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Sample records for tissue repair process

  1. Kinetics and tissue repair process following fractional bipolar radiofrequency treatment.

    Science.gov (United States)

    Kokolakis, G; von Eichel, L; Ulrich, M; Lademann, J; Zuberbier, T; Hofmann, M A

    2018-05-15

    Fractionated radiofrequency (RF) tissue tightening is an alternative method to fractionated laser treatment of skin wrinkling, laxity and acne scars, with reduced risk of scarring or persistent pigmentation. The aim of this study was to evaluate and quantify the wound healing process after RF treatment. 12 patients were treated with a 64-pin fractional bipolar RF device with 60 mJ/pin applied energy. Confocal laser scanning microscopy (CLSM) examination was performed on day 1, day 2, day 7 and day 14 after treatment. Clinical wound healing process was measured and expressed as a percentage. All patients developed erythema, mild edema and crusts at the treated areas. Two weeks after treatment clinical symptoms resolved. During ablation patients reported moderate pain. Directly after ablation microscopic ablation zones could be detected in CLSM. Measurement of MAZ at epidermis, dermo-epidermal junction and papilary dermis showed a constant diameter until two weeks after treatment. Re-epithelization of the MAZ could be detected already 1 week after treatment. However, 2 weeks after ablation the honeycomb pattern of the epidermis was not yet completely restored. Bipolar fractionated RF treatment demonstrates clinically a rapid wound healing response. The subepidermal remodelling process still ongoing after 14 days, showing new granulation tissue. Therefore, treatment intervals of at least 14 days should be recommended to allow completion of the remodelling process.

  2. Repair kinetics in tissues

    International Nuclear Information System (INIS)

    Thames, H.D.

    1989-01-01

    Monoexponential repair kinetics is based on the assumption of a single, dose-independent rate of repair of sublethal injury in the target cells for tissue injury after exposure to ionizing radiation. Descriptions of the available data based on this assumption have proved fairly successful for both acutely responding (skin, lip mucosa, gut) and late-responding (lung, spinal cord) normal tissues. There are indications of biphasic exponential repair in both categories, however. Unfortunately, the data usually lack sufficient resolution to permit unambiguous determination of the repair rates. There are also indications that repair kinetics may depend on the size of the dose. The data are conflicting on this account, however, with suggestions of both faster and slower repair after larger doses. Indeed, experiments that have been explicitly designed to test this hypothesis show either no effect (gut, spinal cord), faster repair after higher doses (lung, kidney), or slower repair after higher doses (skin). Monoexponential repair appears to be a fairly accurate description that provides an approximation to a more complicated picture, the elucidation of whose details will, however, require very careful and extensive experimental study. (author). 30 refs.; 1 fig

  3. Repair process and a repaired component

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, III, Herbert Chidsey; Simpson, Stanley F.

    2018-02-20

    Matrix composite component repair processes are disclosed. The matrix composite repair process includes applying a repair material to a matrix composite component, securing the repair material to the matrix composite component with an external securing mechanism and curing the repair material to bond the repair material to the matrix composite component during the securing by the external securing mechanism. The matrix composite component is selected from the group consisting of a ceramic matrix composite, a polymer matrix composite, and a metal matrix composite. In another embodiment, the repair process includes applying a partially-cured repair material to a matrix composite component, and curing the repair material to bond the repair material to the matrix composite component, an external securing mechanism securing the repair material throughout a curing period, In another embodiment, the external securing mechanism is consumed or decomposed during the repair process.

  4. Turbine repair process, repaired coating, and repaired turbine component

    Science.gov (United States)

    Das, Rupak; Delvaux, John McConnell; Garcia-Crespo, Andres Jose

    2015-11-03

    A turbine repair process, a repaired coating, and a repaired turbine component are disclosed. The turbine repair process includes providing a turbine component having a higher-pressure region and a lower-pressure region, introducing particles into the higher-pressure region, and at least partially repairing an opening between the higher-pressure region and the lower-pressure region with at least one of the particles to form a repaired turbine component. The repaired coating includes a silicon material, a ceramic matrix composite material, and a repaired region having the silicon material deposited on and surrounded by the ceramic matrix composite material. The repaired turbine component a ceramic matrix composite layer and a repaired region having silicon material deposited on and surrounded by the ceramic matrix composite material.

  5. Repair and regeneration: opportunities for carcinogenesis from tissue stem cells

    OpenAIRE

    Perryman, Scott V; Sylvester, Karl G

    2007-01-01

    This review will discuss the mechanisms of repair and regeneration in various tissue types and how dysregulation of these mechaisms may lead to cancer. Normal homeostasis involves a careful balance between cell loss and cell renewal. Stem and progenitor cells perform these biologic processes as the functional units of regeneration during both tissue homeostasis and repair. The concept of tissue stem cells capable of giving rise to all differentiated cells within a given tissue led to the conc...

  6. The long-term behavior of lightweight and heavyweight meshes used to repair abdominal wall defects is determined by the host tissue repair process provoked by the mesh.

    Science.gov (United States)

    Pascual, Gemma; Hernández-Gascón, Belén; Rodríguez, Marta; Sotomayor, Sandra; Peña, Estefania; Calvo, Begoña; Bellón, Juan M

    2012-11-01

    Although heavyweight (HW) or lightweight (LW) polypropylene (PP) meshes are widely used for hernia repair, other alternatives have recently appeared. They have the same large-pore structure yet are composed of polytetrafluoroethylene (PTFE). This study compares the long-term (3 and 6 months) behavior of meshes of different pore size (HW compared with LW) and composition (PP compared with PTFE). Partial defects were created in the lateral wall of the abdomen in New Zealand White rabbits and then repaired by the use of a HW or LW PP mesh or a new monofilament, large-pore PTFE mesh (Infinit). At 90 and 180 days after implantation, tissue incorporation, gene and protein expression of neocollagens (reverse transcription-polymerase chain reaction/immunofluorescence), macrophage response (immunohistochemistry), and biomechanical strength were determined. Shrinkage was measured at 90 days. All three meshes induced good host tissue ingrowth, yet the macrophage response was significantly greater in the PTFE implants (P .05). Host collagen deposition is mesh pore size dependent whereas the macrophage response induced is composition dependent with a greater response shown by PTFE. In the long term, macroporous meshes show comparable biomechanical behavior regardless of their pore size or composition. Copyright © 2012 Mosby, Inc. All rights reserved.

  7. An evaluation of Admedus' tissue engineering process-treated (ADAPT) bovine pericardium patch (CardioCel) for the repair of cardiac and vascular defects.

    Science.gov (United States)

    Strange, Geoff; Brizard, Christian; Karl, Tom R; Neethling, Leon

    2015-03-01

    Tissue engineers have been seeking the 'Holy Grail' solution to calcification and cytotoxicity of implanted tissue for decades. Tissues with all of the desired qualities for surgical repair of congenital heart disease (CHD) are lacking. An anti-calcification tissue engineering process (ADAPT TEP) has been developed and applied to bovine pericardium (BP) tissue (CardioCel, AdmedusRegen Pty Ltd, Perth, WA, Australia) to eliminate cytotoxicity, improve resistance to acute and chronic inflammation, reduce calcification and facilitate controlled tissue remodeling. Clinical data in pediatric patients, and additional pre-market authorized prescriber data demonstrate that CardioCel performs extremely well in the short term and is safe and effective for a range of congenital heart deformations. These data are supported by animal studies which have shown no more than normal physiologic levels of calcification, with good durability, biocompatibility and controlled healing.

  8. Chitosan adhesive for laser tissue repair

    Science.gov (United States)

    Lauto, A.; Stoodley, M.; Avolio, A.; Foster, L. J. R.

    2006-02-01

    Background. Laser tissue repair usually relies on haemoderivate solders, based on serum albumin. These solders have intrinsic limitations that impair their widespread use, such as limited repair strength, high solubility, brittleness and viral transmission. Furthermore, the solder activation temperature (65-70 °C) can induce significant damage to tissue. In this study, a new laser-activated biomaterial for tissue repair was developed and tested in vitro and in vivo to overcome some of the shortcomings of traditional solders. Materials and Methods. Flexible and insoluble strips of chitosan adhesive (surface area ~34 mm2, thickness ~20 μm) were developed and bonded on sheep intestine with a laser fluence and irradiance of 52 +/- 2 J/cm2 and ~15 W/cm2 respectively. The temperature between tissue and adhesive was measured using small thermocouples. The strength of repaired tissue was tested by a calibrated tensiometer. The adhesive was also bonded in vivo to the sciatic nerve of rats to assess the thermal damage induced by the laser (fluence = 65 +/- 11 J/cm2, irradiance = 15 W/cm2) four days post-operatively. Results. Chitosan adhesives successfully repaired intestine tissue, achieving a repair strength of 0.50 +/- 0.15 N (shear stress = 14.7 +/- 4.7 KPa, n=30) at a temperature of 60-65 °C. The laser caused demyelination of axons at the operated site; nevertheless, the myelinated axons retained their normal morphology proximally and distally.

  9. Mesenchymal Stem Cells in Tissue Repair

    Directory of Open Access Journals (Sweden)

    Amy M DiMarino

    2013-09-01

    Full Text Available The advent of mesenchymal stem cell (MSC based therapies for clinical therapeutics has been an exciting and new innovation for the treatment of a variety of diseases associated with inflammation, tissue damage and subsequent regeneration and repair. Application-based ability to measure MSC potency and fate of the cells post-MSC therapy are the variables that confound the use of MSCs therapeutics in human diseases. An evaluation of MSC function and applications with attention to detail in the preparation as well as quality control (QC and quality assurance (QA are only as good as the assays that are developed. In vivo measures of efficacy and potency require an appreciation of the overall pathophysiology of the model and standardization of outcome measures. The new concepts of how MSC’s participate in the tissue regeneration and wound repair process and further, how this is impacted by estimates of efficacy and potency Are important new topics. In this regard,,, this chapter will review some of the in vitro and in vivo assays for MSC function and activity and their application to the clinical arena.

  10. Stem Cells in Tissue Repair and Regeneration

    OpenAIRE

    Falanga, Vincent

    2012-01-01

    The field of tissue repair and wound healing has blossomed in the last 30 years. We have gone from recombinant growth factors, to living tissue engineering constructs, to stem cells. The task now is to pursue true regeneration, thus achieving full restoration of structures and their function.

  11. Tissue repair capacity and repair kinetics deduced from multifractionated or continuous irradiation regimens with incomplete repair

    International Nuclear Information System (INIS)

    Thames, H.D. Jr.; Peters, L.J.

    1984-01-01

    A model is proposed for cell survival after multiple doses, when the interfraction interval is insufficient for complete Elkind repair. In the limit of ever-increasing number of ever-smaller fractional doses, the model transforms into the accumulation model of survival after continuous irradiation. When adapted to describe tissue responses to isoeffective multifractionated regimens, wherein repair is incomplete, a generalization of the usually linear plot of reciprocal total dose versus dose per fraction is obtained, in which downward curvature is evident. There is an advantage in studying tissue responses to multifractionated regimens with incomplete repair in the interfraction intervals, or continuous exposures at various dose rates since, in addition to determination of repair capacity, there is an estimate of repair kinetics. Results of analyses of previously published data are presented as illustration. Estimated from the response of three acutely responding normal tissues in the mouse (jejunum, colon and bone marrow), repair halftimes ranged from 0.3-0.9 h and values of β/delta were approximately 0.1 Gy -1 . From the response of mouse lung (LD50 for pneumonitis) to multifractionated regimens with incomplete repair, the repair halftime was estimated at 1.5 h and β/delta was 0.27 Gy -1 . In the rat spinal cord β/delta was 0.7 Gy -1 and Tsub(1/2) was 1.5 h. (U.K.)

  12. Fibrocytes and the tissue niche in lung repair

    Directory of Open Access Journals (Sweden)

    Bjermer Leif

    2011-06-01

    Full Text Available Abstract Human fibrocytes are bone marrow-derived mesenchymal progenitor cells that express a variety of markers related to leukocytes, hematopoietic stem cells and a diverse set of fibroblast phenotypes. Fibrocytes can be recruited from the circulation to the tissue where they further can differentiate and proliferate into various mesenchymal cell types depending on the tissue niche. This local tissue niche is important because it modulates the fibrocytes and coordinates their role in tissue behaviour and repair. However, plasticity of a niche may be co-opted in chronic airway diseases such as asthma, idiopathic pulmonary fibrosis and obliterative bronchiolitis. This review will therefore focus on a possible role of fibrocytes in pathological tissue repair processes in those diseases.

  13. Customized Fabrication of Osteochondral Tissue for Articular Joint Surface Repair

    Science.gov (United States)

    2016-09-01

    AWARD NUMBER: W81XWH-14-1-0217 TITLE: Customized Fabrication of Osteochondral Tissue for Articular Joint Surface Repair PRINCIPAL INVESTIGATOR...4. TITLE AND SUBTITLE Customized Fabrication of Osteochondral Tissue for Articular Joint Surface Repair 5a. CONTRACT NUMBER 5b. GRANT NUMBER W81XWH...applicability of these novel osteochondral tissues for articular cartilage repair in rabbit model, using medical imaging-guided PSL. Such an approach may

  14. Repair of radiation injury by transplantation of hemopoietic tissue

    International Nuclear Information System (INIS)

    Smith, L.H.

    1978-01-01

    The following topics are discussed: endogenous repair of tissue by surviving cells; exogenous repair by transplantation of tissue from unirradiated donor; repair of hematopoietic tissue following sublethal exposure or exposure in the LD 1 to LD 100 range; early studies on regeneration of hematopoietic tissue in x-irradiated dogs by giving bone marrow; hypotheses as to how bone marrow injections result in regeneration of blood-forming tissue; effects of rat bone marrow transplants on survival of lethally irradiated mice; and effect of tissue transplants on dose-response curve

  15. Apparatus for enhancing tissue repair in mammals

    Science.gov (United States)

    Goodwin, Thomas J. (Inventor); Parker, Clayton R. (Inventor)

    2007-01-01

    An apparatus is disclosed for enhancing tissue repair in mammals, with the apparatus comprising: a sleeve for encircling a portion of a mammalian body part, said sleeve comprising an electrically conductive coil capable of generating an electromagnetic field when an electrical current is applied thereto, means for supporting the sleeve on the mammalian body part; and means for supplying the electrically conductive coil with a square wave time varying electrical current sufficient to create a time varying electromagnetic force of from approximately 0.05 gauss to 0.05 gauss within the interior of the coil in order that when the sleeve is placed on a mammalian body part and the time varying electromagnetic force of from approximately 0.05 gauss to 0.05 gauss is generated on the mammalian body part for an extended period of time, tissue regeneration within the mammalian body part is increased to a rate in excess of the normal tissue regeneration rate that would occur without application of the time varying electromagnetic force.

  16. Bioactive Polymeric Materials for Tissue Repair

    Directory of Open Access Journals (Sweden)

    Diane R. Bienek

    2017-01-01

    Full Text Available Bioactive polymeric materials based on calcium phosphates have tremendous appeal for hard tissue repair because of their well-documented biocompatibility. Amorphous calcium phosphate (ACP-based ones additionally protect against unwanted demineralization and actively support regeneration of hard tissue minerals. Our group has been investigating the structure/composition/property relationships of ACP polymeric composites for the last two decades. Here, we present ACP’s dispersion in a polymer matrix and the fine-tuning of the resin affects the physicochemical, mechanical, and biological properties of ACP polymeric composites. These studies illustrate how the filler/resin interface and monomer/polymer molecular structure affect the material’s critical properties, such as ion release and mechanical strength. We also present evidence of the remineralization efficacy of ACP composites when exposed to accelerated acidic challenges representative of oral environment conditions. The utility of ACP has recently been extended to include airbrushing as a platform technology for fabrication of nanofiber scaffolds. These studies, focused on assessing the feasibility of incorporating ACP into various polymer fibers, also included the release kinetics of bioactive calcium and phosphate ions from nanofibers and evaluate the biorelevance of the polymeric ACP fiber networks. We also discuss the potential for future integration of the existing ACP scaffolds into therapeutic delivery systems used in the precision medicine field.

  17. Connexin Communication Compartments and Wound Repair in Epithelial Tissue.

    Science.gov (United States)

    Chanson, Marc; Watanabe, Masakatsu; O'Shaughnessy, Erin M; Zoso, Alice; Martin, Patricia E

    2018-05-03

    Epithelial tissues line the lumen of tracts and ducts connecting to the external environment. They are critical in forming an interface between the internal and external environment and, following assault from environmental factors and pathogens, they must rapidly repair to maintain cellular homeostasis. These tissue networks, that range from a single cell layer, such as in airway epithelium, to highly stratified and differentiated epithelial surfaces, such as the epidermis, are held together by a junctional nexus of proteins including adherens, tight and gap junctions, often forming unique and localised communication compartments activated for localised tissue repair. This review focuses on the dynamic changes that occur in connexins, the constituent proteins of the intercellular gap junction channel, during wound-healing processes and in localised inflammation, with an emphasis on the lung and skin. Current developments in targeting connexins as corrective therapies to improve wound closure and resolve localised inflammation are also discussed. Finally, we consider the emergence of the zebrafish as a concerted whole-animal model to study, visualise and track the events of wound repair and regeneration in real-time living model systems.

  18. Connexin Communication Compartments and Wound Repair in Epithelial Tissue

    Directory of Open Access Journals (Sweden)

    Marc Chanson

    2018-05-01

    Full Text Available Epithelial tissues line the lumen of tracts and ducts connecting to the external environment. They are critical in forming an interface between the internal and external environment and, following assault from environmental factors and pathogens, they must rapidly repair to maintain cellular homeostasis. These tissue networks, that range from a single cell layer, such as in airway epithelium, to highly stratified and differentiated epithelial surfaces, such as the epidermis, are held together by a junctional nexus of proteins including adherens, tight and gap junctions, often forming unique and localised communication compartments activated for localised tissue repair. This review focuses on the dynamic changes that occur in connexins, the constituent proteins of the intercellular gap junction channel, during wound-healing processes and in localised inflammation, with an emphasis on the lung and skin. Current developments in targeting connexins as corrective therapies to improve wound closure and resolve localised inflammation are also discussed. Finally, we consider the emergence of the zebrafish as a concerted whole-animal model to study, visualise and track the events of wound repair and regeneration in real-time living model systems.

  19. Epithelial-mesenchymal transition in tissue repair and fibrosis.

    Science.gov (United States)

    Stone, Rivka C; Pastar, Irena; Ojeh, Nkemcho; Chen, Vivien; Liu, Sophia; Garzon, Karen I; Tomic-Canic, Marjana

    2016-09-01

    The epithelial-mesenchymal transition (EMT) describes the global process by which stationary epithelial cells undergo phenotypic changes, including the loss of cell-cell adhesion and apical-basal polarity, and acquire mesenchymal characteristics that confer migratory capacity. EMT and its converse, MET (mesenchymal-epithelial transition), are integral stages of many physiologic processes and, as such, are tightly coordinated by a host of molecular regulators. Converging lines of evidence have identified EMT as a component of cutaneous wound healing, during which otherwise stationary keratinocytes (the resident skin epithelial cells) migrate across the wound bed to restore the epidermal barrier. Moreover, EMT plays a role in the development of scarring and fibrosis, as the matrix-producing myofibroblasts arise from cells of the epithelial lineage in response to injury but are pathologically sustained instead of undergoing MET or apoptosis. In this review, we summarize the role of EMT in physiologic repair and pathologic fibrosis of tissues and organs. We conclude that further investigation into the contribution of EMT to the faulty repair of fibrotic wounds might identify components of EMT signaling as common therapeutic targets for impaired healing in many tissues. Graphical Abstract Model for injury-triggered EMT activation in physiologic wound repair (left) and fibrotic wound healing (right).

  20. Experiment K-7-29: Connective Tissue Studies. Part 3; Rodent Tissue Repair: Skeletal Muscle

    Science.gov (United States)

    Stauber, W.; Fritz, V. K.; Burkovskaya, T. E.; Ilyina-Kakueva, E. I.

    1994-01-01

    Myofiber injury-repair was studied in the rat gastrocnemius following a crush injury to the lower leg prior to flight in order to understand if the regenerative responses of muscles are altered by the lack of gravitational forces during Cosmos 2044 flight. After 14 days of flight, the gastrocnemius muscle was removed from the 5 injured flight rodents and various Earth-based treatment groups for comparison. The Earth-based animals consisted of three groups of five rats with injured muscles from a simulated, tail-suspended, and vivarium as well as an uninjured basal group. The gastrocnemius muscle from each was evaluated by histochemical and immunohistochemical techniques to document myofiber, vascular, and connective tissue alterations following injury. In general the repair process was somewhat similar in all injured muscle samples with regard to extracellular matrix organization and myofiber regeneration. Small and large myofibers were present with a newly organized extracellular matrix indicative of myogenesis and muscle regeneration. In the tail-suspended animals, a more complete repair was observed with no enlarged area of non-muscle cells or matrix material visible. In contrast, the muscle samples from the flight animals were less well differentiated with more macrophages and blood vessels in the repair region but small myofibers and proteoglycans, nevertheless, were in their usual configuration. Thus, myofiber repair did vary in muscles from the different groups, but for the most part, resulted in functional muscle tissue.

  1. Repair in normal tissues and the possible relevance to radiotherapy

    International Nuclear Information System (INIS)

    Field, S.B.; Hornsey, S.

    1977-01-01

    Between each fraction in radiotherapy, there is repair and recovery of both normal and neoplastic tissues. Several different types of repair have been identified. Some relate specifically to the effect of changing the number of fractions and others to the overall treatment time. Each will be discussed and particular attention will be paid to slow repair phenomena which have recently been the subject of much interest. (orig.) [de

  2. Use of NASA Bioreactor in Engineering Tissue for Bone Repair

    Science.gov (United States)

    Duke, Pauline

    1998-01-01

    This study was proposed in search for a new alternative for bone replacement or repair. Because the systems commonly used in repair of bony defects form bone by going through a cartilaginous phase, implantation of a piece of cartilage could enhance the healing process by having a more advanced starting point. However, cartilage has seldom been used to replace bone due, in part, to the limitations in conventional culture systems that did not allow production of enough tissue for implants. The NASA-developed bioreactors known as STLV (Slow Turning Lateral Vessel) provide homogeneous distribution of cells, nutrients, and waste products, with less damaging turbulence and shear forces than conventional systems. Cultures under these conditions have higher growth rates, viability, and longevity, allowing larger "tissue-like" aggregates to form, thus opening the possibilities of producing enough tissue for implantation, along with the inherent advantages of in vitro manipulations. To assure large numbers of cells and to eliminate the use of timed embryos, we proposed to use an immortalized mouse limb bud cell line as the source of cells.

  3. Epithelial-Mesenchymal Transition in Tissue Repair and Fibrosis

    Science.gov (United States)

    Stone, Rivka C.; Pastar, Irena; Ojeh, Nkemcho; Chen, Vivien; Liu, Sophia; Garzon, Karen I.; Tomic-Canic, Marjana

    2016-01-01

    Epithelial-mesenchymal transition (EMT) describes the global process by which stationary epithelial cells undergo phenotypic changes, including loss of cell-cell adhesion and apical-basal polarity, and acquire mesenchymal characteristics which confer migratory capacity. EMT and its converse, MET (mesenchymal-to-epithelial transition), are integral stages of many physiologic processes, and as such are tightly coordinated by a host of molecular regulators. Converging lines of evidence have identified EMT as a component of cutaneous wound healing, during which otherwise stationary keratinocytes - the resident skin epithelial cells - migrate across the wound bed to restore the epidermal barrier. Moreover, EMT also plays a role in the development of scarring and fibrosis, as the matrix-producing myofibroblast arises from cells of epithelial lineage in response to injury but is pathologically sustained instead of undergoing MET or apoptosis. In this review, we summarize the role of EMT in physiologic repair and pathologic fibrosis of tissues and organs. We conclude that further investigation into the contribution of EMT to the impaired repair of fibrotic wounds may identify components of EMT signaling as common therapeutic targets for impaired healing in many tissues. PMID:27461257

  4. Mathematical models of soft tissue injury repair : towards understanding musculoskeletal disorders

    OpenAIRE

    Dunster, Joanne L.

