masahiro; Sasajima, Satoshi; Ota, Junko; Igarashi, Aiko; Mimura, Iyo; Morita, Hidetoshi; Fujioka, Yuki; Sugiyama, Daisuke; Nishikawa, Hiroyoshi; Shimazu, Yutaka; Suda, Wataru; Takeshita, Kozue; Atarashi, Koji; Hattori, Masahira; Sato, Eiichi; Watakabe-Inamoto, Kyoko; Yoshioka, Kosuke; Najima, Yuho; Kobayashi, Takeshi; Kakihana, Kazuhiko; Takahashi, Naoto; Sakamaki, Hisashi; Honda, Kenya; Ohashi, Kazuteru

    2017-09-01

    Post-transplant microbial diversity in the gastrointestinal tract is closely associated with clinical outcomes following allogeneic hematopoietic stem cell transplantation (allo-HSCT). However, little is known about the impact of the fecal microbiota before allo-HSCT. We analyzed fecal samples approximately 2 weeks before conditioning among 107 allo-HSCT recipients between 2013 and 2015. Microbial analysis was performed using 16S rRNA gene sequencing. Operational taxonomic unit-based microbial diversity was estimated by calculating the Shannon index. Patients were classified into three groups based on the diversity index: low (3) diversity (18 (16.8%), 48 (44.9%), and 41 (38.3%) patients, respectively). There were no significant differences in the 20-month overall survival, cumulative incidence of relapse, and non-relapse mortality among three groups. The cumulative incidence of grade II to IV acute graft-versus-host disease (aGVHD) was similar among the three groups (low 55.6%; intermediate 35.4%; high 48.8%, p = 0.339, at day 100). Furthermore, we found no differences in the cumulative incidence of grade II to IV acute gastrointestinal GVHD among the three groups (low 38.9%; intermediate 21.3%; high 24.4%, p = 0.778, at day 100). Regarding the composition of microbiota before allo-HSCT, aGVHD patients showed a significantly higher abundance of phylum Firmicutes (p strategy to prevent aGVHD.

  1. Cell-assisted lipotransfer for facial lipoatrophy: efficacy of clinical use of adipose-derived stem cells.

    Yoshimura, Kotaro; Sato, Katsujiro; Aoi, Noriyuki; Kurita, Masakazu; Inoue, Keita; Suga, Hirotaka; Eto, Hitomi; Kato, Harunosuke; Hirohi, Toshitsugu; Harii, Kiyonori

    2008-09-01

    Lipoinjection is a promising treatment, but its efficacy in recontouring facial lipoatrophy remains to be established. The objective was to evaluate the efficacy and adverse effects of lipoinjection and supplementation of adipose-derived stem/stromal cells (ASCs) to adipose grafts. To overcome drawbacks of autologous lipoinjection, we have developed a novel strategy called cell-assisted lipotransfer (CAL). In CAL, stromal vascular fraction containing ASCs was freshly isolated from half of an aspirated fat sample and attached to the other half of aspirated fat sample with the fat acting as a scaffold. This process converts relatively ASC-poor aspirated fat into ASC-rich fat. We performed conventional lipoinjection (non-CAL; n=3) or CAL (n=3) on six patients with facial lipoatrophy due to lupus profundus or Parry-Romberg syndrome. All patients obtained improvement in facial contour, but the CAL group had a better clinical improvement score than did the non-CAL patients, although the difference did not reach statistical significance (p=.11). Adipose necrosis was found in one non-CAL case who took perioperative oral corticosteroids. Our results suggest that CAL is both effective and safe and potentially superior to conventional lipoinjection for facial recontouring. The authors have indicated no significant interest with commercial supporters.

  2. Process of preparing hydraulic cement

    1919-12-11

    A process of preparing hydraulic cement from oil shale or shale coke is characterized in that the oil shale or shale coke after the distillation is burned long and hot to liberate the usual amount of carbonic acid and then is fine ground to obtain a slow hardening hydraulic cement.

  3. Health hazards of cement dust

    Meo, Sultan A.

    2004-01-01

    ven in the 21st century, millions of people are working daily in a dusty environment. They are exposed to different types of health hazards such as fume, gases and dust, which are risk factors in developing occupational disease. Cement industry is involved in the development of structure of this advanced and modern world but generates dust during its production. Cement dust causes lung function impairment, chronic obstructive lung disease, restrictive lung disease, pneumoconiosis and carcinoma of the lungs, stomach and colon. Other studies have shown that cement dust may enter into the systemic circulation and thereby reach the essentially all the organs of body and affects the different tissues including heart, liver, spleen, bone, muscles and hairs and ultimately affecting their micro-structure and physiological performance. Most of the studies have been previously attempted to evaluate the effects of cement dust exposure on the basis of spirometry or radiology, or both. However, collective effort describing the general effects of cement dust on different organ and systems in humans or animals, or both has not been published. Therefore, the aim of this review is to gather the potential toxic effects of cement dust and to minimize the health risks in cement mill workers by providing them with information regarding the hazards of cement dust. (author)

  4. Ceramic microspheres for cementing applications

    2011-01-01

    A method and apparatus for manufacturing ceramic microspheres from industrial slag. The microspheres have a particle size of about 38 microns to about 150 microns. The microspheres are used to create a cement slurry having a density of at least about 11 lbs/g. The resultant cement slurry may then be

  5. Ceramic microspheres for cementing applications

    2010-01-01

    A method and apparatus for manufacturing ceramic microspheres from industrial slag. The microspheres have a particle size of about 38 microns to about 150 microns. The microspheres are used to create a cement slurry having a density of at least about 11 lbs/g. The resultant cement slurry may then be

  6. Ceramic microspheres for cementing applications

    2012-01-01

    A method and apparatus for manufacturing ceramic microspheres from industrial slag. The microspheres have a particle size of about 38 microns to about 150 microns. The microspheres are used to create a cement slurry having a density of at least about 11 lbs/g. The resultant cement slurry may then be

  7. Autologous hematopoietic stem cell transplantation vs intravenous pulse cyclophosphamide in diffuse cutaneous systemic sclerosis: a randomized clinical trial.

    van Laar, Jacob M; Farge, Dominique; Sont, Jacob K; Naraghi, Kamran; Marjanovic, Zora; Larghero, Jérôme; Schuerwegh, Annemie J; Marijt, Erik W A; Vonk, Madelon C; Schattenberg, Anton V; Matucci-Cerinic, Marco; Voskuyl, Alexandre E; van de Loosdrecht, Arjan A; Daikeler, Thomas; Kötter, Ina; Schmalzing, Marc; Martin, Thierry; Lioure, Bruno; Weiner, Stefan M; Kreuter, Alexander; Deligny, Christophe; Durand, Jean-Marc; Emery, Paul; Machold, Klaus P; Sarrot-Reynauld, Francoise; Warnatz, Klaus; Adoue, Daniel F P; Constans, Joël; Tony, Hans-Peter; Del Papa, Nicoletta; Fassas, Athanasios; Himsel, Andrea; Launay, David; Lo Monaco, Andrea; Philippe, Pierre; Quéré, Isabelle; Rich, Éric; Westhovens, Rene; Griffiths, Bridget; Saccardi, Riccardo; van den Hoogen, Frank H; Fibbe, Willem E; Socié, Gérard; Gratwohl, Alois; Tyndall, Alan

    2014-06-25

    High-dose immunosuppressive therapy and autologous hematopoietic stem cell transplantation (HSCT) have shown efficacy in systemic sclerosis in phase 1 and small phase 2 trials. To compare efficacy and safety of HSCT vs 12 successive monthly intravenous pulses of cyclophosphamide. The Autologous Stem Cell Transplantation International Scleroderma (ASTIS) trial, a phase 3, multicenter, randomized (1:1), open-label, parallel-group, clinical trial conducted in 10 countries at 29 centers with access to a European Group for Blood and Marrow Transplantation-registered transplant facility. From March 2001 to October 2009, 156 patients with early diffuse cutaneous systemic sclerosis were recruited and followed up until October 31, 2013. HSCT vs intravenous pulse cyclophosphamide. The primary end point was event-free survival, defined as time from randomization until the occurrence of death or persistent major organ failure. A total of 156 patients were randomly assigned to receive HSCT (n = 79) or cyclophosphamide (n = 77). During a median follow-up of 5.8 years, 53 events occurred: 22 in the HSCT group (19 deaths and 3 irreversible organ failures) and 31 in the control group (23 deaths and 8 irreversible organ failures). During the first year, there were more events in the HSCT group (13 events [16.5%], including 8 treatment-related deaths) than in the control group (8 events [10.4%], with no treatment-related deaths). At 2 years, 14 events (17.7%) had occurred cumulatively in the HSCT group vs 14 events (18.2%) in the control group; at 4 years, 15 events (19%) had occurred cumulatively in the HSCT group vs 20 events (26%) in the control group. Time-varying hazard ratios (modeled with treatment × time interaction) for event-free survival were 0.35 (95% CI, 0.16-0.74) at 2 years and 0.34 (95% CI, 0.16-0.74) at 4 years. Among patients with early diffuse cutaneous systemic sclerosis, HSCT was associated with increased treatment-related mortality in the first year

  8. Corrosion resistant cemented carbide

    Hong, J.

    1990-01-01

    This paper describes a corrosion resistant cemented carbide composite. It comprises: a granular tungsten carbide phase, a semi-continuous solid solution carbide phase extending closely adjacent at least a portion of the grains of tungsten carbide for enhancing corrosion resistance, and a substantially continuous metal binder phase. The cemented carbide composite consisting essentially of an effective amount of an anti-corrosion additive, from about 4 to about 16 percent by weight metal binder phase, and with the remaining portion being from about 84 to about 96 percent by weight metal carbide wherein the metal carbide consists essentially of from about 4 to about 30 percent by weight of a transition metal carbide or mixtures thereof selected from Group IVB and of the Periodic Table of Elements and from about 70 to about 96 percent tungsten carbide. The metal binder phase consists essentially of nickel and from about 10 to about 25 percent by weight chromium, the effective amount of an anti-corrosion additive being selected from the group consisting essentially of copper, silver, tine and combinations thereof

  9. Creep and fatigue behavior of a novel 2-component paste-like formulation of acrylic bone cements

    Köster, U.; Jaeger, R.; Bardts, M.; Wahnes, C.; Büchner, H.; Kühn, K.-D.; Vogt, S.

    2013-01-01

    The fatigue and creep performance of two novel acrylic bone cement formulations (one bone cement without antibiotics, one with antibiotics) was compared to the performance of clinically used bone cements (Osteopal V, Palacos R, Simplex P, SmartSet GHV, Palacos R+G and CMW1 with Gentamicin). The preparation of the novel bone cement formulations involves the mixing of two paste-like substances in a static mixer integrated into the cartridge which is used to apply the bone cement. The fatigue pe...

  10. Glass ionomer cement: literature review

    Sérgio Spezzia

    2017-12-01

    Full Text Available Introduction: In the dental area preventive actions occur in an attempt to avoid the installation of caries, a disease that has an increased prevalence in the population and which is a Public Health problem. Some resources are used for such, such as: performing early diagnosis and the option for conservative treatments of minimal intervention. The glass ionomer cement (CIV, coming from its beneficial characteristics that meet current trends, is closely related to the precepts of Preventive and Minimally Invasive Dentistry and the new preservative techniques recommended. Objective: The objective of the present article was to carry out a literature review study, to determine the characteristics of CIV that has a prominent role in the Minimally Invasive Dentistry profile. Results: The dentist surgeon must be aware of the classification, according to its composition and physical-chemical nature: conventional ionomers; ionomers reinforced by metals; high viscosity and various types of resin modified glass ionomers to correctly choose the CIV that will be used in their clinical interventions, which should occur based on the properties of the material and its clinical indication. Conclusion: It was concluded that the implementation of preventive techniques with CIV in public health care, tend to minimize curative treatments, concurrently valuing the low complexity dental procedures performed in Primary Care, avoiding referrals for treatment of cases of greater complexity at the level Secondary and tertiary care, saving resources.

  11. Nine Things to Know About Stem Cell Treatments

    ... Search Toggle Nav Nine Things To Know About Stem Cell Treatments Home > Stem Cells and Medicine > Nine Things ... Know About Stem Cell Treatments Many clinics offering stem cell treatments make claims that are not supported by ...

  12. The behavior of implant-supported dentures and abutments using the cemented cylinder technique with different resinous cements

    Ivete Aparecida de Mathias Sartori

    2008-01-01

    Full Text Available Objective: Evaluate the behavior of implant-supported dentures and their components, made by cemented cylinder technique, using threetypes of resin cements. Methods: Fifty three patients, of whom 26 were women and 27 men, aged between 25 and 82 years. Results: With partial (54.43% and total (45.57% implant-supported dentures, of the Cone Morse, external and internal hexagon types (Neodent®, Curitiba, Brazil, totaling 237 fixations, were analyzed. The resin cements used were Panavia® (21.94%, EnForce® (58.23% and Rely X® (19.83% and the components were used in accordance with the Laboratory Immediate Loading - Neodent® sequence. The period of time of denture use ranged between 1 and 5 years. The results reported that 5(2.1% cylinders were loosened from metal structure (both belonging to Rely X group, 2(0.48% implants were lost after the first year of use, 16(6.75% denture retention screws wereloosened and 31(13.08% abutment screws were unloosened.Conclusion: The reasons for these failures probably are: metal structure internal retention failure, occlusal pattern, cementation technique and loading conditions. The cemented cylinder technique was effective when used in partial and total implant-supported rehabilitations, keeping prosthetic components stable, despite the resin cement utilized. However, further clinical studies must be conducted.

  13. 21 CFR 888.4200 - Cement dispenser.

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cement dispenser. 888.4200 Section 888.4200 Food... DEVICES ORTHOPEDIC DEVICES Surgical Devices § 888.4200 Cement dispenser. (a) Identification. A cement dispenser is a nonpowered syringe-like device intended for use in placing bone cement (§ 888.3027) into...

  14. A cement based syntactic foam

    Li Guoqiang; Muthyala, Venkata D.

    2008-01-01

    In this study, a cement based syntactic foam core was proposed and experimentally investigated for composite sandwich structures. This was a multi-phase composite material with microballoon dispersed in a rubber latex toughened cement paste matrix. A trace amount of microfiber was also incorporated to increase the number of mechanisms for energy absorption and a small amount of nanoclay was added to improve the crystal structure of the hydrates. Three groups of cement based syntactic foams with varying cement content were investigated. A fourth group of specimens containing pure cement paste were also prepared as control. Each group contained 24 beam specimens. The total number of beam specimens was 96. The dimension of each beam was 30.5 cm x 5.1 cm x 1.5 cm. Twelve foam specimens from each group were wrapped with plain woven 7715 style glass fabric reinforced epoxy to prepare sandwich beams. Twelve cubic foam specimens, three from each group, with a side length of 5.1 cm, were also prepared. Three types of testing, low velocity impact test and four-point bending test on the beam specimens and compression test on the cubic specimens, were conducted to evaluate the impact energy dissipation, stress-strain behavior, and residual strength. Scanning electron microscope (SEM) was also used to examine the energy dissipation mechanisms in the micro-length scale. It was found that the cement based syntactic foam has a higher capacity for dissipating impact energy with an insignificant reduction in strength as compared to the control cement paste core. When compared to a polymer based foam core having similar compositions, it was found that the cement based foam has a comparable energy dissipation capacity. The developed cement based syntactic foam would be a viable alternative for core materials in impact-tolerant composite sandwich structures

  15. A defined and xeno-free culture method enabling the establishment of clinical-grade human embryonic, induced pluripotent and adipose stem cells.

    Kristiina Rajala

    2010-04-01

    Full Text Available The growth of stem cells in in vitro conditions requires optimal balance between signals mediating cell survival, proliferation, and self-renewal. For clinical application of stem cells, the use of completely defined conditions and elimination of all animal-derived materials from the establishment, culture, and differentiation processes is desirable.Here, we report the development of a fully defined xeno-free medium (RegES, capable of supporting the expansion of human embryonic stem cells (hESC, induced pluripotent stem cells (iPSC and adipose stem cells (ASC. We describe the use of the xeno-free medium in the derivation and long-term (>80 passages culture of three pluripotent karyotypically normal hESC lines: Regea 06/015, Regea 07/046, and Regea 08/013. Cardiomyocytes and neural cells differentiated from these cells exhibit features characteristic to these cell types. The same formulation of the xeno-free medium is capable of supporting the undifferentiated growth of iPSCs on human feeder cells. The characteristics of the pluripotent hESC and iPSC lines are comparable to lines derived and cultured in standard undefined culture conditions. In the culture of ASCs, the xeno-free medium provided significantly higher proliferation rates than ASCs cultured in medium containing allogeneic human serum (HS, while maintaining the differentiation potential and characteristic surface marker expression profile of ASCs, although significant differences in the surface marker expression of ASCs cultured in HS and RegES media were revealed.Our results demonstrate that human ESCs, iPSCs and ASCs can be maintained in the same defined xeno-free medium formulation for a prolonged period of time while maintaining their characteristics, demonstrating the applicability of the simplified xeno-free medium formulation for the production of clinical-grade stem cells. The basic xeno-free formulation described herein has the potential to be further optimized for specific

  16. Cement/slag chemistry studies

    Glasser, F.P.; Macphee, D.; Atkins, M.; Beckley, N.; Carson, S.O.; Wilding, C.R.; McHugh, G.

    1988-01-01

    The performance of cement-based matrices intended for radwaste immobilization is assessed. The long-term performance of the matrix is characterized by thermodynamic evaluation of experimental data. The results are presented in a general form, amenable to a range of specific formulations. The interaction of specific radwaste components with cements has been studied, using Iodine as an example. It occurs as both I - and IO 3 - species, but these differ sharply in sorption characteristics. The effect of ionizing radiation of the pH and E h of cement matrices is reported. (author)

  17. Cements in Radioactive Waste Disposal

    Glasser, F.P.

    2013-01-01

    The use of cement and concrete to immobilise radioactive waste is complicated by the wide- ranging nature of inorganic cementing agents available as well as the range of service environments in which cement is used and the different functions expected of cement. For example, Portland cement based concretes are widely used as structural materials for construction of vaults and tunnels. These constructions may experience a long pre-closure performance lifetime during which they are required to protect against collapse and ingress of water: strength and impermeability are key desirable characteristics. On the other hand, cement and concrete may be used to form backfills, ranging in permeability. Permeable formulations allow gas readily to escape, while impermeable barriers retard radionuclide transport and reduce access of ground water to the waste. A key feature of cements is that, while fresh, they pass through a fluid phase and can be formed into any shape desired or used to infiltrate other materials thereby enclosing them into a sealed matrix. Thereafter, setting and hardening is automatic and irreversible. Where concrete is used to form structural elements, it is also natural to use cement in other applications as it minimises potential for materials incompatibility. Thus cement- mainly Portland cement- has been widely used as an encapsulant for storage, transport and as a radiation shield for active wastes. Also, to form and stabilise structures such as vaults and silos. Relative to other potential matrices, cement also has a chemical immobilisation potential, reacting with and binding with many radionuclides. The chemical potential of cements is essentially sacrificial, thus limiting their performance lifetime. However performance may also be required in the civil engineering sense, where strength is important, so many factors, including a geochemical description of service conditions, may require to be assessed in order to predict performance lifetime. The

  18. Cements in Radioactive Waste Disposal

    Glasser, F. P. [University of Aberdeen, Scotland (United Kingdom)

    2013-09-15

    The use of cement and concrete to immobilise radioactive waste is complicated by the wide- ranging nature of inorganic cementing agents available as well as the range of service environments in which cement is used and the different functions expected of cement. For example, Portland cement based concretes are widely used as structural materials for construction of vaults and tunnels. These constructions may experience a long pre-closure performance lifetime during which they are required to protect against collapse and ingress of water: strength and impermeability are key desirable characteristics. On the other hand, cement and concrete may be used to form backfills, ranging in permeability. Permeable formulations allow gas readily to escape, while impermeable barriers retard radionuclide transport and reduce access of ground water to the waste. A key feature of cements is that, while fresh, they pass through a fluid phase and can be formed into any shape desired or used to infiltrate other materials thereby enclosing them into a sealed matrix. Thereafter, setting and hardening is automatic and irreversible. Where concrete is used to form structural elements, it is also natural to use cement in other applications as it minimises potential for materials incompatibility. Thus cement- mainly Portland cement- has been widely used as an encapsulant for storage, transport and as a radiation shield for active wastes. Also, to form and stabilise structures such as vaults and silos. Relative to other potential matrices, cement also has a chemical immobilisation potential, reacting with and binding with many radionuclides. The chemical potential of cements is essentially sacrificial, thus limiting their performance lifetime. However performance may also be required in the civil engineering sense, where strength is important, so many factors, including a geochemical description of service conditions, may require to be assessed in order to predict performance lifetime. The

  19. Evaluation of the delivery of mesenchymal stem cells into the root canal space of necrotic immature teeth after clinical regenerative endodontic procedure.

    Lovelace, Tyler W; Henry, Michael A; Hargreaves, Kenneth M; Diogenes, Anibal

    2011-02-01

    Immature teeth with open apices treated with conventional nonsurgical root canal treatment often have a poor prognosis as a result of the increased risk of fracture and susceptibility to recontamination. Regenerative endodontics represents a new treatment modality that focuses on reestablishment of pulp vitality and continued root development. This clinical procedure relies on the intracanal delivery of a blood clot (scaffold), growth factors (possibly from platelets and dentin), and stem cells. However, to date, the clinical presence of stem cells in the canal space after this procedure has not been demonstrated. The purpose of this clinical study was to evaluate whether regenerative endodontic procedures are able to deliver stem cells into the canal space of immature teeth in young patients and to identify the possible tissue origin for these cells. After informed consent, the first appointment consisted of NaOCl irrigation and treatment with a triple antibiotic paste. One month later, the root canal space was irrigated with sterile saline, and bleeding was evoked with collection of samples on paper points. Real-time reverse-transcription polymerase chain reaction and immunocytochemistry were conducted to compare the gene transcripts and proteins found in the root canal sample with levels found in the systemic circulation. Molecular analyses of blood collected from the canal system indicated the significant accumulation of transcripts for the stem cell markers CD73 and CD105 (up to 600-fold), compared with levels found in the systemic blood. Furthermore, this effect was selective because there was no change in expression of the differentiation markers ALK-P, DSPP, ZBTB16, and CD14. Histologic analyses demonstrated that the delivered cells expressed both CD105 and STRO-1, markers for a subpopulation of mesenchymal stem cells. Collectively, these findings demonstrate that the evoked-bleeding step in regenerative procedures triggers the significant accumulation of

  20. Cementation of Glass-Ceramic Posterior Restorations: A Systematic Review

    van den Breemer, Carline R. G.; Gresnigt, Marco M. M.; Cune, Marco S.

    2015-01-01

    Aim. The aim of this comprehensive review is to systematically organize the current knowledge regarding the cementation of glass-ceramic materials and restorations, with an additional focus on the benefits of Immediate Dentin Sealing (IDS). Materials and Methods. An extensive literature search concerning the cementation of single-unit glass-ceramic posterior restorations was conducted in the databases of MEDLINE (Pubmed), CENTRAL (Cochrane Central Register of Controlled Trials), and EMBASE. To be considered for inclusion, in vitro and in vivo studies should compare different cementation regimes involving a “glass-ceramic/cement/human tooth” complex. Results and Conclusions. 88 studies were included in total. The in vitro data were organized according to the following topics: (micro)shear and (micro)tensile bond strength, fracture strength, and marginal gap and integrity. For in vivo studies survival and quality of survival were considered. In vitro studies showed that adhesive systems (3-step, etch-and-rinse) result in the best (micro)shear bond strength values compared to self-adhesive and self-etch systems when luting glass-ceramic substrates to human dentin. The highest fracture strength is obtained with adhesive cements in particular. No marked clinical preference for one specific procedure could be demonstrated on the basis of the reviewed literature. The possible merits of IDS are most convincingly illustrated by the favorable microtensile bond strengths. No clinical studies regarding IDS were found. PMID:26557651

  1. Antibacterial Activity of Dental Cements Containing Quaternary Ammonium Polyethylenimine Nanoparticles

    Beyth, N.; Weiss, E.I.; Pilo, R.