    2012-01-01

    The process of soft tissue injury repair at the cellular lew I can be decomposed into three phases: acute inflammation including coagulation, proliferation and remodelling. While the later phases are well understood the early phase is less so. We produce a series of new mathematical models for the early phases coagulation and inflammation. The models produced are relevant not only to soft tissue injury repair but also to the many disease states in which coagulation and inflammation play a rol...

  5. Pulse frequency in pulsed brachytherapy based on tissue repair kinetics

    International Nuclear Information System (INIS)

    Sminia, Peter; Schneider, Christoph J.; Koedooder, Kees; Tienhoven, Geertjan van; Blank, Leo E.C.M.; Gonzalez Gonzalez, Dionisio

    1998-01-01

    Purpose: Investigation of normal tissue sparing in pulsed brachytherapy (PB) relative to continuous low-dose rate irradiation (CLDR) by adjusting pulse frequency based on tissue repair characteristics. Method: Using the linear quadratic model, the relative effectiveness (RE) of a 20 Gy boost was calculated for tissue with an α/β ratio ranging from 2 to 10 Gy and a half-time of sublethal damage repair between 0.1 and 3 h. The boost dose was considered to be delivered either in a number of pulses varying from 2 to 25, or continuously at a dose rate of 0.50, 0.80, or 1.20 Gy/h. Results: The RE of 20 Gy was found to be identical for PB in 25 pulses of 0.80 Gy each h and CLDR delivered at 0.80 Gy/h for any α/β value and for a repair half-time > 0.75 h. When normal tissue repair half-times are assumed to be longer than tumor repair half-times, normal tissue sparing can be obtained, within the restriction of a fixed overall treatment time, with higher dose per pulse and longer period time (time elapsed between start of pulse n and start of pulse n + 1). An optimum relative normal tissue sparing larger than 10% was found with 4 pulses of 5 Gy every 8 h. Hence, a therapeutic gain might be obtained when changing from CLDR to PB by adjusting the physical dose in such a way that the biological dose on the tumor is maintained. The normal tissue-sparing phenomenon can be explained by an increase in RE with longer period time for tissue with high α/β ratio and fast or intermediate repair half-time, and the RE for tissue with low α/β ratio and long repair half-time remains almost constant. Conclusion: Within the benchmark of the LQ model, advantage in normal tissue-sparing is expected when matching the pulse frequency to the repair kinetics of the normal tissue exposed. A period time longer than 1 h may lead to a reduction of late normal tissue complications. This theoretical advantage emphasizes the need for better knowledge of human tissue-repair kinetics

  6. The tissue injury and repair in cancer radiotherapy

    International Nuclear Information System (INIS)

    Matsuzawa, Taiju

    1975-01-01

    One of the difficulties in cancer radiotherapy arises from the fact that the tissue tolerance dose is much smaller than the tumor lethal dose. In our opinion the former depends upon the tolerance of the endothelial cell of the blood vessel in the normal tissue. In this introduction, a new concept regarding the estimation of tissue radiosensitivity was described, and the possible significance of the mode of radiation injury and the repair capability of normal tissue in the cancer radiotheraphy was discussed. (author)

  7. Cell-based and biomaterial approaches to connective tissue repair

    Science.gov (United States)

    Stalling, Simone Suzette

    Connective tissue injuries of skin, tendon and ligament, heal by a reparative process in adults, filling the wound site with fibrotic, disorganized scar tissue that poorly reflects normal tissue architecture or function. Conversely, fetal skin and tendon have been shown to heal scarlessly. Complete regeneration is not intrinsically ubiquitous to all fetal tissues; fetal diaphragmatic and gastrointestinal injuries form scars. In vivo studies suggest that the presence of fetal fibroblasts is essential for scarless healing. In the orthopaedic setting, adult anterior cruciate ligament (ACL) heals poorly; however, little is known about the regenerative capacity of fetal ACL or fetal ACL fibroblasts. We characterized in vitro wound healing properties of fetal and adult ACL fibroblasts demonstrating that fetal ACL fibroblasts migrate faster and elaborate greater quantities of type I collagen, suggesting the healing potential of the fetal ACL may not be intrinsically poor. Similar to fetal ACL fibroblasts, fetal dermal fibroblasts also exhibit robust cellular properties. We investigated the age-dependent effects of dermal fibroblasts on tendon-to-bone healing in rat supraspinatus tendon injuries, a reparative injury model. We hypothesized delivery of fetal dermal fibroblasts would increase tissue organization and mechanical properties in comparison to adult dermal fibroblasts. However, at 1 and 8 weeks, the presence of dermal fibroblasts, either adult or fetal, had no significant effect on tissue histology or mechanical properties. There was a decreasing trend in cross-sectional area of repaired tendons treated with fetal dermal fibroblasts in comparison to adult, but this finding was not significant in comparison to controls. Finally, we synthesized a novel polysaccharide, methacrylated methylcellulose (MA-MC), and fabricated hydrogels using a well-established photopolymerization technique. We characterized the physical and mechanical properties of MA-MC hydrogels in

  8. The Vascular Niche in Tissue Repair: A Therapeutic Target for Regeneration

    OpenAIRE

    Rivera, Francisco J.; Silva, Maria Elena; Aigner, Ludwig

    2017-01-01

    Editorial on the Research Topic The Vascular Niche in Tissue Repair: A Therapeutic Target for Regeneration In mammals, although regeneration is quite restricted to a number of tissues and organs, this particular healing process is possible through the existence of tissue-resident stem/progenitor cells. Upon injury, these cells are activated, they proliferate, migrate, and differentiate into tissue-specific cells and functionally replace the damaged or lost cells. Besides this, angio...

  9. Spinal Cord Repair with Engineered Nervous Tissue

    Science.gov (United States)

    2014-04-01

    ganglia ( DRG ) and axons that can be stretch-grown to a length necessary to bridge extensive lesions. In current studies, we have optimized in vivo...survival of DRGs up to 6 weeks post-transplant. If successful, this approach will provide an alternative or additional means to repair large spinal...lesions. 15. SUBJECT TERMS- none listed 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT 18. NUMBER OF PAGES 19a. NAME OF

  10. Tissue and cellular biomechanics during corneal wound injury and repair.

    Science.gov (United States)

    Raghunathan, Vijay Krishna; Thomasy, Sara M; Strøm, Peter; Yañez-Soto, Bernardo; Garland, Shaun P; Sermeno, Jasmyne; Reilly, Christopher M; Murphy, Christopher J

    2017-08-01

    Corneal wound healing is an enormously complex process that requires the simultaneous cellular integration of multiple soluble biochemical cues, as well as cellular responses to the intrinsic chemistry and biophysical attributes associated with the matrix of the wound space. Here, we document how the biomechanics of the corneal stroma are altered through the course of wound repair following keratoablative procedures in rabbits. Further we documented the influence that substrate stiffness has on stromal cell mechanics. Following corneal epithelial debridement, New Zealand white rabbits underwent phototherapeutic keratectomy (PTK) on the right eye (OD). Wound healing was monitored using advanced imaging modalities. Rabbits were euthanized and corneas were harvested at various time points following PTK. Tissues were characterized for biomechanics with atomic force microscopy and with histology to assess inflammation and fibrosis. Factor analysis was performed to determine any discernable patterns in wound healing parameters. The matrix associated with the wound space was stiffest at 7days post PTK. The greatest number of inflammatory cells were observed 3days after wounding. The highest number of myofibroblasts and the greatest degree of fibrosis occurred 21days after wounding. While all clinical parameters returned to normal values 400days after wounding, the elastic modulus remained greater than pre-surgical values. Factor analysis demonstrated dynamic remodeling of stroma occurs between days 10 and 42 during corneal stromal wound repair. Elastic modulus of the anterior corneal stroma is dramatically altered following PTK and its changes coincide initially with the development of edema and inflammation, and later with formation of stromal haze and population of the wound space with myofibroblasts. Factor analysis demonstrates strongest correlation between elastic modulus, myofibroblasts, fibrosis and stromal haze thickness, and between edema and central corneal

  11. The 23rd Annual Meeting of the European Tissue Repair Society (ETRS) in Reims, France

    NARCIS (Netherlands)

    Hoff, J.W. Von den; Agren, M.S.; Coulomb, B.; Eming, S.A.; Lataillade, J.J.

    2014-01-01

    The 23rd Annual Meeting of the European Tissue Repair Society, Reims, France, October 23 to 25, 2013 focused on tissue repair and regenerative medicine covering topics such as stem cells, biomaterials, tissue engineering, and burns.

  12. The 23rd Annual Meeting of the European Tissue Repair Society (ETRS) in Reims, France

    DEFF Research Database (Denmark)

    Von den Hoff, Johannes W; Ågren, Sven Per Magnus; Coulomb, Bernard

    2014-01-01

    The 23rd Annual Meeting of the European Tissue Repair Society, Reims, France, October 23 to 25, 2013 focused on tissue repair and regenerative medicine covering topics such as stem cells, biomaterials, tissue engineering, and burns.......The 23rd Annual Meeting of the European Tissue Repair Society, Reims, France, October 23 to 25, 2013 focused on tissue repair and regenerative medicine covering topics such as stem cells, biomaterials, tissue engineering, and burns....

  13. Adipose stem cells for bone tissue repair

    OpenAIRE

    Ciuffi, Simone; Zonefrati, Roberto; Brandi, Maria Luisa

    2017-01-01

    Adipose-derived stem/stromal cells (ASCs), together with adipocytes, vascular endothelial cells, and vascular smooth muscle cells, are contained in fat tissue. ASCs, like the human bone marrow stromal/stem cells (BMSCs), can differentiate into several lineages (adipose cells, fibroblast, chondrocytes, osteoblasts, neuronal cells, endothelial cells, myocytes, and cardiomyocytes). They have also been shown to be immunoprivileged, and genetically stable in long-term cultures. Nevertheless, unlik...

  14. Recombinant Gelatin Microspheres : Novel Formulations for Tissue Repair?

    NARCIS (Netherlands)

    Tuin, Annemarie; Kluijtmans, Sebastiaan G.; Bouwstra, Jan B.; Harmsen, Martin C.; Van Luyn, Marja J. A.

    Microspheres (MSs) can function as multifunctional scaffolds in different approaches of tissue repair (TR), as a filler, a slow-release depot for growth factors, or a delivery vehicle for cells. Natural cell adhesion-supporting extracellular matrix components like gelatin are good materials for

  15. Prediction of cartilaginous tissue repair after knee joint distraction

    NARCIS (Netherlands)

    van der Woude, J A D; Welsing, P M; van Roermund, P M; Custers, R J H; Kuchuk, N O; Lafeber, F P J G G

    2016-01-01

    BACKGROUND: For young patients (<65years), knee joint distraction (KJD) may be a joint-saving treatment option for end-stage knee osteoarthritis. Distracting the femur from the tibia by five millimeters for six to eight weeks using an external fixation frame results in cartilaginous tissue repair,

  16. Matrix metalloproteinase-8 overexpression prevents proper tissue repair

    DEFF Research Database (Denmark)

    Danielsen, Patricia L; Holst, Anders V; Maltesen, Henrik R

    2011-01-01

    The collagenolytic matrix metalloproteinase-8 (MMP-8) is essential for normal tissue repair but is often overexpressed in wounds with disrupted healing. Our aim was to study the impact of a local excess of this neutrophil-derived proteinase on wound healing using recombinant adenovirus...

  17. Magnetization transfer analysis of cartilage repair tissue: a preliminary study

    International Nuclear Information System (INIS)

    Palmieri, F.; Keyzer, F. de; Maes, F.; Breuseghem, I. van

    2006-01-01

    To evaluate the magnetization transfer ratio (MTR) after two different cartilage repair procedures, and to compare these data with the MTR of normal cartilage. Twenty-seven patients with a proven cartilage defect were recruited: 13 were treated with autologous chondrocyte implantation (ACI) and 14 were treated with the microfracture technique (MFR). All patients underwent MRI examinations with MT-sequences before the surgical treatment, after 12 months (26 patients) and after 24 months (11 patients). Eleven patients received a complete follow-up study at all three time points (five of the ACI group and six of the MFR group). All images were transferred to a workstation to calculate MTR images. For every MT image set, different ROIs were delineated by two radiologists. Means were calculated per ROI type in the different time frames and in both groups of cartilage repair. The data were analyzed with unpaired t- and ANOVA tests, and by calculating Pearson's correlation coefficient. No significant differences were found in the MTR of fatty bone marrow, muscle and normal cartilage in the different time frames. There was a significant but small difference between the MTR of normal cartilage and the cartilage repair area after 12 months for both procedures. After 24 months, the MTR of ACI repaired cartilage (0.31±0.07) was not significantly different from normal cartilage MTR (0.34±0.05). The MTR of MFR repaired cartilage (0.28±0.02), still showed a significant difference from normal cartilage. The differences between damaged and repaired cartilage MTR are too small to enable MT-imaging to be a useful tool for postoperative follow-up of cartilage repair procedures. There is, however, an evolution towards normal MTR-values in the cartilage repair tissue (especially after ACI repair). (orig.)

  18. Repair and tissue engineering techniques for articular cartilage.

    Science.gov (United States)

    Makris, Eleftherios A; Gomoll, Andreas H; Malizos, Konstantinos N; Hu, Jerry C; Athanasiou, Kyriacos A

    2015-01-01

    Chondral and osteochondral lesions due to injury or other pathology commonly result in the development of osteoarthritis, eventually leading to progressive total joint destruction. Although current progress suggests that biologic agents can delay the advancement of deterioration, such drugs are incapable of promoting tissue restoration. The limited ability of articular cartilage to regenerate renders joint arthroplasty an unavoidable surgical intervention. This Review describes current, widely used clinical repair techniques for resurfacing articular cartilage defects; short-term and long-term clinical outcomes of these techniques are discussed. Also reviewed is a developmental pipeline of acellular and cellular regenerative products and techniques that could revolutionize joint care over the next decade by promoting the development of functional articular cartilage. Acellular products typically consist of collagen or hyaluronic-acid-based materials, whereas cellular techniques use either primary cells or stem cells, with or without scaffolds. Central to these efforts is the prominent role that tissue engineering has in translating biological technology into clinical products; therefore, concomitant regulatory processes are also discussed.

  19. A hypothesis: factor VII governs clot formation, tissue repair and apoptosis.

    Science.gov (United States)

    Coleman, Lewis S

    2007-01-01

    A hypothesis: thrombin is a "Universal Enzyme of Energy Transduction" that employs ATP energy in flowing blood to activate biochemical reactions and cell effects in both hemostasis and tissue repair. All cells possess PAR-1 (thrombin) receptors and are affected by thrombin elevations, and thrombin effects on individual cell types are determined by their unique complement of PAR-1 receptors. Disruption of the vascular endothelium (VE) activates a tissue repair mechanism (TRM) consisting of the VE, tissue factor (TF), and circulating Factors VII, IX and X that governs localized thrombin elevations to activate clot formation and cellular effects that repair tissue damage. The culmination of the repair process occurs with the restoration of the VE followed by declines in thrombin production that causes Apoptosis ("programmed cell death") in wound-healing fibroblasts, which functions as a mechanism to draw wound edges together. The location and magnitude of TRM activity governs the location and magnitude of Factor VIII activity and clot formation, but the large size of Factor VIII prevents it from penetrating the clot formed by its activity, so that its effects are self-limiting. Factors VII, IX and X function primarily as tissue repair enzymes, while Factor VIII and Factor XIII are the only serine protease enzymes in the "Coagulation Cascade" that are exclusively associated with hemostasis.

  20. The tissue injury and repair in cancer radiotherapy. A concept of tissue architecture and radio sensitivity

    Energy Technology Data Exchange (ETDEWEB)

    Matsuzawa, T [Tohoku Univ., Sendai (Japan). Research Inst. for Tuberculosis, Leprosy and Cancer

    1975-06-01

    One of the difficulties in cancer radiotherapy arises from the fact that the tissue tolerance dose is much smaller than the tumor lethal dose. In our opinion the former depends upon the tolerance of the endothelial cell of the blood vessel in the normal tissue. In this introduction, a new concept regarding the estimation of tissue radiosensitivity was described, and the possible significance of the mode of radiation injury and the repair capability of normal tissue in the cancer radiotheraphy was discussed.

  1. Renewal Processes and Repairable Systems

    NARCIS (Netherlands)

    2003-01-01

    In this thesis we discuss the following topics: 1. Renewal reward processes The marginal distributions of renewal reward processes and its version, which we call in this thesis instantaneous reward processes, are derived. Our approach is based on the theory of point processes, especially Poisson

  2. Stem cell-derived angiogenic/vasculogenic cells: Possible therapies for tissue repair and tissue engineering

    NARCIS (Netherlands)

    Zwaginga, J. J.; Doevendans, P.

    2003-01-01

    1. The recent ability to isolate stem cells and study their specific capacity of self-renewal with the formation of different cell types has opened up exciting vistas to help the repair of damaged tissue and even the formation of new tissue. In the present review, we deal with the characteristics

  3. [Application of the xenogenic acellular dermal matrix membrane application used in the postoperative tissue shortage repair].

    Science.gov (United States)

    Bai, Yanxia; Yan, Liying; Zhang, Shaoqiang; Shao, Yuan; Yao, Xiaobao; Li, Honghui; Zhao, Ruimin; Zhao, Qian; Zhang, Pengfei; Yang, Qi

    2014-09-01

    To observe the short-term and long-term curative effect of the xenogenic acellular dermal matrix membrane (or joint muscle flap transfer) application used in the 82 cases postoperative tissue shortage repair that after the head neck carcinoma resection. To held the 82 cases head neck carcinoma postoperative mucosa shortage repaired after resection by the xenogenic acellular dermal matrix membrane (or joint muscle flap transfer), 65 cases mucosa shortage wound be directly covered by the repair membrane and the other 17 cases mucosa shortage wound be repaired by the tranfered muscle tissue flap with the repair membrane covered; 53 cases underwent additional postoperative radiotherapy between 2-4 weeks and follow-up in 1, 3, 6, 12, 18, 24, 30, 36, 48, 60 months and observed the operation site repair process through the electronic laryngoscope, observed the patients respiration, swallow, phonation function. Seventy-seven cases patients operation incision reached I phase healing standard, another 5 cases patients operation incision reached II phase healing standard because of the wound infection and fully-recovered through the local wound drainage,dressing process. All the patients tracheal cannula,the stomach tube be extubated successfully and without the local cicatricial constriction occurred. Seventy-eight cases follow up period reached 1 year including 53 cases who underwent postoperative radiotherapy, 49 cases follow up period reached 3 years including 32 cases who underwent postoperative radiotherapy, 14 cases follow up period reached 5 years including 12 cases who underwent postoperative radiotherapy. The patients with static local lesions discovered no reaction such as exclusion, allergy. The application of xenogenic acellular dermal matrix membrane (or joint muscle flap transfer used in in the postoperative tissue shortage repair that after the head neck carcinoma resection have several advantage such as comparatively easily implementation, operation safety

  4. Meniscal repair by fibrocartilage in the dog : Characterization of the repair tissue and the role of vascularity

    NARCIS (Netherlands)

    Veth, RPH; Jansen, HWB; Nielsen, HKL; deGroot, JH; Pennings, AJ; Kuijer, R

    Lesions in the avascular part of 20 canine menisci were repaired by implantation of a porous polyurethane. Seven menisci were not repaired and served as controls. The repair tissue was characterized by biochemical and immunological analysis. The role of vascularity in healing was studied by

  5. HYDROGEL-BASED NANOCOMPOSITES OF THERAPEUTIC PROTEINS FOR TISSUE REPAIR.

    Science.gov (United States)

    Zhu, Suwei; Segura, Tatiana

    2014-05-01

    The ability to design artificial extracellular matrices as cell instructive scaffolds has opened the door to technologies capable of studying cell fates in vitro and to guide tissue repair in vivo . One main component of the design of artificial extracellular matrices is the incorporation of protein-based biochemical cues to guide cell phenotypes and multicellular organizations. However, promoting the long-term bioactivity, controlling the bioavailability and understanding how the physical presentations of these proteins impacts cellular fates are among the challenges of the field. Nanotechnolgy has advanced to meet the challenges of protein therapeutics. For example, the approaches to incorporating proteins into tissue repairing scaffolds have ranged from bulk encapsulations to smart nanodepots that protect proteins from degradations and allow opportunities for controlled release.

  6. [Decellularized fish skin: characteristics that support tissue repair].

    Science.gov (United States)

    Magnússon, Skúli; Baldursson, Baldur Tumi; Kjartansson, Hilmar; Thorlacius, Guðný Ella; Axelsson, Ívar; Rolfsson, Óttar; Petersen, Pétur Henry; Sigurjónsson, Guðmundur Fertram

    2015-12-01

    Acellular fish skin of the Atlantic cod (Gadus morhua) is being used to treat chronic wounds. The prevalence of diabetes and the comorbidity of chronic wounds is increasing globally. The aim of the study was to assess the biocompatibility and biological characteristics of acellular fish skin, important for tissue repair. The structure of the acellular fish skin was examined with microscopy. Biocompatibility of the graft was conducted by a specialized certified laboratory. Protein extracts from the material were analyzed using gel electrophoresis. Cytokine levels were measured with an enzyme linked immunosorbent assay (ELISA). Angiogenic properties were assessed with a chick chorioallantoic membrane (chick CAM) assay. The structure of acellular fish skin is porous and the material is biocompatible. Electrophoresis revealed proteins around the size 115-130 kDa, indicative of collagens. The material did not have significant effect on IL-10, IL-12p40, IL-6 or TNF-α secretion from monocytes or macrophages. Acellular fish skin has significant effect on angiogenesis in the chick CAM assay. The acellular fish skin is not toxic and is not likely to promote inflammatory responses. The graft contains collagen I, promotes angiogenesis and supports cellular ingrowth. Compared to similar products made from mammalian sources, acellular fish skin does not confer a disease risk and contains more bioactive compounds, due to less severe processing.

  7. Mesenchymal Stem Cells in Tissue Growth and Repair

    OpenAIRE

    Kalinina, N.I.; Sysoeva, V.Yu.; Rubina, K.A.; Parfenova, Ye.V.; Tkachuk, V.A.

    2011-01-01

    It has been established in the recent several decades that stem cells play a crucial role in tissue renewal and regeneration. Mesenchymal stem cells (MSCs) are part of the most important population of adult stem cells. These cells have hereby been identified for the very first time and subsequently isolated from bone marrow stroma. Bone marrow-derived MSCs have been believed to play the role of a source of cells for the renewal and repair of connective tissues, including bone, cartilage and a...

  8. DNA-repair, cell killing and normal tissue damage

    International Nuclear Information System (INIS)

    Dahm-Daphi, J.; Dikomey, E.; Brammer, I.

    1998-01-01

    Background: Side effects of radiotherapy in normal tissue is determined by a variety of factors of which cellular and genetic contributions are described here. Material and methods: Review. Results: Normal tissue damage after irradiation is largely due to loss of cellular proliferative capacity. This can be due to mitotic cell death, apoptosis, or terminal differentiation. Dead or differentiated cells release cytokines which additionally modulate the tissue response. DNA damage, in particular non-reparable or misrepaired double-strand breaks are considered the basic lesion leading to G1-arrest and ultimately to cell inactivation. Conclusion: Evidence for genetic bases of normal tissue response, cell killing and DNA-repair capacity is presented. However, a direct link of all 3 endpoints has not yet been proved directly. (orig.) [de

  9. Apparatus and method for enhancing tissue repair in mammals

    Science.gov (United States)

    Goodwin, Thomas J. (Inventor); Parker, Clayton R. (Inventor)

    2009-01-01

    An apparatus is introduced for the use of enhancing tissue repair in mammals. The apparatus includes a sleeve; an electrically conductive coil; a sleeve support; an electrical circuit configured to supply the coil with a square wave time varying electrical current sufficient to create approximately 0.05 gauss to 0.5 gauss. When in use, the sleeve of the apparatus is placed on a mammalian body part and the time varying electromagnetic force of from approximately 0.05 gauss to 0.5 gauss is generated on the mammalian body for an extended period of time so that the tissue is encouraged to be regenerated in the mammalian body part at a rate in excess of the normal tissue regeneration rate relative to regeneration without application of the time varying electromagnetic force.

  10. Adaptive growth factor delivery from a polyelectrolyte coating promotes synergistic bone tissue repair and reconstruction

    Science.gov (United States)

    Shah, Nisarg J.; Hyder, Md. Nasim; Quadir, Mohiuddin A.; Dorval Courchesne, Noémie-Manuelle; Seeherman, Howard J.; Nevins, Myron; Spector, Myron; Hammond, Paula T.