    2012-01-01

    Glass ionomer cements (GICs) are commonly used for cementing full cast crown restorations. Regrettably, although the dental cements fill the gap between the tooth and the crown, bacterial micro leakage may occur, resulting in secondary caries. As micro leakage cannot be completely prevented, GCS possessing antibacterial properties are in demand. In the present study the antibacterial activity of insoluble, cross-linked quaternary ammonium polyethylenimine (Qp) nanoparticles incorporated at 1% w/w in two clinically available GCS were studied. The antibacterial activity was tested against Streptococcus mutans and Lactobacillus casei using the direct contact test (Dct) and the agar diffusion test (Ad). Using the direct contact test, antibacterial activity (P<0.05) was found in both tested GICs with incorporated QPEI nanoparticles, the effect lasting for at least one month. However, the ADT showed no inhibition halo in the test bacteria, indicating that the antimicrobial nanoparticles do not diffuse into the agar. The results show that the incorporation of QPEI nanoparticles in glass ionomer cements has a long-lasting antibacterial effect against Streptococcus mutans and Lactobacillus casei. Changing the antibacterial properties of glass ionomer cements by incorporating QPEI antibacterial nanoparticles may prolong the clinical performance of dental crowns.

  2. Antibacterial Activity of Dental Cements Containing Quaternary Ammonium Polyethylenimine Nanoparticles

    Nurit Beyth

    2012-01-01

    Full Text Available Glass ionomer cements (GICs are commonly used for cementing full cast crown restorations. Regrettably, although the dental cements fill the gap between the tooth and the crown, bacterial microleakage may occur, resulting in secondary caries. As microleakage cannot be completely prevented, GICs possessing antibacterial properties are in demand. In the present study the antibacterial activity of insoluble, cross-linked quaternary ammonium polyethylenimine (QPEI nanoparticles incorporated at 1% w/w in two clinically available GICs were studied. The antibacterial activity was tested against Streptococcus mutans and Lactobacillus casei using the direct contact test (DCT and the agar diffusion test (ADT. Using the direct contact test, antibacterial activity (<0.05 was found in both tested GICs with incorporated QPEI nanoparticles, the effect lasting for at least one month. However, the ADT showed no inhibition halo in the test bacteria, indicating that the antimicrobial nanoparticles do not diffuse into the agar. The results show that the incorporation of QPEI nanoparticles in glass ionomer cements has a long-lasting antibacterial effect against Streptococcus mutans and Lactobacillus casei. Changing the antibacterial properties of glass ionomer cements by incorporating QPEI antibacterial nanoparticles may prolong the clinical performance of dental crowns.

  3. Understanding mineral trioxide aggregate/Portland-cement: a review of literature and background factors.

    Steffen, R; van Waes, H

    2009-06-01

    This was to carry out a review of the literature concerning mineral trioxide aggregate (MTA) and Portland cement with regards to clinical, biological and mechanical findings and a possible substitution of MTA through Portland cement for endodontic use. Electronic literature search of scientific papers from January 1993 to January 2009 was carried out on the MEDLINE and Scopus databases using specific key words. In total, 57 papers were identified that dealt with MTA and Portland cement in a relevant way. The review of 50 papers conforming to the applied criteria showed that MTA and Portland cements have the same clinical, biological and mechanical properties. In animal experiments and technical characterisations both materials seemed to have very similar properties. The only difference is bismuth oxide in MTA added for better radio opacity. It seems likely that MTA materials are based on industrial Portland cements mixed with bismuth oxide. More studies, especially some long-term studies comparing MTA and Portland cement, are necessary. The existing literature gives a solid base for clinical studies with Portland cement in order to replace MTA as an endodontic material. Portland cement could be a substitute for most endodontic materials used in primary teeth.

  4. Alternative Fuels in Cement Production

    Larsen, Morten Boberg

    The substitution of alternative for fossil fuels in cement production has increased significantly in the last decade. Of these new alternative fuels, solid state fuels presently account for the largest part, and in particular, meat and bone meal, plastics and tyre derived fuels (TDF) accounted...... for the most significant alternative fuel energy contributors in the German cement industry. Solid alternative fuels are typically high in volatile content and they may differ significantly in physical and chemical properties compared to traditional solid fossil fuels. From the process point of view......, considering a modern kiln system for cement production, the use of alternative fuels mainly influences 1) kiln process stability (may accelerate build up of blockages preventing gas and/or solids flow), 2) cement clinker quality, 3) emissions, and 4) decreased production capacity. Kiln process stability...

  5. Calcium Aluminate Cement Hydration Model

    Matusinović, T.

    2011-01-01

    Full Text Available Calcium aluminate cement (AC is a very versatile special cement used for specific applications. As the hydration of AC is highly temperature dependent, yielding structurally different hydration products that continuously alter material properties, a good knowledge of thermal properties at early stages of hydration is essential. The kinetics of AC hydration is a complex process and the use of single mechanisms models cannot describe the rate of hydration during the whole stage.This paper examines the influence of temperature (ϑ=5–20 °C and water-to-cement mass ratio (mH /mAC = 0.4; 0.5 and 1.0 on hydration of commercial iron-rich AC ISTRA 40 (producer: Istra Cement, Pula, Croatia, which is a part of CALUCEM group, Figs 1–3. The flow rate of heat generation of cement pastes as a result of the hydration reactions was measured with differential microcalorimeter. Chemically bonded water in the hydrated cement samples was determined by thermo-gravimetry.Far less heat is liberated when cement and water come in contact for the first time, Fig. 1, than in the case for portland cement (PC. Higher water-to-cement ratio increases the heat evolved at later ages (Fig. 3 due to higher quantity of water available for hydration. A significant effect of the water-to-cement ratio on the hydration rate and hydration degree showed the importance of water as being the limiting reactant that slows down the reaction early. A simplified stoichiometric model of early age AC hydration (eq. (8 based on reaction schemes of principal minerals, nominally CA, C12A7 and C4AF (Table 1, was employed. Hydration kinetics after the induction period (ϑ < 20 °C had been successfully described (Fig. 4 and Table 2 by a proposed model (eq. (23 which simultaneously comprised three main mechanisms: nucleation and growth, interaction at phase boundary, and mass transfer. In the proposed kinetic model the nucleation and growth is proportional to the amount of reacted minerals (eq

  6. Clinical Effects of Novel Nanoscaled Core Decompression Rods Combined with Umbilical Cord Mesenchymal Stem Cells on the Treatment of Early Osteonecrosis of the Femoral Head

    Hongyang Gao

    2015-01-01

    Full Text Available Osteonecrosis of the femoral head (ONFH is one of the most common diseases in orthopedics. In this study, we investigated the clinical effects of novel nanoscaled core decompression rods combined with mesenchymal stem cells on the treatment of the ONFH. 12 adult patients with early ONFH (at the stage of Ficat II received the treatment using the implantation of novel nanoscaled core decompression rods combined with umbilical cord mesenchymal stem cells. The grade of the patients’ hip was scored by Harris marking system before and after the surgery, and then paired t-test was done. We assessed the curative efficiency based on the change of the patients before and after the surgery. In particular, the survival rate of femoral head was assessed at 12 months after the surgery. The results demonstrated that according to the standard of Harris Scoring, the average grade of hip joint before the surgery was 54.16 ± 4.23 points while average grade of hip joint at 12 months after the surgery was 85.28 ± 3.65 points. So, the implantation of the novel nanoscaled core decompression rods combined with mesenchymal stem cells had satisfactory clinical effects, suggesting that this implantation should be effective to treat early ONFH.

  7. Rheological measurements on cement grouts

    Dalton, M.J.

    1986-06-01

    This report describes the techniques which have been developed at Winfrith for assessing the rheological properties of cement grouts. A discussion of the theory of rheology and its application to cement is given and the methodology for calibrating a special paddle measuring system for a commercial viscometer is described. The use of the system for determining flow curves, equilibrium viscosity, viscosity as a function of shearing time and structure changes is also discussed. (author)

  8. [Correlation analysis of cement leakage with volume ratio of intravertebral bone cement to vertebral body and vertebral body wall incompetence in percutaneous vertebroplasty for osteoporotic vertebral compression fractures].

    Liang, De; Ye, Linqiang; Jiang, Xiaobing; Huang, Weiquan; Yao, Zhensong; Tang, Yongchao; Zhang, Shuncong; Jin, Daxiang

    2014-11-01

    To investigate the risk factors of cement leakage in percutaneous vertebroplasty (PVP) for osteoporotic vertebral compression fracture (OVCF). Between March 2011 and March 2012, 98 patients with single level OVCF were treated by PVP, and the clinical data were analyzed retrospectively. There were 13 males and 85 females, with a mean age of 77.2 years (range, 54-95 years). The mean disease duration was 43 days (range, 15-120 days), and the mean T score of bone mineral density (BMD) was -3.8 (range, -6.7- -2.5). Bilateral transpedicular approach was used in all the patients. The patients were divided into cement leakage group and no cement leakage group by occurrence of cement leakage based on postoperative CT. Single factor analysis was used to analyze the difference between 2 groups in T score of BMD, operative level, preoperative anterior compression degree of operative vertebrae, preoperative middle compression degree of operative vertebrae, preoperative sagittal Cobb angle of operative vertebrae, preoperative vertebral body wall incompetence, cement volume, and volume ratio of intravertebral bone cement to vertebral body. All relevant factors were introduced to logistic regression analysis to analyze the risk factors of cement leakage. All procedures were performed successfully. The mean operation time was 40 minutes (range, 30-50 minutes), and the mean volume ratio of intravertebral bone cement to vertebral body was 24.88% (range, 7.84%-38.99%). Back pain was alleviated significantly in all the patients postoperatively. All patients were followed up with a mean time of 8 months (range, 6-12 months). Cement leakage occurred in 49 patients. Single factor analysis showed that there were significant differences in the volume ratio of intravertebral bone cement to vertebral body and preoperative vertebral body wall incompetence between 2 groups (P 0.05). The logistic regression analysis showed that the volume ratio of intravertebral bone cement to vertebral body (P

  9. Portland cement versus MTA as a root-end filling material. A pilot study.

    da Silva, Sérgio Ribeiro; da Silva Neto, José Dias; Veiga, Daniela Francescato; Schnaider, Taylor Brandão; Ferreira, Lydia Masako

    2015-02-01

    To assess periradicular lesions clinically and by computed tomography (CT) after endodontic surgery using either Portland cement or mineral trioxide aggregate (MTA) as a root-end filling material. Three patients diagnosed with periradicular lesions by cone-beam CT underwent endodontic surgery with root-end filling. Patient A was treated with MTA as the root-end filling material, patient B was treated with Portland cement and patient C had two teeth treated, one with MTA and the other with Portland cement. Six months after surgery, the patients were assessed clinically and by CT scan and the obtained results were compared. Periradicular tissue regeneration was observed in all cases, with no significant differences in bone formation when comparing the use of MTA and Portland cement as root-end filling materials. Both mineral trioxide aggregate and Portland cement were successful in the treatment of periradicular lesions.

  10. Evaluation of four biodegradable, injectable bone cements in an experimental drill hole model in sheep.

    von Rechenberg, Brigitte; Génot, Oliver R; Nuss, Katja; Galuppo, Larry; Fulmer, Mark; Jacobson, Evan; Kronen, Peter; Zlinszky, Kati; Auer, Jörg A

    2013-09-01

    Four cement applications were tested in this investigation. Two dicalcium phosphate dihydrate (DCPD-brushite) hydraulic cements, an apatite hydraulic fiber loaded cement, and a calcium sulfate cement (Plaster of Paris) were implanted in epiphyseal and metaphyseal cylindrical bone defects in sheep. The in vivo study was performed to assess the biocompatibility and bone remodeling of four cement formulations. After time periods of 2, 4, and 6 months, the cement samples were clinically and histologically evaluated. Histomorphometrically, the amount of new bone formation, fibrous tissue, and bone marrow and the area of remaining cement were measured. In all specimens, no signs of inflammation were detectable either macroscopically or microscopically. Cements differed mainly in their resorption time. Calcium sulfate was already completely resorbed at 2 months and showed a variable amount of new bone formation and/or fibrous tissue in the original drill hole over all time periods. The two DCPD cements in contrast were degraded to a large amount at 6 months, whereas the apatite was almost unchanged over all time periods. Copyright © 2013. Published by Elsevier B.V.

  11. Comparison of the physical and mechanical properties of MTA and portland cement.

    Islam, Intekhab; Chng, Hui Kheng; Yap, Adrian U Jin

    2006-03-01

    This study evaluated and compared the pH, radiopacity, setting time, solubility, dimensional change, and compressive strength of ProRoot MTA (PMTA), ProRoot MTA (tooth colored formula) (WMTA), white Portland cement (WP), and ordinary Portland cement (OP). The results showed that PMTA and Portland cement have very similar physical properties. However, the radiopacity of Portland cement is much lower than that of PMTA. The compressive strength of PMTA was greater than Portland cement at 28 days. The major constituent of PMTA is Portland cement. Given the low cost of Portland cement and similar properties when compared to PMTA, it is reasonable to consider Portland cement as a possible substitute for PMTA in endodontic applications. However, industrially manufactured Portland cement is not approved currently for use in the United States and therefore no clinical recommendation can be made for its use in the human body. Further in vitro and in vivo tests, especially with regards its biocompatibility, should be conducted to ascertain if it meets the FDA requirements for use as a medical device.

  12. Effect of different resin luting cements on the marginal fit of lithium disilicate pressed crowns.

    Mounajjed, Radek; Salinas, Thomas J; Ingr, Tomas; Azar, Basel

    2017-11-15

    The vertical marginal discrepancy of restorations can increase upon cementation, and poor marginal fit can lead to cement dissolution, marginal discoloration, microleakage, and secondary caries. The amount of increase is related to the type of luting cement used, but how lithium disilicate pressed crowns are affected by different resin cements is unclear. The purpose of this in vitro study was to compare the effect of using different resin luting cements on the vertical marginal discrepancy of lithium disilicate pressed crowns. A total of 18 intact extracted mandibular third molars were disinfected in a solution of 10% formalin for 7 days and were then prepared to receive a ceramic crown. Impressions were made with polyvinyl siloxane and lithium disilicate pressed crowns made and cemented with 1 of 3 resin luting cements. The marginal discrepancy was measured at 4 points on the finishing line of each tooth, with optical microscopy at ×200 magnification before and after cementation. Statistical analysis was done with the Kruskal-Wallis test to compare the median marginal increase among the 3 groups. The least amount of marginal increase after cementation was with Harvard PremiumFlow cement, with an average marginal increase of 42 ±11 μm. RelyX Ultimate cement increased the margins by an average 45 ±29 μm. The highest marginal increase was found in the Enamel Plus HRi preheated composite resin group (116 ±47 μm). The marginal increase of pressed crowns cemented with preheated composite resin (Enamel Plus HRi) exceeded the clinically acceptable range of marginal discrepancy. Copyright © 2017 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  13. Calcium Orthophosphate Cements and Concretes

    Sergey V. Dorozhkin

    2009-03-01

    Full Text Available In early 1980s, researchers discovered self-setting calcium orthophosphate cements, which are a bioactive and biodegradable grafting material in the form of a powder and a liquid. Both phases form after mixing a viscous paste that after being implanted, sets and hardens within the body as either a non-stoichiometric calcium deficient hydroxyapatite (CDHA or brushite, sometimes blended with unreacted particles and other phases. As both CDHA and brushite are remarkably biocompartible and bioresorbable (therefore, in vivo they can be replaced with newly forming bone, calcium orthophosphate cements represent a good correction technique for non-weight-bearing bone fractures or defects and appear to be very promising materials for bone grafting applications. Besides, these cements possess an excellent osteoconductivity, molding capabilities and easy manipulation. Furthermore, reinforced cement formulations are available, which in a certain sense might be described as calcium orthophosphate concretes. The concepts established by calcium orthophosphate cement pioneers in the early 1980s were used as a platform to initiate a new generation of bone substitute materials for commercialization. Since then, advances have been made in the composition, performance and manufacturing; several beneficial formulations have already been introduced as a result. Many other compositions are in experimental stages. In this review, an insight into calcium orthophosphate cements and concretes, as excellent biomaterials suitable for both dental and bone grafting application, has been provided.

  14. All-ceramic crowns: bonding or cementing?

    Pospiech, Peter

    2002-12-01

    Despite the wide variety of all-ceramic systems available today, the majority of dental practitioners hesitate to recommend and insert all-ceramic crowns. This article regards the nature of the ceramic materials, the principles of bonding and adhesion, and the clinical problems of the acid-etch technique for crowns. Advantages and disadvantages are discussed, and the influences of different factors on the strength of all-ceramic crowns are presented. Finally, the conclusion is drawn that conventional cementing of all-ceramic crowns is possible when the specific properties of the ceramics are taken into consideration.

  15. Migration and strains induced by different designs of force-closed stems for THA.

    Griza, Sandro; Gomes, Luiz Sérgio Marcelino; Cervieri, André; Strohaecker, Telmo Roberto

    2015-01-01

    Subtle differences in stem design can result in different mechanical responses of the total hip arthroplasty. Tests measuring migration of the stem relative to the femur, as well as the strains in the cement mantle and on the femur can detect different mechanical behavior between stems. In this article, conical, double and triple tapered stems were implanted in composite femurs and subjected to static and cyclic loads. Stems differed mainly on taper angle, calcar radius and proximal stiffness. Stem migration and strains on the femur and in the cement mantle were achieved. Significant differences (p mechanical tests were able to detect significant differences in the behavior of these resembling stems. Stem proximal stiffness and the calcar radius of the stem influence its rotational stability and the strain transmission to the femur.

  16. Peri-implant stress correlates with bone and cement morphology: Micro-FE modeling of implanted cadaveric glenoids.

    Wee, Hwabok; Armstrong, April D; Flint, Wesley W; Kunselman, Allen R; Lewis, Gregory S

    2015-11-01

    Aseptic loosening of cemented joint replacements is a complex biological and mechanical process, and remains a clinical concern especially in patients with poor bone quality. Utilizing high resolution finite element analysis of a series of implanted cadaver glenoids, the objective of this study was to quantify relationships between construct morphology and resulting mechanical stresses in cement and trabeculae. Eight glenoid cadavers were implanted with a cemented central peg implant. Specimens were imaged by micro-CT, and subject-specific finite element models were developed. Bone volume fraction, glenoid width, implant-cortex distance, cement volume, cement-cortex contact, and cement-bone interface area were measured. Axial loading was applied to the implant of each model and stress distributions were characterized. Correlation analysis was completed across all specimens for pairs of morphological and mechanical variables. The amount of trabecular bone with high stress was strongly negatively correlated with both cement volume and contact between the cement and cortex (r = -0.85 and -0.84, p implant-cortex distance. Contact between the cement and underlying cortex may dramatically reduce trabecular bone stresses surrounding the cement, and this contact depends on bone shape, cement amount, and implant positioning. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  17. Development of cement material using inorganic additives

    Toyohara, Masumitsu; Satou, Tatsuaki; Wada, Mikio; Ishii, Tomoharu; Matsuo, Kazuaki.

    1997-01-01

    Inorganic admixtures to enhance the fluidity of cement material was developed. These admixtures turned into easy to immobilize the miscellaneous radioactive waste using cement material. It was found that the ζ potential of cement particles was directly proportional to the content of the inorganic admixtures in cement paste and the particles of cement were dispersed at the high ζ potential. The condensed sodium phosphate, which was the main component of the inorganic admixtures, retarded the dissolution of Ca 2+ ion from the cement, and generated the colloids by incorporating dissolved Ca 2+ ion. The cement material containing the inorganic admixtures was found to have the same mechanical strength and adsorption potential of radionuclides in comparison to normal cement materials. It was confirmed that the cement material containing the inorganic admixture was effectively filled gaps of miscellaneous radioactive waste. (author)

  18. Development of high-performance blended cements

    Wu, Zichao

    2000-10-01

    This thesis presents the development of high-performance blended cements from industrial by-products. To overcome the low-early strength of blended cements, several chemicals were studied as the activators for cement hydration. Sodium sulfate was discovered as the best activator. The blending proportions were optimized by Taguchi experimental design. The optimized blended cements containing up to 80% fly ash performed better than Type I cement in strength development and durability. Maintaining a constant cement content, concrete produced from the optimized blended cements had equal or higher strength and higher durability than that produced from Type I cement alone. The key for the activation mechanism was the reaction between added SO4 2- and Ca2+ dissolved from cement hydration products.

  19. FLT3 mutations in early T-cell precursor ALL characterize a stem cell like leukemia and imply the clinical use of tyrosine kinase inhibitors.

    Martin Neumann

    Full Text Available Early T-cell precursor acute lymphoblastic leukemia (ETP-ALL has been identified as high-risk subgroup of acute T-lymphoblastic leukemia (T-ALL with a high rate of FLT3-mutations in adults. To unravel the underlying pathomechanisms and the clinical course we assessed molecular alterations and clinical characteristics in a large cohort of ETP-ALL (n = 68 in comparison to non-ETP T-ALL adult patients. Interestingly, we found a high rate of FLT3-mutations in ETP-ALL samples (n = 24, 35%. Furthermore, FLT3 mutated ETP-ALL was characterized by a specific immunophenotype (CD2+/CD5-/CD13+/CD33-, a distinct gene expression pattern (aberrant expression of IGFBP7, WT1, GATA3 and mutational status (absence of NOTCH1 mutations and a low frequency, 21%, of clonal TCR rearrangements. The observed low GATA3 expression and high WT1 expression in combination with lack of NOTCH1 mutations and a low rate of TCR rearrangements point to a leukemic transformation at the pluripotent prothymocyte stage in FLT3 mutated ETP-ALL. The clinical outcome in ETP-ALL patients was poor, but encouraging in those patients with allogeneic stem cell transplantation (3-year OS: 74%. To further explore the efficacy of targeted therapies, we demonstrate that T-ALL cell lines transfected with FLT3 expression constructs were particularly sensitive to tyrosine kinase inhibitors. In conclusion, FLT3 mutated ETP-ALL defines a molecular distinct stem cell like leukemic subtype. These data warrant clinical studies with the implementation of FLT3 inhibitors in addition to early allogeneic stem cell transplantation for this high risk subgroup.

  20. Cost-effective master cell bank validation of multiple clinical-grade human pluripotent stem cell lines from a single donor.

    Devito, Liani; Petrova, Anastasia; Miere, Cristian; Codognotto, Stefano; Blakely, Nicola; Lovatt, Archie; Ogilvie, Caroline; Khalaf, Yacoub; Ilic, Dusko

    2014-10-01

    Standardization guidelines for human pluripotent stem cells are still very broadly defined, despite ongoing clinical trials in the U.S., U.K., and Japan. The requirements for validation of human embryonic (hESCs) and induced pluripotent stem cells (iPSCs) in general follow the regulations for other clinically compliant biologics already in place but without addressing key differences between cell types or final products. In order to realize the full potential of stem cell therapy, validation criteria, methodology, and, most importantly, strategy, should address the shortfalls and efficiency of current approaches; without this, hESC- and, especially, iPSC-based therapy will not be able to compete with other technologies in a cost-efficient way. We addressed the protocols for testing cell lines for human viral pathogens and propose a novel strategy that would significantly reduce costs. It is highly unlikely that the multiple cell lines derived in parallel from a tissue sample taken from one donor would have different profiles of endogenous viral pathogens; we therefore argue that samples from the Master Cell Banks of sibling lines could be safely pooled for validation. We illustrate this approach with tiered validation of two sibling clinical-grade hESC lines, KCL033 and KCL034 (stage 1, sterility; stage 2, specific human pathogens; and stage 3, nonspecific human pathogens). The results of all tests were negative. This cost-effective strategy could also be applied for validation of Master Cell Banks of multiple clinical-grade iPSC lines derived from a single donor. ©AlphaMed Press.

  1. Clinical Impact of Pretransplant Multidrug-Resistant Gram-Negative Colonization in Autologous and Allogeneic Hematopoietic Stem Cell Transplantation.

    Forcina, Alessandra; Lorentino, Francesca; Marasco, Vincenzo; Oltolini, Chiara; Marcatti, Magda; Greco, Raffaella; Lupo-Stanghellini, Maria Teresa; Carrabba, Matteo; Bernardi, Massimo; Peccatori, Jacopo; Corti, Consuelo; Ciceri, Fabio

    2018-03-02

    Multidrug-resistant Gram-negative bacteria (MDR-GNB) are an emerging cause of morbidity and mortality after hematopoietic stem cell transplantation (HSCT). Three-hundred forty-eight consecutive patients transplanted at our hospital from July 2012 to January 2016 were screened for a pretransplant MDR-GNB colonization and evaluated for clinical outcomes. A pretransplant MDR-GNB colonization was found in 16.9% of allo-HSCT and in 9.6% of auto-HSCT recipients. Both in auto- and in allo-HSCT, carriers of a MDR-GNB showed no significant differences in overall survival (OS), transplant-related mortality (TRM), or infection-related mortality (IRM) compared with noncarriers. OS at 2 years for carriers compared with noncarriers was 85% versus 81% (P = .262) in auto-HSCT and 50% versus 43% (P = .091) in allo-HSCT. TRM at 2 years was 14% versus 5% (P = .405) in auto-HSCT and 31% versus 25% (P = .301) in allo-HSCT. IRM at 2 years was 14% versus 2% (P = .142) in auto-HSCT and 23% versus 14% (P = .304) in allo-HSCT. In multivariate analysis, only grade III to IV acute graft-versus-host disease was an independent factor for reduced OS (P < .001) and increased TRM (P < .001) and IRM (P < .001). During the first year after transplant, we collected 73 GNB bloodstream infectious (BSI) episodes in 54 patients, 42.4% of which sustained by a MDR-GNB. Rectal swabs positivity associated with the pathogen causing subsequent MDR-GNB BSI episodes in 13 of 31 (41.9%). Overall, OS at 4 months from MDR-GNB BSI episode onset was of 67.9%, with a 14-day attributed mortality of 12.9%, not being significantly different between carriers and noncarriers (P = .207). We conclude that in this extended single-center experience, a pretransplant MDR-GNB colonization did not significantly influence OS, TRM, and IRM both in auto- and allo-HSCT settings and that MDR-GNB attributed mortality can be controlled in carriers when an early pre-emptive antimicrobial therapy is

  2. Polymer-cement interactions towards improved wellbore cement fracture sealants

    Beckingham, B. S.; Iloejesi, C.; Minkler, M. J.; Schindler, A. K.; Beckingham, L. E.