    2014-01-01

    Traumatic wounds and congenital defects that require large-scale bone tissue repair have few successful clinical therapies, particularly for craniomaxillofacial defects. Although bioactive materials have demonstrated alternative approaches to tissue repair, an optimized materials system for reproducible, safe, and targeted repair remains elusive. We hypothesized that controlled, rapid bone formation in large, critical-size defects could be induced by simultaneously delivering multiple biological growth factors to the site of the wound. Here, we report an approach for bone repair using a polyelectrolye multilayer coating carrying as little as 200 ng of bone morphogenetic protein-2 and platelet-derived growth factor-BB that were eluted over readily adapted time scales to induce rapid bone repair. Based on electrostatic interactions between the polymer multilayers and growth factors alone, we sustained mitogenic and osteogenic signals with these growth factors in an easily tunable and controlled manner to direct endogenous cell function. To prove the role of this adaptive release system, we applied the polyelectrolyte coating on a well-studied biodegradable poly(lactic-co-glycolic acid) support membrane. The released growth factors directed cellular processes to induce bone repair in a critical-size rat calvaria model. The released growth factors promoted local bone formation that bridged a critical-size defect in the calvaria as early as 2 wk after implantation. Mature, mechanically competent bone regenerated the native calvaria form. Such an approach could be clinically useful and has significant benefits as a synthetic, off-the-shelf, cell-free option for bone tissue repair and restoration. PMID:25136093

  11. Radiation processing of biological tissues for nuclear disaster management

    International Nuclear Information System (INIS)

    Singh, Rita

    2012-01-01

    A number of surgical procedures require tissue substitutes to repair or replace damaged or diseased tissues. Biological tissues from human donor like bone, skin, amniotic membrane and other soft tissues can be used for repair or reconstruction of the injured part of the body. Tissues from human donor can be processed and banked for orthopaedic, spinal, trauma and other surgical procedures. Allograft tissues provide an excellent alternative to autografts. The use of allograft tissue avoids the donor site morbidity and reduces the operating time, expense and trauma associated with the acquisition of autografts. Further, allografts have the added advantage of being available in large quantities. This has led to a global increase in allogeneic transplantation and development of tissue banking. However, the risk of infectious disease transmission via tissue allografts is a major concern. Therefore, tissue allografts should be sterilized to make them safe for clinical use. Radiation processing has well appreciated technological advantages and is the most suitable method for sterilization of biological tissues. Radiation processed biological tissues can be provided by the tissue banks for the management of injuries due to a nuclear disaster. A nuclear detonation will result in a large number of casualties due to the heat, blast and radiation effects of the weapon. Skin dressings or skin substitutes like allograft skin, xenograft skin and amniotic membrane can be used for the treatment of thermal burns and radiation induced skin injuries. Bone grafts can be employed for repairing fracture defects, filling in destroyed regions of bone, management of open fractures and joint injuries. Radiation processed tissues have the potential to repair or reconstruct damaged tissues and can be of great assistance in the treatment of injuries due to the nuclear weapon. (author)

  12. Method of tissue repair using a composite material

    Energy Technology Data Exchange (ETDEWEB)

    Hutchens, Stacy A.; Woodward, Jonathan; Evans, Barbara R.; O' Neill, Hugh M.

    2016-03-01

    A composite biocompatible hydrogel material includes a porous polymer matrix, the polymer matrix including a plurality of pores and providing a Young's modulus of at least 10 GPa. A calcium comprising salt is disposed in at least some of the pores. The porous polymer matrix can comprise cellulose, including bacterial cellulose. The composite can be used as a bone graft material. A method of tissue repair within the body of animals includes the steps of providing a composite biocompatible hydrogel material including a porous polymer matrix, the polymer matrix including a plurality of pores and providing a Young's modulus of at least 10 GPa, and inserting the hydrogel material into cartilage or bone tissue of an animal, wherein the hydrogel material supports cell colonization in vitro for autologous cell seeding.

  13. Method of tissue repair using a composite material

    Science.gov (United States)

    Hutchens, Stacy A; Woodward, Jonathan; Evans, Barbara R; O'Neill, Hugh M

    2014-03-18

    A composite biocompatible hydrogel material includes a porous polymer matrix, the polymer matrix including a plurality of pores and providing a Young's modulus of at least 10 GPa. A calcium comprising salt is disposed in at least some of the pores. The porous polymer matrix can comprise cellulose, including bacterial cellulose. The composite can be used as a bone graft material. A method of tissue repair within the body of animals includes the steps of providing a composite biocompatible hydrogel material including a porous polymer matrix, the polymer matrix including a plurality of pores and providing a Young's modulus of at least 10 GPa, and inserting the hydrogel material into cartilage or bone tissue of an animal, wherein the hydrogel material supports cell colonization in vitro for autologous cell seeding.

  14. Pulp and periodontal tissue repair - regeneration or tissue metaplasia after dental trauma. A review

    DEFF Research Database (Denmark)

    Andreasen, Jens O

    2012-01-01

    Healing subsequent to dental trauma is known to be very complex, a result explained by the variability of the types of dental trauma (six luxations, nine fracture types, and their combinations). On top of that, at least 16 different cellular systems get involved in more severe trauma types each o...... of tissue replaces the injured). In this study, a review is given of the impact of trauma to various dental tissues such as alveolar bone, periodontal ligament, cementum, Hertvigs epithelial root sheath, and the pulp....... of them with a different potential for healing with repair, i.e. (re-establishment of tissue continuity without functional restitution) and regeneration (where the injured or lost tissue is replaced with new tissue with identical tissue anatomy and function) and finally metaplasia (where a new type...

  15. Fibroblast growth factors as tissue repair and regeneration therapeutics

    Directory of Open Access Journals (Sweden)

    Quentin M. Nunes

    2016-01-01

    Full Text Available Cell communication is central to the integration of cell function required for the development and homeostasis of multicellular animals. Proteins are an important currency of cell communication, acting locally (auto-, juxta-, or paracrine or systemically (endocrine. The fibroblast growth factor (FGF family contributes to the regulation of virtually all aspects of development and organogenesis, and after birth to tissue maintenance, as well as particular aspects of organism physiology. In the West, oncology has been the focus of translation of FGF research, whereas in China and to an extent Japan a major focus has been to use FGFs in repair and regeneration settings. These differences have their roots in research history and aims. The Chinese drive into biotechnology and the delivery of engineered clinical grade FGFs by a major Chinese research group were important enablers in this respect. The Chinese language clinical literature is not widely accessible. To put this into context, we provide the essential molecular and functional background to the FGF communication system covering FGF ligands, the heparan sulfate and Klotho co-receptors and FGF receptor (FGFR tyrosine kinases. We then summarise a selection of clinical reports that demonstrate the efficacy of engineered recombinant FGF ligands in treating a wide range of conditions that require tissue repair/regeneration. Alongside, the functional reasons why application of exogenous FGF ligands does not lead to cancers are described. Together, this highlights that the FGF ligands represent a major opportunity for clinical translation that has been largely overlooked in the West.

  16. Improved repair of bone defects with prevascularized tissue-engineered bones constructed in a perfusion bioreactor.

    Science.gov (United States)

    Li, De-Qiang; Li, Ming; Liu, Pei-Lai; Zhang, Yuan-Kai; Lu, Jian-Xi; Li, Jian-Min

    2014-10-01

    Vascularization of tissue-engineered bones is critical to achieving satisfactory repair of bone defects. The authors investigated the use of prevascularized tissue-engineered bone for repairing bone defects. The new bone was greater in the prevascularized group than in the non-vascularized group, indicating that prevascularized tissue-engineered bone improves the repair of bone defects. [Orthopedics. 2014; 37(10):685-690.]. Copyright 2014, SLACK Incorporated.

  17. Advances and Perspectives on Tissue Repair and Healing

    Science.gov (United States)

    Pinheiro, Antonio L. B.; Marques, Aparecida M. C.; de Sousa, Ana Paula C.; Aciole, Jouber M. S.; Soares, Luiz G. P.

    2011-08-01

    Wound healing involves local and systemic responses that reflect the etiology of the lesion, type of tissue, systemic condition and others. Despite being essentially the same for different wounds, the pattern of healing may change due to intrinsic and/or extrinsic factors. The type of tissue has also to be considered. Several therapeutic approaches have been used to improve healing including phototherapies such as Laser, LEDs and Lamps. Their effects on soft and mineralized tissues are well reported. The choice of appropriated parameters is essential for the results of the treatment and includes wavelength, power density, energy, duration and frequency of application and others. We studied the effects of different types of light on the healing of both soft and mineralized tissues using different models. We found that the use of Laser and polarized light are effective on improving the healing of diabetic and undernourished animals. We also found that Laser light is capable of improving the healing of drug-induced impairment and on increasing the survival rate of flaps on both diabetic and non-diabetic animals. We have also studied and shown the influence of the laser parameters on the healing of surgical and laser wounds. Lately we verified the positive effect of LEDs on healing. We used Laser/LED light for improving bone healing in conditions such as in dental implants, autologous grafts, biomaterials and fractures. From these reports and our own experience we have no doubt whatsoever that the use of phototherapies, carried out with appropriate parameters, promotes quicker tissue repair.

  18. Abnormal Base Excision Repair at Trinucleotide Repeats Associated with Diseases: A Tissue-Selective Mechanism

    Directory of Open Access Journals (Sweden)

    Agathi-Vasiliki Goula

    2013-07-01

    Full Text Available More than fifteen genetic diseases, including Huntington’s disease, myotonic dystrophy 1, fragile X syndrome and Friedreich ataxia, are caused by the aberrant expansion of a trinucleotide repeat. The mutation is unstable and further expands in specific cells or tissues with time, which can accelerate disease progression. DNA damage and base excision repair (BER are involved in repeat instability and might contribute to the tissue selectivity of the process. In this review, we will discuss the mechanisms of trinucleotide repeat instability, focusing more specifically on the role of BER.

  19. Repairable-conditionally repairable damage model based on dual Poisson processes.

    Science.gov (United States)

    Lind, B K; Persson, L M; Edgren, M R; Hedlöf, I; Brahme, A

    2003-09-01

    The advent of intensity-modulated radiation therapy makes it increasingly important to model the response accurately when large volumes of normal tissues are irradiated by controlled graded dose distributions aimed at maximizing tumor cure and minimizing normal tissue toxicity. The cell survival model proposed here is very useful and flexible for accurate description of the response of healthy tissues as well as tumors in classical and truly radiobiologically optimized radiation therapy. The repairable-conditionally repairable (RCR) model distinguishes between two different types of damage, namely the potentially repairable, which may also be lethal, i.e. if unrepaired or misrepaired, and the conditionally repairable, which may be repaired or may lead to apoptosis if it has not been repaired correctly. When potentially repairable damage is being repaired, for example by nonhomologous end joining, conditionally repairable damage may require in addition a high-fidelity correction by homologous repair. The induction of both types of damage is assumed to be described by Poisson statistics. The resultant cell survival expression has the unique ability to fit most experimental data well at low doses (the initial hypersensitive range), intermediate doses (on the shoulder of the survival curve), and high doses (on the quasi-exponential region of the survival curve). The complete Poisson expression can be approximated well by a simple bi-exponential cell survival expression, S(D) = e(-aD) + bDe(-cD), where the first term describes the survival of undamaged cells and the last term represents survival after complete repair of sublethal damage. The bi-exponential expression makes it easy to derive D(0), D(q), n and alpha, beta values to facilitate comparison with classical cell survival models.

  20. ADENOSINE RECEPTOR STIMULATION BY POLYDEOXYRIBONUCLEOTIDE IMPROVES TISSUE REPAIR AND SYMPTOMOLOGY IN EXPERIMENTAL COLITIS.

    Directory of Open Access Journals (Sweden)

    Giovanni Pallio

    2016-08-01

    Full Text Available Activation of the adenosine receptor pathway has been demonstrated to be effective in improving tissue remodelling and blunting the inflammatory response. Active colitis is characterized by an intense inflammatory reaction resulting in extensive tissue damage. Symptomatic improvement requires both control of the inflammatory process and repair and remodelling of damaged tissues. We investigated the ability of an A2A receptor agonist, polydeoxyribonucleotide (PDRN, to restore tissue structural integrity in two experimental colitis models using male Sprague-Dawley rats. In the first model, colitis was induced with a single intra-colonic instillation of dinitro-benzene-sulfonic acid (DNBS, 25mg diluted in 0.8ml 50% ethanol. After 6 hrs, animals were randomized to receive either PDRN (8mg/kg/i.p., or PDRN + the A2A antagonist (DMPX; 10mg/kg/i.p., or vehicle (0.8 ml saline solution daily. In the second model, dextran sodium sulphate (DSS was dissolved in drinking water at a concentration of 8%. Control animals received standard drinking water. After 24 hrs animals were randomized to receive PDRN or PDRN+DMPX as described above. Rats were sacrificed 7 days after receiving DNBS or 5 days after DSS. In both experimental models of colitis, PDRN ameliorated the clinical symptoms and weight loss associated with disease as well as promoted the histological repair of damaged tissues. Moreover, PDRN reduced expression of inflammatory cytokines, myeloperoxydase activity, and malondialdheyde. All these effects were abolished by the concomitant administration of the A2a antagonist DMPX. Our study suggests that PDRN may represent a promising treatment for improving tissue repair during inflammatory bowel diseases.

  1. A geometric process repair model for a repairable cold standby system with priority in use and repair

    International Nuclear Information System (INIS)

    Zhang Yuanlin; Wang Guanjun

    2009-01-01

    In this paper, a deteriorating cold standby repairable system consisting of two dissimilar components and one repairman is studied. For each component, assume that the successive working times form a decreasing geometric process while the consecutive repair times constitute an increasing geometric process, and component 1 has priority in use and repair. Under these assumptions, we consider a replacement policy N based on the number of repairs of component 1 under which the system is replaced when the number of repairs of component 1 reaches N. Our problem is to determine an optimal policy N* such that the average cost rate (i.e. the long-run average cost per unit time) of the system is minimized. The explicit equation of the average cost rate of the system is derived and the corresponding optimal replacement policy N* can be determined analytically or numerically. Finally, a numerical example with Weibull distribution is given to illustrate some theoretical results in this paper.

  2. Soft tissue reinforcement interposition flaps in hypospadias repair

    Directory of Open Access Journals (Sweden)

    Singh R

    2007-01-01

    Full Text Available Purpose: To discuss the role and mechanism of action of soft tissue reinforcement interposition flaps (STRIFs in hypospadias repairs (reinforced hypospadiac urethroplasties. Materials and Methods: Between 2000-2005, 120 consecutive hypospadiacs (distal 85, mid 20, proximal 15, who underwent primary reinforced urethroplasties employing different types of STRIFs, were retrospectively analyzed. The STRIFs were highly vascular soft tissue pedicled flaps (devoid of epithelium interposed between neo-urethras and the covering skin to reinforce the neo-urethras against fistula formation. The STRIFs were harvested, without much donor site deformity, from: preputial skin, penile skin and scrotal skin by de-epithelialization. Those from Buck′s fascia, corpus spongiosum and tunica vaginalis are STRIFs without epithelium anyway, therefore do not need de-epithelialization. Redo urethroplasties and micropenises were not included. Seven patients were excluded because they had incomplete follow-up. The remaining 113 (distal 84, mid 17, proximal 12 were followed up for nine to 40 months for number, size, location, spontaneous closure and persistence of urethro-cutaneous fistula (UCF, and other complications with regard to the severity of hypospadias, method of neourethral re-construction, types of STRIFs employed and skin cover used. A total of 158 STRIFs and 124 skin covers were used in 113 hypospadiac urethroplasties. Results: The first surgery was curative in 74 (65% of 113 patients. In the remaining 39 (35%, various complications included 12 urethro-cutaneous fistulas (UCFs, 10 urethral strictures, six cases each of penile torsion and meatal stenosis and five cases each of superficial necrosis and poor cosmesis. Of these 39 patients, 25 (64% recovered with conservative treatment and 14 (36% required re-operation, i.e. UCFs and strictures in four cases each and penile torsion, meatal stenosis and dog-ears in two cases each. All the 12 UCFs were single

  3. Cell-based tissue engineering strategies used in the clinical repair of articular cartilage.

    Science.gov (United States)

    Huang, Brian J; Hu, Jerry C; Athanasiou, Kyriacos A

    2016-08-01

    One of the most important issues facing cartilage tissue engineering is the inability to move technologies into the clinic. Despite the multitude of current research in the field, it is known that 90% of new drugs that advance past animal studies fail clinical trials. The objective of this review is to provide readers with an understanding of the scientific details of tissue engineered cartilage products that have demonstrated a certain level of efficacy in humans, so that newer technologies may be developed upon this foundation. Compared to existing treatments, such as microfracture or autologous chondrocyte implantation, a tissue engineered product can potentially provide more consistent clinical results in forming hyaline repair tissue and in filling the entirety of the defect. The various tissue engineering strategies (e.g., cell expansion, scaffold material, media formulations, biomimetic stimuli, etc.) used in forming these products, as collected from published literature, company websites, and relevant patents, are critically discussed. The authors note that many details about these products remain proprietary, not all information is made public, and that advancements to the products are continuously made. Nevertheless, by understanding the design and production processes of these emerging technologies, one can gain tremendous insight into how to best use them and also how to design the next generation of tissue engineered cartilage products. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Cell-based tissue engineering strategies used in the clinical repair of articular cartilage

    Science.gov (United States)

    Huang, Brian J.; Hu, Jerry C.; Athanasiou, Kyriacos A.

    2016-01-01

    One of the most important issues facing cartilage tissue engineering is the inability to move technologies into the clinic. Despite the multitude of review articles on the paradigm of biomaterials, signals, and cells, it is reported that 90% of new drugs that advance past animal studies fail clinical trials (1). The intent of this review is to provide readers with an understanding of the scientific details of tissue engineered cartilage products that have demonstrated a certain level of efficacy in humans, so that newer technologies may be developed upon this foundation. Compared to existing treatments, such as microfracture or autologous chondrocyte implantation, a tissue engineered product can potentially provide more consistent clinical results in forming hyaline repair tissue and in filling the entirety of the defect. The various tissue engineering strategies (e.g., cell expansion, scaffold material, media formulations, biomimetic stimuli, etc.) used in forming these products, as collected from published literature, company websites, and relevant patents, are critically discussed. The authors note that many details about these products remain proprietary, not all information is made public, and that advancements to the products are continuously made. Nevertheless, by fully understanding the design and production processes of these emerging technologies, one can gain tremendous insight into how to best use them and also how to design the next generation of tissue engineered cartilage products. PMID:27177218

  5. Repair processes for photochemical damage in mammalian cells

    International Nuclear Information System (INIS)

    Cleaver, J.E.

    1974-01-01

    Repair processes for photochemical damage in cells following uv irradiation are reviewed. Cultured fibroblast cells from human patients with xeroderma pigmentosum were used as an example to illustrate aspects of repair of injuries to DNA and proteins. (250 references) (U.S.)

  6. Further proof of the plasticity of adult stem cells and their role in tissue repair

    OpenAIRE

    Prockop, Darwin J.

    2003-01-01

    In this issue, De Bari et al. (2003) present elegant data to counter the recent claims that adult stem cells have a limited plasticity. Further, they provide evidence that adult stem cells can seek out damaged tissues and repair them.

  7. Radiosensitivity and repair capacity of two xenografted human soft tissue sarcomas to photons and fast neutrons

    International Nuclear Information System (INIS)

    Budach, V.; Stuschke, M.; Budach, W.; Krause, U.; Streffer, C.; Sack, H.

    1989-01-01

    The radiation response, the relative biological effectiveness (RBE) and sublethal damage repair of two xenografted human soft tissue sarcomas after single doses and fractionated irradiation with 60 Co and 5.8 MeV fast neutrons are presented. (author)

  8. Evaluation of histological scoring systems for tissue-engineered, repaired and osteoarthritic cartilage

    NARCIS (Netherlands)

    Rutgers, M.; van Pelt, M.J.; Dhert, W.J.A.; Creemers, L.B.; Saris, D.B.F.

    2010-01-01

    Osteoarthritis and Cartilage Volume 18, Issue 1, January 2010, Pages 12-23 -------------------------------------------------------------------------------- Review Evaluation of histological scoring systems for tissue-engineered, repaired and osteoarthritic cartilage M. Rutgers†, M.J.P. van Pelt†,

  9. Hematopoietic tissue repair under chronic low daily dose irradiation

    International Nuclear Information System (INIS)

    Seed, T.M.

    1994-01-01

    The capacity of the hematopoietic system to repair constantly accruing cellular damage under chronic, low daily dose gamma irradiation is essential for the maintenance of a functional hematopoietic system, and, in turn, long term survival. In certain individuals, however, such continuous cycles of damage and repair provide an essential inductive environment for selected types of hematopathologies, e.g., myeloid leukemia (ML). We have been studying temporal and causal relationships between hematopoietic capacity, associated repair functions, and propensities for hematologic disease in canines under variable levels of chronic radiation stress (0.3-26.3 cGy d -1 ). Results indicate that the maximum exposure rate tolerated by the hematopoietic system is highly individual-specific and is based largely on the degree to which repair capacity, and, in turn, hematopoietic restoration, is augmented under chronic exposure. In low-tolerance individuals (prone to aplastic anemia, subgroup (1), the failure to augment basic m-pair functions seemingly results in a progressive accumulation of genetic and cellular damage within vital progenitorial marrow compartments particularly marked within erythroid compartments. that results in loss of reproductive capacity and ultimately in collapse of the hematopoietic system. The high-tolerance individuals (radioaccomodated and either prone- or not prone to ML, subgroup 2 ampersand 3 appear to minimize the accumulating damage effect of daily exposures by extending repair functions, which preserves reproductive integrity and fosters regenerative hematopoietic responses. As the strength of the regenerative response manifests the extent of repair augmentation, the relatively strong response of high- tolerance individuals progressing to patent ML suggests an insufficiency of repair quality rather than repair quantity

  10. Tissue repair genes: the TiRe database and its implication for skin wound healing

    OpenAIRE

    Yanai, Hagai; Budovsky, Arie; Tacutu, Robi; Barzilay, Thomer; Abramovich, Amir; Ziesche, Rolf; Fraifeld, Vadim E.

    2016-01-01

    Wound healing is an inherent feature of any multicellular organism and recent years have brought about a huge amount of data regarding regular and abnormal tissue repair. Despite the accumulated knowledge, modulation of wound healing is still a major biomedical challenge, especially in advanced ages. In order to collect and systematically organize what we know about the key players in wound healing, we created the TiRe (Tissue Repair) database, an online collection of genes and proteins that ...

  11. The application of lesion sterilization and tissue repair 3Mix-MP for treating rat's dental pulp tissue

    Directory of Open Access Journals (Sweden)

    Raditya Nugroho

    2015-03-01

    Full Text Available Background: Lesion sterilization and tissue repair (LSTR 3Mix-MP are three broad-spectrum antibiotics, including metronidazole, ciprofloxacin and minocycline are mixed with propylene glycol or macrogol. There is the possibility ofthe healing process that marked proliferation ofnew blood vessels and proliferation offibroblasts in the treatment ofirreversible pulpitis by pulp capping LSTR 3MixMP because of  the principle of the method LSTR 3Mix-MP is to kill bacteria. Purpose: The purpose of this study to prove the effect of LSTR 3Mix-MP on chronic inflammation and the healing process in rat dental pulp tissue in vivo. Methods: Rattus norvegicus anaesthetized by using ketamine and xylazine dissolved in sterile isotonic saline solution (0.2 ml/50gr mm on the upper right thigh. Cavity preparation class I to perforation by using a low speed tapered diamond round bur. In the treatment group, rats were treated 3Mix-MP at a dose of10 mg and then covered with glass ionomer cement for 7 days on the pulp that has been opened for 3 days. The control group treated with saline irrigation on the pulp that has been opened for 3 days. Rats were killed after seven days, and then made preparations pulp tissue to count the number oflymphocytes, macrophages, plasma cells, blood vessels, and fibroblasts Results: There is an increase in the average number ofmacrophage cells, plasma, and fibroblasts; and decreased lymphocytes and blood vessels in the treated group exposure LSTR 3Mix-MP. Conclusion:LSTR 3Mix-MP can reduce chronic inflammation process and enhance the healing process in rat dental pulp tissue.

  12. Analysis of DNA vulnerability to damage, repair and degradation in tissues of irradiated animals

    International Nuclear Information System (INIS)

    Ryabchenko, N.I.; Ivannik, B.P.

    1982-01-01

    Single-strand and paired ruptures of DNA were found to result in appearance of locally denaturated areas in its secondary structure and to disordered protein-DNA interaction. It was shown with the use of the viscosimeter method of measuring the molecular mass of single stranded high-polymeric DNA that cells of various tissues by the intensity of DNA repair can be divided into two groups, rapid- and slow-repair ones. Tissue specificity of enzyme function of the repair systems and systems responsible for post-irradiation DNA degradation depends on the activity of endonucleases synthesized by the cells both in health and in their irradiation-induced synthesis

  13. Mussel-inspired tough hydrogels with self-repairing and tissue adhesion

    Science.gov (United States)

    Gao, Zijian; Duan, Lijie; Yang, Yongqi; Hu, Wei; Gao, Guanghui

    2018-01-01

    The mussel-inspired polymeric hydrogels have been attractively explored owing to their self-repairing or adhesive property when the catechol groups of dopamine could chelate metal ions. However, it was a challenge for self-repairing hydrogels owning high mechanical properties. Herein, a synergistic strategy was proposed by combining catechol-Fe3+ complexes and hydrophobic association. The resulting hydrogels exhibited seamless self-repairing behavior, tissue adhesion and high mechanical property. Moreover, the pH-dependent stoichiometry of catechol-Fe3+ and temperature-sensitive hydrophobic association endue hydrogels with pH/thermo responsive characteristics. Subsequently, the self-repairing rate and mechanical property of hydrogels were investigated at different pH and temperature. This bio-inspired strategy would build an avenue for designing and constructing a new generation of self-repairing, tissue-adhesive and tough hydrogel.

  14. An acidic microenvironment sets the humoral pattern recognition molecule PTX3 in a tissue repair mode

    Science.gov (United States)

    Doni, Andrea; Musso, Tiziana; Morone, Diego; Bastone, Antonio; Zambelli, Vanessa; Sironi, Marina; Castagnoli, Carlotta; Cambieri, Irene; Stravalaci, Matteo; Pasqualini, Fabio; Laface, Ilaria; Valentino, Sonia; Tartari, Silvia; Ponzetta, Andrea; Maina, Virginia; Barbieri, Silvia S.; Tremoli, Elena; Catapano, Alberico L.; Norata, Giuseppe D.; Bottazzi, Barbara; Garlanda, Cecilia

    2015-01-01

    Pentraxin 3 (PTX3) is a fluid-phase pattern recognition molecule and a key component of the humoral arm of innate immunity. In four different models of tissue damage in mice, PTX3 deficiency was associated with increased fibrin deposition and persistence, and thicker clots, followed by increased collagen deposition, when compared with controls. Ptx3-deficient macrophages showed defective pericellular fibrinolysis in vitro. PTX3-bound fibrinogen/fibrin and plasminogen at acidic pH and increased plasmin-mediated fibrinolysis. The second exon-encoded N-terminal domain of PTX3 recapitulated the activity of the intact molecule. Thus, a prototypic component of humoral innate immunity, PTX3, plays a nonredundant role in the orchestration of tissue repair and remodeling. Tissue acidification resulting from metabolic adaptation during tissue repair sets PTX3 in a tissue remodeling and repair mode, suggesting that matrix and microbial recognition are common, ancestral features of the humoral arm of innate immunity. PMID:25964372

  15. Augmentation of Rotator Cuff Repair With Soft Tissue Scaffolds

    Science.gov (United States)

    Thangarajah, Tanujan; Pendegrass, Catherine J.; Shahbazi, Shirin; Lambert, Simon; Alexander, Susan; Blunn, Gordon W.

    2015-01-01

    Background Tears of the rotator cuff are one of the most common tendon disorders. Treatment often includes surgical repair, but the rate of failure to gain or maintain healing has been reported to be as high as 94%. This has been substantially attributed to the inadequate capacity of tendon to heal once damaged, particularly to bone at the enthesis. A number of strategies have been developed to improve tendon-bone healing, tendon-tendon healing, and tendon regeneration. Scaffolds have received considerable attention for replacement, reconstruction, or reinforcement of tendon defects but may not possess situation-specific or durable mechanical and biological characteristics. Purpose To provide an overview of the biology of tendon-bone healing and the current scaffolds used to augment rotator cuff repairs. Study Design Systematic review; Level of evidence, 4. Methods A preliminary literature search of MEDLINE and Embase databases was performed using the terms rotator cuff scaffolds, rotator cuff augmentation, allografts for rotator cuff repair, xenografts for rotator cuff repair, and synthetic grafts for rotator cuff repair. Results The search identified 438 unique articles. Of these, 214 articles were irrelevant to the topic and were therefore excluded. This left a total of 224 studies that were suitable for analysis. Conclusion A number of novel biomaterials have been developed into biologically and mechanically favorable scaffolds. Few clinical trials have examined their effect on tendon-bone healing in well-designed, long-term follow-up studies with appropriate control groups. While there is still considerable work to be done before scaffolds are introduced into routine clinical practice, there does appear to be a clear indication for their use as an interpositional graft for large and massive retracted rotator cuff tears and when repairing a poor-quality degenerative tendon. PMID:26665095

  16. Role of the immune system in cardiac tissue damage and repair following myocardial infarction.

    Science.gov (United States)

    Saparov, Arman; Ogay, Vyacheslav; Nurgozhin, Talgat; Chen, William C W; Mansurov, Nurlan; Issabekova, Assel; Zhakupova, Jamilya

    2017-09-01

    The immune system plays a crucial role in the initiation, development, and resolution of inflammation following myocardial infarction (MI). The lack of oxygen and nutrients causes the death of cardiomyocytes and leads to the exposure of danger-associated molecular patterns that are recognized by the immune system to initiate inflammation. At the initial stage of post-MI inflammation, the immune system further damages cardiac tissue to clear cell debris. The excessive production of reactive oxygen species (ROS) by immune cells and the inability of the anti-oxidant system to neutralize ROS cause oxidative stress that further aggravates inflammation. On the other hand, the cells of both innate and adaptive immune system and their secreted factors are critically instrumental in the very dynamic and complex processes of regulating inflammation and mediating cardiac repair. It is important to decipher the balance between detrimental and beneficial effects of the immune system in MI. This enables us to identify better therapeutic targets for reducing the infarct size, sustaining the cardiac function, and minimizing the likelihood of heart failure. This review discusses the role of both innate and adaptive immune systems in cardiac tissue damage and repair in experimental models of MI.

  17. The influence of platelet- derived products on angiogenesis and tissue repair: a concise update

    Directory of Open Access Journals (Sweden)

    Constanza E Martínez

    2015-10-01

    Full Text Available Platelet degranulation allows the release of a large amount of soluble mediators, is an essential step for wound healing initiation, and stimulates clotting and angiogenesis. The latter process is one of the most critical biological events observed during tissue repair,increasing the growth of blood vessels in the maturing wound. Angiogenesis requires the action of a variety of growth factors that act in an appropriate physiological ratio to assure functional blood vessel restoration. Platelets release main regulators of angiogenesis: Vascular Endothelial Growth Factors (VEGFs, basic fibroblast growth factor (FGF-2, and Platelet derived growth factors (PDGFs, among others. In order to stimulate tissue repair, platelet derived fractions have been used as an autologous source of growth factors and biomolecules, namely Platelet Rich Plasma (PRP, Platelet Poor Plasma (PPP and Platelet Rich Fibrin(PRF. The continuous release of these growth factors has been proposed to promote angiogenesis both in vitro and in vivo. Considering the existence of clinical trials currently evaluating the efficacy of autologous PRP, the present review analyses fundamental questions regarding the putative role of platelet derived fractions as regulators of angiogenesis and evaluates the possible clinical implications of these formulations.

  18. Friction stir welding process to repair voids in aluminum alloys

    Science.gov (United States)

    Rosen, Charles D. (Inventor); Litwinski, Edward (Inventor); Valdez, Juan M. (Inventor)

    1999-01-01

    The present invention provides an in-process method to repair voids in an aluminum alloy, particularly a friction stir weld in an aluminum alloy. For repairing a circular void or an in-process exit hole in a weld, the method includes the steps of fabricating filler material of the same composition or compatible with the parent material into a plug form to be fitted into the void, positioning the plug in the void, and friction stir welding over and through the plug. For repairing a longitudinal void (30), the method includes machining the void area to provide a trough (34) that subsumes the void, fabricating filler metal into a strip form (36) to be fitted into the trough, positioning the strip in the trough, and rewelding the void area by traversing a friction stir welding tool longitudinally through the strip. The method is also applicable for repairing welds made by a fusing welding process or voids in aluminum alloy workpieces themselves.

  19. The Application of Tissue Engineering Procedures to Repair the Larynx

    Science.gov (United States)

    Ringel, Robert L.; Kahane, Joel C.; Hillsamer, Peter J.; Lee, Annie S.; Badylak, Stephen F.

    2006-01-01

    The field of tissue engineering/regenerative medicine combines the quantitative principles of engineering with the principles of the life sciences toward the goal of reconstituting structurally and functionally normal tissues and organs. There has been relatively little application of tissue engineering efforts toward the organs of speech, voice,…

  20. Transcriptional profiling differences for articular cartilage and repair tissue in equine joint surface lesions

    Directory of Open Access Journals (Sweden)

    Stromberg Arnold J

    2009-09-01

    Full Text Available Abstract Background Full-thickness articular cartilage lesions that reach to the subchondral bone yet are restricted to the chondral compartment usually fill with a fibrocartilage-like repair tissue which is structurally and biomechanically compromised relative to normal articular cartilage. The objective of this study was to evaluate transcriptional differences between chondrocytes of normal articular cartilage and repair tissue cells four months post-microfracture. Methods Bilateral one-cm2 full-thickness defects were made in the articular surface of both distal femurs of four adult horses followed by subchondral microfracture. Four months postoperatively, repair tissue from the lesion site and grossly normal articular cartilage from within the same femorotibial joint were collected. Total RNA was isolated from the tissue samples, linearly amplified, and applied to a 9,413-probe set equine-specific cDNA microarray. Eight paired comparisons matched by limb and horse were made with a dye-swap experimental design with validation by histological analyses and quantitative real-time polymerase chain reaction (RT-qPCR. Results Statistical analyses revealed 3,327 (35.3% differentially expressed probe sets. Expression of biomarkers typically associated with normal articular cartilage and fibrocartilage repair tissue corroborate earlier studies. Other changes in gene expression previously unassociated with cartilage repair were also revealed and validated by RT-qPCR. Conclusion The magnitude of divergence in transcriptional profiles between normal chondrocytes and the cells that populate repair tissue reveal substantial functional differences between these two cell populations. At the four-month postoperative time point, the relative deficiency within repair tissue of gene transcripts which typically define articular cartilage indicate that while cells occupying the lesion might be of mesenchymal origin, they have not recapitulated differentiation to

  1. Development of biodegradable hyper-branched tissue adhesives for the repair of meniscus tears

    NARCIS (Netherlands)

    Bochynska, A. I.; Van Tienen, T. G.; Hannink, G.; Buma, P.; Grijpma, D. W.

    2016-01-01

    Meniscus tears are one of the most commonly occurring injuries of the knee joint. Current meniscus repair techniques are challenging and do not bring fully satisfactory results. Tissue adhesives are a promising alternative, since they are easy to apply and cause minimal tissue trauma. In this study,

  2. Traumatic hallux varus repair utilizing a soft-tissue anchor: a case report.

    Science.gov (United States)

    Labovitz, J M; Kaczander, B I

    2000-01-01

    Hallux varus is usually iatrogenic in nature; however, congenital and acquired etiologies have been described in the literature. The authors present a case of traumatic hallux varus secondary to rupture of the adductor tendon. Surgical correction was performed using a soft tissue anchor for maintenance of the soft tissues utilized for repair.

  3. Investigating the use of curcumin-loaded electrospun filaments for soft tissue repair applications

    Directory of Open Access Journals (Sweden)

    Mouthuy PA

    2017-05-01

    Full Text Available Pierre-Alexis Mouthuy,1,2 Maja Somogyi Škoc,3 Ana Čipak Gašparović,1 Lidija Milković,1 Andrew J Carr,2 Neven Žarković1 1Laboratory for Oxidative Stress, Rudjer Boskovic Institute, Zagreb, Croatia; 2Botnar Research Centre, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, Medical Science Division, University of Oxford, Oxford, UK; 3Department of Materials, Fibres and Textile Testing, University of Zagreb, Zagreb, Croatia Abstract: Electrospun filaments represent a new generation of medical textiles with promising applications in soft tissue repair. A potential strategy to improve their design is to combine them with bioactive molecules. Curcumin, a natural compound found in turmeric, is particularly attractive for its antioxidant, anti-inflammatory, and antimicrobial properties. However, investigating the range of relevant doses of curcumin in materials designed for tissue regeneration has remained limited. In this paper, a wide range of curcumin concentrations was explored and the potential of the resulting materials for soft tissue repair applications was assessed. Polydioxanone (PDO filaments were prepared with various amounts of curcumin: 0%, 0.001%, 0.01%, 0.1%, 1%, and 10% (weight to weight ratio. The results from the present study showed that, at low doses (≤0.1%, the addition of curcumin has no influence on the spinning process or on the physicochemical properties of the filaments, whereas higher doses lead to smaller fiber diameters and improved mechanical properties. Moreover, filaments with 0.001% and 0.01% curcumin stimulate the metabolic activity and proliferation of normal human dermal fibroblasts (NHDFs compared with the no-filament control. However, this stimulation is not significant when compared to the control filaments (0%. Highly dosed filaments induce either the inhibition of proliferation (with 1% or cell apoptosis (with 10% as a result of the concentrations of curcumin found in the

  4. Immunohistochemical analysis of oxidative stress and DNA repair proteins in normal mammary and breast cancer tissues

    International Nuclear Information System (INIS)

    Curtis, Carol D; Thorngren, Daniel L; Nardulli, Ann M

    2010-01-01

    During the course of normal cellular metabolism, oxygen is consumed and reactive oxygen species (ROS) are produced. If not effectively dissipated, ROS can accumulate and damage resident proteins, lipids, and DNA. Enzymes involved in redox regulation and DNA repair dissipate ROS and repair the resulting damage in order to preserve a functional cellular environment. Because increased ROS accumulation and/or unrepaired DNA damage can lead to initiation and progression of cancer and we had identified a number of oxidative stress and DNA repair proteins that influence estrogen responsiveness of MCF-7 breast cancer cells, it seemed possible that these proteins might be differentially expressed in normal mammary tissue, benign hyperplasia (BH), ductal carcinoma in situ (DCIS) and invasive breast cancer (IBC). Immunohistochemistry was used to examine the expression of a number of oxidative stress proteins, DNA repair proteins, and damage markers in 60 human mammary tissues which were classified as BH, DCIS or IBC. The relative mean intensity was determined for each tissue section and ANOVA was used to detect statistical differences in the relative expression of BH, DCIS and IBC compared to normal mammary tissue. We found that a number of these proteins were overexpressed and that the cellular localization was altered in human breast cancer tissue. Our studies suggest that oxidative stress and DNA repair proteins not only protect normal cells from the damaging effects of ROS, but may also promote survival of mammary tumor cells

  5. Quantitative assessment of optical properties in healthy cartilage and repair tissue by optical coherence tomography and histology (Conference Presentation)

    Science.gov (United States)

    Jansen, Sanne M. A.; Cernohorsky, Paul; de Bruin, Daniel M.; van der Pol, Edwin; Savci-Heijink, Cemile D.; Strackee, Simon D.; Faber, Dirk J.; van Leeuwen, Ton G.

    2016-02-01

    Quantification of the OCT signal is an important step toward clinical implementation of a diagnostic tool in cartilage imaging. Discrimination of structural cartilage differences in patients with osteoarthritis is critical, yet challenging. This study assesses the variation in the optical attenuation coefficient (μOCT) between healthy cartilage, repair tissue, bone and layers within repair tissue in a controlled setting. OCT and histology was used to assess goat talus articular surfaces in which central osteochondral defects were created. Exact matches of OCT and histology were selected for research. μOCT measurements were taken from healthy cartilage, repair tissue and bone. Measured μOCT in healthy cartilage was higher compared to both repair tissue and bone tissue. Two possible mechanisms for the difference in attenuation were investigated. We studied morphological parameters in terms of nucleus count, nucleus size and inter-nucleus distance. Collagen content in healthy cartilage and repair tissue was assessed using polarization microscopy. Quantitative analysis of the nuclei did not demonstrate a difference in nucleus size and count between healthy cartilage and repair tissue. In healthy cartilage, cells were spaced farther apart and had a lower variation in local nuclear density compared to repair tissue. Polarization microscopy suggested higher collagen content in healthy cartilage compared to repair tissue. μOCT measurements can distinguish between healthy cartilage, repair tissue and bone. Results suggest that cartilage OCT attenuation measurements could be of great impact in clinical diagnostics of osteoarthritis.

  6. Tissue engineered devices for ligament repair, replacement and ...

    African Journals Online (AJOL)

    potential, severe damage warrants surgical intervention including complete replacement. Ligaments are longitudinally arranged, complex tissues; the mechanical properties of ligaments are a direct result of their components and the arrangement of these components in the tissue. It is these mechanics that have made ...

  7. Tissue engineered devices for ligament repair, replacement and ...

    African Journals Online (AJOL)

    PRECIOUS

    2009-12-29

    Dec 29, 2009 ... These devices use a wide variety of materials and designs to replicate ligament mechanics and allow for new tissue regeneration. Key words: Anterior cruciate ligament (ACL), tissue engineering, cells, tensile, stress relaxation, polymer, allograft, xenograft. INTRODUCTION. The anterior cruciate ligament ...

  8. Autologous Cartilage Chip Transplantation Improves Repair Tissue Composition Compared With Marrow Stimulation.

    Science.gov (United States)

    Christensen, Bjørn Borsøe; Olesen, Morten Lykke; Lind, Martin; Foldager, Casper Bindzus

    2017-06-01

    Repair of chondral injuries by use of cartilage chips has recently demonstrated clinical feasibility. To investigate in vivo cartilage repair outcome of autologous cartilage chips compared with marrow stimulation in full-thickness cartilage defects in a minipig model. Controlled laboratory study. Six Göttingen minipigs received two 6-mm chondral defects in the medial and lateral trochlea of each knee. The two treatment groups were (1) autologous cartilage chips embedded in fibrin glue (ACC) (n = 12) and (2) marrow stimulation (MST) (n = 12). The animals were euthanized after 6 months, and the composition of repair tissue was quantitatively determined using histomorphometry. Semiquantitative evaluation was performed by means of the International Cartilage Repair Society (ICRS) II score. Collagen type II staining was used to further evaluate the repair tissue composition. Significantly more hyaline cartilage was found in the ACC (17.1%) compared with MST (2.9%) group ( P cartilage repair tissue compared with MST at 6 months postoperatively. Further studies are needed to investigate ACC as a possible alternative first-line treatment for focal cartilage injuries in the knee.

  9. The necessity of a theory of biology for tissue engineering: metabolism-repair systems.

    Science.gov (United States)

    Ganguli, Suman; Hunt, C Anthony

    2004-01-01

    Since there is no widely accepted global theory of biology, tissue engineering and bioengineering lack a theoretical understanding of the systems being engineered. By default, tissue engineering operates with a "reductionist" theoretical approach, inherited from traditional engineering of non-living materials. Long term, that approach is inadequate, since it ignores essential aspects of biology. Metabolism-repair systems are a theoretical framework which explicitly represents two "functional" aspects of living organisms: self-repair and self-replication. Since repair and replication are central to tissue engineering, we advance metabolism-repair systems as a potential theoretical framework for tissue engineering. We present an overview of the framework, and indicate directions to pursue for extending it to the context of tissue engineering. We focus on biological networks, both metabolic and cellular, as one such direction. The construction of these networks, in turn, depends on biological protocols. Together these concepts may help point the way to a global theory of biology appropriate for tissue engineering.

  10. NOD-Like Receptors in Intestinal Homeostasis and Epithelial Tissue Repair

    Science.gov (United States)

    Parlato, Marianna; Yeretssian, Garabet

    2014-01-01

    The intestinal epithelium constitutes a dynamic physical barrier segregating the luminal content from the underlying mucosal tissue. Following injury, the epithelial integrity is restored by rapid migration of intestinal epithelial cells (IECs) across the denuded area in a process known as wound healing. Hence, through a sequence of events involving restitution, proliferation and differentiation of IECs the gap is resealed and homeostasis reestablished. Relapsing damage followed by healing of the inflamed mucosa is a hallmark of several intestinal disorders including inflammatory bowel diseases (IBD). While several regulatory peptides, growth factors and cytokines stimulate restitution of the epithelial layer after injury, recent evidence in the field underscores the contribution of innate immunity in controlling this process. In particular, nucleotide-binding and oligomerization domain-like receptors (NLRs) play critical roles in sensing the commensal microbiota, maintaining homeostasis, and regulating intestinal inflammation. Here, we review the process of intestinal epithelial tissue repair and we specifically focus on the impact of NLR-mediated signaling mechanisms involved in governing epithelial wound healing during disease. PMID:24886810

  11. A tissue regeneration approach to bone and cartilage repair

    CERN Document Server

    Dunstan, Colin; Rosen, Vicki

    2015-01-01

    Reviewing exhaustively the current state of the art of tissue engineering strategies for regenerating bones and joints through the use of biomaterials, growth factors and stem cells, along with an investigation of the interactions between biomaterials, bone cells, growth factors and added stem cells and how together skeletal tissues can be optimised, this book serves to highlight the importance of biomaterials composition, surface topography, architectural and mechanical properties in providing support for tissue regeneration. Maximizing reader insights into the importance of the interplay of these attributes with bone cells (osteoblasts, osteocytes and osteoclasts) and cartilage cells (chondrocytes), this book also provides a detailed reference as to how key signalling pathways are activated. The contribution of growth factors to drive tissue regeneration and stem cell recruitment is discussed along with a review the potential and challenges of adult or embryonic mesenchymal stem cells to further enhance the...

  12. Repairing an installation and processing the residues

    International Nuclear Information System (INIS)

    Malet, J.C.; Duverger de Cuy, G.; Sophy, Y.; Cucinotta, A.

    1989-01-01

    After a sodium leak in a locale, producing a fire, the operator's first concern is to repair the plant. Since the residual sodium and the products of combustion are chemically aggressive, the personnel will have to perform this operation in a hostile environment. This paper presents answers which can be given to the three questions which will however rise: When can the intervention begin? How will it be performed? What should be done with the residues of combustion? This document aims at presenting the different solutions to this problem, these solutions being derived from experiments carried out in France either in the Esmeralda Programme, which is managed jointly by CEA and ENEA, or in the other French programmes. As a general rule, the intervention inside the locale can be made much more easier if: it was foreseen right from the beginning of the design (access under the pipes, anchorage for handling, etc.); the incident can have been localised thanks to the monitoring of locales, enabling the video recording of the first instants, that is, as long as visibility does not fall to zero due to the aerosols from the fire. (author)

  13. Tissue-Derived Extracellular Matrix Bioscaffolds: Emerging Applications in Cartilage and Meniscus Repair.

    Science.gov (United States)

    Monibi, Farrah A; Cook, James L

    2017-08-01

    Musculoskeletal injuries are a common problem in orthopedic practice. Given the long-term consequences of unaddressed cartilage and meniscal pathology, a number of treatments have been attempted to stimulate repair or to replace the injured tissue. Despite advances in orthopedic surgery, effective treatments for cartilage and meniscus injuries remain a significant clinical challenge. Tissue engineering is a developing field that aims to regenerate injured tissues with a combination of cells, scaffolds, and signals. Many natural and synthetic scaffold materials have been developed and tested for the repair and restoration of a number of musculoskeletal tissues. Among these, biological scaffolds derived from cell and tissue-derived extracellular matrix (ECM) have shown great promise in tissue engineering given the critical role of the ECM for maintaining the biological and biomechanical properties, structure, and function of native tissues. This review article presents emerging applications for tissue-derived ECM scaffolds in cartilage and meniscus repair. We examine normal ECM composition and the current and future methods for potential treatment of articular cartilage and meniscal defects with decellularized scaffolds.