    2017-12-01

    Carbon capture, utilization, and storage (CCUS) in deep geologic formations is a promising means of reducing point source emissions of CO2. In these systems, CO2 is captured at the source and then injected to be utilized (eg. in enhanced oil recovery or as a working fluid in enhanced geothermal energy plants) or stored in geologic formations such as depleted oil and gas reservoirs or saline aquifers. While CCUS in subsurface systems could aid in reducing atmospheric CO2 emissions, the potential for CO2 leakage from these systems to overlying formations remains a major limitation and poses a significant risk to the security of injected CO2. Thus, improved materials for both initial wellbore isolation and repairing leakage pathways that develop over time are sought. One approach for the repair of cement fractures in wellbore (and other) systems is the injection of polymer materials into the fracture with a subsequent environmentally dependent (temperature, pressure, pH, etc.) densification or solidification. Here, we aim to investigate novel polymer materials for use to repair leaking wellbores in the context of CCUS. We synthesize and fully characterize a series of novel polymer materials and utilize a suite of analysis techniques to examine polymer-cement interactions at a range of conditions (namely temperature, pressure and pH). Initial findings will be leveraged to design novel polymer materials for further evaluation in polymer-cement composite cores, cement fracture healing, and the aging behavior of healed cements.

  3. Does Vertebroplasty Affect Radiation Dose Distribution?: Comparison of Spatial Dose Distributions in a Cement-Injected Vertebra as Calculated by Treatment Planning System and Actual Spatial Dose Distribution

    Komemushi, A.; Tanigawa, N.; Kariya, Sh.; Yagi, R.; Nakatani, M.; Suzuki, S.; Sano, A.; Ikeda, K.; Utsunomiya, K.; Harima, Y.; Sawada, S.

    2012-01-01

    Purpose. To assess differences in dose distribution of a vertebral body injected with bone cement as calculated by radiation treatment planning system (RTPS) and actual dose distribution. Methods. We prepared two water-equivalent phantoms with cement, and the other two phantoms without cement. The bulk density of the bone cement was imported into RTPS to reduce error from high CT values. A dose distribution map for the phantoms with and without cement was calculated using RTPS with clinical setting and with the bulk density importing. Actual dose distribution was measured by the film density. Dose distribution as calculated by RTPS was compared to the dose distribution measured by the film dosimetry. Results. For the phantom with cement, dose distribution was distorted for the areas corresponding to inside the cement and on the ventral side of the cement. However, dose distribution based on film dosimetry was undistorted behind the cement and dose increases were seen inside cement and around the cement. With the equivalent phantom with bone cement, differences were seen between dose distribution calculated by RTPS and that measured by the film dosimetry. Conclusion. The dose distribution of an area containing bone cement calculated using RTPS differs from actual dose distribution

  4. In vitro evaluation of microleakage of various types of dental cements

    Medić Vesna

    2010-01-01

    Full Text Available Introduction. Microleakage is defined as the clinically undetectable seepage of oral fluids containing bacteria and debris between cement layer and tooth restoration. Objective. This in vitro study investigated the effect of different dental cements (zinc-phosphate, polycarboxylate, glass-ionomer and resin cement on microleakage in different ceramic crown systems (metal ceramic crown, metal ceramic crown with a porcelain margin, Empress 2 and In Ceram all-ceramic crowns fixed on extracted human teeth. Methods. One hundred and sixty intact human premolars were randomized to four groups of forty teeth each, according to the different ceramic crown systems. They were prepared in a standardized manner for metal-ceramic and all-ceramic crowns. Crowns were made following a standard laboratory technique, and each group of crowns were divided into four groups according to the different cement agents and cemented on their respective abutments. The specimens were subjected to thermocycling, placed in methylene blue solutions, embedded in resin blocks and vertically cut in the bucco-oral and meso-distal direction. The microleakage in the area of tooth-cement interface was defined as linear penetration of methylene blue and was determined with a microscope to assign microleakage scores using a five-point scale. Results. A significant association was found between a cement type and degree of microleakage (p=0.001. No statistically significant differences were found among the different ceramic crown systems luted with the same dental cement. The smallest degree of microleakage was observed in specimens luted with resin cement (X=1.73, followed by glass-ionomer cement (X=2.45 and polycarboxylate cement (X=3.20. The greatest degree of microleakage was detected in the crowns fixed with zincphosphate cement (X=3.33. Conclusion. The investigated dental cements revealed different sealing abilities. The use of resin cement resulted in the percentage of 0

  5. Pluripotent stem cells reveal the developmental biology of human megakaryocytes and provide a source of platelets for clinical application.

    Takayama, Naoya; Eto, Koji

    2012-10-01

    Human pluripotent stem cells [PSCs; including human embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs)] can infinitely proliferate in vitro and are easily accessible for gene manipulation. Megakaryocytes (MKs) and platelets can be created from human ESCs and iPSCs in vitro and represent a potential source of blood cells for transfusion and a promising tool for studying the human thrombopoiesis. Moreover, disease-specific iPSCs are a powerful tool for elucidating the pathogenesis of hematological diseases and for drug screening. In that context, we and other groups have developed in vitro MK and platelet differentiation systems from human pluripotent stem cells (PSCs). Combining this co-culture system with a drug-inducible gene expression system enabled us to clarify the novel role played by c-MYC during human thrombopoiesis. In the next decade, technical advances (e.g., high-throughput genomic sequencing) will likely enable the identification of numerous gene mutations associated with abnormal thrombopoiesis. Combined with such technology, an in vitro system for differentiating human PSCs into MKs and platelets could provide a novel platform for studying human gene function associated with thrombopoiesis.

  6. Physical properties and comparative strength of a bioactive luting cement.

    Jefferies, Steven; Lööf, Jesper; Pameijer, Cornelis H; Boston, Daniel; Galbraith, Colin; Hermansson, Leif

    2013-01-01

    cement at Vickers hardness of 51.4 plus or equal to 10. There was no evidence of cracks due to radial expansion in PJCs by the Ceramir C and B cement. All luting cements tested demonstrated compressive strengths well in excess of the ISO requirement for water-based cements of no less than 50 MPa. Ceramir C and B showed significantly higher CS than RelyX Luting Cement after 24 hours, but was not significantly higher than either Fuji Plus or RelyX Unicem. The ST and FT values of CC and B conform to and are within the boundaries of the requirements of the standard. Surface hardness was statistically higher than and comparable to zinc phosphate cement. There was no evidence of potentially clinically significant and deleterious expansion behavior by this cement. All cements tested demonstrated acceptable strength properties. Within the limits of this study, Ceramir C and B is deemed to possess physical properties suitable for a dental luting cement.

  7. SHBG is an important factor in stemness induction of cells by DHT in vitro and associated with poor clinical features of prostate carcinomas.

    Ma, Yuanyuan; Liang, Dongming; Liu, Jian; Wen, Jian-Guo; Servoll, Einar; Waaler, Gudmund; Sæter, Thorstein; Axcrona, Karol; Vlatkovic, Ljiljana; Axcrona, Ulrika; Paus, Elisabeth; Yang, Yue; Zhang, Zhiqian; Kvalheim, Gunnar; Nesland, Jahn M; Suo, Zhenhe

    2013-01-01

    Androgen plays a vital role in prostate cancer development. However, it is not clear whether androgens influence stem-like properties of prostate cancer, a feature important for prostate cancer progression. In this study, we show that upon DHT treatment in vitro, prostate cancer cell lines LNCaP and PC-3 were revealed with higher clonogenic potential and higher expression levels of stemness related factors CD44, CD90, Oct3/4 and Nanog. Moreover, sex hormone binding globulin (SHBG) was also simultaneously upregulated in these cells. When the SHBG gene was blocked by SHBG siRNA knock-down, the induction of Oct3/4, Nanog, CD44 and CD90 by DHT was also correspondingly blocked in these cells. Immunohistochemical evaluation of clinical samples disclosed weakly positive, and areas negative for SHBG expression in the benign prostate tissues, while most of the prostate carcinomas were strongly positive for SHBG. In addition, higher levels of SHBG expression were significantly associated with higher Gleason score, more seminal vesicle invasions and lymph node metastases. Collectively, our results show a role of SHBG in upregulating stemness of prostate cancer cells upon DHT exposure in vitro, and SHBG expression in prostate cancer samples is significantly associated with poor clinicopathological features, indicating a role of SHBG in prostate cancer progression.

  8. Up-to-date Clinical Trials of Hair Regeneration Using Conditioned Media of Adipose-Derived Stem Cells in Male and Female Pattern Hair Loss.

    Shin, Hyoseung; Won, Chong Hyun; Chung, Woon-Kyung; Park, Byung-Soon

    2017-01-01

    The primary roles of mesenchymal stem cells (MSCs) are to maintain the stem cell niche, facilitate recovery after injury, and ensure healthy aging and the homeostasis of organ and tissues. MSCs have recently emerged as a new therapeutic option for hair loss. Since adipose-derived stem cells (ADSCs) are the most accessible sources of MSCs, ADSCbased hair regeneration is investigated. Besides replacing degenerated cells in affected organs, ADSCs exhibit their beneficial effects through the paracrine actions of various cytokines and growth factors. Several laboratory experiments and animal studies have shown that ADSC-related proteins can stimulate hair growth. In addition, we introduce our clinical pilot studies using conditioned media of ADSCs for pattern hair loss in men and women. We believe that conditioned media of ADSCs represents a promising alternative therapeutic strategy for hair loss. We also discuss practical therapeutic challenges and the direction of future research. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  9. SHBG is an important factor in stemness induction of cells by DHT in vitro and associated with poor clinical features of prostate carcinomas.

    Yuanyuan Ma

    Full Text Available Androgen plays a vital role in prostate cancer development. However, it is not clear whether androgens influence stem-like properties of prostate cancer, a feature important for prostate cancer progression. In this study, we show that upon DHT treatment in vitro, prostate cancer cell lines LNCaP and PC-3 were revealed with higher clonogenic potential and higher expression levels of stemness related factors CD44, CD90, Oct3/4 and Nanog. Moreover, sex hormone binding globulin (SHBG was also simultaneously upregulated in these cells. When the SHBG gene was blocked by SHBG siRNA knock-down, the induction of Oct3/4, Nanog, CD44 and CD90 by DHT was also correspondingly blocked in these cells. Immunohistochemical evaluation of clinical samples disclosed weakly positive, and areas negative for SHBG expression in the benign prostate tissues, while most of the prostate carcinomas were strongly positive for SHBG. In addition, higher levels of SHBG expression were significantly associated with higher Gleason score, more seminal vesicle invasions and lymph node metastases. Collectively, our results show a role of SHBG in upregulating stemness of prostate cancer cells upon DHT exposure in vitro, and SHBG expression in prostate cancer samples is significantly associated with poor clinicopathological features, indicating a role of SHBG in prostate cancer progression.

  10. SHBG Is an Important Factor in Stemness Induction of Cells by DHT In Vitro and Associated with Poor Clinical Features of Prostate Carcinomas

    Ma, Yuanyuan; Liang, Dongming; Liu, Jian; Wen, Jian-Guo; Servoll, Einar; Waaler, Gudmund; Sæter, Thorstein; Axcrona, Karol; Vlatkovic, Ljiljana; Axcrona, Ulrika; Paus, Elisabeth; Yang, Yue; Zhang, Zhiqian; Kvalheim, Gunnar; Nesland, Jahn M.; Suo, Zhenhe

    2013-01-01

    Androgen plays a vital role in prostate cancer development. However, it is not clear whether androgens influence stem-like properties of prostate cancer, a feature important for prostate cancer progression. In this study, we show that upon DHT treatment in vitro, prostate cancer cell lines LNCaP and PC-3 were revealed with higher clonogenic potential and higher expression levels of stemness related factors CD44, CD90, Oct3/4 and Nanog. Moreover, sex hormone binding globulin (SHBG) was also simultaneously upregulated in these cells. When the SHBG gene was blocked by SHBG siRNA knock-down, the induction of Oct3/4, Nanog, CD44 and CD90 by DHT was also correspondingly blocked in these cells. Immunohistochemical evaluation of clinical samples disclosed weakly positive, and areas negative for SHBG expression in the benign prostate tissues, while most of the prostate carcinomas were strongly positive for SHBG. In addition, higher levels of SHBG expression were significantly associated with higher Gleason score, more seminal vesicle invasions and lymph node metastases. Collectively, our results show a role of SHBG in upregulating stemness of prostate cancer cells upon DHT exposure in vitro, and SHBG expression in prostate cancer samples is significantly associated with poor clinicopathological features, indicating a role of SHBG in prostate cancer progression. PMID:23936228

  11. Mesenchymal stem cells: Properties and clinical potential for cell based therapies in reconstructive surgery with a focus on peripheral nerve surgery

    Kuhbier, Jörn W.

    2015-08-01

    Full Text Available The isolation and expansion of multipotent mesenchymal stem cells (MSCs could be demonstrated from bone marrow, peripheral blood, skin, umbilical cord blood and adipose issue. They can be differentiated to different mesodermal cell lines like bone, cartilage, muscle or adipose tissue cells as well as . Thus MSCs represent an attractive cell population for the substitution of mesenchymal tissues via tissue engineering due to their potential of differentiation and their favourable expansion properties. In contrast to embryonic stem cells (ESCs they have the advantage that they can be autologously harvested in high numbers. Besides, there are fewer ethical issues in the use of MSCs. Another advantage of MSCs is the highly regenerative secretion profile of cytokines and growth factors, in particular supporting angiogenesis. A plethora of studies describe the morphological and phenotypical characterization of this cell type as well as regulatory mechanisms lying the differentiation into specific tissues aiming to optimize conditions for differentiation and thus clinical application. This review describes the definition of a mesenchymal stem cell, methods for isolation and phenotypical characterization, possibilities of differentiation and possible therapeutical applications of MSCs.

  12. Clinical-grade generation of peptide-stimulated CMV/EBV-specific T cells from G-CSF mobilized stem cell grafts.

    Gary, Regina; Aigner, Michael; Moi, Stephanie; Schaffer, Stefanie; Gottmann, Anja; Maas, Stefanie; Zimmermann, Robert; Zingsem, Jürgen; Strobel, Julian; Mackensen, Andreas; Mautner, Josef; Moosmann, Andreas; Gerbitz, Armin

    2018-05-09

    A major complication after allogeneic hematopoietic stem cell transplantation (aSCT) is the reactivation of herpesviruses such as cytomegalovirus (CMV) and Epstein-Barr virus (EBV). Both viruses cause significant mortality and compromise quality of life after aSCT. Preventive transfer of virus-specific T cells can suppress reactivation by re-establishing functional antiviral immune responses in immunocompromised hosts. We have developed a good manufacturing practice protocol to generate CMV/EBV-peptide-stimulated T cells from leukapheresis products of G-CSF mobilized and non-mobilized donors. Our procedure selectively expands virus-specific CD8+ und CD4+ T cells over 9 days using a generic pool of 34 CMV and EBV peptides that represent well-defined dominant T-cell epitopes with various HLA restrictions. For HLA class I, this set of peptides covers at least 80% of the European population. CMV/EBV-specific T cells were successfully expanded from leukapheresis material of both G-CSF mobilized and non-mobilized donors. The protocol allows administration shortly after stem cell transplantation (d30+), storage over liquid nitrogen for iterated applications, and protection of the stem cell donor by avoiding a second leukapheresis. Our protocol allows for rapid and cost-efficient production of T cells for early transfusion after aSCT as a preventive approach. It is currently evaluated in a phase I/IIa clinical trial.

  13. Static coefficient of friction between stainless steel and PMMA used in cemented hip and knee implants.

    Nuño, N; Groppetti, R; Senin, N

    2006-11-01

    Design of cemented hip and knee implants, oriented to improve the longevity of artificial joints, is largely based on numerical models. The static coefficient of friction between the implant and the bone cement is necessary to characterize the interface conditions in these models and must be accurately provided. The measurement of this coefficient using a repeatable and reproducible methodology for materials used in total hip arthroplasty is missing from the literature. A micro-topographic surface analysis characterized the surfaces of the specimens used in the experiments. The coefficient of friction between stainless steel and bone cement in dry and wet conditions using bovine serum was determined using a prototype computerized sliding friction tester. The effects of surface roughness (polished versus matt) and of contact pressure on the coefficient of friction have also been investigated. The serum influences little the coefficient of friction for the matt steel surface, where the mechanical interactions due to higher roughness are still the most relevant factor. However, for polished steel surfaces, the restraining effect of proteins plays a very relevant role in increasing the coefficient of friction. When the coefficient of friction is used in finite element analysis, it is used for the debonded stem-cement situation. It can thus be assumed that serum will propagate between the stem and the cement mantle. The authors believe that the use of a static coefficient of friction of 0.3-0.4, measured in the present study, is appropriate in finite element models.

  14. Comparison between three glass fiber post cementation techniques.

    Migliau, Guido; Piccoli, Luca; Di Carlo, Stefano; Pompa, Giorgio; Besharat, Laith Konstantinos; Dolci, Marco

    2017-01-01

    The aim of this experimental study was to compare the traditional cement systems with those of the latest generation, to assess if indeed these could represent of viable substitutes in the cementation of indirect restorations, and in the specific case of endodontic posts. The assessment of the validity of the cementing methods was performed according to the test of the push-out, conducted on sections obtained from the roots of treated teeth. The samples were divided into three groups. Group A (10 samples): etching for 30 seconds with 37% orthophosphoric acid (Superlux-Thixo-etch-DMG) combined with a dual-curing adhesive system (LuxaBond-Total Etch-DMG), dual-cured resin-composite cement (LuxaCore-DMG) and glass fiber posts (LuxaPost-DMG). Group B (10 samples): self-adhesive resin cement (Breeze-Pentron Clinical) and glass fiber posts (LuxaPost-DMG). Group C (10 samples): 3 steps light-curing, self-etching, self-conditioning bonding agent (Contax-Total-etch-DMG), dual-cured resin-composite cement (LuxaCore-DMG) and glass fiber posts (LuxaPost-DMG). The survey was conducted by examining the breaking resistance of the post-cement-tooth complex, subjected to a mechanical force. Statistical analysis was performed using SPSS Inc. ver. 13.0, Chicago, IL, USA. Group A values of bond strenth ranged from a minimum of 10.14 Mpa to a maximum value of 14.73 Mpa with a mean value of 12.58 Mpa. In Group B the highest value of bond strength was 6.54 Mpa and the minimum 5.55 Mpa. The mean value of the bond strength for the entire group was 6.58 Mpa. In Group C the highest bond strength was 6.59 Mpa whereas the lowest bond strength was 4.84 Mpa. Mean value of the bond strength of Group C was calculated at 5.7 Mpa. Etching with orthophosphoric acid combined with a dual-curing adhesive system and a dual-cured resin-composite cement was the technique that guaranteed the highest bond strength. Lowest bond strength values were obtained when dual self-adhesive cement was used.

  15. 76 FR 76760 - Gray Portland Cement and Cement Clinker From Japan

    2011-12-08

    ... and Cement Clinker From Japan Determination On the basis of the record \\1\\ developed in the subject... duty order on gray Portland cement and cement clinker from Japan would be likely to lead to... and Cement Clinker from Japan: Investigation No. 731- TA-461 (Third Review). By order of the...

  16. Seating load parameters impact on dental ceramic reinforcement conferred by cementation with resin-cements.

    Addison, Owen

    2010-09-01

    Cementation of all-ceramic restorations with resin-cements has been demonstrated to reduce the incidence of fracture in service. The aim was to investigate the influence of loading force and loading duration applied during cementation on the reinforcement conferred by a resin-cement on a leucite reinforced glass-ceramic.

  17. Clinical activity of azacitidine in patients who relapse after allogeneic stem cell transplantation for acute myeloid leukemia

    Craddock, Charles; Labopin, Myriam; Robin, Marie

    2016-01-01

    Disease relapse is the most common cause of treatment failure after allogeneic stem cell transplantation for acute myeloid leukemia and myelodysplastic syndromes, yet treatment options for such patients remain extremely limited. Azacitidine is an important new therapy in high-risk myelodysplastic...... syndromes and acute myeloid leukemia but its role in patients who relapse post allograft has not been defined. We studied the tolerability and activity of azacitidine in 181 patients who relapsed after an allograft for acute myeloid leukemia (n=116) or myelodysplastic syndromes (n=65). Sixty-nine patients...... conclude that azacitidine represents an important new therapy in selected patients with acute myeloid leukemia/myelodysplastic syndromes who relapse after allogeneic stem cell transplantation. Prospective studies to confirm optimal treatment options in this challenging patient population are required....

  18. Adipose-Derived Mesenchymal Stem Cells for the Treatment of Articular Cartilage: A Systematic Review on Preclinical and Clinical Evidence

    Francesco Perdisa

    2015-01-01

    Full Text Available Among the current therapeutic approaches for the regeneration of damaged articular cartilage, none has yet proven to offer results comparable to those of native hyaline cartilage. Recently, it has been claimed that the use of mesenchymal stem cells (MSCs provides greater regenerative potential than differentiated cells, such as chondrocytes. Among the different kinds of MSCs available, adipose-derived mesenchymal stem cells (ADSCs are emerging due to their abundancy and easiness to harvest. However, their mechanism of action and potential for cartilage regeneration are still under investigation, and many other aspects still need to be clarified. The aim of this systematic review is to give an overview of in vivo studies dealing with ADSCs, by summarizing the main evidence for the treatment of cartilage disease of the knee.

  19. Cement radwaste solidification studies third annual report

    Brown, D.J.; James, J.M.; Lee, D.J.; Smith, D.L.; Walker, A.T.

    1982-03-01

    This report summarises cement radwaste studies carried out at AEE Winfrith during 1981 on the encapsulation of medium and low active waste in cement. During the year more emphasis has been placed on the work which is directly related to the solidification of SGHWR active sludge. Information has been obtained on the properties of 220 dm 3 drums of cemented waste. The use of cement grouts for the encapsulation of solid items has also been investigated during 1981. (U.K.)

  20. Characterization of cement-stabilized Cd wastes

    Maria Diez, J.; Madrid, J.; Macias, A.

    1996-01-01

    Portland cement affords both physical and chemical immobilization of cadmium. The immobilization has been studied analyzing the pore fluid of cement samples and characterizing the solid pastes by X-ray diffraction. The influence of cadmium on the cement hydration and on its mechanical properties has been also studied by isothermal conduction calorimetry and by the measure of strength and setting development. Finally, the effect of cement carbonation on the immobilization of cadmium has been analyzed

  1. Substantial global carbon uptake by cement carbonation

    Xi, Fengming; Davis, Steven J.; Ciais, Philippe; Crawford-Brown, Douglas; Guan, Dabo; Pade, Claus; Shi, Tiemao; Syddall, Mark; Lv, Jie; Ji, Lanzhu; Bing, Longfei; Wang, Jiaoyue; Wei, Wei; Yang, Keun-Hyeok; Lagerblad, Björn

    2016-01-01

    Calcination of carbonate rocks during the manufacture of cement produced 5% of global CO2 emissions from all industrial process and fossil-fuel combustion in 20131, 2. Considerable attention has been paid to quantifying these industrial process emissions from cement production2, 3, but the natural reversal of the process—carbonation—has received little attention in carbon cycle studies. Here, we use new and existing data on cement materials during cement service life, demolition, and secondar...

  2. Colon Cancer Stem Cells: Bench-to-Bedside—New Therapeutical Approaches in Clinical Oncology for Disease Breakdown

    Di Franco Simone, Simone; Mancuso, Pietro; Benfante, Antonina; Spina, Marisa; Iovino, Flora; Dieli, Francesco; Stassi, Giorgio; Todaro, Matilde

    2011-01-01

    It is widely accepted by the scientific community that cancer, including colon cancer, is a “stem cell disease”. Until a few years ago, common opinion was that all neoplastic cells within a tumor contained tumorigenic growth capacity, but recent evidences hint to the possibility that such a feature is confined to a small subset of cancer-initiating cells, also called cancer stem cells (CSCs). Thus, malignant tumors are organized in a hierarchical fashion in which CSCs give rise to more differentiated tumor cells. CSCs possess high levels of ATP-binding cassette (ABC) transporters and anti-apoptotic molecules, active DNA-repair, slow replication capacities and they produce growth factors that confer refractoriness to antineoplastic treatments. The inefficacy of conventional therapies towards the stem cell population might explain cancer chemoresistance and the high frequency of relapse shown by the majority of tumors. Nowadays, in fact all the therapies available are not sufficient to cure patients with advanced forms of colon cancer since they target differentiated cancer cells which constitute most of the tumor mass and spare CSCs. Since CSCs are the entities responsible for the development of the tumor and represent the only cell population able to sustain tumor growth and progression, these cells represent the elective target for innovative therapies

  3. An update clinical application of amniotic fluid-derived stem cells (AFSCs) in cancer cell therapy and tissue engineering.

    Gholizadeh-Ghaleh Aziz, Shiva; Fathi, Ezzatollah; Rahmati-Yamchi, Mohammad; Akbarzadeh, Abolfazl; Fardyazar, Zahra; Pashaiasl, Maryam

    2017-06-01

    Recent studies have elucidated that cell-based therapies are promising for cancer treatments. The human amniotic fluid stem (AFS) cells are advantageous cells for such therapeutic schemes that can be innately changed to express therapeutic proteins. HAFSCs display a natural tropism to cancer cells in vivo. They can be useful in cancer cells targeting. Moreover, they are easily available from surplus diagnostic samples during pregnancy and less ethical and legal concern are associated with the collection and application than other putative cells are subjected. This review will designate representatives of amniotic fluid and stem cell derived from amniotic fluid. For this propose, we collect state of human AFS cells data applicable in cancer therapy by dividing this approach into two main classes (nonengineered and engineered based approaches). Our study shows the advantage of AFS cells over other putative cells types in terms differentiation ability to a wide range of cells by potential and effective use in preclinical studies for a variety of diseases. This study has shown the elasticity of human AFS cells and their favorable potential as a multipotent cell source for regenerative stem cell therapy and capable of giving rise to multiple lineages including such as osteoblasts and adipocyte.

  4. Physicochemical properties and biocompatibility of chitosan oligosaccharide/gelatin/calcium phosphate hybrid cements

    Chiang, Ting-Yi [Department of Dental Laboratory Technology, Central Taiwan University of Science and Technology, Taichung 406, Taiwan (China); Ho, Chia-Che [Institute of Oral Biology and Biomaterials Science, Chung-Shan Medical University, Taichung 402, Taiwan (China); Chen, David Chan-Hen [Institute of Veterinary Microbiology, National Chung-Hsing University, Taichung 402, Taiwan (China); Lai, Meng-Heng [Institute of Oral Biology and Biomaterials Science, Chung-Shan Medical University, Taichung 402, Taiwan (China); Ding, Shinn-Jyh, E-mail: sjding@csmu.edu.tw [Institute of Oral Biology and Biomaterials Science, Chung-Shan Medical University, Taichung 402, Taiwan (China); Department of Dentistry, Chung-Shan Medical University Hospital, Taichung 402, Taiwan (China)

    2010-04-15

    A bone substitute material was developed consisting of a chitosan oligosaccharide (COS) solution in a liquid phase and gelatin (GLT) containing calcium phosphate powder in a solid phase. The physicochemical and biocompatible properties of the hybrid cements were evaluated. The addition of COS to cement did not affect the setting time or diametral tensile strength of the hybrid cements, whereas GLT significantly prolonged the setting time and decreased the strength slightly. The setting reaction was inhibited by the addition of GLT to the initial mixture, but not by COS. However, the presence of GLT appreciably improved the anti-washout properties of the hybrid cement compared with COS. COS may promote the cement's biocompatibility as an approximate twofold increase in cell proliferation for 10% COS-containing cements was observed on day 3 as compared with the controls. The combination of GLT and COS was chosen due to the benefits achieved from several synergistic effects and for their clinical applications. Cement with 5% GLT and 10% COS may be a better choice among cements in terms of anti-washout properties and biological activity.

  5. Effect of process variables on the preparation of artificial bone cements

    Santos Junior, J.G.F.; Melo, P.A.; Pinto, J.C., E-mail: pinto@peq.coppe.ufrj.br, E-mail: jjunior@peq.coppe.ufrj.br, E-mail: melo@peq.coppe.ufrj.br [Coordenacao dos Programas de Pos-Graduacao de Engenharia (COPPE/UFRJ), RJ (Brazil). Programa de Engenharia Quimica; Pita, V.J.R.R., E-mail: vjpita@ima.ufrj.br [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Instituto de Macromoleculas; Nele, M., E-mail: nele@eq.ufrj.br [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Escola de Quimica

    2013-10-15

    The present work concerns the preparation of bone cements based on poly(methyl methacrylate) (PMMA), used mainly for prosthesis fixation and cavity filling for correction of human bone failures. A typical bone cement recipe contains methyl methacrylate, which polymerizes in situ during cement application. An inherent problem of this reaction is the large amount of heat released during the cement preparation, which may lead to irreparable damage of living tissues. Optimization of PMMA-based bone cement recipes is thus an important step towards safe and reliable clinical usage of these materials. Important process variables related to the reaction temperature profile and the mixing of the recipe constituents were studied in order to allow for the adequate production of bone cements. It is shown that the average molar mass and size of the PMMA particles used in the production of the bone cement, as well as incorporation of radiopaque contrast, co-monomers and fillers into the bone recipe play fundamental roles in the course of the polymerization reaction. Furthermore, the injection vessel geometry may interfere dramatically with the temperature profile and the time for its occurrence. Finally, it has been observed that the morphology of the PMMA particles strongly affects the mixing of the bone cement components. (author)

  6. Effect of process variables on the preparation of artificial bone cements

    J. G. F. Santos Jr.

    2013-12-01

    Full Text Available The present work concerns the preparation of bone cements based on poly(methyl methacrylate (PMMA, used mainly for prosthesis fixation and cavity filling for correction of human bone failures. A typical bone cement recipe contains methyl methacrylate, which polymerizes in situ during cement application. An inherent problem of this reaction is the large amount of heat released during the cement preparation, which may lead to irreparable damage of living tissues. Optimization of PMMA-based bone cement recipes is thus an important step towards safe and reliable clinical usage of these materials. Important process variables related to the reaction temperature profile and the mixing of the recipe constituents were studied in order to allow for the adequate production of bone cements. It is shown that the average molar mass and size of the PMMA particles used in the production of the bone cement, as well as incorporation of radiopaque contrast, co-monomers and fillers into the bone recipe play fundamental roles in the course of the polymerization reaction. Furthermore, the injection vessel geometry may interfere dramatically with the temperature profile and the time for its occurrence. Finally, it has been observed that the morphology of the PMMA particles strongly affects the mixing of the bone cement components.

  7. Cementation unit for radioactive wastes

    Dellamano, Jose Claudio; Vicente, Roberto; Lima, Jose Rodrigues de

    2001-01-01

    This communication describes the waste cementation process and facility developed at Instituto de Pesquisas Energeticas e Nucleares - IPEN. The process is based on 200 litres batch operation, in drum mixing, with continuous cement feeding. The equipment is a single recoverable helicoidal mixer and a turning table that allows the drum to rotate during the mixing operation, simulating a planetary mixer. The facility was designed to treat contact handled liquids and wet solid wastes, but can be adapted for shielded equipment and remote operation. (author)

  8. 21 CFR 872.3275 - Dental cement.

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Dental cement. 872.3275 Section 872.3275 Food and... DENTAL DEVICES Prosthetic Devices § 872.3275 Dental cement. (a) Zinc oxide-eugenol—(1) Identification... filling or as a base cement to affix a temporary tooth filling, to affix dental devices such as crowns or...

  9. Cement production from coal conversion residues

    Brown, L.D.; Clavenna, L.R.; Eakman, J.M.; Nahas, N.C.

    1981-01-01

    Cement is produced by feeding residue solids containing carbonaceous material and ash constituents obtained from converting a carbonaceous feed material into liquids and/or gases into a cement-making zone and burning the carbon in the residue solids to supply at least a portion of the energy required to convert the solids into cement

  10. Multicomponent modelling of Portland cement hydration reactions

    Ukrainczyk, N.; Koenders, E.A.B.; Van Breugel, K.

    2012-01-01

    The prospect of cement and concrete technologies depends on more in depth understanding of cement hydration reactions. Hydration reaction models simulate the development of the microstructures that can finally be used to estimate the cement based material properties that influence performance and

  11. The Corail stem as a reverse hybrid - survivorship and x-ray analysis at 10 years.

    Wangen, Helge; Nordsletten, Lars; Boldt, Jens G; Fenstad, Anne M; Beverland, David E

    2017-07-25

    The use of a cemented cup together with an uncemented stem in total hip arthroplasty (THA) has become popular in Norway and Sweden during the last decade. The results of this prosthetic concept, reverse hybrid THA have been sparsely described.We report our experience of reverse hybrid THA, using the Elite plus polyethylene cemented cup together with the Corail fully hydroxyapatite-coated uncemented stem and a 28-mm alumina ceramic head. 132 consecutive reverse hybrid hip arthroplasties were performed from January 2000 to December 2003 in 126 patients with a mean age of 54.3 years (28-65). All patients were routinely reviewed at 3 months, 1, 5, 7 and 10 years postoperatively. At each follow-up patients were seen either by a consultant orthopaedic surgeon or a senior trainee. Anteroposterior pelvic and lateral x-rays of the hip were taken at each visit. To estimate the survival of the THAs we used the Kaplan-Meier method with 95% confidence interval (CI). Logistic regression analysis was performed to determine which factors affected the presence of radiolucency around the femoral stem. The mean follow-up was 11.1 years (9.0-14.2). 1 patient was lost to follow-up, and 7 patients were deceased at the time of 10-year follow up. At 10 years 7 patients have had further surgery. 5 for infection, 1 periprosthetic femoral fracture and 1 heterotopic bone formation. All stems were classified as well fixed. 2 cups were defined as loose at 10 years. 1 patient is scheduled for revision the other refused revision. The clinical outcome and radiological findings were assessed in 123 hips. The mean Harris Hip Score was 94 (35-100) at 10 years and the mean WOMAC score was 89 (30.2-100). We report good results with respect to clinical outcome and survival of the reverse hybrid concept in patients younger than 65. A successful outcome depends on meticulous preoperative planning, use of modern cementing techniques in the acetabulum and experience in implanting an uncemented stem.

  12. Particulate metallic debris in cemented total hip arthroplasty.

    Salvati, E A; Betts, F; Doty, S B

    1993-08-01

    Several studies conducted by the authors in the last six years demonstrate that the generation of metallic debris is more severe with titanium alloy than with cobalt-chrome alloy femoral components in cemented total hip arthroplasty (THA). The debris is generated from the articulating surface, particularly if entrapped acrylic debris produces three-body wear, and from the stem surface when the component loosens and abrades against fragmented cement. In selected cases in which the titanium metallic debris is copious, premature failure and severe progressive bone loss occurs. Electron microscopy demonstrates that the particles of metallic debris can be extremely small (a few hundredths of 1 micron). They are phagocytized by the macrophages and transported to the phagolysosomes. In this highly corrosive environment, the very high surface area of the particles may release toxic concentrations of the constituents of the alloy intracellularly, probably leading to progressive cell degeneration and death, with subsequent release of intracellular enzymes and ingested metallic debris. This cycle most likely repeats itself, leading to tissue necrosis. The results presented do not support the use of titanium alloy femoral components for cemented THA, particularly for the articulating surface.

  13. Stem cell therapy for diabetes

    K O Lee

    2012-01-01

    Full Text Available Stem cell therapy holds immense promise for the treatment of patients with diabetes mellitus. Research on the ability of human embryonic stem cells to differentiate into islet cells has defined the developmental stages and transcription factors involved in this process. However, the clinical applications of human embryonic stem cells are limited by ethical concerns, as well as the potential for teratoma formation. As a consequence, alternative forms of stem cell therapies, such as induced pluripotent stem cells, umbilical cord stem cells and bone marrow-derived mesenchymal stem cells, have become an area of intense study. Recent advances in stem cell therapy may turn this into a realistic treatment for diabetes in the near future.

  14. Continuous monitoring of the zinc-phosphate acid-base cement setting reaction by proton nuclear magnetic relaxation

    Apih, T.; Lebar, A.; Pawlig, O.; Trettin, R.

    2001-01-01

    Proton nuclear magnetic relaxation is a well-established technique for continuous and non destructive monitoring of hydration of conventional Portland building cements. Here, we demonstrate the feasibility of nuclear magnetic resonance (NMR) monitoring of the setting reaction of zinc-phosphate acid-base dental cements, which harden in minutes as compared to days, as in the case of Portland cements. We compare the setting of cement powder (mainly, zinc oxide) prepared with clinically used aluminum-modified orthophosphoric acid solution with the setting of a model system where cement powder is mixed with pure orthophosphoric acid solution. In contrast to previously published NMR studies of setting Portland cements, where a decrease of spin-lattice relaxation time is attributed to enhanced relaxation at the growing internal surface, spin-lattice relaxation time T 1 increases during the set of clinically used zinc-phosphate cement. Comparison of these results with a detailed study of diffusion, viscosity, and magnetic-field dispersion of T 1 in pure and aluminum-modified orthophosphoric acid demonstrates that the increase of T 1 in the setting cement is connected with the increase of molecular mobility in the residual phosphoric acid solution. Although not taken into account so far, such effects may also significantly influence the relaxation times in setting Portland cements, particularly when admixtures with an effect on water viscosity are used. [copyright] 2001 American Institute of Physics

  15. Electrically conductive Portland cement concrete.

    1986-01-01

    There is a need for an effective, simple-to-install secondary anode system for use in the cathodic protection of reinforced concrete bridge decks. In pursuit of such a system, carbon fibers and carbon black were incorporated in portland cement concre...

  16. Polymer reinforcement of cement systems

    Swamy, R.N.

    1979-01-01

    In the last couple of decades several cement- and concrete-based composites have come into prominence. Of these, cement-polymer composites, like cement-fibre composites, have been recognised as very promising, and considerable research and development on their properties, fabrication methods and application are in progress. Of the three types of concrete materials which incorporate polymers to form composites, polymer impregnated concrete forms a major development in which hardened concrete is impregnated with a liquid monomer which is subsequently polymerized to form a rigid polymer network in the pores of the parent material. In this first part of the extensive review of the polymer reinforcement of cement systems, the process technology of the various monomer impregnation techniques and the properties of the impregnated composite are assessed critically. It is shown that the high durability and superior performance of polymer impregnated concrete can provide an economic and competitive alternative in in situ strengthening, and in other areas where conventional concrete can only at best provide adequate performance. The review includes a section on radiation-induced polymerization. (author)

  17. Types of Stem Cells

    ... Stem Cell Glossary Search Toggle Nav Types of Stem Cells Stem cells are the foundation from which all ... Learn About Stem Cells > Types of Stem Cells Stem cells Stem cells are the foundation for every organ ...

  18. [Cement augmentation on the spine : Biomechanical considerations].

    Kolb, J P; Weiser, L; Kueny, R A; Huber, G; Rueger, J M; Lehmann, W

    2015-09-01

    Vertebral compression fractures are the most common osteoporotic fractures. Since the introduction of vertebroplasty and screw augmentation, the management of osteoporotic fractures has changed significantly. The biomechanical characteristics of the risk of adjacent fractures and novel treatment modalities for osteoporotic vertebral fractures, including pure cement augmentation by vertebroplasty, and cement augmentation of screws for posterior instrumentation, are explored. Eighteen human osteoporotic lumbar spines (L1-5) adjacent to vertebral bodies after vertebroplasty were tested in a servo-hydraulic machine. As augmentation compounds we used standard cement and a modified low-strength cement. Different anchoring pedicle screws were tested with and without cement augmentation in another cohort of human specimens with a simple pull-out test and a fatigue test that better reflects physiological conditions. Cement augmentation in the osteoporotic spine leads to greater biomechanical stability. However, change in vertebral stiffness resulted in alterations with the risk of adjacent fractures. By using a less firm cement compound, the risk of adjacent fractures is significantly reduced. Both screw augmentation techniques resulted in a significant increase in the withdrawal force compared with the group without cement. Augmentation using perforated screws showed the highest stability in the fatigue test. The augmentation of cement leads to a significant change in the biomechanical properties. Differences in the stability of adjacent vertebral bodies increase the risk of adjacent fractures, which could be mitigated by a modified cement compound with reduced strength. Screws that were specifically designed for cement application displayed greatest stability in the fatigue test.

  19. CO2 Capture by Cement Raw Meal

    Pathi, Sharat Kumar; Lin, Weigang; Illerup, Jytte Boll

    2013-01-01

    The cement industry is one of the major sources of CO2 emissions and is likely to contribute to further increases in the near future. The carbonate looping process has the potential to capture CO2 emissions from the cement industry, in which raw meal for cement production could be used...... as the sorbent. Cyclic experiments were carried out in a TGA apparatus using industrial cement raw meal and synthetic raw meal as sorbents, with limestone as the reference. The results show that the CO2 capture capacities of the cement raw meal and the synthetic raw meal are comparable to those of pure limestone...... that raw meal could be used as a sorbent for the easy integration of the carbonate looping process into the cement pyro process for reducing CO2 emissions from the cement production process....

  20. Leaching of tritium from a cement composite

    Matsuzuru, Hideo; Ito, Akihiko

    1978-10-01

    Leaching of tritium from cement composites into an aqueous phase has been studied to evaluate the safety of incorporation of the tritiated liquid waste into cement. Leaching tests were performed by the method recommended by the International Atomic Energy Agency. The Leaching fraction was measured as functions of waste-cement ratio (Wa/C), temperature of leachant and curing time. The tritium leachability of cement in the long term test follows the order: alumina cement portland cement slag cement. The fraction of tritium leached increases with increasing Wa/C and temperature and decreasing curing period. A deionized water as a leachant gives a slightly higher leachability than synthetic sea water. The amount leached of tritium from a 200 l drum size specimen was estimated on the basis of the above results. (author)

  1. BK Virus-Hemorrhagic Cystitis Following Allogeneic Stem Cell Transplantation: Clinical Characteristics and Utility of Leflunomide Treatment

    Young Hoon Park

    2016-08-01

    Full Text Available Objective: BK virus-hemorrhagic cystitis (BKV-HC is a potential cause of morbidity and mortality in patients having undergone allogeneic stem cell transplantation (Allo-SCT. We analyzed the clinical features of BKV-HC following Allo-SCT and reported the utility of leflunomide therapy for BKV-HC. Materials and methods: From January 2005 to June 2014, among the 69 patients underwent Allo-SCT in our institution, the patients who experienced BKV-HC were investigated retrospectively. Results: Hemorrhagic cystitis (HC was observed in 30 patients (43.5%, and among them, 18 patients (26.1% were identified as BKV-HC. The median age of the patients (12 males and 6 females was 45 years (range, 13-63. Patients received Allo-SCT from acute myeloid leukemia (n=11, aplastic anemia (n=4, myelodysplastic syndrome (n=2, and non-Hodgkin lymphoma (n=1.The donor types were a HLA-matched sibling donor for 6 patients, HLA-matched unrelated donor for 9, and a haploidentical familial donor for 2. The median onset and duration of BKV-HC was on day 21 (range, 7-97 after transplantation and 22 days (range, 6-107. Eleven patients (62.1% had grade I-II HC and seven patients (38.9% had grade III-IV (high-grade HC. Among the seven patients who had high-grade HC, one had complete response (CR, one partial response (PR, and five no response (NR. Among the five non-responders, one died of BKV-HC associated complications. The remaining four patients were treated with leflunomide, with achieving CR (n=2 and PR (n=2. The median duration from the start of leflunomide therapy to response was 13 days (range, 8–17 days. All patients tolerated the leflunomide treatment well, with three patients having mild gastrointestinal symptoms, including anorexia and abdominal bloating. Conclusion: BKV-HC was commonly observed in patients with HC following Allo-SCT. In high-grade BKV-HC patients who fail supportive care, leflunomide may be a feasible option without significant toxicity. Materials

  2. Physical characteristics, antimicrobial and odontogenesis potentials of calcium silicate cement containing hinokitiol

    Huang, Ming-Hsien [Institute of Oral Science, Chung Shan Medical University, Taichung City, Taiwan (China); Shen, Yu-Fang; Hsu, Tuan-Ti [3D Printing Medical Research Center, China Medical University Hospital, China Medical University, Taichung City, Taiwan (China); Huang, Tsui-Hsien [School of Dentistry, Chung Shan Medical University, Taichung City, Taiwan (China); Department of Stomatology, Chung Shan Medical University Hospital, Taichung City, Taiwan (China); Shie, Ming-You, E-mail: eviltacasi@gmail.com [3D Printing Medical Research Center, China Medical University Hospital, China Medical University, Taichung City, Taiwan (China)

    2016-08-01

    Hinokitiol is a natural material and it has antibacterial and anti-inflammatory effects. The purpose of this study was to evaluate the material characterization, cell viability, antibacterial and anti-inflammatory abilities of the hinokitiol-modified calcium silicate (CS) cement as a root end filling material. The setting times, diametral tensile strength (DTS) values and XRD patterns of CS cements with 0–10 mM hinokitiol were examined. Then, the antibacterial effect and the expression levels of cyclooxygenase 2 (COX-2) and interleukin-1 (IL-1) of the hinokitiol-modified CS cements were evaluated. Furthermore, the cytocompatibility, the expression levels of the markers of odontoblastic differentiation, mineralized nodule formation and calcium deposition of human dental pulp cells (hDPCs) cultured on hinokitiol-modified CS cements were determined. The hinokitiol-modified CS cements had better antibacterial and anti-inflammatory abilities and cytocompatibility than non-modified CS cements. Otherwise, the hinokitiol-modified CS cements had suitable setting times and better odontoblastic potential of hDPCs. Previous report pointed out that the root-end filling materials may induce inflammatory cytokines reaction. In our study, hinokitiol-modified CS cements not only inhibited the expression level of inflammatory cytokines, but also had better cytocompatibility, antimicrobial properties and active ability of odontoblastic differentiation of hDPCs. Therefore, the hinokitiol-modified CS cement may be a potential root end filling material for clinic. - Highlights: • The hinokitiol-modified CS up-regulation of odontogenic of hDPCs. • Promoted proliferation of hDPCs on hinokitiol-modified CS. • The hinokitiol-modified CS cements not only inhibited the expression level of inflammatory cytokines, but also had better cytocompatibility. • The hinokitiol-modified CS up-regulation of odontogenic of hPDLs.

  3. Physical characteristics, antimicrobial and odontogenesis potentials of calcium silicate cement containing hinokitiol

    Huang, Ming-Hsien; Shen, Yu-Fang; Hsu, Tuan-Ti; Huang, Tsui-Hsien; Shie, Ming-You

    2016-01-01

    Hinokitiol is a natural material and it has antibacterial and anti-inflammatory effects. The purpose of this study was to evaluate the material characterization, cell viability, antibacterial and anti-inflammatory abilities of the hinokitiol-modified calcium silicate (CS) cement as a root end filling material. The setting times, diametral tensile strength (DTS) values and XRD patterns of CS cements with 0–10 mM hinokitiol were examined. Then, the antibacterial effect and the expression levels of cyclooxygenase 2 (COX-2) and interleukin-1 (IL-1) of the hinokitiol-modified CS cements were evaluated. Furthermore, the cytocompatibility, the expression levels of the markers of odontoblastic differentiation, mineralized nodule formation and calcium deposition of human dental pulp cells (hDPCs) cultured on hinokitiol-modified CS cements were determined. The hinokitiol-modified CS cements had better antibacterial and anti-inflammatory abilities and cytocompatibility than non-modified CS cements. Otherwise, the hinokitiol-modified CS cements had suitable setting times and better odontoblastic potential of hDPCs. Previous report pointed out that the root-end filling materials may induce inflammatory cytokines reaction. In our study, hinokitiol-modified CS cements not only inhibited the expression level of inflammatory cytokines, but also had better cytocompatibility, antimicrobial properties and active ability of odontoblastic differentiation of hDPCs. Therefore, the hinokitiol-modified CS cement may be a potential root end filling material for clinic. - Highlights: • The hinokitiol-modified CS up-regulation of odontogenic of hDPCs. • Promoted proliferation of hDPCs on hinokitiol-modified CS. • The hinokitiol-modified CS cements not only inhibited the expression level of inflammatory cytokines, but also had better cytocompatibility. • The hinokitiol-modified CS up-regulation of odontogenic of hPDLs.