  14. Native-tissue repair of isolated primary rectocele compared with nonabsorbable mesh

    DEFF Research Database (Denmark)

    Madsen, Lene Duch; Nussler, Emil; Kesmodel, Ulrik Schioler

    2017-01-01

    and included 3988 women with a primary operation for rectocele between 2006 and 2014: 3908 women had native-tissue repair, 80 were operated with nonabsorbable mesh. No concurrent operations were performed. Pre- and perioperative data were collected from doctors and patients. Patient-reported outcomes were......INTRODUCTION: We evaluated patient-reported outcomes and complications after treatment of isolated primary rectocele in routine health-care settings using native-tissue repair or nonabsorbable mesh. METHODS: We used prospective data from the Swedish National Register for Gynaecological Surgery...

  15. Effect of low-level laser therapy on tissue repair after dental extraction in rats administered zoledronic acid and dexamethasone

    Science.gov (United States)

    Weber, João Batista Blessmann; Camilotti, Renata Stifelman; Jasper, Juliana; Casagrande, Liliane Cristina Onofre; Maito, Fábio Luiz Dal Moro

    2017-05-01

    Bisphosphonates (BPs) are being increasingly used for the treatment of metabolic and oncological pathologies involving the skeletal system. Because of the severity of the BP associated osteonecrosis of the jaws, the difficulties of treatment, and patient discomfort, additional support methods for their management are needed. Laser therapy has an easy handling, photobiostimulator effect on tissues healing, so it can be considered a preferred therapy. The aim of this study was to evaluate the influence of low-level laser therapy in the 685- and 830-nm wavelength in the healing process of the bone and soft tissues in rats under BP therapy [zoledronic acid (ZA)] and dexamethasone concomitantly that underwent a surgery for the extraction of upper molars. There were statistically significant differences in the clinical evaluation of the wound and the weight of the animals. Regarding the histological evaluation, it was possible to observe the different maturations of the healing stage between groups. The effect of drug therapy with ZA and dexamethasone in the bone tissue repair process induces osteonecrosis of the jaw in rats and slows down the healing process. In the laser groups, at the stipulated dosimetry, a positive influence on the bone and soft tissue repair process was observed.

  16. Full incorporation of Strattice™ Reconstructive Tissue Matrix in a reinforced hiatal hernia repair: a case report

    Directory of Open Access Journals (Sweden)

    Freedman Bruce E

    2012-08-01

    Full Text Available Abstract Introduction A non-cross-linked porcine acellular dermal matrix was used to reinforce an esophageal hiatal hernia repair. A second surgery was required 11 months later to repair a slipped Nissen; this allowed for examination of the hiatal hernia repair and showed the graft to be well vascularized and fully incorporated. Case presentation A 71-year-old Caucasian woman presented with substernal burning and significant dysphagia. An upper gastrointestinal series revealed a type III complex paraesophageal hiatal hernia. She underwent laparoscopic surgery to repair a hiatal hernia that was reinforced with a xenograft (Strattice™ Reconstructive Tissue Matrix, LifeCell, Branchburg, NJ, USA along with a Nissen fundoplication. A second surgery was required to repair a slipped Nissen; this allowed for examination of the hiatal repair and graft incorporation 11 months after the initial surgery. Conclusion In this case, a porcine acellular dermal matrix was an effective tool to reinforce the crural hiatal hernia repair. The placement of the mesh and method of fixation are believed to be crucial to the success of the graft. It was found to be well vascularized 11 months after the original placement with no signs of erosion, stricture, or infection. Further studies and long-term follow-up are required to support the findings of this case report.

  17. Electrosleeve process for in-situ nuclear steam generator repair

    International Nuclear Information System (INIS)

    Barton, R.A.; Moran, T.E.; Renaud, E.

    1997-01-01

    Degradation of steam generator (SG) tubing by localized corrosion is a widespread problem in the nuclear industry that can lead to costly forced out-ages, unit de-rating, SG replacement or even the permanent shutdown of a reactor. In response to the onset of SG tubing degradation at Ontario Hydro's Pickering Nuclear Generating Station (PNGS) Unit 5, and the determined unsuitability of conventional repair methods (mechanically expanded or welded sleeves) for Alloy 400, an alternative repair technology was developed. Electrosleeve is a non-intrusive, low-temperature process that involves the electrodeposition of a nanocrystalline nickel microalloy forming a continuously bonded, structural layer over the internal diameter of the degraded region. This technology is designed to provide a long-term pressure boundary repair, fully restoring the structural integrity of the damaged region to its original state. This paper describes the Electrosleeve process for SG tubing repair and the unique properties of the advanced sleeve material. The successful installation of Electrosleeves that have been in service for more than three years in Alloy 400 SG tubing at the Pickering-5 CANDU unit, the more recent extension of the technology to Alloy 600 and its demonstration in a U.S. pressurized water reactor (PWR), is presented. A number of PWR operators have requested plant operating technical specification changes to permit Electrosleeve SG tube repair. Licensing of the Electrosleeve by the U.S. Nuclear Regulatory Commission (NRC) is expected imminently. (author)

  18. Repairing process models to reflect reality

    NARCIS (Netherlands)

    Fahland, D.; Aalst, van der W.M.P.; Barros, A.; Gal, A.; Kindler, E.

    2012-01-01

    Process mining techniques relate observed behavior (i.e., event logs) to modeled behavior (e.g., a BPMN model or a Petri net). Processes models can be discovered from event logs and conformance checking techniques can be used to detect and diagnose differences between observed and modeled behavior.

  19. Current Therapeutic Strategies for Adipose Tissue Defects/Repair Using Engineered Biomaterials and Biomolecule Formulations

    Directory of Open Access Journals (Sweden)

    Christopher M. Mahoney

    2018-05-01

    Full Text Available Tissue engineered scaffolds for adipose restoration/repair has significantly evolved in recent years. Patients requiring soft tissue reconstruction, caused by defects or pathology, require biomaterials that will restore void volume with new functional tissue. The gold standard of autologous fat grafting (AFG is not a reliable option. This review focuses on the latest therapeutic strategies for the treatment of adipose tissue defects using biomolecule formulations and delivery, and specifically engineered biomaterials. Additionally, the clinical need for reliable off-the-shelf therapies, animal models, and challenges facing current technologies are discussed.

  20. Current Therapeutic Strategies for Adipose Tissue Defects/Repair Using Engineered Biomaterials and Biomolecule Formulations.

    Science.gov (United States)

    Mahoney, Christopher M; Imbarlina, Cayla; Yates, Cecelia C; Marra, Kacey G

    2018-01-01

    Tissue engineered scaffolds for adipose restoration/repair has significantly evolved in recent years. Patients requiring soft tissue reconstruction, caused by defects or pathology, require biomaterials that will restore void volume with new functional tissue. The gold standard of autologous fat grafting (AFG) is not a reliable option. This review focuses on the latest therapeutic strategies for the treatment of adipose tissue defects using biomolecule formulations and delivery, and specifically engineered biomaterials. Additionally, the clinical need for reliable off-the-shelf therapies, animal models, and challenges facing current technologies are discussed.

  1. Single-stage soft tissue reconstruction and orbital fracture repair for complex facial injuries.

    Science.gov (United States)

    Wu, Peng Sen; Matoo, Reshvin; Sun, Hong; Song, Li Yuan; Kikkawa, Don O; Lu, Wei

    2017-02-01

    Orbital fractures with open periorbital wounds cause significant morbidity. Timing of debridement with fracture repair and soft tissue reconstruction is controversial. This study focuses on the efficacy of early single-stage repair in combined bony and soft tissue injuries. Retrospective review. Twenty-three patients with combined open soft tissue wounds and orbital fractures were studied for single-stage orbital reconstruction and periorbital soft tissue repair. Inclusion criteria were open soft tissue wounds with clinical and radiographic evidence of orbital fractures and repair performed within 48 h after injury. Surgical complications and reconstructive outcomes were assessed over 6 months. The main outcome measures were enophthalmos, pre- and post-CT imaging of orbits, scar evaluation, presence of diplopia, and eyelid position. Enophthalmos was corrected in 16/19 cases and improved in 3/19 cases. 3D reconstruction of CT images showed markedly improved orbital alignment with objective measurements of the optic foramen to cornea distance (mm) in reconstructed orbits relative to intact orbits of 0.66, 95% confidence interval [CI] (lower 0.33, upper 0.99) mm. The mean baseline of Stony Brook Scar Evaluation Scale was 0.6, 95%CI (0.30-0.92), and for 6 months, the mean score was 3.4, 95%CI (3.05-3.73). Residual diplopia in secondary gazes was present in two patients; one patient had ectropion. Complications included one case of local wound infection. An early single-stage repair of combined soft tissue and orbital fractures yields satisfactory functional and aesthetic outcomes. Complications are low and likely related to trauma severity. Copyright © 2016 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

  2. Repair and tissue engineering techniques for articular cartilage

    OpenAIRE

    Makris, Eleftherios A.; Gomoll, Andreas H.; Malizos, Konstantinos N.; Hu, Jerry C.; Athanasiou, Kyriacos A.

    2014-01-01

    © 2015 Macmillan Publishers Limited. All rights reserved. Chondral and osteochondral lesions due to injury or other pathology commonly result in the development of osteoarthritis, eventually leading to progressive total joint destruction. Although current progress suggests that biologic agents can delay the advancement of deterioration, such drugs are incapable of promoting tissue restoration. The limited ability of articular cartilage to regenerate renders joint arthroplasty an unavoidable s...

  3. Digital design of scaffold for mandibular defect repair based on tissue engineering.

    Science.gov (United States)

    Liu, Yun-feng; Zhu, Fu-dong; Dong, Xing-tao; Peng, Wei

    2011-09-01

    Mandibular defect occurs more frequently in recent years, and clinical repair operations via bone transplantation are difficult to be further improved due to some intrinsic flaws. Tissue engineering, which is a hot research field of biomedical engineering, provides a new direction for mandibular defect repair. As the basis and key part of tissue engineering, scaffolds have been widely and deeply studied in regards to the basic theory, as well as the principle of biomaterial, structure, design, and fabrication method. However, little research is targeted at tissue regeneration for clinic repair operations. Since mandibular bone has a special structure, rather than uniform and regular structure in existing studies, a methodology based on tissue engineering is proposed for mandibular defect repair in this paper. Key steps regarding scaffold digital design, such as external shape design and internal microstructure design directly based on triangular meshes are discussed in detail. By analyzing the theoretical model and the measured data from the test parts fabricated by rapid prototyping, the feasibility and effectiveness of the proposed methodology are properly verified. More works about mechanical and biological improvements need to be done to promote its clinical application in future.

  4. Digital design of scaffold for mandibular defect repair based on tissue engineering

    Institute of Scientific and Technical Information of China (English)

    Yun-feng LIU; Fu-dong ZHU; Xing-tao DONG; Wei PENG

    2011-01-01

    Mandibular defect occurs more frequently in recent years,and clinical repair operations via bone transplantation are difficult to be further improved due to some intrinsic flaws.Tissue engineering,which is a hot research field of biomedical engineering,provides a new direction for mandibular defect repair.As the basis and key part of tissue engineering,scaffolds have been widely and deeply studied in regards to the basic theory,as well as the principle of biomaterial,structure,design,and fabrication method.However,little research is targeted at tissue regeneration for clinic repair operations.Since mandibular bone has a special structure,rather than uniform and regular structure in existing studies,a methodology based on tissue engineering is proposed for mandibular defect repair in this paper.Key steps regarding scaffold digital design,such as external shape design and internal microstructure design directly based on triangular meshes are discussed in detail.By analyzing the theoretical model and the measured data from the test parts fabricated by rapid prototyping,the feasibility and effectiveness of the proposed methodology are properly verified.More works about mechanical and biological improvements need to be done to promote its clinical application in future.

  5. Dual growth factor delivery from bilayered, biodegradable hydrogel composites for spatially-guided osteochondral tissue repair

    NARCIS (Netherlands)

    Lu, S.; Lam, J.; Trachtenberg, J.E.; Lee, E.J.; Seyednejad, H.; van den Beucken, J.J.; Tabata, Y.; Wong, M.E.; Jansen, J.A.; Mikos, A.G.; Kasper, F.K.

    2014-01-01

    The present work investigated the use of biodegradable hydrogel composite scaffolds, based on the macromer oligo(poly(ethylene glycol) fumarate) (OPF), to deliver growth factors for the repair of osteochondral tissue in a rabbit model. In particular, bilayered OPF composites were used to mimic the

  6. Electrosleeve process for in-situ nuclear steam generator repair

    International Nuclear Information System (INIS)

    Renaud, E.; Brennenstuhl, A.M.; Stewart, D.R.; Gonzalez, F.

    2000-01-01

    Degradation of steam generator tubing by localized corrosion is a widespread problem in the nuclear industry that can lead to costly forced outages, unit derating, steam generator replacement or even the permanent shutdown of a reactor. In response to the onset of steam generator degradation at Ontario Power Generation's Pickering Nuclear Generating Station (PNGS) Unit 5, and the determined unsuitability of conventional repair methods (mechanically expanded or welded sleeves) for Alloy 400, an alternative repair technology was developed. Electrosleeve is a non-intrusive, low-temperature process that involves the electrodeposition of a nanocrystalline nickel microalloy forming a continuously bonded, structural layer over the internal diameter of the degraded region. This technology is designed to provide a long-term pressure boundary repair, fully restoring the structural integrity of the damaged region to its original state. This paper describes the Electrosleeve process for steam generator tubing repair and the unique properties of the advanced sleeve material. The successful installation of fourteen Electrosleeves that have been in service for more than six years in Alloy 400 tubing at the Pickering-S CANDU unit, and the more recent (Nov. 99) extension of the technology to Alloy 600 by the installation of 57 sleeves in a U.S. pressurized water reactor (PWR) at Callaway, is presented. The Electrosleeve process has been granted a conditional license by the U.S. Nuclear Regulatory Commission (NRC). In Canada, the process of licensing Electrosleeve with the CNSC / TSSA has begun. (author)

  7. The effect of low radiation doses on DNA repair processes

    International Nuclear Information System (INIS)

    Tuschl, H.

    1978-08-01

    Error free DNA repair processes are an important preprequisite for the maintenance of genetic integrity of cells. They are of special importance for persons therapeutically or occupationally exposed to radiation. Therefore the effect of radiation therapy and elevated natural background radiation on unscheduled DNA synthesis was tested in peripheral lymphocytes of exposed persons. Both, autoradiographic studies of unscheduled DNA synthesis and measurement of 3 H-thymidine uptake into double stranded and single-strand containing DNA fractions revealed an increase of capacity for DNA repair. (author)

  8. [Biomarkers of radiation-induced DNA repair processes].

    Science.gov (United States)

    Vallard, Alexis; Rancoule, Chloé; Guy, Jean-Baptiste; Espenel, Sophie; Sauvaigo, Sylvie; Rodriguez-Lafrasse, Claire; Magné, Nicolas

    2017-11-01

    The identification of DNA repair biomarkers is of paramount importance. Indeed, it is the first step in the process of modulating radiosensitivity and radioresistance. Unlike tools of detection and measurement of DNA damage, DNA repair biomarkers highlight the variations of DNA damage responses, depending on the dose and the dose rate. The aim of the present review is to describe the main biomarkers of radiation-induced DNA repair. We will focus on double strand breaks (DSB), because of their major role in radiation-induced cell death. The most important DNA repair biomarkers are DNA damage signaling proteins, with ATM, DNA-PKcs, 53BP1 and γ-H2AX. They can be analyzed either using immunostaining, or using lived cell imaging. However, to date, these techniques are still time and money consuming. The development of "omics" technologies should lead the way to new (and usable in daily routine) DNA repair biomarkers. Copyright © 2017 Société Française du Cancer. Published by Elsevier Masson SAS. All rights reserved.

  9. Leucine Supplementation Accelerates Connective Tissue Repair of Injured Tibialis Anterior Muscle

    Directory of Open Access Journals (Sweden)

    Marcelo G. Pereira

    2014-09-01

    Full Text Available This study investigated the effect of leucine supplementation on the skeletal muscle regenerative process, focusing on the remodeling of connective tissue of the fast twitch muscle tibialis anterior (TA. Young male Wistar rats were supplemented with leucine (1.35 g/kg per day; then, TA muscles from the left hind limb were cryolesioned and examined after 10 days. Although leucine supplementation induced increased protein synthesis, it was not sufficient to promote an increase in the cross-sectional area (CSA of regenerating myofibers (p > 0.05 from TA muscles. However, leucine supplementation reduced the amount of collagen and the activation of phosphorylated transforming growth factor-β receptor type I (TβR-I and Smad2/3 in regenerating muscles (p < 0.05. Leucine also reduced neonatal myosin heavy chain (MyHC-n (p < 0.05, increased adult MyHC-II expression (p < 0.05 and prevented the decrease in maximum tetanic strength in regenerating TA muscles (p < 0.05. Our results suggest that leucine supplementation accelerates connective tissue repair and consequent function of regenerating TA through the attenuation of TβR-I and Smad2/3 activation. Therefore, future studies are warranted to investigate leucine supplementation as a nutritional strategy to prevent or attenuate muscle fibrosis in patients with several muscle diseases.

  10. Chitinase-like proteins as regulators of innate immunity and tissue repair: helpful lessons for asthma?

    Science.gov (United States)

    Sutherland, Tara E

    2018-02-19

    Chitinases and chitinase-like proteins (CLPs) belong to the glycoside hydrolase family 18 of proteins. Chitinases are expressed in mammals and lower organisms, facilitate chitin degradation, and hence act as host-defence enzymes. Gene duplication and loss-of-function mutations of enzymatically active chitinases have resulted in the expression of a diverse range of CLPs across different species. CLPs are genes that are increasingly associated with inflammation and tissue remodelling not only in mammals but also across distant species. While the focus has remained on understanding the functions and expression patterns of CLPs during disease in humans, studies in mouse and lower organisms have revealed important and overlapping roles of the CLP family during physiology, host defence and pathology. This review will summarise recent insights into the regulatory functions of CLPs on innate immune pathways and discuss how these effects are not only important for host defence and tissue injury/repair after pathogen invasion, but also how they have extensive implications for pathological processes involved in diseases such as asthma. © 2018 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

  11. Cytoprotection: Immune and Matrix Modulation of Tissue Repair

    Science.gov (United States)

    2013-04-01

    TREM-2 and DAP12, and tested them in THP -1 cells, a monocyte-like cell line  Initiated tests of additional antibodies for detection of TREM-2 and...interactions. The goal of Aim 2 is to develop an engineered tissue model (a “myobridge” for replacement of skeletal muscle) and use it as a test -bed to...Regulation Task 1 (Months 1–9) Develop and test stable, shear-resistant HMW-HA/fibrillar collagen hydrogels on dye-cut 2.9 mm nylon mesh rings

  12. Evaluation of native hyaline cartilage and repair tissue after two cartilage repair surgery techniques with 23Na MR imaging at 7 T: initial experience.

    Science.gov (United States)

    Zbýň, S; Stelzeneder, D; Welsch, G H; Negrin, L L; Juras, V; Mayerhoefer, M E; Szomolanyi, P; Bogner, W; Domayer, S E; Weber, M; Trattnig, S

    2012-08-01

    To compare the sodium normalized mean signal intensity (NMSI) values between patients after bone marrow stimulation (BMS) and matrix-associated autologous chondrocyte transplantation (MACT) cartilage repair procedures. Nine BMS and nine MACT patients were included. Each BMS patient was matched with one MACT patient according to age [BMS 36.7 ± 10.7 (mean ± standard deviation) years; MACT 36.9 ± 10.0 years], postoperative interval (BMS 33.5 ± 25.3 months; MACT 33.2 ± 25.7 months), and defect location. All magnetic resonance imaging (MRI) measurements were performed on a 7 T system. Proton images served for morphological evaluation of repair tissue using the magnetic resonance observation of cartilage repair tissue (MOCART) scoring system. Sodium NMSI values in the repair area and morphologically normal cartilage were calculated. Clinical outcome was assessed right after MRI. Analysis of covariance, t-tests, and Pearson correlation coefficients were evaluated. Sodium NMSI was significantly lower in BMS (P = 0.004) and MACT (P = 0.006) repair tissue, compared to reference cartilage. Sodium NMSI was not different between the reference cartilage in MACT and BMS patients (P = 0.664), however it was significantly higher in MACT than in BMS repair tissue (P = 0.028). Better clinical outcome was observed in BMS than in MACT patients. There was no difference between MOCART scores for MACT and BMS patients (P = 0.915). We did not observe any significant correlation between MOCART score and sodium repair tissue NMSI (r = -0.001; P = 0.996). Our results suggest higher glycosaminoglycan (GAG) content, and therefore, repair tissue of better quality in MACT than in BMS patients. Sodium imaging might be beneficial in non-invasive evaluation of cartilage repair surgery efficacy. Copyright © 2012 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

  13. Autophagy, Innate Immunity and Tissue Repair in Acute Kidney Injury

    Directory of Open Access Journals (Sweden)

    Pu Duann

    2016-05-01

    Full Text Available Kidney is a vital organ with high energy demands to actively maintain plasma hemodynamics, electrolytes and water homeostasis. Among the nephron segments, the renal tubular epithelium is endowed with high mitochondria density for their function in active transport. Acute kidney injury (AKI is an important clinical syndrome and a global public health issue with high mortality rate and socioeconomic burden due to lack of effective therapy. AKI results in acute cell death and necrosis of renal tubule epithelial cells accompanied with leakage of tubular fluid and inflammation. The inflammatory immune response triggered by the tubular cell death, mitochondrial damage, associative oxidative stress, and the release of many tissue damage factors have been identified as key elements driving the pathophysiology of AKI. Autophagy, the cellular mechanism that removes damaged organelles via lysosome-mediated degradation, had been proposed to be renoprotective. An in-depth understanding of the intricate interplay between autophagy and innate immune response, and their roles in AKI pathology could lead to novel therapies in AKI. This review addresses the current pathophysiology of AKI in aspects of mitochondrial dysfunction, innate immunity, and molecular mechanisms of autophagy. Recent advances in renal tissue regeneration and potential therapeutic interventions are also discussed.

  14. Genipin crosslinker releasing sutures for improving the mechanical/repair strength of damaged connective tissue.

    Science.gov (United States)

    Sundararaj, Sharath; Slusarewicz, Paul; Brown, Matt; Hedman, Thomas

    2017-11-01

    The most common mode of surgical repair of ruptured tendons and ligaments involves the use of sutures for reattachment. However, there is a high incidence of rerupture and repair failure due to pulling out of the suture material from the damaged connective tissue. The main goal of this research was to achieve a localized delivery of crosslinking agent genipin (GP) from rapid-release biodegradable coatings on sutures, for strengthening the repair of ruptured connective tissue. Our hypothesis is that GP released from the suture coating will lead to exogenous crosslinking of native connective tissue resulting in beneficial effects on clinically relevant mechanical parameters such as tear resistance, tissue strength, and energy required to rupture the tissue (toughness). Sutures were successfully coated with a biodegradable polymer layer loaded with the crosslinking agent genipin, without compromising the mechanical properties of the suture. The rapid-release of genipin was achieved under both in vitro and ex vivo conditions. Exogenous crosslinking using these genipin releasing sutures was demonstrated using equine tendons. The tendons treated with genipin releasing sutures showed significant improvement in failure load, energy required for pull-out failure, and stiffness. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 2199-2205, 2017. © 2016 Wiley Periodicals, Inc.

  15. Bioactive Molecule-loaded Drug Delivery Systems to Optimize Bone Tissue Repair.

    Science.gov (United States)

    Oshiro, Joao Augusto; Sato, Mariana Rillo; Scardueli, Cassio Rocha; Lopes de Oliveira, Guilherme Jose Pimentel; Abucafy, Marina Paiva; Chorilli, Marlus

    2017-01-01

    Bioactive molecules such as peptides and proteins can optimize the repair of bone tissue; however, the results are often unpredictable when administered alone, owing to their short biological half-life and instability. Thus, the development of bioactive molecule-loaded drug delivery systems (DDS) to repair bone tissue has been the subject of intense research. DDS can optimize the repair of bone tissue owing to their physicochemical properties, which improve cellular interactions and enable the incorporation and prolonged release of bioactive molecules. These characteristics are fundamental to favor bone tissue homeostasis, since the biological activity of these factors depends on how accessible they are to the cell. Considering the importance of these DDS, this review aims to present relevant information on DDS when loaded with osteogenic growth peptide and bone morphogenetic protein. These are bioactive molecules that are capable of modulating the differentiation and proliferation of mesenchymal cells in bone tissue cells. Moreover, we will present different approaches using these peptide and protein-loaded DDS, such as synthetic membranes and scaffolds for bone regeneration, synthetic grafts, bone cements, liposomes, and micelles, which aim at improving the therapeutic effectiveness, and we will compare their advantages with commercial systems. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  16. Microwave processing of gustatory tissues for immunohistochemistry

    Science.gov (United States)

    Bond, Amanda; Kinnamon, John C.