  4. Through BHA (Bottom Hole Assembly) cementing with proprietary cementing technology

    Fanguy, Charles ' Joey' ; Mueller, Dan T. [BJ Services Company, Houston, TX (United States); Garrett, J.C. [Palm Energy Partners, LLC, Metairie, LA (United States)

    2004-07-01

    There are many problems that can arise when drilling into sub-normally pressured or naturally fractured zones. Lost circulation is one problem that is commonly encountered while drilling oil and gas wells. Lost circulation can lead to increased costs associated with drilling due to rig time, spreadsheet costs, and expensive mud system losses. Cement is one of the most effective treatment options, although it is not normally considered the first option because most operators are forced to trip out of the wellbore and utilize a squeeze packer. This is not always a viable option because of potential well control issues associated with the hydrostatic pressure reduction due to the losses of the whole mud. One treatment option that is commonly overlooked is pumping cement slurries through the bottom hole assembly and drill bit. This is generally not attempted for a variety of reasons. These reasons include: I Concern about 'squeezing off' of the cement in the bit II Lack of potential quality control associated with mixing 'on the fly' III Lack of the ability to test the actual mixed slurry samples The use of a pre-mixed, storable cement slurry has eliminated the concerns associated with pumping cement slurries through mud motors, MWD tools, BHA's, and drill bits. This advanced cement technology has been successfully utilized while reducing the risks associated with these lost circulation treatments. In addition, this technology has eliminated the costs associated with using a squeeze packer and the rig time required for several trips out of the wellbore. The paper will describe the premixed slurry properties and QA/QC procedures that are required for successful through the bit operations. This paper will also provide case histories of successful through the bit operation, as well as background information leading to the treatments. The case histories include successful through the bit remediation of severe lost circulation zones and as well the

  5. Three-Dimensional Bioprinting Nanotechnologies towards Clinical Application of Stem Cells and Their Secretome in Salivary Gland Regeneration

    Joao N. Ferreira

    2016-01-01

    Full Text Available Salivary gland (SG functional damage and severe dry mouth (or xerostomia are commonly observed in a wide range of medical conditions from autoimmune to metabolic disorders as well as after radiotherapy to treat specific head and neck cancers. No effective therapy has been developed to completely restore the SG functional damage on the long-term and reverse the poor quality of life of xerostomia patients. Cell- and secretome-based strategies are currently being tested in vitro and in vivo for the repair and/or regeneration of the damaged SG using (1 epithelial SG stem/progenitor cells from salispheres or explant cultures as well as (2 nonepithelial stem cell types and/or their bioactive secretome. These strategies will be the focus of our review. Herein, innovative 3D bioprinting nanotechnologies for the generation of organotypic cultures and SG organoids/mini-glands will also be discussed. These bioprinting technologies will allow researchers to analyze the secretome components and extracellular matrix production, as well as their biofunctional effects in 3D mini-glands ex vivo. Improving our understanding of the SG secretome is critical to develop effective secretome-based therapies towards the regeneration and/or repair of all SG compartments for proper restoration of saliva secretion and flow into the oral cavity.

  6. The brain stem function in patients with brain bladder; Clinical evaluation using dynamic CT scan and auditory brainstem response

    Takahashi, Toshihiro (Yokohama City Univ. (Japan). Faculty of Medicine)

    1990-11-01

    A syndrome of detrusor-sphincter dyssynergia (DSD) is occasionally found in patients with brain bladder. To evaluate the brain stem function in cases of brain bladder, urodynamic study, dynamic CT scan of the brain stem (DCT) and auditory brainstem response (ABR) were performed. The region of interest of DCT aimed at the posterolateral portion of the pons. The results were analysed in contrast with the presense of DSD in urodynamic study. DCT studies were performed in 13 cases with various brain diseases and 5 control cases without neurological diseases. Abnormal patterns of the time-density curve consisted of low peak value, prolongation of filling time and low rapid washout ratio (low clearance ratio) of the contrast medium. Four of 6 cases with DSD showed at least one of the abnormal patterns of the time-density curve bilaterally. In 7 cases without DSD none showed bilateral abnormality of the curve and in 2 of 7 cases only unilateral abnormality was found. ABR was performed in 8 patients with brain diseases. The interpeak latency of the wave I-V (I-V IPL) was considered to be prolonged in 2 cases with DSD compared to that of 4 without DSD. In 2 cases with DSD who had normal DCT findings, measurement of the I-V IPL was impossible due to abnormal pattern of the ABR wave. Above mentioned results suggests the presence of functional disturbance at the posterolateral portion of the pons in cases of brain bladder with DSD. (author).

  7. Analysis of cement-treated clay behavior by micromechanical approach

    Zhang , Dong-Mei; Yin , Zhenyu; Hicher , Pierre Yves; Huang , Hong-Wei

    2013-01-01

    International audience; Experimental results show the significant influence of cement content on the mechanical properties of cement-treated clays. Cementation is produced by mixing a certain amount of cement with the saturated clay. The purpose of this paper is to model the cementation effect on the mechanical behavior of cement-treated clay. A micromechanical stress-strain model is developed considering explicitly the cementation at inter-cluster contacts. The inter-cluster bonding and debo...

  8. The effect of distal ulnar implant stem material and length on bone strains.

    Austman, Rebecca L; Beaton, Brendon J B; Quenneville, Cheryl E; King, Graham J W; Gordon, Karen D; Dunning, Cynthia E

    2007-01-01

    Implant design parameters can greatly affect load transfer from the implant stem to the bone. We have investigated the effect of length or material of distal ulnar implant stems on the surrounding bone strains. Eight cadaveric ulnas were instrumented with 12 strain gauges and secured in a customized jig. Strain data were collected while loads (5-30 N) were applied to the medial surface of the native ulnar head. The native ulnar head was removed, and a stainless steel implant with an 8-cm-long finely threaded stem was cemented into the canal. After the cement had cured, the 8-cm stem was removed, leaving a threaded cement mantle in the canal that could accept shorter threaded stems of interest. The loading protocol was then repeated for stainless steel stems that were 7, 5, and 3 cm in length, as well as for a 5-cm-long titanium alloy (TiAl(6)V(4)) stem. Other stainless steel stem lengths between 3 and 7 cm were tested at intervals of 0.5 cm, with only a 20 N load applied. No stem length tested matched the native strains at all gauge locations. No significant differences were found between any stem length and the native bone at the 5th and 6th strain gauge positions. Strains were consistently closer to the native bone strains with the titanium stem than the stainless steel stem for each gauge pair that was positioned on the bone overlying the stem. The 3-cm stem results were closer to the native strains than the 7-cm stem for all loads at gauges locations that were on top of the stem. The results from this study suggest that the optimal stem characteristics for distal ulnar implants from a load transfer point of view are possessed by shorter (approximately 3 to 4 cm) titanium stems.

  9. Per-operative vibration analysis: a valuable tool for defining correct stem insertion: preliminary report.

    Mulier, Michiel; Pastrav, Cesar; Van der Perre, Georges

    2008-01-01

    Defining the stem insertion end point during total hip replacement still relies on the surgeon's feeling. When a custom-made stem prosthesis with an optimal fit into the femoral canal is used, the risk of per-operative fractures is even greater than with standard prostheses. Vibration analysis is used in other clinical settings and has been tested as a means to detect optimal stem insertion in the laboratory. The first per-operative use of vibration analysis during non-cemented custom-made stem insertion in 30 patients is reported here. Thirty patients eligible for total hip replacement with uncemented stem prosthesis were included. The neck of the stem was connected with a shaker that emitted white noise as excitation signal and an impedance head that measured the frequency response. The response signal was sent to a computer that analyzed the frequency response function after each insertion phase. A technician present in the operating theatre but outside the laminated airflow provided feed-back to the surgeon. The correlation index between the frequency response function measured during the last two insertion hammering sessions was >0.99 in 86.7% of the cases. In four cases the surgeon stopped the insertion procedure because of a perceived risk of fracture. Two special cases illustrating the potential benefit of per-operative vibration analysis are described. The results of intra-operative vibration analysis indicate that this technique may be a useful tool assisting the orthopaedic surgeon in defining the insertion endpoint of the stem. The development of a more user-friendly device is therefore warranted.

  10. Clinical follow-up of horses treated with allogeneic equine mesenchymal stem cells derived from umbilical cord blood for different tendon and ligament disorders.

    Van Loon, Vic J F; Scheffer, Carmen J W; Genn, Herman J; Hoogendoorn, Arie C; Greve, Jan W

    2014-01-01

    Mesenchymal stem cells (MSCs) offer promise as therapeutic aids in the repair of tendon and ligament disorders in sport horses. Equine allogeneic MSCs derived from umbilical cord blood (eUCB-MSCs) can be obtained in a minimally invasive fashion with successful propagation of MSCs. The objective of this study was to determine the applicability and therapeutic effect of eUCB-MSCs on tendinitis of the superficial digital flexor tendon, desmitis of the suspensory ligament, tendinitis of the deep digital flexor tendon, and desmitis of the inferior check ligament in clinical cases. A retrospective clinical study was performed. At two equine clinics, 52 warmblood horses were treated with cultured eUCB-MSCs between 2009 and 2012. About 2-10 × 10(6) cells per lesion were administered. When a lesion was treated twice, the total amount could run up to 20 × 10(6) cells. Pearson's chi-squared test was used to compare the effect of the injured structure on the success rate, as well as the effect of the age of the horse. Based on repeated examinations, 40 horses (77%) returned to work on the same or a higher level based on information provided by the owner. Neither the injured structure nor the age of the horse had a statistically significant influence on the result. Overall, the results of treatment of some tendon and ligament injuries with eUCB-MSCs in clinical cases are promising.

  11. Improving the transition of highly complex patients into the community: impact of a pharmacist in an allogeneic stem cell transplant (SCT) outpatient clinic.

    Chieng, Ruth; Coutsouvelis, John; Poole, Susan; Dooley, Michael J; Booth, Diana; Wei, Andrew

    2013-12-01

    Patients having undergone allogeneic stem cell transplantation (SCT) require complex medication regimens. To ensure the safe and effective management of this patient group, specialised care in a centre with a dedicated and experienced healthcare team is essential. The aim of this study was to evaluate the effectiveness of a specialty clinical pharmacist working in an ambulatory SCT clinic. A prospective cohort study was conducted on patients post SCT and discharged to the ambulatory setting. Patients were reviewed by a clinical pharmacist weekly for six visits. At these visits a medication review was undertaken. Interventions from these reviews were recorded. Interventions were then assigned a risk rating by a multidisciplinary panel. Adherence was also assessed by a Morisky questionnaire and review of dose administration aids. Comparison of data over the six-visit period was undertaken. In total 23 patients were enrolled in the study. All six visits were completed in 17 patients and 161 interventions were recorded at an average of 1.4 interventions per patient visit. The panel rated 40 % of interventions as high risk, 46 % as medium risk and 14 % as low risk. At all visit points high- and medium-risk interventions constituted >80 % of the total. Morisky scores improved by an average of 1.53 (p SCT outpatient clinic resulted in regular and effective intervention contributing to improved medication management and adherence.

  12. Patient-reported outcomes and socioeconomic status as predictors of clinical outcomes following hematopoietic stem cell transplantation: A study from the BMT CTN 0902 trial

    Knight, Jennifer M; Syrjala, Karen L; Majhail, Navneet S; Martens, Michael; Le-Rademacher, Jennifer; Logan, Brent R; Lee, Stephanie J; Jacobsen, Paul B; Wood, William A; Jim, Heather SL; Wingard, John R; Horowitz, Mary M; Abidi, Muneer H; Fei, Mingwei; Rawls, Laura; Rizzo, J Douglas

    2016-01-01

    This secondary analysis of a large, multi-center Blood and Marrow Transplant Clinical Trials Network (BMT CTN) randomized trial assessed whether patient-reported outcomes (PROs) and socioeconomic status (SES) before hematopoietic stem cell transplantation (HCT) are associated with each other and predictive of clinical outcomes including time to hematopoietic recovery, acute graft-versus-host disease, hospitalization days, and overall survival (OS) among 646 allogeneic and autologous HCT recipients. Pre-transplant Cancer and Treatment Distress (CTXD), Pittsburgh Sleep Quality Index (PSQI), and mental and physical component scores (MCS and PCS) of the SF-36 were correlated with each other and with SES variables. PROs and SES variables were further evaluated as predictors of clinical outcomes, with the PSQI and CTXD evaluated as OS predictors (pincome was related to worse physical functioning (p=.005) and increased distress (p=.008); lack of employment pre-transplant was associated with worse physical functioning (p<.01); unmarried status was associated with worse sleep (p=.003). In this large heterogeneous cohort of HCT recipients, while PROs and SES variables were correlated at baseline, they were not associated with any clinical outcomes. Future research should focus on HCT recipients at greater psychosocial disadvantage. PMID:27565521

  13. Autologous Bone Marrow Stem Cells in Spinal Cord Injury; Our Experience in Clinical Studies, Animal Studies, Obstacles faced and steps for future

    Ayyappan S

    2010-01-01

    , Santos M. Cell therapy using bone marrow stromal cells in chronic paraplegic rats: systemic or local administration? Neurosci Lett. 2006 May.3.de Haro J, Zurita M, Ayllón L, Vaquero J. Detection of 111.In-oxine-labeled bone marrow stromal cells after intravenous or intralesional administration inchronic paraplegic rats. Neurosci Lett. 2005 Mar4.Yano S, Kuroda S, Lee JB, Shichinohe H, Seki T, Ikeda J, Nishimura G, Hida K, Tamura M, Iwasaki Y. In vivo fluorescence tracking of bone marrow stromal cells transplanted into pneumatic injury model of rat spinal cord. J Neurotrauma.2005 Aug5.Ravikumar R, Narayanan S, Baskar S, SenthilNagarajan R, Abraham S. Autologous Stem Cell Injection for Spinal Cord Injury- A Clinical Study from India. PASRM 2007-0046.Justin William B, Ayyappan S, DhanaJayaRao G, Pushkinraj H, Kannan TA , Sureshkumar R, Manjunath S, Murugan P, Srinivasan V, Abraham S. Intralesional Application of Autologous Bone Marrow Stem Cells with Scaffold in Canine for Spinal Cord Injury. PASRM, IV annual symposium , 2009.7.Yasuda H, Kuroda S, Shichinohe H, Kamei S, Kawamura R, Iwasaki Y. Effect of biodegradable fibrin scaffold on survival, migration, and differentiation of transplanted bone marrow stromal cells after cortical injury in rats. J Neurosurg. 2010 ;112(2:336-44. 8.Abraham et al. Stem cell Clinical trials Session. Stem cell Global blue Print Conference (21-22 May2010 Toronto, Canada

  14. New Insights into Osteogenic and Chondrogenic Differentiation of Human Bone Marrow Mesenchymal Stem Cells and Their Potential Clinical Applications for Bone Regeneration in Pediatric Orthopaedics

    Nicola Giuliani

    2013-01-01

    Full Text Available Human mesenchymal stem cells (hMSCs are pluripotent adult stem cells capable of being differentiated into osteoblasts, adipocytes, and chondrocytes. The osteogenic differentiation of hMSCs is regulated either by systemic hormones or by local growth factors able to induce specific intracellular signal pathways that modify the expression and activity of several transcription factors. Runt-related transcription factor 2 (Runx2 and Wnt signaling-related molecules are the major factors critically involved in the osteogenic differentiation process by hMSCs, and SRY-related high-mobility-group (HMG box transcription factor 9 (SOX9 is involved in the chondrogenic one. hMSCs have generated a great interest in the field of regenerative medicine, particularly in bone regeneration. In this paper, we focused our attention on the molecular mechanisms involved in osteogenic and chondrogenic differentiation of hMSC, and the potential clinical use of hMSCs in osteoarticular pediatric disease characterized by fracture nonunion and pseudarthrosis.

  15. Protein and Molecular Characterization of a Clinically Compliant Amniotic Fluid Stem Cell-Derived Extracellular Vesicle Fraction Capable of Accelerating Muscle Regeneration Through Enhancement of Angiogenesis.

    Mellows, Ben; Mitchell, Robert; Antonioli, Manuela; Kretz, Oliver; Chambers, David; Zeuner, Marie-Theres; Denecke, Bernd; Musante, Luca; Ramachandra, Durrgah L; Debacq-Chainiaux, Florence; Holthofer, Harry; Joch, Barbara; Ray, Steve; Widera, Darius; David, Anna L; Huber, Tobias B; Dengjel, Joern; De Coppi, Paolo; Patel, Ketan

    2017-09-15

    The secretome of human amniotic fluid stem cells (AFSCs) has great potential as a therapeutic agent in regenerative medicine. However, it must be produced in a clinically compliant manner before it can be used in humans. In this study, we developed a means of producing a biologically active secretome from AFSCs that is free of all exogenous molecules. We demonstrate that the full secretome is capable of promoting stem cell proliferation, migration, and protection of cells against senescence. Furthermore, it has significant anti-inflammatory properties. Most importantly, we show that it promotes tissue regeneration in a model of muscle damage. We then demonstrate that the secretome contains extracellular vesicles (EVs) that harbor much, but not all, of the biological activity of the whole secretome. Proteomic characterization of the EV and free secretome fraction shows the presence of numerous molecules specific to each fraction that could be key regulators of tissue regeneration. Intriguingly, we show that the EVs only contain miRNA and not mRNA. This suggests that tissue regeneration in the host is mediated by the action of EVs modifying existing, rather than imposing new, signaling pathways. The EVs harbor significant anti-inflammatory activity as well as promote angiogenesis, the latter may be the mechanistic explanation for their ability to promote muscle regeneration after cardiotoxin injury.

  16. Synthesis of Portland cement and calcium sulfoaluminate-belite cement for sustainable development and performance

    Chen, Irvin Allen

    Portland cement concrete, the most widely used manufactured material in the world, is made primarily from water, mineral aggregates, and portland cement. The production of portland cement is energy intensive, accounting for 2% of primary energy consumption and 5% of industrial energy consumption globally. Moreover, portland cement manufacturing contributes significantly to greenhouse gases and accounts for 5% of the global CO2 emissions resulting from human activity. The primary objective of this research was to explore methods of reducing the environmental impact of cement production while maintaining or improving current performance standards. Two approaches were taken, (1) incorporation of waste materials in portland cement synthesis, and (2) optimization of an alternative environmental friendly binder, calcium sulfoaluminate-belite cement. These approaches can lead to less energy consumption, less emission of CO2, and more reuse of industrial waste materials for cement manufacturing. In the portland cement part of the research, portland cement clinkers conforming to the compositional specifications in ASTM C 150 for Type I cement were successfully synthesized from reagent-grade chemicals with 0% to 40% fly ash and 0% to 60% slag incorporation (with 10% intervals), 72.5% limestone with 27.5% fly ash, and 65% limestone with 35% slag. The synthesized portland cements had similar early-age hydration behavior to commercial portland cement. However, waste materials significantly affected cement phase formation. The C3S--C2S ratio decreased with increasing amounts of waste materials incorporated. These differences could have implications on proportioning of raw materials for cement production when using waste materials. In the calcium sulfoaluminate-belite cement part of the research, three calcium sulfoaluminate-belite cement clinkers with a range of phase compositions were successfully synthesized from reagent-grade chemicals. The synthesized calcium sulfoaluminate

  17. The cement recycling of the earthquake disaster debris by Hachinohe Cement Co., Ltd

    Kataoka, Masayuki

    2015-01-01

    A tremendous quantity of earthquake disaster debris and tsunami sediment was resulted by the Great East Japan Earthquake on March 11, 2011. Hachinohe Cement Co., Ltd., a Sumitomo Osaka Cement subsidiary, was the first cement industry company to receive and process such waste materials outside of their usual prefecture area, while the company is performing their treatment and recycling services locally in Hachinohe City and Aomori Prefecture. This report provides an explanation about the recycling mechanism of waste materials and by-products in cement manufacturing process, and introduces an example of actual achievements for the disaster debris treatment by utilizing the cement recycling technologies at the Hachinohe Cement Plant. (author)

  18. Biocompatibility of Portland cement combined with different radiopacifying agents.

    Lourenço Neto, Natalino; Marques, Nádia C T; Fernandes, Ana Paula; Rodini, Camila O; Duarte, Marco A H; Lima, Marta C; Machado, Maria A A M; Abdo, Ruy C C; Oliveira, Thais M

    2014-03-01

    The aim of this study was to evaluate the response of rat subcutaneous tissue to Portland cement combined with two different radiopacifying agents, iodoform (CHI3) and zirconium oxide (ZrO2). These materials were placed in polyethylene tubes and implanted into the dorsal connective tissue of Wistar rats for 7 and 15 days. The specimens were then stained with hematoxylin and eosin, and inflammatory reaction parameters were evaluated by light microscopy. The intensity of the inflammatory response to the sealants was analyzed by two blind calibrated observers throughout the experimental period. Histological analysis showed that all the materials caused a moderated inflammatory reaction at 7 days, which then diminished with time. At 15 days, the inflammatory reaction was almost absent, and fibroblasts and collagen fibers were observed indicating normal tissue healing. The degrees of the inflammatory reaction on different days throughout the experimental period were compared using the non-parametric Kruskal-Wallis test. Statistical analysis demonstrated no significant differences amongst the groups, and Portland cement associated with radiopacifying agents gave satisfactory results. Therefore, Portland cement used in combination with radiopacifying agents can be considered a biocompatible material. Although our results are very encouraging, further studies are needed in order to establish safe clinical indications for Portland cement combined with radiopacifying agents.

  19. Dental Stem Cell in Tooth Development and Advances of Adult Dental Stem Cell in Regenerative Therapies.

    Tan, Jiali; Xu, Xin; Lin, Jiong; Fan, Li; Zheng, Yuting; Kuang, Wei

    2015-01-01

    Stem cell-based therapies are considered as a promising treatment for many clinical usage such as tooth regeneration, bone repairation, spinal cord injury, and so on. However, the ideal stem cell for stem cell-based therapy still remains to be elucidated. In the past decades, several types of stem cells have been isolated from teeth, including dental pulp stem cells (DPSCs), stem cells from human exfoliated deciduous teeth (SHED), periodontal ligament stem cells (PDLSCs), dental follicle progenitor stem cells (DFPCs) and stem cells from apical papilla (SCAP), which may be a good source for stem cell-based therapy in certain disease, especially when they origin from neural crest is considered. In this review, the specific characteristics and advantages of the adult dental stem cell population will be summarized and the molecular mechanisms of the differentiation of dental stem cell during tooth development will be also discussed.

  20. 21 CFR 888.3353 - Hip joint metal/ceramic/polymer semi-constrained cemented or nonporous uncemented prosthesis.

    2010-04-01

    ... linkage across-the-joint. The two-part femoral component consists of a femoral stem made of alloys to be... ceramic (aluminium oxide, A1203) head of the femoral component. The acetabular component is made of ultra... nonporous metal alloys, and used with or without bone cement. (b) Classification. Class II. [54 FR 48239...

  1. Safety and efficacy of allogeneic adipose tissue-derived mesenchymal stem cells for treatment of dogs with inflammatory bowel disease: Clinical and laboratory outcomes.

    Pérez-Merino, E M; Usón-Casaús, J M; Zaragoza-Bayle, C; Duque-Carrasco, J; Mariñas-Pardo, L; Hermida-Prieto, M; Barrera-Chacón, R; Gualtieri, M

    2015-12-01

    Mesenchymal stem cells (MSCs) have shown immunomodulatory and anti-inflammatory effects in experimental colitis, and promising clinical results have been obtained in humans with Crohn's disease and ulcerative colitis. The aim of this study was to determine the safety and feasibility of adipose tissue-derived MSC (ASC) therapy in dogs with inflammatory bowel disease (IBD). Eleven dogs with confirmed IBD received one ASC intravascular (IV) infusion (2 × 10(6) cells/kg bodyweight). The outcome measures were clinical response based on percentage reduction of the validated Clinical Inflammatory Bowel Disease Activity Index (CIBDAI) and Canine Chronic Enteropathy Clinical Activity Index (CCECAI), as well as normalisation of C-reactive protein (CRP), albumin, folate and cobalamin serum concentrations at day 42 post-treatment. The Wilcoxon test was used to compare variables before and after treatment. No acute reaction to ASC infusion and no side effects were reported during follow-up in any dog. Six weeks post-treatment, the CIBDAI and CCECAI decreased significantly and albumin, cobalamin and folate concentrations increased substantially. Differences in CRP concentrations pre- and post-treatment were not significant (P = 0.050). Clinical remission (defined by a reduction of initial CIBDAI and CCECAI >75%) occurred in 9/11 dogs at day 42. The two remaining dogs showed a partial response with reduction percentages of 69.2% and 71.4%. In conclusion, a single IV infusion of allogeneic ASCs was well tolerated and appeared to produce clinical benefits in dogs with severe IBD. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Clinical application prospect of umbilical cord-derived mesenchymal stem cells on clearance of advanced glycation end products through autophagy on diabetic wound.

    Han, Yanfu; Sun, Tianjun; Tao, Ran; Han, Yanqing; Liu, Jing

    2017-03-24

    Nowadays, wound healing delay due to diabetes is considered to be closely related to the accumulation of advanced glycation end products (AGEs). Although mesenchymal stem cells (MSCs) exhibit positive effects on diabetic wound healing, related mechanisms are still not fully elucidated. It has been reported that MSCs can improve the activity of autophagy in injured tissues, thereby playing an important role in wound healing. The autophagy induced by MSCs may be beneficial to diabetic wound healing via removing AGEs, which provide new ideas for clinical treatment of diabetic wounds with the potential of broad application prospects. In this study, the current research situation and application prospect of umbilical cord-derived MSCs on the clearance of AGEs in diabetic wound were reviewed.

  3. Stem cells

    Jukes, Jojanneke; Both, Sanne; Post, Janine; van Blitterswijk, Clemens; Karperien, Marcel; de Boer, Jan; van Blitterswijk, Clemens A.

    2008-01-01

    This chapter defines stem cells and their properties. It identifies the major differences between embryonic and adult stem cells. Stem cells can be defined by two properties: the ability to make identical copies of themselves and the ability to form other cell types of the body. These properties are

  4. Use sulfoferritic cements in construction

    Samchenko, Svetlana V.; Zorin, Dmitriy A.

    2018-03-01

    Currently, high-rise construction has received increasing attention around the world. In the big cities under construction is less space and one solution is the high-rise construction. However, high-rise buildings use special requirements, such as strength, thermal insulation, wind load and others. When concrete is exposed to continuous loads by wind or to mechanical loads, it undergoes abrasion. Resistance to this process depends on the characteristics of materials that the concrete and finishing seams are made of. Research on increasing impact and abrasion resistance of calcium sulfoferrite-based cement stone from the perspective of formation of cement stone structure will be instrumental in developing durable materials for application in high-rise construction.

  5. Concrete research using blended cements

    Butler, W.B.

    2001-01-01

    Concrete research increasingly involves the use of mixes containing one or more of the supplementary cementitious materials (SCMs), often in conjunction with chemical admixtures. The influence of materials is commonly evaluated on the basis of water/ cement or water/ binder ratio and SCM content as a percentage of total binder, with dosage level of chemical admixture varied to maintain workability. As a result, more than one variable is introduced at a time and the objectives of the research may not be achieved. The significance of water/ cement ratio and addition rates of admixtures are examined from a practical standpoint with suggestions for more appropriate means of evaluation of the influence of individual materials. Copyright (2001) The Australian Ceramic Society

  6. The density of cement phases

    Balonis, M.; Glasser, F.P.

    2009-01-01

    The densities of principal crystalline phases occurring in Portland cement are critically assessed and tabulated, in some cases with addition of new data. A reliable and self-consistent density set for crystalline phases was obtained by calculating densities from crystallographic data and unit cell contents. Independent laboratory work was undertaken to synthesize major AFm and AFt cement phases, determine their unit cell parameters and compare the results with those recorded in the literature. Parameters were refined from powder diffraction patterns using CELREF 2 software. A density value is presented for each phase, showing literature sources, in some cases describing limitations on the data, and the weighting attached to numerical values where an averaging process was used for accepted data. A brief discussion is made of the consequences of the packing of water to density changes in AFm and AFt structures.

  7. [Dislocated fracture of the lesser trochanter with malrotation of the stem after robot assisted implantation of a cementless hip prosthesis: a casuistic report].

    Prymka, M; Hassenpflug, J

    2003-08-01

    This paper presents the case of a 63 year old female with a severe coxarthrosis. She got a robot assited implantation of a cementless hip prosthesis (Osteolock, Stryker-Howmedica, Mühlheim). As operation robot the CASPAR-System (Orto-Maquet, Rastatt) was used. Initially, the clinical progress of the patient was fine. She was nearly painfree within 14 days and showed an acceptable range of motion in the operated joint (flexion/ extension 90 degrees /05 degrees /00 degrees ). She was mobilized with crutches and 15 kg weight bearing at the operated leg. 3 weeks postoperative the patient complaint about increasing pain without trauma or intensification of the weight bearing. X-rays showed not only a dislocated fracture of the lesser trochanter, but also a sinking combined with a malrotation of the stem. A revision operation was necessary,where we implanted a cemented stem. Now clinical progress was completely satisfying.

  8. Glass ionomer cement: literature review

    Sérgio Spezzia

    2017-01-01

    Introduction: In the dental area preventive actions occur in an attempt to avoid the installation of caries, a disease that has an increased prevalence in the population and which is a Public Health problem. Some resources are used for such, such as: performing early diagnosis and the option for conservative treatments of minimal intervention. The glass ionomer cement (CIV), coming from its beneficial characteristics that meet current trends, is closely related to the precepts of Preventive a...

  9. WHITE CEMENT IN SUSTAINABLE DEVELOPMENT

    Y.C.P RAMANA BABU; B.SAI DOONDI; N. M .V .VAMSI KRISHNA; K.PRASANTHI

    2013-01-01

    India is one among the fast developing countries in the world in the areas of Infrastructure. Now a day, Carbon monoxide (CO) and carbon dioxide (CO2) are the temporary atmospheric pollutants in the environment chiefly emitted from the fuel burning vehicles and street lights which lead to global warming and pose a major threat tothe survival and sustainable development. This paper deals with the principal purpose of use of white cement in pavement design which will take care of the Green hous...

  10. Modernization of Byuzmeyinsky Cement Plant

    NONE

    2001-03-01

    With an objective of saving energy and reducing greenhouse gas emission, investigations and discussions were given on a modernization project for Byuzmeyinsky Cement Factory, the only cement factory in Turkmenistan. Byuzmeyinsky Cement Factory uses the wet process which consumes a large amount of energy, is inferior in production efficiency and quality, and discharging a great amount of greenhouse effect gas. The present project will execute change of the raw material crusher into a vertical roll mill for one of the four wet kilns, and change of the facilities for raw material powder mixing and storing and clinker manufacturing into dry-type facilities using the NSP system. As a result of the discussions, the energy saving effect would be 86,321 tons of crude oil equivalent annually, and the greenhouse gas emission reducing effect would be 224,467 t-CO2 annually. The total fund amount required for the project is estimated to be 90,211,000 dollars. With regard to the profitability, the internal financial profit rate would be 9.71% after tax, and the ROE would be 18.62%, whereas the project is considered feasible. (NEDO)

  11. Noninvasive in vivo tracking of mesenchymal stem cells and evaluation of cell therapeutic effects in a murine model using a clinical 3.0 T MRI.

    Drey, Florian; Choi, Yeong-Hoon; Neef, Klaus; Ewert, Birgit; Tenbrock, Arne; Treskes, Philipp; Bovenschulte, Henning; Liakopoulos, Oliver J; Brenkmann, Meike; Stamm, Christof; Wittwer, Thorsten; Wahlers, Thorsten

    2013-01-01

    Cardiac cell therapy with mesenchymal stem cells (MSCs) represents a promising treatment approach for end-stage heart failure. However, little is known about the underlying mechanisms and the fate of the transplanted cells. The objective of the presented work is to determine the feasibility of magnetic resonance imaging (MRI) and in vivo monitoring after transplantation into infarcted mouse hearts using a clinical 3.0 T MRI device. The labeling procedure of bone marrow-derived MSCs with micron-sized paramagnetic iron oxide particles (MPIOs) did not affect the viability of the cells and their cell type-defining properties when compared to unlabeled cells. Using a clinical 3.0 T MRI scanner equipped with a dedicated small animal solenoid coil, 10(5) labeled MSCs could be detected and localized in the mouse hearts for up to 4 weeks after intramyocardial transplantation. Weekly ECG-gated scans using T1-weighted sequences were performed, and left ventricular function was assessed. Histological analysis of hearts confirmed the survival of labeled MSCs in the target area up to 4 weeks after transplantation. In conclusion, in vivo tracking of labeled MSCs using a clinical 3.0 T MRI scanner is feasible. In combination with assessment of heart function, this technology allows the monitoring of the therapeutic efficacy of regenerative therapies in a small animal model.

  12. [Perinatal sources of stem cells].

    Piskorska-Jasiulewicz, Magdalena Maria; Witkowska-Zimny, Małgorzata

    2015-03-08

    Recently, stem cell biology has become an interesting topic. Several varieties of human stem cells have been isolated and identified in vivo and in vitro. Successful application of hematopoietic stem cells in hematology has led to the search for other sources of stem cells and expanding the scale of their application. Perinatal stem cells are a versatile cell population, and they are interesting for both scientific and practical objectives. Stem cells from perinatal tissue may be particularly useful in the clinic for autologous transplantation for fetuses and newborns, and after banking in later stages of life, as well as for in utero transplantation in the case of genetic disorders. In this review paper we focus on the extraction and therapeutic potential of stem cells derived from perinatal tissues such as the placenta, the amnion, amniotic fluid, umbilical cord blood and Wharton's jelly.

  13. Perinatal sources of stem cells

    Magdalena Maria Piskorska-Jasiulewicz

    2015-03-01

    Full Text Available Recently, stem cell biology has become an interesting topic. Several varieties of human stem cells have been isolated and identified in vivo and in vitro. Successful application of hematopoietic stem cells in hematology has led to the search for other sources of stem cells and expanding the scale of their application. Perinatal stem cells are a versatile cell population, and they are interesting for both scientific and practical objectives. Stem cells from perinatal tissue may be particularly useful in the clinic for autologous transplantation for fetuses and newborns, and after banking in later stages of life, as well as for in utero transplantation in the case of genetic disorders. In this review paper we focus on the extraction and therapeutic potential of stem cells derived from perinatal tissues such as the placenta, the amnion, amniotic fluid, umbilical cord blood and Wharton’s jelly.

  14. [Effect of ceramic thickness and resin cement shades on final color of heat-pressed ceramic veneers].

    Ren, D F; Zhan, K R; Chen, X D; Xing, W Z

    2017-02-09

    Objective: To analyze the effect of ceramic materials thickness and resin cement shades on the final color of ceramic veneers in the discolored teeth, and to investigate the color agreement of try-in pastes to the corresponding resin cements. Methods: Sixty artificial maxillary central incisor teeth (C2 shade) were used to simulate the natural discolored teeth and prepared according to veneer tooth preparation protocol. Veneers of different thickness in the body region (0.50 and 0.75 mm) were fabricated using ceramic materials (LT A2 shade, IPS e.max Press). The ceramic veneer specimens were bonded to the artificial teeth using the 6 shades of resin cements (Variolink Veneer: shades of LV-3, LV-2, HV+3; RelyX™ Veneer: shades of TR, A3, WO) ( n= 5). A clinical spectrophotometer was used to measure the color parameters of ceramic veneers at the cervical, body and incisal regions. Color changes of veneers before and after cementation were calculated and registered as ΔE1, and the changes between try-in paste and the corresponding resin cements were registered as ΔE2. Results: Three-way ANOVA indicated that ΔE1 and ΔE2 values were significantly affected by the ceramic thickness, resin cement shades and measuring regions ( Pceramic veneers were cemented with resin cements in shades of HV+3 and WO. The ΔE2 values of six shades ranged from 0.60-2.56. The shades of HV+3, WO and A3 resin cements were more than 1.60. Conclusions: Different thickness of ceramic materials, resin cement shades and measuring regions could affect the final color of ceramic veneers. The color differences of some resin cements and corresponding try-in pastes might be observed in clinical practice.

  15. Use of Incineration Solid Waste Bottom Ash as Cement Mixture in Cement Production

    Jun, N. H.; Abdullah, M. M. A. B.; Jin, T. S.; Kadir, A. A.; Tugui, C. A.; Sandu, A. V.

    2017-06-01

    Incineration solid waste bottom ash was use to examine the suitability as a substitution in cement production. This study enveloped an innovative technology option for designing new equivalent cement that contains incineration solid waste bottom ash. The compressive strength of the samples was determined at 7, 14, 28 and 90 days. The result was compared to control cement with cement mixture containing incineration waste bottom ash where the result proved that bottom ash cement mixture able achieve its equivalent performance compared to control cement which meeting the requirement of the standards according to EN 196-1. The pozzolanic activity index of bottom ash cement mixture reached 0.92 at 28 days and 0.95 at 90 and this values can be concluded as a pozzolanic material with positive pozzolanic activity. Calcium hydroxide in Portland cement decreasing with the increasing replacement of bottom ash where the reaction occur between Ca(OH)2 and active SiO2.

  16. Natural cement as the precursor of Portland cement: Methodology for its identification

    Varas, M.J.; Alvarez de Buergo, M.; Fort, R.

    2005-01-01

    When cements appeared in the 19th century, they took the place of traditional binding materials (lime, gypsum, and hydraulic lime) which had been used until that time. Early cements can be divided into two groups, natural and artificial (Portland) cements. Natural cements were introduced first, but their widespread usage was short-lived as they were quickly replaced by artificial cements (Portland), still the most important and predominant today. The main differences between natural and artificial cements arise during the manufacturing process. The final properties of the cements are greatly influenced by differences in the raw materials and burning temperatures employed. The aim of this paper is to assess the efficiency of traditional analytical techniques (petrographic microscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR)) used to differentiate natural and artificial cements

  17. Effects of cement particle size distribution on performance properties of Portland cement-based materials

    Bentz, D.P.; Garboczi, E.J.; Haecker, C.J.; Jensen, O.M.

    1999-10-01

    The original size, spatial distribution, and composition of Portland cement particles have a large influence on hydration kinetics, microstructure development, and ultimate properties of cement-based materials. In this paper, the effects of cement particle size distribution on a variety of performance properties are explored via computer simulation and a few experimental studies. Properties examined include setting time, heat release, capillary porosity percolation, diffusivity, chemical shrinkage, autogenous shrinkage, internal relative humidity evolution, and interfacial transition zone microstructure. The effects of flocculation and dispersion of the cement particles in the starting microstructures on resultant properties are also briefly evaluated. The computer simulations are conducted using two cement particle size distributions that bound those commonly in use today and three different water-to-cement ratios: 0.5, 0.3, and 0.246. For lower water-to-cement ratio systems, the use of coarser cements may offer equivalent or superior performance, as well as reducing production costs for the manufacturer.

  18. Cement replacement materials. Properties, durability, sustainability

    Ramezanianpour, Ali Akbar

    2014-01-01

    The aim of this book is to present the latest findings in the properties and application of Supplementary Cementing Materials and blended cements currently used in the world in concrete. Sustainability is an important issue all over the world. Carbon dioxide emission has been a serious problem in the world due to the greenhouse effect. Today many countries agreed to reduce the emission of CO2. Many phases of cement and concrete technology can affect sustainability. Cement and concrete industry is responsible for the production of 7% carbon dioxide of the total world CO2 emission. The use of supplementary cementing materials (SCM), design of concrete mixtures with optimum content of cement and enhancement of concrete durability are the main issues towards sustainability in concrete industry.

  19. The cement solidification systems at LANL

    Veazey, G.W.

    1990-01-01

    There are two major cement solidification systems at Los Alamos National Laboratory. Both are focused primarily around treating waste from the evaporator at TA-55, the Plutonium Processing Facility. The evaporator receives the liquid waste stream from TA-55's nitric acid-based, aqueous-processing operations and concentrates the majority of the radionuclides in the evaporator bottoms solution. This is sent to the TA-55 cementation system. The evaporator distillate is sent to the TA-50 facility, where the radionuclides are precipitated and then cemented. Both systems treat TRU-level waste, and so are operated according to the criteria for WIPP-destined waste, but they differ in both cement type and mixing method. The TA-55 systems uses Envirostone, a gypsum-based cement and in-drum prop mixing; the TA-50 systems uses Portland cement and drum tumbling for mixing

  20. Characterization of experimental cements with endodontic goal

    Dantas, A.M.X.; Sousa, W.J.B.; Oliveira, E.D.C.; Carrodeguas, R.G.; Fook, M.V. Lia; Universidade Estadual da Paraiba

    2017-01-01

    The present study aimed to characterize experimental endodontic cements using as comparative parameter MTA cement. Two experimental endodontic cements were assessed: one based on 95% tri-strontium aluminate and 5% gypsum (CE1) and another based on 50% Sr_3Al_2O_6 and 50% non-structural white cement (CE2). Experimental cements were manipulated and characterized by scanning electron microscopy (SEM), coupled to EDS mode, X-ray diffractometer (XRD) and Thermogravimetric (TG) analysis. Data analysis demonstrated that the particles of the materials used presented varied shapes and sizes, with similar elements and crystalline behavior. However, CE1 presented increased mass loss. Experimental cements presents similarities to MTA, nevertheless, further studies are encourage to determinate comparative properties with the commercially material. (author)

  1. Modelling porewater chemistry in hydrated Portland cement

    Berner, U.R.

    1987-01-01

    Extensive employment of concrete is foreseen in radioactive waste repositories. A prerequisite for modelling the interactions between concrete and formation waters is characterization of the concrete system. Available experimental data from high pressure squeezing of cement pore-water indicate that, besides the high pH due to alkali hydroxide dissolution, cement composition itself influences the solubility determining solid phases. A model which simulates the hydration of Portland cement assuming complete hydration of the main clinker minerals is presented. The model also includes parameters describing the reactions between the cement and blending agents. Comparison with measured pore-water data generally gives a consistent picture and, as expected, the model gives correct predictions for pure Portland cements. For blended cements, the required additional parameters can, to some extent, be derived from pore-water analysis. 14 references, 1 figure, 4 tables

  2. Chemistry of cements for nuclear applications

    Barrett, P.; Glasser, F.P.

    1992-01-01

    In recent times the nuclear industry has thrown up challenges which cannot be met by the application of conventional civil and materials engineering knowledge. The contributions in this volume investigate all aspects of cement performance. The scope of the papers demonstrates the current balance of activities which have as their objective the elucidation of kinetics and immobilization, determining material interactions and of assessing future performance. The papers reflect the varied goals of the sponsors who include national governments, the Commission of the European Communities and the nuclear industries. In six parts attention is paid to the durability of cement and concrete in repository environment; interactions between cement, waste components and ground water; properties and performance of cement materials; leach behavior and mechanisms, diffusional properties of cement and concrete, including porosity-permeability relationships; and thermodynamics of cementitious systems and modelling of cement performance

  3. Mechanism of Action of Prostate Stem Cell Antigen Targeted Antibody Therapy and its Relevance to Clinical Application in Prostate Cancer

    Reiter, Robert; Tran, Chau

    2008-01-01

    .... A better understanding of PSCA function and its antibody activity will enable rational patient selection and trial design all of which are particularly relevant to subsequent clinical trials of PSCA antibody...

  4. Mechanism of Action of Prostate Stem Cell Antigen Targeted Antibody Therapy and Its Relevance to Clinical Application in Prostate Cancer

    Reiter, Robert; Tran, Chau

    2007-01-01

    .... A better understanding of PSCA function and its antibody activity will enable rational patient selection and trial design, all of which are particularly relevant to subsequent clinical trials of PSCA antibody...

  5. First-in-human study and clinical case reports of the alveolar bone regeneration with the secretome from human mesenchymal stem cells.

    Katagiri, Wataru; Osugi, Masashi; Kawai, Takamasa; Hibi, Hideharu

    2016-01-15

    Secreted growth factors and cytokines in the conditioned medium from bone marrow-derived mesenchymal stem cells (MSC-CM) have several effects on cell behavior. Our previous studies revealed that MSC-CM enhances bone regeneration by increasing cell mobilization, angiogenesis, and osteogenesis in vitro and in vivo. This clinical study was undertaken to evaluate the safety and use of MSC-CM for alveolar bone regeneration in eight patients who were diagnosed as needing bone augmentation prior to dental implant placement. The protocol of this clinical study was approved by the ethics committee of Nagoya University Hospital. MSC-CM was prepared from conditioned medium from commercially available human bone marrow-derived MSCs. Patients were treated with beta-tricalcium phosphate (β-TCP) or an atelocollagen sponge soaked with MSC-CM. Clinical and radiographic assessments were performed during the follow-up period. Histological assessments were also performed in some cases. Clinical and histological data from patients who underwent the SFE procedure without MSC-CM were also used retrospectively as reference controls. MSC-CM contained several cytokines such as insulin-like growth factor-1, vascular endothelial growth factor, transforming growth factor-β1, and hepatocyte growth factor in relatively low amounts. No systemic or local complications were reported throughout the study. Radiographic evaluation revealed early bone formation in all cases. Histological evaluation also supported the radiographic findings. Furthermore, infiltration of inflammatory cells was scarce throughout the specimens. MSC-CM was used safely and with less inflammatory signs and appears to have great osteogenic potential for regenerative medicine of bone. This is the first in-human clinical study of alveolar bone regeneration using MSC-CM.

  6. Root perforations treatment using mineral trioxide aggregate and Portland cements.

    Silva Neto, José Dias da; Brito, Rafael Horácio de; Schnaider, Taylor Brandão; Gragnani, Alfredo; Engelman, Mírian; Ferreira, Lydia Masako

    2010-12-01

    Clinical, radiological and histological evaluation of root perforations treated with mineral trioxide aggregate (MTA) or Portland cements, and calcium sulfate barrier. One molar and 11 premolar teeth of a male mongrel dog received endodontic treatment and furcations were perforated with a high-speed round bur and treated with a calcium sulfate barrier. MTA, Portland cement type II (PCII) and type V (PCV), and white Portland cement (WPC) were used as obturation materials. The teeth were restored with composite resin and periapical radiographs were taken. The animal was euthanized 120 days post-surgery for treatment evaluation. Right lower first premolar (MTA), right lower third premolar (PCV), left lower second premolar (MTA), and right lower second premolar (WPC): clinically normal, slightly radio-transparent area on the furcation, little inflammatory infiltrate, and new-bone formation. Left lower third premolar (PCII), right upper first premolar (WPC), right upper third premolar (PCII), and left upper first molar (PCV): clinically normal, radiopaque area on the furcation, and new-bone formation. Right upper second premolar (MTA), left upper second premolar (WPC), left upper third premolar (PCII): presence of furcation lesion, large radiolucent area, and intense inflammatory infiltrate. All obturation materials used in this study induced new-bone formation.

  7. Sustainable Development of the Cement Industry and Blended Cements to Meet Ecological Challenges

    Sobolev, Konstantin

    2003-01-01

    The world production of cement has greatly increased in the past 10 years. This trend is the most significant factor affecting technological development and the updating of manufacturing facilities in the cement industry. Existing technology for the production of cement clinker is ecologically damaging; it consumes much energy and natural resources and also emits pollutants. A new approach to the production of blended or high-volume mineral additive (HVMA) cement helps to improve its ecologi...

  8. Pulmonary Cement Embolism following Percutaneous Vertebroplasty

    Ümran Toru

    2014-01-01

    Full Text Available Percutaneous vertebroplasty is a minimal invasive procedure that is applied for the treatment of osteoporotic vertebral fractures. During vertebroplasty, the leakage of bone cement outside the vertebral body leads to pulmonary cement embolism, which is a serious complication of this procedure. Here we report a 48-year-old man who was admitted to our hospital with dyspnea after percutaneous vertebroplasty and diagnosed as pulmonary cement embolism.

  9. Migration and head penetration of Vitamin-E diffused cemented polyethylene cup compared to standard cemented cup in total hip arthroplasty: study protocol for a randomised, double-blind, controlled trial (E1 HIP).

    Sköldenberg, Olof; Rysinska, Agata; Chammout, Ghazi; Salemyr, Mats; Muren, Olle; Bodén, Henrik; Eisler, Thomas

    2016-07-07

    In vitro, Vitamin-E-diffused, highly cross-linked polyethylene (PE) has been shown to have superior wear resistance and improved mechanical properties when compared to those of standard highly cross-linked PE liners used in total hip arthroplasty (THA). The aim of the study is to evaluate the safety of a new cemented acetabular cup with Vitamin-E-doped PE regarding migration, head penetration and clinical results. In this single-centre, double-blinded, randomised controlled trial, we will include 50 patients with primary hip osteoarthritis scheduled for THA and randomise them in a 1:1 ratio to a cemented cup with either argon gas-sterilised PE (control group) or Vitamin-E-diffused PE (vitamin-e group). All patients and the assessor of the primary outcome will be blinded and the same uncemented stem will be used for all participants. The primary end point will be proximal migration of the cup at 2 years after surgery measured with radiostereometry. Secondary end points include proximal migration at other follow-ups, total migration, femoral head penetration, clinical outcome scores and hip-related complications. Patients will be followed up at 3 months and at 1, 2, 5 and 10 years postoperatively. Results will be analysed using 95% CIs for the effect size. A regression model will also be used to adjust for stratification factors. The ethical committee at Karolinska Institutet has approved the study. The first results from the study will be disseminated to the medical community via presentations and publications in relevant medical journals when the last patient included has been followed up for 2 years. NCT02254980. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  10. Influence of bone density on the cement fixation of femoral hip resurfacing components.