    2013-01-01

    We use immunohistochemistry to study taste cell structure and function as a means to elucidate how taste receptor cells communicate with nerve fibers and adjacent taste cells. This conventional method, however, is time consuming. In the present study we used taste buds from rat circumvallate papillae to compare conventional immunohistochemical tissue processing with microwave processing for the colocalization of several biochemical pathway markers (PLCβ2, syntaxin-1, IP3R3, α-gustducin) and the nuclear stain, Sytox. The results of our study indicate that in microwave versus conventional immunocytochemistry: (1) fixation quality is improved; (2) the amount of time necessary for processing tissue is decreased; (3) antigen retrieval is no longer needed; (4) image quality is superior. In sum, microwave tissue processing of gustatory tissues is faster and superior to conventional immunohistochemical tissue processing for many applications. PMID:23473796

  17. Hypospadias repair using laser tissue soldering (LTS): preliminary results of a prospective randomized study

    Science.gov (United States)

    Kirsch, Andrew J.; Cooper, Christopher S.; Canning, Douglas A.; Snyder, Howard M., III; Zderic, Stephen A.

    1998-07-01

    Purpose: The purpose of this study was to evaluate laser tissue soldering using an 808 nm diode laser and wavelength- matched human albumin solder for urethral surgery in children. Methods: Currently, 30 boys, ages 3 months to 8 years were randomized to standard suturing (n equals 22) or 'sutureless' laser hypospadias repair (n equals 18). Laser soldering was performed with a human albumin solder doped with indocyanine green dye (2.5 mg/ml) using a laser power output of 0.5 W, pulse duration of 0.5 sec, and interval of 0.1 sec. Power density was approximately 16 W/cm2. In the laser group, sutures were used for tissue alignment only. At the time of surgery, neourethral and penile lengths, operative time for urethral repair, and number of sutures/throws were measured. Postoperatively, patients were examined for complications of wound healing, stricture, or fistula formation. Results: Mean age, severity of urethral defect, type of repair, and neourethra length were equivalent between the two groups. Operative time was significantly faster for laser soldering in both simple (1.6 plus or minus 0.21 min, p less than 0.001) and complex (5.4 plus or minus 0.28 min, p less than 0.0001) hypospadias repairs compared to controls (10.6 plus or minus 1.4 min and 27.8 plus or minus 2.9 min, respectively). The mean number of sutures used in the laser group for simple and complex repairs (3.3 plus or minus 0.3 and 8.1 plus or minus 0.64, respectively) were significantly (p less than 0.0001) less than for controls (8.2 plus or minus 0.84 and 20 plus or minus 2.3, respectively). Followup was between 3 months and 14 months. The overall complication rate in the laser group (11%) was lower than the controls (23%). However, statistical significance (p less than 0.05) was achieved only for the subgroup of patients undergoing simple repairs (LTS, 100% success versus suturing, 69% success). Conclusions: These preliminary results indicate that laser tissue soldering for hypospadias repair

  18. A new concept of endometriosis and adenomyosis: tissue injury and repair (TIAR).

    Science.gov (United States)

    Leyendecker, Gerhard; Wildt, Ludwig

    2011-03-01

    Pelvic endometriosis, deeply infiltrating endometriosis and uterine adenomyosis share a common pathophysiology and may be integrated into the physiological mechanism and new nosological concept of 'tissue injury and repair' (TIAR) and may, in this context, just represent the extreme of a basically physiological, estrogen-related mechanism that is pathologically exaggerated in an extremely estrogen-sensitive reproductive organ. The acronym TIAR describes a fundamental and apparently ubiquitous biological system that becomes operative in mesenchymal tissues following tissue injury and, upon activation, results in the local production of estradiol. Endometriosis and adenomyosis are caused by trauma. In the spontaneously developing disease, chronic uterine peristaltic activity or phases of hyperperistalsis induce, at the endometrial-myometrial interface near the fundo-cornual raphe, microtraumatisations, with activation of the TIAR mechanism. With ongoing traumatisations, such sites of inflammation might accumulate and the increasingly produced estrogens interfere in a paracrine fashion with ovarian control over uterine peristaltic activity, resulting in permanent hyperperistalsis and a self-perpetuation of the disease process. Overt autotraumatisation of the uterus with dislocation of fragments of basal endometrium into the peritoneal cavity and infiltration of basal endometrium into the depth of the myometrial wall ensues. In most cases of endometriosis/adenomyosis a causal event early in the reproductive period of life must be postulated, rapidly leading to archimetral hyperestrogenism and uterine hyperperistalsis. In late premenopausal adenomyosis such an event might not have occurred. However, as indicated by the high prevalence of the disease, it appears to be unavoidable that, with time, chronic normoperistalsis throughout the reproductive period of life accumulates to the same extent of microtraumatisation. With activation of the TIAR mechanism followed by

  19. Resident enhanced repair: novel repair process action on plasmid DNA transformed into Escherichia coli K-12

    International Nuclear Information System (INIS)

    Strike, P.; Roberts, R.J.

    1982-01-01

    The survival of UV-irradiated DNA of plasmid NTP16 was monitored after its transformation into recipient cells containing an essentially homologous undamaged plasmid, pLV9. The presence of pLV9 resulted in a substantial increase in the fraction of damaged NTP16 molecules which survived in the recipient cells. This enhanced survival requires the host uvrA + and uvrB + gene products, but not the host recA + gene product. The requirement for both homologous DNA and the uvrA + gene products suggests that a novel repair process may act on plasmid DNA. Possible mechanisms for this process are considered

  20. Tissue repair in myxobacteria: A cooperative strategy to heal cellular damage.

    Science.gov (United States)

    Vassallo, Christopher N; Wall, Daniel

    2016-04-01

    Damage repair is a fundamental requirement of all life as organisms find themselves in challenging and fluctuating environments. In particular, damage to the barrier between an organism and its environment (e.g. skin, plasma membrane, bacterial cell envelope) is frequent because these organs/organelles directly interact with the external world. Here, we discuss the general strategies that bacteria use to cope with damage to their cell envelope and their repair limits. We then describe a novel damage-coping mechanism used by multicellular myxobacteria. We propose that cell-cell transfer of membrane material within a population serves as a wound-healing strategy and provide evidence for its utility. We suggest that--similar to how tissues in eukaryotes have evolved cooperative methods of damage repair--so too have some bacteria that live a multicellular lifestyle. © 2016 WILEY Periodicals, Inc.

  1. Repair of dense connective tissues via biomaterial-mediated matrix reprogramming of the wound interface.

    Science.gov (United States)

    Qu, Feini; Pintauro, Michael P; Haughan, Joanne E; Henning, Elizabeth A; Esterhai, John L; Schaer, Thomas P; Mauck, Robert L; Fisher, Matthew B

    2015-01-01

    Repair of dense connective tissues in adults is limited by their intrinsic hypocellularity and is exacerbated by a dense extracellular matrix (ECM) that impedes cellular migration to and local proliferation at the wound site. Conversely, healing in fetal tissues occurs due in part to an environment conducive to cell mobility and division. Here, we investigated whether the application of a degradative enzyme, collagenase, could reprogram the adult wound margin to a more fetal-like state, and thus abrogate the biophysical impediments that hinder migration and proliferation. We tested this concept using the knee meniscus, a commonly injured structure for which few regenerative approaches exist. To focus delivery and degradation to the wound interface, we developed a system in which collagenase was stored inside poly(ethylene oxide) (PEO) electrospun nanofibers and released upon hydration. Through a series of in vitro and in vivo studies, our findings show that partial digestion of the wound interface improves repair by creating a more compliant and porous microenvironment that expedites cell migration to and/or proliferation at the wound margin. This innovative approach of targeted manipulation of the wound interface, focused on removing the naturally occurring barriers to adult tissue repair, may find widespread application in the treatment of injuries to a variety of dense connective tissues. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Influence of surgical decompression on the expression of inflammatory and tissue repair biomarkers in periapical cysts.

    Science.gov (United States)

    Rodrigues, Janderson Teixeira; Dos Santos Antunes, Henrique; Armada, Luciana; Pires, Fábio Ramôa

    2017-12-01

    The biologic effects of surgical decompression on the epithelium and connective tissues of periapical cysts are not fully understood. The aim of this study was to evaluate the expression of tissue repair and inflammatory biomarkers in periapical cysts before and after surgical decompression. Nine specimens of periapical cysts treated with decompression before undergoing complete enucleation were immunohistochemically analyzed to investigate the expression of interleukin-1β, tumor necrosis factor-α, transforming growth factor-β1, matrix metalloproteinase-9, Ki-67, and epidermal growth factor receptor. Expression of the biomarkers was classified as positive, focal, or negative. Ki-67 immunoexpression was calculated as a cell proliferation index. The expression of the biomarkers was compared in the specimens from decompression and from the final surgical procedure. Computed tomography demonstrated that volume was reduced in all cysts after decompression. There were no differences in the immunoexpression of the proinflammatory and tissue repair biomarkers when comparing the specimens obtained before and after the decompression. Surgical decompression was efficient in reducing the volume of periapical cysts before complete enucleation. When comparing the specimens obtained from surgical decompression and from complete surgical removal, the immunohistochemical analysis did not show a decrease in proinflammatory biomarkers; neither did it show an increase in tissue repair biomarkers. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Tissue engineering applications: cartilage lesions repair by the use of autologous chondrocytes

    Directory of Open Access Journals (Sweden)

    L. De Franceschi

    2011-09-01

    Full Text Available Promising new therapies based on tissue engineering have been recently developed for cartilage repair. The association of biomaterials with autologous chondrocytes expanded in vitro can represent a useful tool to regenerate this tissue. The scaffolds utilised in such therapeutical applications should provide a pre-formed three-dimensional shape, prevent cells from floating out of the defect, have sufficient mechanical strength, facilitate uniform spread of cells and stimulate the phenotype of transplanted cells. Hyaff®-11 is a hyaluronic-acid based biodegradable polymer, that has been shown to provide successful cell carrier for tissue-engineered repair. From our findings we can state that human chondrocytes seeded on Hyaff®-11 are able to maintain in vitro the characteristic of differentiated cells, expressing and producing collagen type II and aggrecan which are the main markers of cartilage phenotype, down-regulating collagen type I. Moreover, it seems to be a useful scaffold for cartilage repair both in animal models and clinical trials in humans, favouring the formation of a hyaline-like tissue. In the light of these data, we can hypothesise, for the future, the use of autologous chondrocyte transplantation together with gene therapy as a treatment for rheumatic diseases such as osteoarthritis.

  4. Evaluation of phototherapy in the differentiation of mesenchymal stem cells in the tissue repair of rats submitted to a hyperlipidemic diet

    Science.gov (United States)

    Oliveira, C. R. B.; Santos, L. S.; Silva, V. D. U.; Vitória, L. A.; Rodriguez, T. T.; Marques, A. M. C.; Xavier, F. C. A.; Ramalho, L.

    2018-04-01

    Obese people present a greater risk of developing other systemic diseases and comorbidities such as compromising the tissue repair process. Laser phototherapy can contribute to this repair by improving cellular functions, since stem cells may play an important role in repair due to their pluripotent potential. In this way, the influence of Laser Phototherapy (LP) was evaluated in the tissue repair of rats submitted to a hyperlipid diet through CD49 immunostaining for adipose stem cells. Forty-eight Wistar albinus rats were divided into two experimental groups: Standard Diet (SD) and Hyperlipid Diet (HD) for 20 weeks. After this period, excisional dorsal cutaneous wounds of 1 cm2 were made. The groups were subdivided into control and laser, the laser groups were irradiated (Diode Laser of Gallium and Aluminum Arsenide, λ660nm, 40mW, 6J / cm2) immediately after the surgery and every 48 hours. A group of rats were killed on day 7 and the other group on day 14 and the specimens processed by the immunohistochemical technique. The SD group presented antibodies marked with moderate to intense intensity, whereas in the HD group the weak staining for the time of 14 days prevailed. The irradiation protocol employed had no influence on the CD49 marker when compared to the control and irradiated groups over the same period. According to the methodology used and the results obtained it is concluded that laser light does not influence the recruitment of adipoderivative stem cells for the tissue repair process.

  5. Avaliação do efeito radioprotetor do selenito de sódio no processo de reparação tecidual em ratos Evaluation of the radioprotective effect of sodium selenite in the tissue repair process in rats

    Directory of Open Access Journals (Sweden)

    Fabrício M. Tuji

    2005-09-01

    Full Text Available OBJETIVO: Avaliar a ação radioprotetora do selenito de sódio no processo de reparação tecidual. MATERIAIS E MÉTODOS: Ratos Wistar foram submetidos a procedimento cirúrgico para a realização de ferida na região dorsal. Os animais foram divididos em quatro grupos experimentais: controle, selênio, irradiado e selênio-irradiado. Os grupos selênio e selênio-irradiado receberam 2,0 mg/kg de selenito de sódio, 48 horas após a cirurgia. Os grupos irradiado e selênio-irradiado foram submetidos à irradiação em dose única de 6 Gy, administrada somente nas bordas das feridas. Após 4, 7, 13 e 21 dias do procedimento cirúrgico, os animais foram sacrificados e avaliados por meio de análise morfológica, histoquímica e birrefringência do tecido. RESULTADOS: O aspecto estrutural e morfológico, assim como a qualidade do tecido e sua maturação através da quantidade e disposição dos feixes de fibras colágenas, juntamente com o seu grau de orientação macromolecular, permitiu observar a presença de intenso retardo provocado pela irradiação, bem como o efeito radioprotetor do selenito de sódio no processo de reparação. CONCLUSÃO: Dentro das condições experimentais utilizadas, o selenito de sódio apresentou-se como radioprotetor eficaz, visto que o processo de reparação no grupo selênio-irradiado comportou-se, histologicamente, semelhante ao grupo controle.OBJECTIVE: To evaluate the radioprotective effect of sodium selenite in the tissue repair process. MATERIALS AND METHODS: Male Wistar rats submitted to a surgical procedure to produce a wound in the dorsal region. These animals were then divided in four experimental groups: control, selenium, irradiated and selenium-irradiated. The selenium and selenium-irradiated groups received sodium selenite (2.0 mg/kg, 48 hours after surgery. The irradiated and selenium-irradiated groups received a single dose of 6 Gy, administered only in the borders of the wound. The animals were

  6. Laser-activated nano-biomaterials for tissue repair and controlled drug release

    International Nuclear Information System (INIS)

    Matteini, P; Ratto, F; Rossi, F; Pini, R

    2014-01-01

    We present recent achievements of minimally invasive welding of biological tissue and controlled drug release based on laser-activated nano-biomaterials. In particular, we consider new advancements in the biomedical application of near-IR absorbing gold nano-chromophores as an original solution for the photothermal repair of surgical incisions and as nanotriggers of controlled drug release from hybrid biopolymer scaffolds. (laser biophotonics)

  7. Biomimetic strategies for fracture repair: engineering the cell microenvironment for directed tissue formation

    OpenAIRE

    Vas, Wollis J.; Shah, Mittal; Al Hosni, Rawiya; Owen, Helen C.; Roberts, Scott J.

    2017-01-01

    Complications resulting from impaired fracture healing have major clinical implications on fracture management strategies. Novel concepts taken from developmental biology have driven research strategies towards the elaboration of regenerative approaches that can truly harness the complex cellular events involved in tissue formation and repair. Advances in polymer technology and a better understanding of naturally derived scaffolds have given rise to novel biomaterials with an increasing abili...

  8. A Stereological Method for the Quantitative Evaluation of Cartilage Repair Tissue

    Science.gov (United States)

    Nyengaard, Jens Randel; Lind, Martin; Spector, Myron

    2015-01-01

    Objective To implement stereological principles to develop an easy applicable algorithm for unbiased and quantitative evaluation of cartilage repair. Design Design-unbiased sampling was performed by systematically sectioning the defect perpendicular to the joint surface in parallel planes providing 7 to 10 hematoxylin–eosin stained histological sections. Counting windows were systematically selected and converted into image files (40-50 per defect). The quantification was performed by two-step point counting: (1) calculation of defect volume and (2) quantitative analysis of tissue composition. Step 2 was performed by assigning each point to one of the following categories based on validated and easy distinguishable morphological characteristics: (1) hyaline cartilage (rounded cells in lacunae in hyaline matrix), (2) fibrocartilage (rounded cells in lacunae in fibrous matrix), (3) fibrous tissue (elongated cells in fibrous tissue), (4) bone, (5) scaffold material, and (6) others. The ability to discriminate between the tissue types was determined using conventional or polarized light microscopy, and the interobserver variability was evaluated. Results We describe the application of the stereological method. In the example, we assessed the defect repair tissue volume to be 4.4 mm3 (CE = 0.01). The tissue fractions were subsequently evaluated. Polarized light illumination of the slides improved discrimination between hyaline cartilage and fibrocartilage and increased the interobserver agreement compared with conventional transmitted light. Conclusion We have applied a design-unbiased method for quantitative evaluation of cartilage repair, and we propose this algorithm as a natural supplement to existing descriptive semiquantitative scoring systems. We also propose that polarized light is effective for discrimination between hyaline cartilage and fibrocartilage. PMID:26069715

  9. Hyaluronic acid hydrogels with IKVAV peptides for tissue repair and axonal regeneration in an injured rat brain

    International Nuclear Information System (INIS)

    Wei, Y T; Tian, W M; Yu, X; Cui, F Z; Hou, S P; Xu, Q Y; Lee, In-Seop

    2007-01-01

    A biocompatible hydrogel of hyaluronic acid with the neurite-promoting peptide sequence of IKVAV was synthesized. The characterization of the hydrogel shows an open porous structure and a large surface area available for cell interaction. Its ability to promote tissue repair and axonal regeneration in the lesioned rat cerebrum is also evaluated. After implantation, the polymer hydrogel repaired the tissue defect and formed a permissive interface with the host tissue. Axonal growth occurred within the microstructure of the network. Within 6 weeks the polymer implant was invaded by host-derived tissue, glial cells, blood vessels and axons. Such a hydrogel matrix showed the properties of neuron conduction. It has the potential to repair tissue defects in the central nervous system by promoting the formation of a tissue matrix and axonal growth by replacing the lost tissue

  10. Genetic effects of ionizing radiation and repair processes

    International Nuclear Information System (INIS)

    Tuschl, H.

    1986-11-01

    Since DNA (=desoxyribonucleic acid) is the largest molecule within the cell it is the most important target for direct and indirect radiation effects. Within DNA the total genetic information is stored, thus damage to DNA in germ cells causes genetic disorders and damage in somatic cells is implicated in cancer and immunodeficiences. Alterations of DNA structure are not only due to ionizing radiation effects, but also to spontaneous DNA modifications and damage from interactions with environmental ultraviolet light and chemical agents. To maintain its genetic integrity, each organism had to develop different repair systems able to recognize and remove DNA damage. Repeated exposure to a DNA damaging agent can even lead to adaptation processes and increased resistance to the same agent. At normal function of repair systems it can be assumed that the capacity of those systems is adequate to scope with the effects of low radiation doses. (Author)

  11. Progress in the processing of radioesterilized tissue

    International Nuclear Information System (INIS)

    Zarate S, H; Espinoza B, J; Ribbeck N, J; Vargas Q, M; Gutierrez D, K

    2003-01-01

    Since 1996, the Chilean Nuclear Energy Commission has been carrying out work to implement the first Radiosterilized Tissue Processing Laboratory (RTPL) in Chile, in order to introduce the use of sterilized biological tissue for clinical application. The International Atomic Energy Agency (IAEA) has provided collaboration and technical assistance for this work. The processing of biological tissues has been done in conjunction with physicians from different state hospital centers, mostly in the Metropolitan Region. Among the tissues primarily processed are allografts such as frozen human skin at - 80 o C, freeze-dried human bone and amniotic membrane. We have also been working with xenograft developments such as freeze-dried pig skin and demineralized ground cow bone. All these tissues are sterilized by means of gamma radiation, in order to obtain a sterility assurance level (SAL) of 10 -6 . This laboratory has already completed various stages, from the beginning when it was only just an idea up to the production stage where a large quantity of processed tissues have been delivered to physicians of different specialties, resulting in a contribution to medical science as well as to the treatment quality of a great many patients. The preliminary results and the opinions of those physicians who have used the processed products from our laboratory have encouraged us to continue developing new products, thus enlarging the scope of application (author)

  12. Aging and DNA repair capability. [Review

    Energy Technology Data Exchange (ETDEWEB)

    Tice, R R

    1977-01-01

    A review of the literature on DNA repair processes in relation to aging is presented under the following headings: DNA repair processes; age-related occurrence of unrepaired DNA lesions; DNA repair capability as a function of age; tissue-specific DNA repair capability; acceleration of the aging process by exposure to DNA damaging agents; human genetic syndromes; and longevity and DNA repair processes. (HLW)

  13. Comparison of tissue processing methods for microvascular visualization in axolotls.

    Science.gov (United States)

    Montoro, Rodrigo; Dickie, Renee

    2017-01-01

    The vascular system, the pipeline for oxygen and nutrient delivery to tissues, is essential for vertebrate development, growth, injury repair, and regeneration. With their capacity to regenerate entire appendages throughout their lifespan, axolotls are an unparalleled model for vertebrate regeneration, but they lack many of the molecular tools that facilitate vascular imaging in other animal models. The determination of vascular metrics requires high quality image data for the discrimination of vessels from background tissue. Quantification of the vasculature using perfused, cleared specimens is well-established in mammalian systems, but has not been widely employed in amphibians. The objective of this study was to optimize tissue preparation methods for the visualization of the microvascular network in axolotls, providing a basis for the quantification of regenerative angiogenesis. To accomplish this aim, we performed intracardiac perfusion of pigment-based contrast agents and evaluated aqueous and non-aqueous clearing techniques. The methods were verified by comparing the quality of the vascular images and the observable vascular density across treatment groups. Simple and inexpensive, these tissue processing techniques will be of use in studies assessing vascular growth and remodeling within the context of regeneration. Advantages of this method include: •Higher contrast of the vasculature within the 3D context of the surrounding tissue •Enhanced detection of microvasculature facilitating vascular quantification •Compatibility with other labeling techniques.

  14. Evaluation of cartilage repair tissue in the knee and ankle joint using sodium magnetic resonance imaging at 7 Tesla

    International Nuclear Information System (INIS)

    Zbyn, S.