    Bitsch, Rudi G; Jäger, Sebastian; Lürssen, Marcus; Loidolt, Travis; Schmalzried, Thomas P; Clarius, Michael

    2010-08-01

    In clinical outcome studies, small component sizes, female gender, femoral shape, focal bone defects, bad bone quality, and biomechanics have been associated with failures of resurfacing arthroplasties. We used a well-established experimental setup and human bone specimens to analyze the effects of bone density on cement fixation of femoral hip resurfacing components. Thirty-one fresh frozen femora were prepared for resurfacing using the original instruments. ASR resurfacing prostheses were implanted after dual-energy X-ray densitometer scans. Real-time measurements of pressure and temperature during implantation, analyses of cement penetration, and measurements of micro motions under torque application were performed. The associations of bone density and measurement data were examined calculating regression lines and multiple correlation coefficients; acceptability was tested with ANOVA. We found significant relations between bone density and micro motion, cement penetration, cement mantle thickness, cement pressure, and interface temperature. Mean bone density of the femora was 0.82 +/- 0.13 g/cm(2), t-score was -0.7 +/- 1.0, and mean micro motion between bone and femoral resurfacing component was 17.5 +/- 9.1 microm/Nm. The regression line between bone density and micro motion was equal to -56.7 x bone density + 63.8, R = 0.815 (p density scans are most helpful for patient selection in hip resurfacing, and a better bone quality leads to higher initial component stability. A sophisticated cementing technique is recommended to avoid vigorous impaction and incomplete seating, since increasing bone density also results in higher cement pressures, lower cement penetration, lower interface temperatures, and thicker cement mantles. Copyright 2010 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  11. Impairment of resin cement application on the bond strength of indirect composite restorations

    Jovito Adiel SKUPIEN

    2015-01-01

    Full Text Available The aims of this study were to evaluate the effect of immediate and delayed resin cement application on the microtensile bond strength of indirect composite resin restorations and, to evaluate adhesive strategies (for regular resin cement or humidity parameters for self-adhesive resin cement. Forty-five enamel/dentin discs (0.5 mm height and 10 mm of diameter obtained from bovine teeth were divided into nine groups (n = 5. For regular cement, the variation factors were cementation technique at three levels (immediate cementation, 5 or 30 min after adhesive system application; and type of adhesive system at two levels (three- or two-step. For self-adhesive cement, the dentin moisture was the source of variation at three levels (normal, dry, or wet cementation. The specimens were submitted to microtensile bond strength (μTBS testing using a universal testing machine. Data were analyzed by ANOVA, Tukey’s test, and linear regression. Regular cement and three-step etch-and-rinse adhesive system showed the highest values of bond strength (25.21 MPa–30 min of delay. Only for this condition, three-step adhesive showed higher bond strength than the two-step adhesive. Nevertheless, the linear regression showed that irrespective of the strategy, the use of the two-step approach when compared with three-step adhesive system decreased μTBS (p < 0.001. The failure analysis showed predominant adhesive failures for all tested groups. All groups had comparable values of bond strength to bovine dentin when the same materials were used, even in suboptimal clinical conditions.

  12. Retention of long-term interim restorations with sodium fluoride enriched interim cement

    Strash, Carolyn

    Purpose: Interim fixed dental prostheses, or "provisional restorations", are fabricated to restore teeth when definitive prostheses are made indirectly. Patients undergoing extensive prosthodontic treatment frequently require provisionalization for several months or years. The ideal interim cement would retain the restoration for as long as needed and still allow for ease of removal. It would also avoid recurrent caries by preventing demineralization of tooth structure. This study aims to determine if adding sodium fluoride varnish to interim cement may assist in the retention of interim restorations. Materials and methods: stainless steel dies representing a crown preparation were fabricated. Provisional crowns were milled for the dies using CAD/CAM technology. Crowns were provisionally cemented onto the dies using TempBond NE and NexTemp provisional cements as well as a mixture of TempBond NE and Duraphat fluoride varnish. Samples were stored for 24h then tested or thermocycled for 2500 or 5000 cycles before being tested. Retentive strength of each cement was recorded using a universal testing machine. Results: TempBond NE and NexTemp cements performed similarly when tested after 24h. The addition of Duraphat significantly decreased the retention when added to TempBond NE. NexTemp cement had high variability in retention over all tested time periods. Thermocycling for 2500 and 5000 cycles significantly decreased the retention of all cements. Conclusions: The addition of Duraphat fluoride varnish significantly decreased the retention of TempBond NE and is therefore not recommended for clinical use. Thermocycling significantly reduced the retention of TempBond NE and NexTemp. This may suggest that use of these cements for three months, as simulated in this study, is not recommended.

  13. Tritium sorption by cement and subsequent release

    Ono, F.; Tanaka, S.; Yamawaki, M.

    1994-01-01

    In a fusion reactor or tritium handling facilities, contamination of concrete by tritium and subsequent release from it to the reactor or experimental rooms is a matter of problem for safety control of tritium and management of operational environment. In order to evaluate these tritium behavior, interaction of tritiated water with concrete or cement should be clarified. In the present study, HTO sorption and subsequent release from cement were studied by combining various experimental methods. From the basic studies on tritium-cement interactions, it has become possible to evaluate tritium uptake by cement or concrete and subsequent tritium release behavior as well as tritium removing methods from them

  14. Immobilisation of ion exchange resins in cement

    Howard, C.G.; Jolliffe, C.B.; Lee, D.J.

    1990-09-01

    The removal of activity from spent decontaminating solutions eg LOMI can be achieved using organic ion exchange resins. These resins can be successfully immobilised in cement based matrices. The optimum cement system contained 10% ordinary Portland cement 84% gg blast furnace slag, 6% microsilica with a water cement ratio of 0.5 and a dry resin loading of 36% with respect to total weight. This formulation was successfully scaled up to 200 litres giving a product with acceptable compressive strength, dimensional stability and elastic modulus. Storage of samples under water appears to have no detrimental effects on the product's properties. (author)

  15. Immobilisation of ion exchange resins in cement

    Howard, C.G.; Jolliffe, C.B.; Lee, D.J.

    1990-09-01

    The removal of activity from spent decontaminating solutions eg LOMI can be achieved using organic ion exchange resins. These resins can be successfully immobilised in cement based matrices. The optimum cement system contained 10% ordinary Portland cement, 84% gg blast furnace slag, 6% microsilica with a water cement ratio of 0.5 and a dry resin loading of 36% with respect to total weight. This formulation was successfully scaled up to 200 litres giving a product with acceptable compressive strength, dimensional stability and elastic modulus. Storage of samples under water appears to have no detrimental effects on the products' properties. (author)

  16. Use of rubber crumbs in cement concrete

    Longvinenko, A. A.

    2018-03-01

    Rubber crumb obtained from worn out tires has been increasingly used over the last 15-20 years, especially in manufacture of asphalt and cement concrete mixtures. This review pays principal attention to application of the rubber crumb to cement concrete mixtures. Use of the rubber crumb in cement concrete is not as successful as in asphalt concrete mixtures, due to incompatibility problems linked to chemical composition and a significant difference in rigidity between the rubber crumb and concrete mixture aggregates. Different methods are proposed and studied to mitigate the adverse influence and increase the beneficial effects of the rubber crumb when added to cement concrete.

  17. Controls on Cementation in a Chalk Reservoir

    Meireles, Leonardo Teixeira Pinto; Hussein, A.; Welch, M.J.

    2017-01-01

    In this study, we identify different controls on cementation in a chalk reservoir. Biot’s coefficient, a measure of cementation, stiffness and strength in porous rocks, is calculated from logging data (bulk density and sonic Pwave velocity). We show that Biot’s coefficient is correlated...... that some degree of pore filling cementation occurred in Kraka (Alam, 2010). Lack of correlation between Biot’s coefficient and Gamma Ray (GR) indicates that the small amount of clay present is generally located in the pore space, thus not contributing to frame stiffness. While there was no compositional...... control on cementation via clay, we could infer that stratigraphy impacts on the diagenetic process....

  18. Immobilisation of radwaste in cement based matrices

    Glasser, F.P.; Macphee, D.; Atkins, M.; Pointer, C.; Cowie, J.; Wilding, C.R.; Mattingley, N.J.; Evans, P.A.

    1989-01-01

    The solubilities and influence on cement pH are reported for calcium aluminate and aluminosulphate hydrates. The solubility of Ca(OH) 2 is reported to 700 bars. Polymerization of C-S-H is investigated by NMR. Specific interactions of U 6+ and iodine (I - , IO 3 - ) with cement components are described. The impact of radiation on cements and the influence of higher temperature are documented. The role of dissolved Ca and CO 2 in groundwaters as dissolution media for cements are reported. (author)

  19. Integer programming of cement distribution by train

    Indarsih

    2018-01-01

    Cement industry in Central Java distributes cement by train to meet daily demand in Yogyakarta and Central Java area. There are five destination stations. For each destination station, there is a warehouse to load cements. Decision maker of cement industry have a plan to redesign the infrastructure and transportation system. The aim is to determine how many locomotives, train wagons, and containers and how to arrange train schedules with subject to the delivery time. For this purposes, we consider an integer programming to minimize the total of operational cost. Further, we will discuss a case study and the solution the problem can be calculated by LINGO software.

  20. Prediction of hydroxyl concentrations in cement pore water using a numerical cement hydration model

    Eijk, van R.J.; Brouwers, H.J.H.

    2000-01-01

    In this paper, a 3D numerical cement hydration model is used for predicting alkali and hydroxyl concentrations in cement pore water. First, this numerical model is calibrated for Dutch cement employing both chemical shrinkage and calorimetric experiments. Secondly, the strength development of some

  1. Evaluation of cement thixotropy for the cement of oil wells in areas ...

    ... economical for cementing job operations in wells with loss zones. The results also show that the effect of LHF is positive, since in addition to his contribution to long term performances, especially the durability of hardened concrete, it improves the thixotropy of cement made of plaster. Keywords: cementing; lost circulation; ...

  2. Geotechnical Properties of Clayey Soil Stabilized with Cement ...

    ADOWIE PERE

    2017-12-31

    Dec 31, 2017 ... ... to investigate the different effects of cement-sawdust ash and cement on a ... Keywords: Cement, Saw dust, strength test subgrade material, highway construction ... characteristics of lateritic soil stabilized with sawdust ash.

  3. Pulp tissue response to Portland cement associated with different radio pacifying agents on pulpotomy of human primary molars.

    Marques, N; Lourenço Neto, N; Fernandes, A P; Rodini, C; Hungaro Duarte, M; Rios, D; Machado, M A; Oliveira, T

    2015-12-01

    The objective of this research was to evaluate the response of Portland cement associated with different radio pacifying agents on pulp treatment of human primary teeth by clinical and radiographic exams and microscopic analysis. Thirty mandibular primary molars were randomly divided into the following groups: Group I - Portland cement; Group II - Portland cement with iodoform (Portland cement + CHI3 ); Group III - Portland cement with zirconium oxide (Portland cement + ZrO2 ); and treated by pulpotomy technique (removal of a portion of the pulp aiming to maintain the vitally of the remaining radicular pulp tissue using a therapeutic dressing). Clinical and radiographic evaluations were recorded at 6, 12 and 24 months follow-up. The teeth at the regular exfoliation period were extracted and processed for histological analysis. Data were tested using statistical analysis with a significance level of 5%. The microscopic findings were descriptively analysed. All treated teeth were clinically and radiographically successful at follow-up appointments. The microscopic analysis revealed positive response to pulp repair with hard tissue barrier formation and pulp calcification in the remaining roots of all available teeth. The findings of this study suggest that primary teeth pulp tissue exhibited satisfactory biological response to Portland cement associated with radio pacifying agents. However, further studies with long-term follow-up are needed to determine the safe clinical indication of this alternative material for pulp therapy of primary teeth. © 2015 The Authors Journal of Microscopy © 2015 Royal Microscopical Society.

  4. Creep behavior of bone cement: a method for time extrapolation using time-temperature equivalence.

    Morgan, R L; Farrar, D F; Rose, J; Forster, H; Morgan, I

    2003-04-01

    The clinical lifetime of poly(methyl methacrylate) (PMMA) bone cement is considerably longer than the time over which it is convenient to perform creep testing. Consequently, it is desirable to be able to predict the long term creep behavior of bone cement from the results of short term testing. A simple method is described for prediction of long term creep using the principle of time-temperature equivalence in polymers. The use of the method is illustrated using a commercial acrylic bone cement. A creep strain of approximately 0.6% is predicted after 400 days under a constant flexural stress of 2 MPa. The temperature range and stress levels over which it is appropriate to perform testing are described. Finally, the effects of physical aging on the accuracy of the method are discussed and creep data from aged cement are reported.

  5. Treatment of a Vertical Root Fracture Using Dual-Curing Resin Cement: A Case Report

    Nima Moradi Majd

    2012-01-01

    Full Text Available Introduction. Vertical root fracture (VRF is one of the most frustrating complications of root canal treatment. The prognosis of the root with VRF is poor therefore tooth extraction and root amputation are usually the only treatment options. However, bonding of the fracture line with adhesive resin cement during the intentional replantation procedure was recently suggested as an alternative to tooth extraction. Methods. A vertically fractured left maxillary incisor was carefully extracted, fracture line was treated with adhesive resin cement, a retrograde cavity was produced and filled with calcium-enriched mixture (CEM cement, and tooth was replanted. Results. After 12 months the tooth was asymptomatic. The size of periapical radiolucency was noticeably reduced and there was no clinical sign of ankylosis. Conclusion. Using adhesive resin cement to bond the fracture lines extraorally in roots with VRF and intentional replantation of the reconstructed teeth could be considered as an alternative to tooth extraction, especially for anterior teeth.

  6. Human mesenchymal stem cells

    Abdallah, Basem; Kassem, Moustapha

    2008-01-01

    Mesenchymal stem cells (MSC) are a group of clonogenic cells present among the bone marrow stroma and capable of multilineage differentiation into mesoderm-type cells such as osteoblasts, adipocytes and chondrocytes. Due to their ease of isolation and their differentiation potential, MSC are being...... introduced into clinical medicine in variety of applications and through different ways of administration. Here, we discuss approaches for isolation, characterization and directing differentiation of human mesenchymal stem cells (hMSC). An update of the current clinical use of the cells is also provided....

  7. Clinical and Microbiological Characteristics of Breakthrough Candidemia in Allogeneic Hematopoietic Stem Cell Transplant Recipients in a Japanese Hospital

    Kimura, Muneyoshi; Yamamoto, Hisashi; Asano-Mori, Yuki; Nakamura, Shigeki; Yamagoe, Satoshi; Ohno, Hideaki; Miyazaki, Yoshitsugu; Abe, Masahiro; Yuasa, Mitsuhiro; Kaji, Daisuke; Kageyama, Kosei; Nishida, Aya; Ishiwata, Kazuya; Takagi, Shinsuke; Yamamoto, Go; Uchida, Naoyuki; Izutsu, Koji; Wake, Atsushi; Taniguchi, Shuichi; Yoneyama, Akiko

    2017-01-01

    ABSTRACT Few data on breakthrough candidemia (BC), defined as candidemia that develops on administration of antifungal agents (AFAs), in allogeneic hematopoietic stem cell transplant (allo-HSCT) recipients are available. The medical and microbiological records of recipients of an allo-HSCT obtained between December 2008 and December 2014 were reviewed. Of 768 allo-HSCT cases, 26 developed BC. Among the 26 causative strains, 22 strains were stored and identified by sequencing. The following species were isolated: Candida parapsilosis (9 strains), C. glabrata (4 strains), C. guilliermondii (3 strains), and other Candida species (6 strains). The AFAs being used when BC developed were micafungin (17 cases), liposomal amphotericin B (5 cases), itraconazole (2 cases), and voriconazole (2 cases). All 17 cases who developed BC during micafungin administration were administered 150 mg/day of micafungin. The susceptibilities of the causative Candida species to the administered AFAs when breakthrough occurred ranged from susceptible to resistant. Especially, 85% of the Candida species that caused BC during micafungin administration were susceptible to micafungin. Additionally, 75% of the strains were wild type for susceptibility to the administered AFAs when breakthrough occurred. Systemic steroid administration and a longer severe neutropenic phase (≥5 days) were independent risk factors for BC (P = 0.016 and P = 0.015, respectively). BC developed in allo-HSCT recipients even when they received a sufficient dose of AFA, including micafungin, to which the causative Candida species were susceptible and/or had wild-type susceptibility in vitro. Systemic steroid administration and a longer severe neutropenic phase were host-based factors associated with BC. PMID:28115352

  8. Distress and quality of life after autologous stem cell transplantation: a randomized clinical trial to evaluate the outcome of a web-based stepped care intervention

    Huijgens Peter C

    2010-07-01

    Full Text Available Abstract Background Psychological distress (i.e. depression and anxiety is a strong predictor of functional status and other aspects of quality of life in autologous stem cell transplantation following high-dose chemotherapy. Treatment of psychological distress is hypothesized to result in improvement of functional status and other aspects of quality of life. The aim is to evaluate the outcome of stepped care for psychological distress on functional status and other aspects of quality of life in patients with hematological malignancy treated with autologous stem cell transplantation. Methods/Design The study is designed as a randomized clinical trial with 2 treatment arms: a stepped care intervention program versus care as usual. Patients are randomized immediately pre transplant. Stepped care and care as usual are initiated after a 6 weeks buffer period. Outcome is evaluated at 13, 30, and 42 weeks post transplant. In the experimental group, the first step includes an Internet-based self-help program. If psychological distress persists after the self-help intervention, the second step of the program is executed, i.e. a diagnostic evaluation and a standardized interview, yielding a problem analysis. Based on this information, a contract is made with the patient and treatment is provided consisting of individual face-to-face counseling, medication, or referral to other services. Care as usual comprises an interview with the patient, on ad hoc basis; emotional support and advice, on ad hoc basis; if urgent problems emerge, the patient is referred to other services. Primary outcome variables are psychological distress and functional status. Data are analyzed according to the intention to treat-principle. Discussion This study has several innovative characteristics. First, the outcome of the intervention for psychological distress in patients with hematological malignancy treated with autologous stem cell transplantation is evaluated in a randomized

  9. Umbilical cord mesenchyme stem cell local intramuscular injection for treatment of uterine niche: Protocol for a prospective, randomized, double-blinded, placebo-controlled clinical trial.

    Fan, Dazhi; Wu, Shuzhen; Ye, Shaoxin; Wang, Wen; Guo, Xiaoling; Liu, Zhengping

    2017-11-01

    Uterine niche is defined as a triangular anechoic structure at the site of the scar or a gap in the myometrium at the site of a previous caesarean section. The main clinical manifestations are postmenstrual spotting and intrauterine infection, which may seriously affect the daily life of nonpregnant women. Trials have shown an excellent safety and efficacy for the potential of mesenchymal stem cells (MSCs) as a therapeutic option for scar reconstruction. Therefore, this study is designed to investigate the safety and efficacy of using MSCs in the treatment for the uterine niche. This phase II clinical trial is a single-center, prospective, randomized, double-blind, placebo-controlled with 2 arms. One hundred twenty primiparous participants will be randomly (1:1 ratio) assigned to receive direct intramuscular injection of MSCs (a dose of 1*10 cells in 1 mL of 0.9% saline) (MSCs group) or an identical-appearing 1 mL of 0.9% saline (placebo-controlled group) near the uterine incision. The primary outcome of this trial is to evaluate the proportion of participants at 6 months who is found uterine niche in the uterus by transvaginal utrasonography. Adverse events will be documented in a case report form. The study will be conducted at the Department of Obstetric of Southern Medical University Affiliated Maternal & Child Health Hospital of Foshan. This trial is the first investigation of the potential for therapeutic use of MSCs for the management of uterine niche after cesarean delivery. This protocol will help to determine the efficacy and safety of MSCs treatment in uterine niche and bridge the gap with regards to the current preclinical and clinical evidence. NCT02968459 (Clinical Trials.gov: http://clinicaltrials.gov/).

  10. The effect of isolation and culture methods on epithelial stem cell populations and their progeny-toward an improved cell expansion protocol for clinical application.

    Lenihan, Catherine; Rogers, Caroline; Metcalfe, Anthony D; Martin, Yella H

    2014-12-01

    The use of cultured epithelial keratinocytes in the treatment of burns and skin graft donor sites is well established in clinical practice. The most widely used culture method for clinical use was originally developed by Rheinwald and Green 40 years ago. This system uses irradiated mouse dermal fibroblasts as a feeder cell layer to promote keratinocyte growth, a process that is costly and labor-intensive for health care providers. The medium formulation contains several components of animal origin, which pose further safety risks for patients. Improvements and simplification in the culturing process would lead to clear advantages: improved safety through reduction of xenobiotic components and reduction in cost for health care providers by dispensing with feeder cells. We compared the Rheinwald and Green method to culture in three commercially available, feeder-free media systems with defined/absent components of animal origin. During the isolation process, short incubation times in high-strength trypsin resulted in increased numbers of liberated keratinocyte stem cells compared with longer incubation times. All three commercially available media tested in this study could support the expansion of keratinocytes, with phenotypes comparable to cells expanded using the established Rheinwald and Green method. Growth rates varied, with two of the media displaying comparable growth rates, whereas the third was significantly slower. Our study demonstrates the suitability of such feeder-free media systems in clinical use. It further outlines a range of techniques to evaluate keratinocyte phenotype when assessing the suitability of cells for clinical application. Copyright © 2014 International Society for Cellular Therapy. Published by Elsevier Inc. All rights reserved.

  11. Pooled human platelet lysate versus fetal bovine serum—investigating the proliferation rate, chromosome stability and angiogenic potential of human adipose tissue-derived stem cells intended for clinical use

    Trojahn Kølle, Stig-Frederik; Oliveri, Roberto S; Glovinski, Peter V

    2013-01-01

    Because of an increasing focus on the use of adipose-derived stem cells (ASCs) in clinical trials, the culture conditions for these cells are being optimized. We compared the proliferation rates and chromosomal stability of ASCs that had been cultured in Dulbecco's modified Eagle's Medium (DMEM) ......) supplemented with either pooled human platelet lysate (pHPL) or clinical-grade fetal bovine serum (FBS) (DMEM(pHPL) versus DMEM(FBS))....

  12. Overcoming the bottleneck of platelet lysate supply in large-scale clinical expansion of adipose-derived stem cells

    Glovinski, Peter Viktor; Herly, Mikkel; Mathiasen, Anders B

    2017-01-01

    , we tested PLs prepared via three methods from outdated buffy coat-derived platelet concentrates (PCs) to establish an efficient and feasible expansion of ASCs for clinical use. METHODS: PLs were prepared by the freeze-thaw method from freshly drawn platelets or from outdated buffy coat-derived PCs...

  13. Re-using blood products as an alternative supplement in the optimisation of clinical-grade adipose-derived mesenchymal stem cell culture

    Phetfong, J.; Tawonsawatruk, T.; Seenprachawong, K.; Srisarin, A.; Isarankura-Na-Ayudhya, C.

    2017-01-01

    Objectives Adipose-derived mesenchymal stem cells (ADMSCs) are a promising strategy for orthopaedic applications, particularly in bone repair. Ex vivo expansion of ADMSCs is required to obtain sufficient cell numbers. Xenogenic supplements should be avoided in order to minimise the risk of infections and immunological reactions. Human platelet lysate and human plasma may be an excellent material source for ADMSC expansion. In the present study, use of blood products after their recommended transfusion date to prepare human platelet lysate (HPL) and human plasma (Hplasma) was evaluated for in vitro culture expansion and osteogenesis of ADMSCs. Methods Human ADMSCs were cultured in medium supplemented with HPL, Hplasma and a combination of HPL and Hplasma (HPL+Hplasma). Characteristics of these ADMSCs, including osteogenesis, were evaluated in comparison with those cultured in fetal bovine serum (FBS). Results HPL and HPL+Hplasma had a significantly greater growth-promoting effect than FBS, while Hplasma exhibited a similar growth-promoting effect to that of FBS. ADMSCs cultured in HPL and/or Hplasma generated more colony-forming unit fibroblasts (CFU-F) than those cultured in FBS. After long-term culture, ADMSCs cultured in HPL and/or Hplasma showed reduced cellular senescence, retained typical cell phenotypes, and retained differentiation capacities into osteogenic and adipogenic lineages. Conclusion HPL and Hplasma prepared from blood products after their recommended transfusion date can be used as an alternative and effective source for large-scale ex vivo expansion of ADMSCs. Cite this article: J. Phetfong, T. Tawonsawatruk, K. Seenprachawong, A. Srisarin, C. Isarankura-Na-Ayudhya, A. Supokawej. Re-using blood products as an alternative supplement in the optimisation of clinical-grade adipose-derived mesenchymal stem cell culture. Bone Joint Res 2017;6:414–422. DOI: 10.1302/2046-3758.67.BJR-2016-0342.R1. PMID:28720606

  14. Strength Characteristics of Groundnut Leaf/Stem Ash (GLSA Concrete

    Oseni O. W.

    2016-09-01

    Full Text Available The compressive strength properties of concrete are substantial factors in the design and construction of concrete structures. Compressive strength directly affects the degree to which the concrete can be able to carry a load over time. These changes are complemented by deflections, cracks etc., in the structural elements of concrete. This research investigated the effect of groundnut leaf/stem ash (GLSA on the compressive strength of concrete at 0%, 5 %, 10 % and 15 % replacements of cement. The effect of the water-cement ratio on properties such as the compressive strength, slump, flow and workability properties of groundnut leaf/stem ash (GLSA mixes with OPC were evaluated to determine whether they are acceptable for use in concrete structural elements. A normal concrete mix with cement at 100 % (i.e., GLSA at 0% with concrete grade C25 that can attain an average strength of 25 N/mm2 at 28 days was used as a control at design water-cement ratios of 0.65 and grading of (0.5-32 mm from fine to coarse aggregates was tested for: (1 compressive strength, and the (2 slump and flow Test. The results and observations showed that the concrete mixes from GLSA at 5 – 15 % ratios exhibit: pozzolanic properties and GLSA could be used as a partial replacement for cement at these percentage mix ratios compared with the control concrete; an increase in the water-cement ratio showed a significant decrease in the compressive strength and an increase in workability. Therefore, it is important that all concrete mixes exude an acceptably designed water-cement ratio for compressive strength characteristics for use in structures, water-cement ratio is a significant factor.

  15. Strength Characteristics of Groundnut Leaf/Stem Ash (GLSA) Concrete

    Oseni, O. W.; Audu, M. T.

    2016-09-01

    The compressive strength properties of concrete are substantial factors in the design and construction of concrete structures. Compressive strength directly affects the degree to which the concrete can be able to carry a load over time. These changes are complemented by deflections, cracks etc., in the structural elements of concrete. This research investigated the effect of groundnut leaf/stem ash (GLSA) on the compressive strength of concrete at 0%, 5 %, 10 % and 15 % replacements of cement. The effect of the water-cement ratio on properties such as the compressive strength, slump, flow and workability properties of groundnut leaf/stem ash (GLSA) mixes with OPC were evaluated to determine whether they are acceptable for use in concrete structural elements. A normal concrete mix with cement at 100 % (i.e., GLSA at 0%) with concrete grade C25 that can attain an average strength of 25 N/mm2 at 28 days was used as a control at design water-cement ratios of 0.65 and grading of (0.5-32) mm from fine to coarse aggregates was tested for: (1) compressive strength, and the (2) slump and flow Test. The results and observations showed that the concrete mixes from GLSA at 5 - 15 % ratios exhibit: pozzolanic properties and GLSA could be used as a partial replacement for cement at these percentage mix ratios compared with the control concrete; an increase in the water-cement ratio showed a significant decrease in the compressive strength and an increase in workability. Therefore, it is important that all concrete mixes exude an acceptably designed water-cement ratio for compressive strength characteristics for use in structures, water-cement ratio is a significant factor.

  16. Clinical Trial of Human Fetal Brain-Derived Neural Stem/Progenitor Cell Transplantation in Patients with Traumatic Cervical Spinal Cord Injury

    Ji Cheol Shin

    2015-01-01

    Full Text Available In a phase I/IIa open-label and nonrandomized controlled clinical trial, we sought to assess the safety and neurological effects of human neural stem/progenitor cells (hNSPCs transplanted into the injured cord after traumatic cervical spinal cord injury (SCI. Of 19 treated subjects, 17 were sensorimotor complete and 2 were motor complete and sensory incomplete. hNSPCs derived from the fetal telencephalon were grown as neurospheres and transplanted into the cord. In the control group, who did not receive cell implantation but were otherwise closely matched with the transplantation group, 15 patients with traumatic cervical SCI were included. At 1 year after cell transplantation, there was no evidence of cord damage, syrinx or tumor formation, neurological deterioration, and exacerbating neuropathic pain or spasticity. The American Spinal Injury Association Impairment Scale (AIS grade improved in 5 of 19 transplanted patients, 2 (A → C, 1 (A → B, and 2 (B → D, whereas only one patient in the control group showed improvement (A → B. Improvements included increased motor scores, recovery of motor levels, and responses to electrophysiological studies in the transplantation group. Therefore, the transplantation of hNSPCs into cervical SCI is safe and well-tolerated and is of modest neurological benefit up to 1 year after transplants. This trial is registered with Clinical Research Information Service (CRIS, Registration Number: KCT0000879.

  17. Multipotent Mesenchymal Stromal Stem Cell Expansion by Plating Whole Bone Marrow at a Low Cellular Density: A More Advantageous Method for Clinical Use

    Katia Mareschi

    2012-01-01

    Full Text Available Mesenchymal stem cells (MSCs are a promising source for cell therapy due to their pluripotency and immunomodulant proprieties. As the identification of “optimal” conditions is important to identify a standard procedure for clinical use. Percoll, Ficoll and whole bone marrow directly plated were tested from the same sample as separation methods. The cells were seeded at the following densities: 100 000, 10 000, 1000, 100, 10 cells/cm2. After reaching confluence, the cells were detached, pooled and re-plated at 1000, 500, 100, and 10 cells/cm2. Statistical analyses were performed. Cumulative Population Doublings (PD did not show significant differences for the separation methods and seeding densities but only for the plating density. Some small quantity samples plated in T25 flasks at plating densities of 10 and 100 cells/cm2 did not produce any expansion. However, directly plated whole bone marrow resulted in a more advantageous method in terms of CFU-F number, cellular growth and minimal manipulation. No differences were observed in terms of gross morphology, differentiation potential or immunophenotype. These data suggest that plating whole bone marrow at a low cellular density may represent a good procedure for MSC expansion for clinical use.

  18. Multipotent Mesenchymal Stromal Stem Cell Expansion by Plating Whole Bone Marrow at a Low Cellular Density: A More Advantageous Method for Clinical Use

    Mareschi, Katia; Rustichelli, Deborah; Calabrese, Roberto; Gunetti, Monica; Sanavio, Fiorella; Castiglia, Sara; Risso, Alessandra; Ferrero, Ivana; Tarella, Corrado; Fagioli, Franca

    2012-01-01

    Mesenchymal stem cells (MSCs) are a promising source for cell therapy due to their pluripotency and immunomodulant proprieties. As the identification of “optimal” conditions is important to identify a standard procedure for clinical use. Percoll, Ficoll and whole bone marrow directly plated were tested from the same sample as separation methods. The cells were seeded at the following densities: 100 000, 10 000, 1000, 100, 10 cells/cm2. After reaching confluence, the cells were detached, pooled and re-plated at 1000, 500, 100, and 10 cells/cm2. Statistical analyses were performed. Cumulative Population Doublings (PD) did not show significant differences for the separation methods and seeding densities but only for the plating density. Some small quantity samples plated in T25 flasks at plating densities of 10 and 100 cells/cm2 did not produce any expansion. However, directly plated whole bone marrow resulted in a more advantageous method in terms of CFU-F number, cellular growth and minimal manipulation. No differences were observed in terms of gross morphology, differentiation potential or immunophenotype. These data suggest that plating whole bone marrow at a low cellular density may represent a good procedure for MSC expansion for clinical use. PMID:23715383

  19. HDAC inhibitor-loaded bone cement for advanced local treatment of osteosarcoma and chondrosarcoma.

    Tonak, Marcus; Becker, Marc; Graf, Claudine; Eckhard, Lukas; Theobald, Matthias; Rommens, Pol-Maria; Wehler, Thomas C; Proschek, Dirk

    2014-11-01

    The treatment of osteosarcoma, especially wide resection, is challenging. An additional local drug therapy after resection using anti-neoplastic bone cement (Polymethylmethacrylate (PMMA)) could help improve the outcome of therapy. In this study, we evaluated the effects of PMMA loaded with valproic acid (VPA) and suberoylanilide hydroxamic acid (SAHA) on the cell activity of a SaOs-2 cell culture, as well as the elution rate of the drugs out of the bone cement. In our experiments, we used the SaOs-2 osteosarcoma and the SW1353 chondrosarcoma cell line. Bone cement clots (5 g) were prepared and loaded with different drug concentrations of VPA (25 mg and 50 mg) and SAHA (1 mg, 2.5 mg and 5 mg). Two control groups were established, one with a native cement clot, the other with human mesenchymal stem cells, in order to evaluate toxicity on non tumor-cells. Cell activity was measured using an Alamar Blue assay on days 1, 2, 3, 4 and 7. The cement clots were additionally examined in a material testing unit for biomechanical and structural changes. Tumor cells showed a significant and complete reduction of activity under therapy with VPA and SAHA. Drug release of VPA was extensive between days 0 and 3 and decreased progressively to day 7. Cumulative drug concentration in the medium continuously increased. Biomechanical testing of the cement clots showed no differences in stability and architecture compared to the control group. SaOs-2 and SW1353 cells with medium from native cement clots without drug therapy presented a cell activity of 100% in all groups and during all measurements. Human mesenchymal stem cells were not significantly affected during therapy with VPA and low concentrations of SAHA. In contrast, cell activity of human mesenchymal stem cells was significantly reduced under therapy with higher concentrations of SAHA, with an approximately linear decrease between days 0-3 and a rapidly decreasing activity between days 4-7. A local cytotoxic therapy in the

  20. Rietveld analysis, powder diffraction and cement

    Peterson, V.

    2002-01-01

    Full text: Phase quantification of cement is essential in its industrial use, however many methods are inaccurate and/or time consuming. Powder diffraction is one of the more accurate techniques used for quantitative phase analysis of cement. There has been an increase in the use of Rietveld refinement and powder diffraction for the analysis and phase quantification of cement and its components in recent years. The complex nature of cement components, existence of solid solutions, polymorphic variation of phases and overlapping phase peaks in diffraction patterns makes phase quantification of cements by powder diffraction difficult. The main phase in cement is alite, a solid solution of tricalcium silicate. Tricalcium silicate has been found to exist in seven modifications in three crystal systems, including triclinic, monoclinic, and rhombohedral structures. Hence, phase quantification of cements using Rietveld methods usually involves the simultaneous modelling of several tricalcium silicate structures to fit the complex alite phase. An industry ordinary Portland cement, industry and standard clinker, and a synthetic tricalcium silicate were characterised using neutron, laboratory x-ray and synchrotron powder diffraction. Diffraction patterns were analysed using full-profile Rietveld refinement. This enabled comparison of x-ray, neutron and synchrotron data for phase quantification of the cement and examination of the tricalcium silicate. Excellent Rietveld fits were achieved, however the results showed that the quantitative phase analysis results differed for some phases in the same clinker sample between various data sources. This presentation will give a short introduction about cement components including polymorphism, followed by the presentation of some problems in phase quantification of cements and the role of Rietveld refinement in solving these problems. Copyright (2002) Australian X-ray Analytical Association Inc

  1. Compressive Strength and Physical Properties Behavior of Cement Mortars with addition of Cement Klin Dust

    Auday A Mehatlaf

    2017-01-01

    Cement Klin Dust (CKD) was the waste of almost cement industry factories, so that in this paper utilization of CKD as filler in cement and/or concrete was the main objective. CKD from the Karbala cement factory had been used and analysis to know the chemical composition of the oxides was done. In this paper cement mortars with different weight percentages of CKD (0,5,10,20,30,40) had been prepared. Physical properties such as density and porosity were done in different age curing (3, 7, 28) d...

  2. A Study on the Manufacturing Properties of Crack Self-Healing Capsules Using Cement Powder for Addition to Cement Composites

    Choi, Yun-Wang; Oh, Sung-Rok; Choi, Byung-Keol

    2017-01-01

    We fabricated crack self-healing capsules using cement powder for mixing into cement composites and evaluated the properties of the capsule manufacturing process in this study. The manufacture of the self-healing capsules is divided into core production processing of granulating cement in powder form and a coating process for creating a wall on the surfaces of the granulated cement particles. The produced capsules contain unhardened cement and can be mixed directly with the cement composite m...

  3. Analysis of Chemical Composition of Portland Cement in Ghana: A Key to Understand the Behavior of Cement

    Bediako, Mark; Amankwah, Eric Opoku

    2015-01-01

    The performance of Portland cement in concrete or mortar formation is very well influenced by chemical compositions among other factors. Many engineers usually have little information on the chemical compositions of cement in making decisions for the choice of commercially available Portland cement in Ghana. This work analyzed five different brands of Portland cement in Ghana, namely, Ghacem ordinary Portland cement (OPC) and Portland limestone cement (PLC), CSIR-BRRI Pozzomix, Dangote OPC, a...

  4. Influence of Cements Containing Calcareous Fly Ash as a Main Component Properties of Fresh Cement Mixtures

    Gołaszewski, Jacek; Kostrzanowska-Siedlarz, Aleksandra; Ponikiewski, Tomasz; Miera, Patrycja

    2017-10-01

    The main goal of presented research was to examine usability of cements containing calcareous fly ash (W) from technological point of view. In the paper the results of tests concerning the influence of CEM II and CEM IV cements containing fly ash (W) on rheological properties, air content, setting times and plastic shrinkage of mortars are presented and discussed. Moreover, compatibility of plasticizers with cements containing fly ash (W) was also studied. Additionally, setting time and hydration heat of cements containing calcareous fly ash (W) were determined. In a broader aspect, the research contributes to promulgation of the possibility of using calcareous fly ash (W) in cement and concrete technology, what greatly benefits the environment protection (utilization of waste fly ash). Calcareous fly ash can be used successfully as the main component of cement. Cements produced by blending with processed fly ash or cements produced by interginding are characterized by acceptable technological properties. In respect to CEM I cements, cements containing calcareous fly ash worsen workability, decrease air content, delay setting time of mixtures. Cements with calcareous fly ash show good compatibility with plasticizers.

  5. Thermo-cured glass ionomer cements in restorative dentistry.

    Gorseta, Kristina; Glavina, Domagoj

    2017-01-01

    Numerous positive properties of glass ionomer cements including biocompatibility, bioactivity, releasing of fluoride and good adhesion to hard dental tissue even under wet conditions and easy of handling are reasons for their wide use in paediatric and restorative dentistry. Their biggest drawbacks are the weaker mechanical properties. An important step forward in improving GIC's features is thermo-curing with the dental polymerization unit during setting of the material. Due to their slow setting characteristics the GIC is vulnerable to early exposure to moisture. After thermo curing, cements retain all the benefits of GIC with developed better mechanical properties, improved marginal adaptation, increased microhardness and shear bond strength. Adding external energy through thermocuring or ultrasound during the setting of conventional GIC is crucial to achieve faster and better initial mechanical properties. Further clinical studies are needed to confirm these findings.

  6. Stem cells in dentistry--part I: stem cell sources.

    Egusa, Hiroshi; Sonoyama, Wataru; Nishimura, Masahiro; Atsuta, Ikiru; Akiyama, Kentaro

    2012-07-01

    Stem cells can self-renew and produce different cell types, thus providing new strategies to regenerate missing tissues and treat diseases. In the field of dentistry, adult mesenchymal stem/stromal cells (MSCs) have been identified in several oral and maxillofacial tissues, which suggests that the oral tissues are a rich source of stem cells, and oral stem and mucosal cells are expected to provide an ideal source for genetically reprogrammed cells such as induced pluripotent stem (iPS) cells. Furthermore, oral tissues are expected to be not only a source but also a therapeutic target for stem cells, as stem cell and tissue engineering therapies in dentistry continue to attract increasing clinical interest. Part I of this review outlines various types of intra- and extra-oral tissue-derived stem cells with regard to clinical availability and applications in dentistry. Additionally, appropriate sources of stem cells for regenerative dentistry are discussed with regard to differentiation capacity, accessibility and possible immunomodulatory properties. Copyright © 2012 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

  7. The influence of cement type and temperature on chloride binding in cement paste

    Jensen, Ole Mejlhede; Korzen, Migge Sofie Hoffmann; Skibsted, Jørgen

    1998-01-01

    This paper describes effects of cement type and temperature on chloride binding in cement paste, which is an important subject in relation to life-time modelling of reinforced concrete structures. The influence of cement type on chloride binding is investigated by substituting cement with pure...... cement clinker. Both theoretical considerations and experimental data for chloride binding in cement pastes are presented. A physico-chemically based model to describe the influence of temperature on physical binding of chloride is presented. Solid-state 27Al and 29Si magic-angle spinning (MAS) nuclear...... magnetic resonance (NMR) spectroscopy has been used for quantification of the anhydrous and hydrated aluminate and silicate phases in the chloride exposed cement pastes. The 27Al isotropic chemical shift and nuclear quadrupole coupling is reported for a synthetic sample of Friedel's salt, Ca2Al(OH)6Cl×2H2O....

  8. Feasibility of producing nano cement in a traditional cement factory in Iraq

    Sada Abdalkhaliq Hasan Alyasri

    2017-12-01

    Full Text Available This study investigates the economic feasibility of producing nano cement through the establishment of a production line within an existing cement factory. Creating a nano cement production line within the Alkufa Cement factory in Iraq is selected as a case study. Evaluation measures including internal rate of return (IRR, net present value (NPV and breakeven point (BEP are used to evaluate the possible gain that can be achieved from this option. The results demonstrated a positive NPV. The IRR is found to be 26.8% and BEP is reached within 3 years after the establishment of the line. This indicates that producing nano cement in the existing cement factory is economically feasible and can be more advantageous than the ordinary cement.

  9. Is it cement to be? Downhole cement that uses zeolite additive may offer lightweight alternative

    Mahoney, J.

    2001-05-01

    C2C Zeolite Corporation produces zeolites from a large deposit near Cache Creek, British Columbia, and processes them for use as an additive in downhole cement well casings. Early research indicates that zeolites can significantly improve the way downhole cement is made in the oil industry. Zeolites are made up mostly of silicates of aluminum and calcium. They have a great ability to absorb water, resulting in a lighter and more fluid cement than is currently available. C2C claims that zeolites will reduce cement weight, column pressure and operator costs. The cost benefits of using lighter cement downhole includes easier moving, processing and handling of the mix. Initial research suggests that zeolites might prove to be viable alternatives to other cement lighteners such as silica fumes or flyash. Zeolite-based cement also performed reasonably well in freeze-thaw tests and showed good adhesion and no evidence of shrinkage in downhole tests. 3 figs.

  10. Cements in radioactive waste management. Characterization requirements of cement products for acceptance and quality assurance purposes

    Rahman, A.A.; Glasser, F.P.

    1987-01-01

    Cementitious materials are used as immobilizing matrices for low (LLW) and medium-level wastes (MLW) and are also components of the construction materials in the secondary barriers and the repositories. This report has concerned itself with a critical assessment of the quality assurance aspects of the immobilization and disposal of MLW and LLW cemented wastes. This report has collated the existing knowledge of the use and potential of cementitious materials in radioactive waste immobilization and highlighted the physico-chemical parameters. Subject areas include an assessment of immobilization objectives and cement as a durable material, waste stream and matrix characterization, quality assurance concepts, nature of cement-based systems, chemistry and modelling of cement hydration, role and effect of blending agents, radwaste-cement interaction, assessment of durability, degradative and radiolytic processes in cements and the behaviour of cement-based matrices and their near-field interactions with the environment and the repository conditions

  11. Shrinkage Properties of Cement Stabilized Gravel

    Lund, Mia Schou Møller; Hansen, Kurt Kielsgaard

    2014-01-01

    Cement stabilized gravel is an attractive material in road construction because its strength prop-erties are accommodating the increasingly higher requirements to the bearing capacity of a base course. However, reflection cracking of cement stabilized gravel is a major concern. In this pa...

  12. Development and design of a cementation process

    Vicente, R.

    1986-01-01

    The conceptual design of a facility for the immobilization of intermediate level liquid waste in cement is presented. The cementation process adopted a vibration assisted mixing process. The solidified waste is packed in 200 litres drum with barite concrete lining. The waste package is classified as Type A package for transport. (Author) [pt

  13. Development and design of a cementation process

    Vicente, R.

    1987-01-01

    The conceptual design of a facility for the immobilization of intermediate-level liquid wastes in cement is presented. The cementation process adopted a vibration assisted mixing process. The solidified waste is packed in 200 litres drum with barite concrete lining. The waste package is classified as Type A package for transport. (Author) [pt

  14. Investigation of a Hardened Cement Paste Grout

    Esteves, Luis Pedro; Sørensen, Eigil Verner

    This report documents a series of tests performed on a hardened cement paste grout delivered by the client, Det Norske Veritas A/S.......This report documents a series of tests performed on a hardened cement paste grout delivered by the client, Det Norske Veritas A/S....

  15. Chloride ingress in cement paste and mortar

    Jensen, Ole Mejlhede; Hansen, Per Freiesleben; Coats, Alison M.

    1999-01-01

    In this paper chloride ingress in cement paste and mortar is followed by electron probe microanalysis. The influence of several paste and exposure parameters on chloride ingress are examined (e.g., water-cement ratio, silica fume addition, exposure time, and temperature), The measurements...

  16. Basic Chemistry for the Cement Industry.

    Turner, Mason

    This combined student workbook and instructor's guide contains nine units for inplant classes on basic chemistry for employees in the cement industry. The nine units cover the following topics: chemical basics; measurement; history of cement; atoms; bonding and chemical formulas; solids, liquids, and gases; chemistry of Portland cement…

  17. Facial skeletal augmentation using hydroxyapatite cement.

    Shindo, M L; Costantino, P D; Friedman, C D; Chow, L C

    1993-02-01

    This study investigates the use of a new calcium phosphate cement, which sets to solid, microporous hydroxyapatite, for facial bone augmentation. In six dogs, the supraorbital ridges were augmented bilaterally with this hydroxyapatite cement. On one side, the hydroxyapatite cement was placed directly onto the bone within a subperiosteal pocket. On the opposite side, the cement was contained within a collagen membrane tubule and then inserted into a subperiosteal pocket. The use of collagen tubules facilitated easy, precise placement of the cement. All implants maintained their original augmented height throughout the duration of the study. They were well tolerated without extrusion or migration, and there was no significant sustained inflammatory response. Histologic studies, performed at 3, 6, and 9 months revealed that when the cement was placed directly onto bone, progressive replacement of the implant by bone (osseointegration of the hydroxyapatite with the underlying bone) without a loss of volume was observed. In contrast, when the cement-collagen tubule combination was inserted, primarily a fibrous union was noted. Despite such fibrous union, the hydroxyapatite-collagen implant solidly bonded to the underlying bone, and no implant resorption was observed. Hydroxyapatite cement can be used successfully for the experimental augmentation of the craniofacial skeleton and may be applicable for such uses in humans.

  18. Elaborating the History of Our Cementing Societies

    Cao, Zhi; Shen, Lei; Løvik, Amund N.

    2017-01-01

    Modern cities and societies are built fundamentally based on cement and concrete. The global cement production has risen sharply in the past decades due largely to urbanization and construction. Here we deployed a top-down dynamic material flow analysis (MFA) model to quantify the historical deve...

  19. TECHNOLOGICAL CHANGES IN THE CEMENT MANUFACTURING INDUSTRY.

    WESSON, CARL E.

    THE PURPOSE OF THIS STUDY IS TO PRESENT A PRELIMINARY PICTURE OF OCCUPATIONAL CHANGES BROUGHT ABOUT IN THE MANUFACTURE OF CEMENT AS A RESULT OF INTRODUCING AUTOMATED EQUIPMENT. ONE AUTOMATED AND SEVERAL CONVENTIONAL TYPE CEMENT PLANTS WERE STUDIED. ANALYSIS OF DATA OBTAINED THROUGH RESEARCH AND DATA COLLECTED DURING THE STUDY REVEALED THAT…

  20. Pre-portland cements and geopolymers

    Hanzlíček, Tomáš; Perná, Ivana; Ertl, Z.; Miller, S.M.

    2012-01-01

    Roč. 9, č. 1 (2012), s. 57-62 ISSN 1214-9705 Institutional research plan: CEZ:AV0Z30460519 Keywords : caementum * cement itious * calcareous cement Subject RIV: JN - Civil Engineering Impact factor: 0.530, year: 2011 http://www.irsm.cas.cz/materialy/acta_content/2012_01/5_Hanzlicek.pdf