    2015-01-01

    Articular cartilage of adults shows no or very limited intrinsic capacity for self-repair. Since untreated chondral defects often progress to osteoarthritis, symptomatic defects should be treated. Different cartilage repair procedures have been developed with the goal to restore joint function and prevent further cartilage degeneration by providing repair tissue of the same structure, composition, and biomechanical properties as native cartilage. Various cartilage repair procedures have been developed; including bone marrow stimulation (BMS) techniques such as microfracture (MFX), cell-based techniques such as matrix-associated autologous chondrocyte transplantation (MACT), and others. Since biopsies of cartilage repair tissue are invasive and cannot be repeated, a noninvasive method is needed that could follow-up the quality of cartilage and repair tissue. Negatively charged glycosaminoglycans (GAG) are very important for cartilage function as they attract positive ions such as sodium. The high concentration of ions in cartilage is responsible for osmotic pressure providing cartilage its resilience to compression. Since GAGs are counterbalanced by sodium ions, sodium magnetic resonance imaging (MRI) was validated as a sensitive method for the in vivo evaluation of GAG concentration in native cartilage but not for repair tissue. Thus, the main goal of this thesis was to optimize and validate sodium 7 Tesla MRI for the evaluation of cartilage repair tissue quality in patients after different cartilage repair surgeries in the knee and ankle joint. In our studies, sodium MRI was used for the first time for the clinical evaluation of cartilage repair tissue. A strong correlation found between sodium imaging and dGEMRIC (another GAG-sensitive technique) in patients after MACT on femoral cartilage proved sensitivity of sodium MRI to GAG changes in native cartilage and repair tissue in vivo. Comparison between BMS and MACT patients showed significantly lower sodium values

  15. Preparation and Characterization of Biomimetic Hydroxyapatite-Resorbable Polymer Composites for Hard Tissue Repair

    Science.gov (United States)

    Hiebner, Kristopher Robert

    Autografts are the orthopedic "gold standard" for repairing bone voids. Autografts are osteoconductive and do not elicit an immune response, but they are in short supply and require a second surgery to harvest the bone graft. Allografts are currently the most common materials used for the repair of segmental defects in hard tissue. Unlike autografts, allografts can cause an undesirable immune response and the possibility of disease transmission is a major concern. As an alternative to the above approaches, recent research efforts have focused on the use of composite materials made from hydroxyapatite (HA) and bioresorbable polymers, such as poly-L-lactide (PLLA). Recent results have shown that the surface hydroxides on HA can initiate the ring opening polymerization (ROP) of L-lactide and other lactones creating a composite with superior interfacial strength. This thesis demonstrates that the surface of porous biologically derived HA substrates, such as coralline HA and trabecular bone, can be used to initiate the ROP of L-lactide and other lactones from the vapor phase. This process increases the strength of the porous scaffold through the deposition of a thin, uniform polymer coating, while maintaining the porous structure. The kinetics of the chemical vapor deposition polymerization (CVDP) are described using a quartz crystal microbalance (QCM). The reaction temperature and monomer vapor pressure are found to affect the rate of the polymerization. Also described in this thesis is the preparation of a porous polymer scaffold that mimics the structure of demineralized bone matrix (DBM). This demineralized bone matrix simulant (DBMS) is created using anorganic bovine bone as a template to initiate the polymerization of various lactones, followed by the removal of the HA scaffold. This material retained its shape and exhibits mechanical properties superior to DBM. Finally it is shown that HA can be used to initiate the ROP of a-caprolactam and the biocompatibility

  16. In-situ crosslinkable and self-assembling elastin-like polypeptide block copolymers for cartilage tissue repair

    Science.gov (United States)

    Lim, Dong Woo

    This work describes the development of genetically engineered elastin-like polypeptide (ELP) block copolymers as in-situ gelling scaffolds for cartilage tissue repair. The central hypothesis underlying this work is that ELP based biopolymers can be exploited as injectable biomaterials by rapid chemical crosslinking. To prove this, gene libraries encoding ELP having different molecular weights and amino acid sequences, and ELP block copolymers composed of various ELP blocks having diverse amino acid composition, length, and phase transition behavior were synthesized by recursive directional ligation, expressed in E. Coli and purified by inverse transition cycling. Mannich-type condensation of hydroxymethylphosphines (HMPs) with primary- and secondary-amines of amino acids was developed as a new crosslinking method of polypeptides. Chemically crosslinked ELP hydrogels were formed rapidly in an aqueous solution by reaction of ELPs containing periodic lysine residues with HMPs. The crosslinking density and mechanical property of the ELP hydrogels were controlled at the sequence level by varying the Lys density in ELPs composed of mono-block as well as by segregation of the Lys residues within specific blocks of tri-block architectures. Fibroblasts embedded in ELP hydrogels survived the crosslinking process and were viable after in vitro culture for at least 3 days. The DNA content of fibroblasts within the tri-block gels was significantly higher than that in the mono-block gels at day 3. These results suggest that the HMP crosslinked ELP block copolymer hydrogels show finely tuned mechanical properties and different microenvironments for cell viability as well as potential as in-situ crosslinkable biopolymers for tissue repair applications with load-bearing environments. As an alternative, rheological behavior of the ELP block copolymers and ELP-grafted hyaluronic acids (HAs) as artificial extracellular matrices (ECMs) showed that they were thermally aggregated into

  17. Processing laboratory of radio sterilized biological tissues

    International Nuclear Information System (INIS)

    Aguirre H, Paulina; Zarate S, Herman; Silva R, Samy; Hitschfeld, Mario

    2005-01-01

    The nuclear development applications have also reached those areas related to health. The risk of getting contagious illnesses through applying biological tissues has been one of the paramount worries to be solved since infectious illnesses might be provoked by virus, fungis or bacterias coming from donors or whether they have been introduced by means of intermediate stages before the use of these tissues. Therefore it has been concluded that the tissue allografts must be sterilized. The sterilization of medical products has been one of the main applications of the ionizing radiations and that it is why the International Organization of Atomic Energy began in the 70s promoting works related to the biological tissue sterilization and pharmaceutical products. The development of different tissue preservation methods has made possible the creation of tissue banks in different countries, to deal with long-term preservation. In our country, a project was launched in 1998, 'Establishment of a Tissue Bank in Latino america', this project was supported by the OIEA through the project INT/ 6/ 049, and was the starting of the actual Processing Laboratory of Radioesterilized Biological Tissues (LPTR), leaded by the Chilean Nuclear Energy Commission (CCHEN). This first organization is part of a number of entities compounding the Tissue Bank in Chile, organizations such as the Transplantation Promotion Corporation hospitals and the LPTR. The working system is carried out by means of the interaction between the hospitals and the laboratory. The medical professionals perform the procuring of tissues in the hospitals, then send them to the LPTR where they are processed and sterilized with ionizing radiation. The cycle ends up with the tissues return released to the hospitals, where they are used, and then the result information is sent to the LPTR as a form of feedback. Up to now, human skin has been processed (64 donors), amniotic membranes (35 donors) and pig skin (175 portions

  18. Porous poly (lactic-co-glycolide) microsphere sintered scaffolds for tissue repair applications

    International Nuclear Information System (INIS)

    Wang Yingjun; Shi Xuetao; Ren Li; Wang Chunming; Wang Dongan

    2009-01-01

    In this paper, a new route to preparing porous poly (lactic-co-glycolide) (PLGA) scaffolds for bone tissue repair applications was developed. Novel porous PLGA scaffolds were fabricated via microsphere sintered technique and gas forming technique. Ammonium bicarbonate was used to regulate porosity of these porous scaffolds. Porosity of the scaffolds, and cell attachment, viability and proliferation on the scaffolds were evaluated. The results indicated that PLGA porous scaffolds were with the porosity from around 30% to 95% by regulating ammonium bicarbonate content from 0 to 10%. We also found that PLGA porous microsphere scaffolds benefited cell attachment and viability. Taken together, the achieved porous scaffolds have controlled porosity and also support mesenchymal stem cell proliferation, which could serve as potential scaffolds for bone repair applications.

  19. Engineering dextran-based scaffolds for drug delivery and tissue repair

    Science.gov (United States)

    Sun, Guoming; Mao, Jeremy J

    2015-01-01

    Owing to its chemically reactive hydroxyl groups, dextran can be modified with different functional groups to form spherical, tubular and 3D network structures. The development of novel functional scaffolds for efficient controlled release and tissue regeneration has been a major research interest, and offers promising therapeutics for many diseases. Dextran-based scaffolds are naturally biodegradable and can serve as bioactive carriers for many protein biomolecules. The reconstruction of the in vitro microenvironment with proper signaling cues for large-scale tissue regenerative scaffolds has yet to be fully developed, and remains a significant challenge in regenerative medicine. This paper will describe recent advances in dextran-based polymers and scaffolds for controlled release and tissue engineering. Special attention is given to the development of dextran-based hydrogels that are precisely manipulated with desired structural properties and encapsulated with defined angiogenic growth factors for therapeutic neovascularization, as well as their potential for wound repair. PMID:23210716

  20. Definition of pertinent parameters for the evaluation of articular cartilage repair tissue with high-resolution magnetic resonance imaging

    International Nuclear Information System (INIS)

    Marlovits, Stefan; Striessnig, Gabriele; Resinger, Christoph T.; Aldrian, Silke M.; Vecsei, Vilmos; Imhof, Herwig; Trattnig, Siegfried

    2004-01-01

    To evaluate articular cartilage repair tissue after biological cartilage repair, we propose a new technique of non-invasive, high-resolution magnetic resonance imaging (MRI) and define a new classification system. For the definition of pertinent variables the repair tissue of 45 patients treated with three different techniques for cartilage repair (microfracture, autologous osteochondral transplantation, and autologous chondrocyte transplantation) was analyzed 6 and 12 months after the procedure. High-resolution imaging was obtained with a surface phased array coil placed over the knee compartment of interest and adapted sequences were used on a 1 T MRI scanner. The analysis of the repair tissue included the definition and rating of nine pertinent variables: the degree of filling of the defect, the integration to the border zone, the description of the surface and structure, the signal intensity, the status of the subchondral lamina and subchondral bone, the appearance of adhesions and the presence of synovitis. High-resolution MRI, using a surface phased array coil and specific sequences, can be used on every standard 1 or 1.5 T MRI scanner according to the in-house standard protocols for knee imaging in patients who have had cartilage repair procedures without substantially prolonging the total imaging time. The new classification and grading system allows a subtle description and suitable assessment of the articular cartilage repair tissue

  1. Development of biodegradable hyper-branched tissue adhesives for the repair of meniscus tears.

    Science.gov (United States)

    Bochyńska, A I; Van Tienen, T G; Hannink, G; Buma, P; Grijpma, D W

    2016-03-01

    Meniscus tears are one of the most commonly occurring injuries of the knee joint. Current meniscus repair techniques are challenging and do not bring fully satisfactory results. Tissue adhesives are a promising alternative, since they are easy to apply and cause minimal tissue trauma. In this study, a series of amphiphilic copolymers based on polyethylene glycol, trimethylene carbonate and citric acid were synthesized and subsequently end-functionalized with hexamethylene diisocyanate to form reactive adhesive materials. The shear adhesive strength of the networks to bovine meniscus tissue measured in a lap-shear adhesion test ranged between 20 and 80 kPa, which was better than for fibrin glue (10 kPa). The elastic modulus of the networks depended on composition and was in the same range as that of human meniscus. Cell compatibility was assessed using Alamar Blue staining after incubation of the bovine meniscus cells with different concentrations of the glues for 7 days. Cell viability was not affected after adding up to 3mg of the adhesive/mL of medium. The proposed materials are suitable candidates to be used as resorbable tissue adhesives for meniscus repair. They have excellent mechanical and adhesive properties that can be adjusted by varying the composition of the copolymers. Meniscal tears often occur and current treatment strategies do not bring fully satisfactory results. Use of biodegradable tissue adhesives would be an interesting option, but currently available adhesives are not suited due to toxicity or poor mechanical properties. Here, we describe the development of novel biodegradable, hyper-branched, adhesive copolymers. These adhesives cure upon contact with water forming flexible networks. Their adhesion to bovine meniscus tissue was significantly better than that of clinically used fibrin glue. The tensile properties of the cured networks were in the same range of values of the human meniscus. When physiologically relevant amounts were added to

  2. Experiment K-7-29: Connective Tissue Studies. Part 1; Rat Skin, Normal and Repair

    Science.gov (United States)

    Vailas, A. C.; Grindeland, R.; Ashman, R.; Choy, V.; Durnova, G.; Graf, B.; Griffith, P.; Kaplansky, A. S.; Kolis, S.; Martinez, D.; hide

    1994-01-01

    The skin repair studies started to be problematic for the following reasons: (1) It was very difficult to locate the wound and many lesions were not of the same dimensions. A considerable amount of time was devoted to the identification of the wound using polarized light. We understand that this experiment was added on to the overall project. Marking of the wound site and standard dimensions should be recommended for the next flight experiment. (2) The tissue was frozen, therefore thawing and fixation caused problems with some of the immunocytochemical staining for obtaining better special resolution with light microscopy image processing. Despite these problems, we were unable to detect any significant qualitative differences for the following wound markers: (1) Collagen Type 3, (2) Hematotoxylin and Eosin, and (3) Macrophage Factor 13. All protein markers were isolated from rat sources and antibodies prepared and tested for cross reactivity with other molecules at the University of Wisconsin Hybridoma Facility. However, rat skin from the non lesioned site 'normal' showed interesting biochemical results. Skin was prepared for the following measurements: (1) DNA content, (2) Collagen content by hydroxyproline, and (3) uronic acid content and estimation of ground substance. The results indicated there was a non-significant increase (10%) in the DNA concentration of skin from flight animals. However, the data expressed as a ratio DNA/Collagen estimates the cell or nuclear density that supports a given quantity of collagen showed a dramatic increase in the flight group (33%). This means flight conditions may have slowed down collagen secretion and/or increased cell proliferation in adult rat skin. Further biochemical tests are being done to determine the crosslinking of elastin which will enhance the insight to assessing changes in skin turnover.

  3. Nerve autografts and tissue-engineered materials for the repair of peripheral nerve injuries: a 5-year bibliometric analysis

    Directory of Open Access Journals (Sweden)

    Yuan Gao

    2015-01-01

    Full Text Available With advances in biomedical methods, tissue-engineered materials have developed rapidly as an alternative to nerve autografts for the repair of peripheral nerve injuries. However, the materials selected for use in the repair of peripheral nerve injuries, in particular multiple injuries and large-gap defects, must be chosen carefully. Various methods and materials for protecting the healthy tissue and repairing peripheral nerve injuries have been described, and each method or material has advantages and disadvantages. Recently, a large amount of research has been focused on tissue-engineered materials for the repair of peripheral nerve injuries. Using the keywords "pe-ripheral nerve injury", "autotransplant", "nerve graft", and "biomaterial", we retrieved publications using tissue-engineered materials for the repair of peripheral nerve injuries appearing in the Web of Science from 2010 to 2014. The country with the most total publications was the USA. The institutions that were the most productive in this field include Hannover Medical School (Germany, Washington University (USA, and Nantong University (China. The total number of publications using tissue-engineered materials for the repair of peripheral nerve injuries grad-ually increased over time, as did the number of Chinese publications, suggesting that China has made many scientific contributions to this field of research.

  4. Preliminary Evaluation of Platelet Rich Fibrin-Mediated Tissue Repair in Immature Canine Pulpless Teeth.

    Science.gov (United States)

    Wang, Qi Lin; Yang, Pan Pan; Ge, Li Hong; Liu, He

    2016-03-01

    To evaluate the use of platelet-rich fibrin (PRF) in the regenerative therapy of immature canine permanent teeth. Eight immature premolars of beagle dogs were pulp extracted and cleaned with irrigation, then divided into two groups of empty root canals and those filled with a PRF clot. All of the eight premolars were sealed with mineral trioxide aggregate and glass ionomer cement. Two premolars were left naturally grown as a positive control. The root development was assessed radiographically and histologically after 12 weeks. The radiological findings showed greater increases in the thickness of lateral dentinal wall in the PRF group than in the vacant group. Histologically, dental-associated mineral tissue, connective tissue, and bone-like mineral tissue grew into the root canals independent of PRF clot use. The PRF was able to increase the thickness of dental-associated mineral tissue. However, the vital tissue differed from the pulp dentin complex. Our study demonstrated the feasibility of using PRF-mediated regenerative therapy in pulpless immature teeth for improving tissue repair.

  5. A biocompatible hybrid material with simultaneous calcium and strontium release capability for bone tissue repair

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, J. Carlos [CICECO — Aveiro Institute of Materials, Department of Materials and Ceramic Engineering, University of Aveiro, 3810-193 Aveiro (Portugal); Wacha, András [Research Centre for Natural Sciences, Hungarian Academy of Sciences, Magyar Tudósok körútja 2, Budapest 1117 (Hungary); Gomes, Pedro S. [Laboratory for Bone Metabolism and Regeneration, Faculdade de Medicina Dentária, Universidade do Porto (Portugal); Alves, Luís C. [C2TN, Instituto Superior Técnico, Universidade de Lisboa, E.N.10, 2695-066 Bobadela LRS (Portugal); Fernandes, M. Helena Vaz [CICECO — Aveiro Institute of Materials, Department of Materials and Ceramic Engineering, University of Aveiro, 3810-193 Aveiro (Portugal); Salvado, Isabel M. Miranda, E-mail: isabelmsalvado@ua.pt [CICECO — Aveiro Institute of Materials, Department of Materials and Ceramic Engineering, University of Aveiro, 3810-193 Aveiro (Portugal); Fernandes, M. Helena R. [Laboratory for Bone Metabolism and Regeneration, Faculdade de Medicina Dentária, Universidade do Porto (Portugal)

    2016-05-01

    The increasing interest in the effect of strontium in bone tissue repair has promoted the development of bioactive materials with strontium release capability. According to literature, hybrid materials based on the system PDMS–SiO{sub 2} have been considered a plausible alternative as they present a mechanical behavior similar to the one of the human bone. The main purpose of this study was to obtain a biocompatible hybrid material with simultaneous calcium and strontium release capability. A hybrid material, in the system PDMS–SiO{sub 2}–CaO–SrO, was prepared with the incorporation of 0.05 mol of titanium per mol of SiO{sub 2}. Calcium and strontium were added using the respective acetates as sources, following a sol–gel technique previously developed by the present authors. The obtained samples were characterized by FT-IR, solid-state NMR, and SAXS, and surface roughness was analyzed by 3D optical profilometry. In vitro studies were performed by immersion of the samples in Kokubo's SBF for different periods of time, in order to determine the bioactive potential of these hybrids. Surfaces of the immersed samples were observed by SEM, EDS and PIXE, showing the formation of calcium phosphate precipitates. Supernatants were analyzed by ICP, revealing the capability of the material to simultaneously fix phosphorus ions and to release calcium and strontium, in a concentration range within the values reported as suitable for the induction of the bone tissue repair. The material demonstrated to be cytocompatible when tested with MG63 osteoblastic cells, exhibiting an inductive effect on cell proliferation and alkaline phosphatase activity. - Highlights: • A hybrid PDMS–SiO{sub 2}–CaO–SrO material was prepared with the incorporation of Ti. • Sr was released in concentrations suitable for the induction of bone tissue repair. • The material demonstrated to be cytocompatible when tested with osteoblastic cells.

  6. Instructive role of the vascular niche in promoting tumour growth and tissue repair by angiocrine factors.

    Science.gov (United States)

    Butler, Jason M; Kobayashi, Hideki; Rafii, Shahin

    2010-02-01

    The precise mechanisms whereby anti-angiogenesis therapy blocks tumour growth or causes vascular toxicity are unknown. We propose that endothelial cells establish a vascular niche that promotes tumour growth and tissue repair not only by delivering nutrients and O2 but also through an 'angiocrine' mechanism by producing stem and progenitor cell-active trophogens. Identification of endothelial-derived instructive angiocrine factors will allow direct tumour targeting, while diminishing the unwanted side effects associated with the use of anti-angiogenic agents.

  7. Immunohistochemical Expression of TGF-β1 and Osteonectin in engineered and Ca(OH2-repaired human pulp tissues

    Directory of Open Access Journals (Sweden)

    Luiz Alexandre CHISINI

    Full Text Available Abstract The aim of the present study was to evaluate the expression of transforming growth factor-β1 (TGF-β1 and osteonectin (ON in pulp-like tissues developed by tissue engineering and to compare it with the expression of these proteins in pulps treated with Ca(OH2 therapy. Tooth slices were obtained from non-carious human third molars under sterile procedures. The residual periodontal and pulp soft tissues were removed. Empty pulp spaces of the tooth slice were filled with sodium chloride particles (250–425 µm. PLLA solubilized in 5% chloroform was applied over the salt particles. The tooth slice/scaffold (TS/S set was stored overnight and then rinsed thoroughly to wash out the salt. Scaffolds were previously sterilized with ethanol (100–70° and washed with phosphate-buffered saline (PBS. TS/S was treated with 10% EDTA and seeded with dental pulp stem cells (DPSC. Then, TS/S was implanted into the dorsum of immunodeficient mice for 28 days. Human third molars previously treated with Ca(OH2 for 90 days were also evaluated. Samples were prepared and submitted to histological and immunohistochemical (with anti-TGF-β1, 1:100 and anti-ON, 1:350 analyses. After 28 days, TS/S showed morphological characteristics similar to those observed in dental pulp treated with Ca(OH2. Ca(OH2-treated pulps showed the usual repaired pulp characteristics. In TS/S, newly formed tissues and pre-dentin was colored, which elucidated the expression of TGF-β1 and ON. Immunohistochemistry staining of Ca(OH2-treated pulps showed the same expression patterns. The extracellular matrix displayed a fibrillar pattern under both conditions. Regenerative events in the pulp seem to follow a similar pattern of TGF-β1 and ON expression as the repair processes.

  8. Process methods and levels of automation of wood pallet repair in the United States

    Science.gov (United States)

    Jonghun Park; Laszlo Horvath; Robert J. Bush

    2016-01-01

    This study documented the current status of wood pallet repair in the United States by identifying the types of processing and equipment usage in repair operations from an automation prespective. The wood pallet repair firms included in the sudy received an average of approximately 1.28 million cores (i.e., used pallets) for recovery in 2012. A majority of the cores...

  9. Tissue-engineered bone constructed in a bioreactor for repairing critical-sized bone defects in sheep.

    Science.gov (United States)

    Li, Deqiang; Li, Ming; Liu, Peilai; Zhang, Yuankai; Lu, Jianxi; Li, Jianmin

    2014-11-01

    Repair of bone defects, particularly critical-sized bone defects, is a considerable challenge in orthopaedics. Tissue-engineered bones provide an effective approach. However, previous studies mainly focused on the repair of bone defects in small animals. For better clinical application, repairing critical-sized bone defects in large animals must be studied. This study investigated the effect of a tissue-engineered bone for repairing critical-sized bone defect in sheep. A tissue-engineered bone was constructed by culturing bone marrow mesenchymal-stem-cell-derived osteoblast cells seeded in a porous β-tricalcium phosphate ceramic (β-TCP) scaffold in a perfusion bioreactor. A critical-sized bone defect in sheep was repaired with the tissue-engineered bone. At the eighth and 16th week after the implantation of the tissue-engineered bone, X-ray examination and histological analysis were performed to evaluate the defect. The bone defect with only the β-TCP scaffold served as the control. X-ray showed that the bone defect was successfully repaired 16 weeks after implantation of the tissue-engineered bone; histological sections showed that a sufficient volume of new bones formed in β-TCP 16 weeks after implantation. Eight and 16 weeks after implantation, the volume of new bones that formed in the tissue-engineered bone group was more than that in the β-TCP scaffold group (P bone improved osteogenesis in vivo and enhanced the ability to repair critical-sized bone defects in large animals.

  10. Cell and biomolecule delivery for tissue repair and regeneration in the central nervous system.

    Science.gov (United States)

    Elliott Donaghue, Irja; Tam, Roger; Sefton, Michael V; Shoichet, Molly S

    2014-09-28

    Tissue engineering frequently involves cells and scaffolds to replace damaged or diseased tissue. It originated, in part, as a means of effecting the delivery of biomolecules such as insulin or neurotrophic factors, given that cells are constitutive producers of such therapeutic agents. Thus cell delivery is intrinsic to tissue engineering. Controlled release of biomolecules is also an important tool for enabling cell delivery since the biomolecules can enable cell engraftment, modulate inflammatory response or otherwise benefit the behavior of the delivered cells. We describe advances in cell and biomolecule delivery for tissue regeneration, with emphasis on the central nervous system (CNS). In the first section, the focus is on encapsulated cell therapy. In the second section, the focus is on biomolecule delivery in polymeric nano/microspheres and hydrogels for the nerve regeneration and endogenous cell stimulation. In the third section, the focus is on combination strategies of neural stem/progenitor cell or mesenchymal stem cell and biomolecule delivery for tissue regeneration and repair. In each section, the challenges and potential solutions associated with delivery to the CNS are highlighted. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. Capturing tissue repair in zebrafish larvae with time-lapse brightfield stereomicroscopy.

    Science.gov (United States)

    Lisse, Thomas S; Brochu, Elizabeth A; Rieger, Sandra

    2015-01-31

    The zebrafish larval tail fin is ideal for studying tissue regeneration due to the simple architecture of the larval fin-fold, which comprises of two layers of skin that enclose undifferentiated mesenchyme, and because the larval tail fin regenerates rapidly within 2-3 days. Using this system, we demonstrate a method for capturing the repair dynamics of the amputated tail fin with time-lapse video brightfield stereomicroscopy. We demonstrate that fin amputation triggers a contraction of the amputation wound and extrusion of cells around the wound margin, leading to their subsequent clearance. Fin regeneration proceeds from proximal to distal direction after a short delay. In addition, developmental growth of the larva can be observed during all stages. The presented method provides an opportunity for observing and analyzing whole tissue-scale behaviors such as fin development and growth in a simple microscope setting, which is easily adaptable to any stereomicroscope with time-lapse capabilities.

  12. Determination of bone and tissue concentrations of teicoplanin mixed with hydroxyapatite cement to repair cortical defects.

    Science.gov (United States)

    Eggenreich, K; Zeipper, U; Schwendenwein, E; Hadju, S; Kaltenecker, G; Laslo, I; Lang, S; Roschger, P; Vecsei, V; Wintersteiger, R

    2002-01-01

    A highly specific and sensitive isocratic reversed-phase high performance liquid chromatography (HPLC) method for the determination of the major component of teicoplanin in tissue is reported. Comparing fluorescamine and o-phthalaldehyde (OPA) as derivatizing agents, the derivative formed with the latter exhibits superior fluorescence intensity allowing detection of femtomole quantities. Pretreatment for tissue samples is by solid-phase extraction which uses Bakerbond PolarP C(18) cartridges and gives effective clean up from endogenous by-products. Linearity was given from 0.6 to 100 ng per injection. The coefficient of variation did not exceed 5.8% for both interday and intraday assays. It was found that when bone defects are repaired with a hydroxyapatite-teicoplanin mixture, the antibiotic does not degrade, even when it is in the cement for several months. The stability of teicoplanin in bone cement was determined fluorodensitometrically.

  13. Tissue repair genes: the TiRe database and its implication for skin wound healing.

    Science.gov (United States)

    Yanai, Hagai; Budovsky, Arie; Tacutu, Robi; Barzilay, Thomer; Abramovich, Amir; Ziesche, Rolf; Fraifeld, Vadim E

    2016-04-19

    Wound healing is an inherent feature of any multicellular organism and recent years have brought about a huge amount of data regarding regular and abnormal tissue repair. Despite the accumulated knowledge, modulation of wound healing is still a major biomedical challenge, especially in advanced ages. In order to collect and systematically organize what we know about the key players in wound healing, we created the TiRe (Tissue Repair) database, an online collection of genes and proteins that were shown to directly affect skin wound healing. To date, TiRe contains 397 entries for four organisms: Mus musculus, Rattus norvegicus, Sus domesticus, and Homo sapiens. Analysis of the TiRe dataset of skin wound healing-associated genes showed that skin wound healing genes are (i) over-conserved among vertebrates, but are under-conserved in invertebrates; (ii) enriched in extracellular and immuno-inflammatory genes; and display (iii) high interconnectivity and connectivity to other proteins. The latter may provide potential therapeutic targets. In addition, a slower or faster skin wound healing is indicative of an aging or longevity phenotype only when assessed in advanced ages, but not in the young. In the long run, we aim for TiRe to be a one-station resource that provides researchers and clinicians with the essential data needed for a better understanding of the mechanisms of wound healing, designing new experiments, and the development of new therapeutic strategies. TiRe is freely available online at http://www.tiredb.org.

  14. A novel basalt fiber-reinforced polylactic acid composite for hard tissue repair.

    Science.gov (United States)

    Chen, Xi; Li, Yan; Gu, Ning

    2010-08-01

    A basalt fiber (BF) was, for the first time, introduced into a poly(l-lactic acid) (PLLA) matrix as innovative reinforcement to fabricate composite materials for hard tissue repair. Firstly, BF/PLLA composites and pure PLLA were produced by the methods of solution blending and freeze drying. The results showed that basalt fibers can be uniformly dispersed in the PLLA matrix and significantly improve the mechanical properties and hydrophilicity of the PLLA matrix. The presence of basalt fibers may retard the polymer degradation rate and neutralize the acid degradation from PLLA. Osteoblasts were cultured in vitro to evaluate the cytocompatibility of the composite. An MTT assay revealed that osteoblasts proliferated well for 7 days and there was little difference found in their viability on both PLLA and BF/PLLA films, which was consistent with the alkaline phosphatase (ALP) activity results. A fluorescent staining observation showed that osteoblasts grew well on the composites. SEM images displayed that osteoblasts tended to grow along the fiber axis. The formation of mineralized nodules was observed on the films by Alizarin red S staining. These results suggest that the presence of basalt fibers does not noticeably affect osteoblastic behavior and the designed composites are osteoblast compatible. It is concluded that basalt fibers, as reinforcing fibers, may have promising applications in hard tissue repair.

  15. A novel basalt fiber-reinforced polylactic acid composite for hard tissue repair

    International Nuclear Information System (INIS)

    Chen Xi; Li Yan; Gu Ning

    2010-01-01

    A basalt fiber (BF) was, for the first time, introduced into a poly(l-lactic acid) (PLLA) matrix as innovative reinforcement to fabricate composite materials for hard tissue repair. Firstly, BF/PLLA composites and pure PLLA were produced by the methods of solution blending and freeze drying. The results showed that basalt fibers can be uniformly dispersed in the PLLA matrix and significantly improve the mechanical properties and hydrophilicity of the PLLA matrix. The presence of basalt fibers may retard the polymer degradation rate and neutralize the acid degradation from PLLA. Osteoblasts were cultured in vitro to evaluate the cytocompatibility of the composite. An MTT assay revealed that osteoblasts proliferated well for 7 days and there was little difference found in their viability on both PLLA and BF/PLLA films, which was consistent with the alkaline phosphatase (ALP) activity results. A fluorescent staining observation showed that osteoblasts grew well on the composites. SEM images displayed that osteoblasts tended to grow along the fiber axis. The formation of mineralized nodules was observed on the films by Alizarin red S staining. These results suggest that the presence of basalt fibers does not noticeably affect osteoblastic behavior and the designed composites are osteoblast compatible. It is concluded that basalt fibers, as reinforcing fibers, may have promising applications in hard tissue repair.

  16. Cell sensitivity to irradiation and DNA repair processes

    International Nuclear Information System (INIS)

    Kozubek, S.; Krasavin, E.A.

    1984-01-01

    A new model of oxygen effect realisation is proposed for E.coli cells. The model explains differencies in oxygen enhancement ratio (OER) between wild type cells and repair deficient mutants. These differencies are logically linked to corresponding defects in repair systems. A quantitative analysis has been performed. The dependence of OER and cell sensitivity on the properties of cultivation medium is considered, too. Decreasing OER and increasing sensitivity in poor conditions are explained as the consequence of the shift of repair capacity from slow to fast repair system

  17. Hydrogel derived from porcine decellularized nerve tissue as a promising biomaterial for repairing peripheral nerve defects.

    Science.gov (United States)

    Lin, Tao; Liu, Sheng; Chen, Shihao; Qiu, Shuai; Rao, Zilong; Liu, Jianghui; Zhu, Shuang; Yan, Liwei; Mao, Haiquan; Zhu, Qingtang; Quan, Daping; Liu, Xiaolin

    2018-06-01

    Decellularized matrix hydrogels derived from tissues or organs have been used for tissue repair due to their biocompatibility, tunability, and tissue-specific extracellular matrix (ECM) components. However, the preparation of decellularized peripheral nerve matrix hydrogels and their use to repair nerve defects have not been reported. Here, we developed a hydrogel from porcine decellularized nerve matrix (pDNM-G), which was confirmed to have minimal DNA content and retain collagen and glycosaminoglycans content, thereby allowing gelatinization. The pDNM-G exhibited a nanofibrous structure similar to that of natural ECM, and a ∼280-Pa storage modulus at 10 mg/mL similar to that of native neural tissues. Western blot and liquid chromatography tandem mass spectrometry analysis revealed that the pDNM-G consisted mostly of ECM proteins and contained primary ECM-related proteins, including fibronectin and collagen I and IV). In vitro experiments showed that pDNM-G supported Schwann cell proliferation and preserved cell morphology. Additionally, in a 15-mm rat sciatic nerve defect model, pDNM-G was combined with electrospun poly(lactic-acid)-co-poly(trimethylene-carbonate)conduits to bridge the defect, which did not elicit an adverse immune response and promoted the activation of M2 macrophages associated with a constructive remodeling response. Morphological analyses and electrophysiological and functional examinations revealed that the regenerative outcomes achieved by pDNM-G were superior to those by empty conduits and closed to those using rat decellularized nerve matrix allograft scaffolds. These findings indicated that pDNM-G, with its preserved ECM composition and nanofibrous structure, represents a promising biomaterial for peripheral nerve regeneration. Decellularized nerve allografts have been widely used to treat peripheral nerve injury. However, given their limited availability and lack of bioactive factors, efforts have been made to improve the efficacy

  18. How Can Nanotechnology Help to Repair the Body? Advances in Cardiac, Skin, Bone, Cartilage and Nerve Tissue Regeneration

    Directory of Open Access Journals (Sweden)

    Juan Antonio Marchal

    2013-03-01

    Full Text Available Nanotechnologists have become involved in regenerative medicine via creation of biomaterials and nanostructures with potential clinical implications. Their aim is to develop systems that can mimic, reinforce or even create in vivo tissue repair strategies. In fact, in the last decade, important advances in the field of tissue engineering, cell therapy and cell delivery have already been achieved. In this review, we will delve into the latest research advances and discuss whether cell and/or tissue repair devices are a possibility. Focusing on the application of nanotechnology in tissue engineering research, this review highlights recent advances in the application of nano-engineered scaffolds designed to replace or restore the followed tissues: (i skin; (ii cartilage; (iii bone; (iv nerve; and (v cardiac.

  19. Exploiting global information in complex network repair processes

    Institute of Scientific and Technical Information of China (English)

    Tianyu WANG; Jun ZHANG; Sebastian WANDELT

    2017-01-01

    Robustness of complex networks has been studied for decades,with a particular focus on network attack.Research on network repair,on the other hand,has been conducted only very lately,given the even higher complexity and absence of an effective evaluation metric.A recently proposed network repair strategy is self-healing,which aims to repair networks for larger compo nents at a low cost only with local information.In this paper,we discuss the effectiveness and effi ciency of self-healing,which limits network repair to be a multi-objective optimization problem and makes it difficult to measure its optimality.This leads us to a new network repair evaluation metric.Since the time complexity of the computation is very high,we devise a greedy ranking strategy.Evaluations on both real-world and random networks show the effectiveness of our new metric and repair strategy.Our study contributes to optimal network repair algorithms and provides a gold standard for future studies on network repair.

  20. Detection of abnormalities in the superficial zone of cartilage repaired using a tissue engineered construct derived from synovial stem cells

    Directory of Open Access Journals (Sweden)

    W Ando

    2012-09-01

    Full Text Available The present study investigated the surface structure and mechanical properties of repair cartilage generated from a tissue engineered construct (TEC derived from synovial mesenchymal stem cells at six months post-implantation compared to those of uninjured cartilage. TEC-mediated repair tissue was cartilaginous with Safranin O staining, and had comparable macro-scale compressive properties with uninjured cartilage. However, morphological assessments revealed that the superficial zone of TEC-mediated tissue was more fibrocartilage-like, in contrast to the middle or deep zones that were more hyaline cartilage-like with Safranin O staining. Histological scoring of the TEC-mediated tissue was significantly lower in the superficial zone than in the middle and deep zones. Scanning electron microscopy showed a thick tangential bundle of collagen fibres at the most superficial layer of uninjured cartilage, while no corresponding structure was detected at the surface of TEC-mediated tissue. Immunohistochemical analysis revealed that PRG4 was localised in the superficial area of uninjured cartilage, as well as the TEC-mediated tissue. Friction testing showed that the lubrication properties of the two tissues was similar, however, micro-indentation analysis revealed that the surface stiffness of the TEC-repair tissue was significantly lower than that of uninjured cartilage. Permeability testing indicated that the TEC-mediated tissue exhibited lower water retaining capacity than did uninjured cartilage, specifically at the superficial zone. Thus, TEC-mediated tissue exhibited compromised mechanical properties at the superficial zone, properties which need improvement in the future for maintenance of long term repair cartilage integrity.

  1. Detection of abnormalities in the superficial zone of cartilage repaired using a tissue engineered construct derived from synovial stem cells.

    Science.gov (United States)

    Ando, Wataru; Fujie, Hiromichi; Moriguchi, Yu; Nansai, Ryosuke; Shimomura, Kazunori; Hart, David A; Yoshikawa, Hideki; Nakamura, Norimasa

    2012-09-28

    The present study investigated the surface structure and mechanical properties of repair cartilage generated from a tissue engineered construct (TEC) derived from synovial mesenchymal stem cells at six months post-implantation compared to those of uninjured cartilage. TEC-mediated repair tissue was cartilaginous with Safranin O staining, and had comparable macro-scale compressive properties with uninjured cartilage. However, morphological assessments revealed that the superficial zone of TEC-mediated tissue was more fibrocartilage-like, in contrast to the middle or deep zones that were more hyaline cartilage-like with Safranin O staining. Histological scoring of the TEC-mediated tissue was significantly lower in the superficial zone than in the middle and deep zones. Scanning electron microscopy showed a thick tangential bundle of collagen fibres at the most superficial layer of uninjured cartilage, while no corresponding structure was detected at the surface of TEC-mediated tissue. Immunohistochemical analysis revealed that PRG4 was localised in the superficial area of uninjured cartilage, as well as the TEC-mediated tissue. Friction testing showed that the lubrication properties of the two tissues was similar, however, micro-indentation analysis revealed that the surface stiffness of the TEC-repair tissue was significantly lower than that of uninjured cartilage. Permeability testing indicated that the TEC-mediated tissue exhibited lower water retaining capacity than did uninjured cartilage, specifically at the superficial zone. Thus, TEC-mediated tissue exhibited compromised mechanical properties at the superficial zone, properties which need improvement in the future for maintenance of long term repair cartilage integrity.

  2. [Repair of soft tissue defect in hand or foot with lobulated medial sural artery perforator flap].

    Science.gov (United States)

    Fengjing, Zhao; Jianmin, Yao; Xingqun, Zhang; Liang, Ma; Longchun, Zhang; Yibo, Xu; Peng, Wang; Zhen, Zhu

    2015-11-01

    To explore the clinical effect of the lobulated medial sural artery perforator flap in repairing soft tissue defect in hand or foot. Since March 2012 to September 2014, 6 cases with soft tissue defects in hands or feet were treated by lobulated medial sural artery flaps pedicled with 1st musculo-cutaneous perforator and 2st musculo-cutaneous perforator of the medial sural artery. The size of the flaps ranged from 4.5 cm x 10.0 cm to 6.0 cm x 17.0 cm. 5 cases of lobulated flap survived smoothly, only 1 lobulated flap had venous articulo, but this flap also survived after the articulo was removed by vascular exploration. All flaps had desirable appearance and sensation and the two-point discrimination was 6 mm in mean with 4 to 12 months follow-up (average, 7 months). Linear scar was left in donor sites in 3 cases and skin scar in 3 cases. There was no malfunction in donor sites. Lobulated medial sural artery perforator flap is feasible and ideal method for the treatment of soft tissue defect in hand or foot with satisfactory effect.

  3. Fibrinogen-Related Proteins in Tissue Repair: How a Unique Domain with a Common Structure Controls Diverse Aspects of Wound Healing.

    Science.gov (United States)

    Zuliani-Alvarez, Lorena; Midwood, Kim S

    2015-05-01

    Significance: Fibrinogen-related proteins (FRePs) comprise an intriguing collection of extracellular molecules, each containing a conserved fibrinogen-like globe (FBG). This group includes the eponymous fibrinogen as well as the tenascin, angiopoietin, and ficolin families. Many of these proteins are upregulated during tissue repair and exhibit diverse roles during wound healing. Recent Advances: An increasing body of evidence highlights the specific expression of a number of FRePs following tissue injury and infection. Upon induction, each FReP uses its FBG domain to mediate quite distinct effects that contribute to different stages of tissue repair, such as driving coagulation, pathogen detection, inflammation, angiogenesis, and tissue remodeling. Critical Issues: Despite a high degree of homology among FRePs, each contains unique sequences that enable their diversification of function. Comparative analysis of the structure and function of FRePs and precise mapping of regions that interact with a variety of ligands has started to reveal the underlying molecular mechanisms by which these proteins play very different roles using their common domain. Future Directions: Fibrinogen has long been used in the clinic as a synthetic matrix serving as a scaffold or a delivery system to aid tissue repair. Novel therapeutic strategies are now emerging that harness the use of other FRePs to improve wound healing outcomes. As we learn more about the underlying mechanisms by which each FReP contributes to the repair response, specific blockade, or indeed potentiation, of their function offers real potential to enable regulation of distinct processes during pathological wound healing.

  4. Damage-induced DNA repair processes in Escherichia coli cells

    International Nuclear Information System (INIS)

    Slezarikova, V.

    1986-01-01

    The existing knowledge is summed up of the response of Escherichia coli cells to DNA damage due to various factors including ultraviolet radiation. So far, three inducible mechanisms caused by DNA damage are known, viz., SOS induction, adaptation and thermal shock induction. Greatest attention is devoted to SOS induction. Its mechanism is described and the importance of the lexA recA proteins is shown. In addition, direct or indirect role is played by other proteins, such as the ssb protein binding the single-strand DNA sections. The results are reported of a study of induced repair processes in Escherichia coli cells repeatedly irradiated with UV radiation. A model of induction by repeated cell irradiation discovered a new role of induced proteins, i.e., the elimination of alkali-labile points in the daughter DNA synthetized on a damaged model. The nature of the alkali-labile points has so far been unclear. In the adaptation process, regulation proteins are synthetized whose production is induced by the presence of alkylation agents. In the thermal shock induction, new proteins synthetize in cells, whose function has not yet been clarified. (E.S.)

  5. PTX3, a Humoral Pattern Recognition Molecule, in Innate Immunity, Tissue Repair, and Cancer.

    Science.gov (United States)

    Garlanda, Cecilia; Bottazzi, Barbara; Magrini, Elena; Inforzato, Antonio; Mantovani, Alberto

    2018-04-01

    Innate immunity includes a cellular and a humoral arm. PTX3 is a fluid-phase pattern recognition molecule conserved in evolution which acts as a key component of humoral innate immunity in infections of fungal, bacterial, and viral origin. PTX3 binds conserved microbial structures and self-components under conditions of inflammation and activates effector functions (complement, phagocytosis). Moreover, it has a complex regulatory role in inflammation, such as ischemia/reperfusion injury and cancer-related inflammation, as well as in extracellular matrix organization and remodeling, with profound implications in physiology and pathology. Finally, PTX3 acts as an extrinsic oncosuppressor gene by taming tumor-promoting inflammation in murine and selected human tumors. Thus evidence suggests that PTX3 is a key homeostatic component at the crossroad of innate immunity, inflammation, tissue repair, and cancer. Dissecting the complexity of PTX3 pathophysiology and human genetics paves the way to diagnostic and therapeutic exploitation.

  6. Modulation of the tissue regenerative process in fish by ß-glucans

    DEFF Research Database (Denmark)

    Nielsen, Michael Engelbrecht; Jiménez, Natalia Ivonne Vera; Przybylska, Dominika Alicja

    the importance of fibroblasts, macrophages, reactive oxygen species (especially hydrogen peroxide) and certain cytokines during wound healing processes. In fish however, only a few studies have been devoted tissue regeneration and modulation of cell proliferation during wound healing, even though mechanical...... the immune response towards pathogen eradication or tissue repair....... but not in animals. are commonly used as immune modulators, but the mechanisms through which the modulation is achieved remains to be understood. Wound healing and tissue regeneration are essential mechanisms to ensure the survival and health of any organism. Studies from the mammalian systems have shown...

  7. Combination of the mutation process with the sensitization and repair processes leading to increased frequencies of mutations in algal populations

    International Nuclear Information System (INIS)

    Necas, J.

    1977-01-01

    The possibility of combining the mutation process with the induction of the repair processes was studied to increase the mutation frequencies in algal populations after UV treatment. The repair process induced by visible light was found to be much more effective than the dark repair processes in the chlorococcal algae used. In these algae, visible light possibly does not induce only those repair processes which affect their DNA, but probably also certain recovery processes which affect their damaged structures and physiological functions. A suitable combination of the sensitization of algae cells by a DNA-base analogue before UV treatment and the induction of the light repair and recovery processes resulted in a rather high increase of viable mutations in chlorococcal algae. These findings may be useful in breeding chlorococcal algae, which have no possibility of hybridization other than somatic. (author)

  8. Extending minimal repair models for repairable systems: A comparison of dynamic and heterogeneous extensions of a nonhomogeneous Poisson process

    International Nuclear Information System (INIS)

    Asfaw, Zeytu Gashaw; Lindqvist, Bo Henry

    2015-01-01

    For many applications of repairable systems, the minimal repair assumption, which leads to nonhomogeneous Poisson processes (NHPP), is not adequate. We review and study two extensions of the NHPP, the dynamic NHPP and the heterogeneous NHPP. Both extensions are motivated by specific aspects of potential applications. It has long been known, however, that the two paradigms are essentially indistinguishable in an analysis of failure data. We investigate the connection between the two approaches for extending NHPP models, both theoretically and numerically in a data example and a simulation study. - Highlights: • Review of dynamic extension of a minimal repair model (LEYP), introduced by Le Gat. • Derivation of likelihood function and comparison to NHPP model with heterogeneity. • Likelihood functions and conditional intensities are similar for the models. • ML estimation is considered for both models using a power law baseline. • A simulation study illustrates and confirms findings of the theoretical study

  9. Opening of the inward rectifier potassium channel alleviates maladaptive tissue repair following myocardial infarction.

    Science.gov (United States)

    Liu, Chengfang; Liu, Enli; Luo, Tiane; Zhang, Weifang; He, Rongli

    2016-08-01

    Activation of the inward rectifier potassium current (IK1) channel has been reported to be associated with suppression of ventricular arrhythmias. In this study, we tested the hypothesis that opening of the IK1 channel with zacopride (ZAC) was involved in the modulation of tissue repair after myocardial infarction. Sprague-Dawley rats were subject to coronary artery ligation and ZAC was administered intraperitoneally (15 µg/kg/day) for 28 days. Compared with the ischemia group, treatment with ZAC significantly reduced the ratio of heart/body weight and the cross-sectional area of cardiomyocytes, suggesting less cardiac hypertrophy. ZAC reduced the accumulation of collagen types I and III, accompanied with decrease of collagen area, which were associated with a reduction of collagen deposition in the fibrotic myocardium. Echocardiography showed improved cardiac function, evidenced by the reduced left ventricular end-diastolic dimension and left ventricular end-systolic dimension, and the increased ejection fraction and fractional shortening in ZAC-treated animals (all P < 0.05 vs. ischemia group). In coincidence with these changes, ZAC up-regulated the protein level of the IK1 channel and down-regulated the phosphorylation of mammalian target of rapamycin (mTOR) and 70-kDa ribosomal protein S6 (p70S6) kinase. Administration of chloroquine alone, an IK1 channel antagonist, had no effect on all the parameters measured, but significantly blocked the beneficial effects of ZAC on cardiac repair. In conclusion, opening of the IK1 channel with ZAC inhibits maladaptive tissue repair and improves cardiac function, potentially mediated by the inhibition of ischemia-activated mTOR-p70S6 signaling pathway via the IK1 channel. So the development of pharmacological agents specifically targeting the activation of the IK1 channel may protect the heart against myocardial ischemia-induced cardiac dysfunction. © The Author 2016. Published by Oxford University Press on behalf of

  10. Ectopic bone formation during tissue-engineered cartilage repair using autologous chondrocytes and novel plasma-derived albumin scaffolds.

    Science.gov (United States)

    Robla Costales, David; Junquera, Luis; García Pérez, Eva; Gómez Llames, Sara; Álvarez-Viejo, María; Meana-Infiesta, Álvaro

    2016-10-01

    The aims of this study were twofold: first, to evaluate the production of cartilaginous tissue in vitro and in vivo using a novel plasma-derived scaffold, and second, to test the repair of experimental defects made on ears of New Zealand rabbits (NZr) using this approach. Scaffolds were seeded with chondrocytes and cultured in vitro for 3 months to check in vitro cartilage production. To evaluate in vivo cartilage production, a chondrocyte-seeded scaffold was transplanted subcutaneously to a nude mouse. To check in vivo repair, experimental defects made in the ears of five New Zealand rabbits (NZr) were filled with chondrocyte-seeded scaffolds. In vitro culture produced mature chondrocytes with no extracellular matrix (ECM). Histological examination of redifferentiated in vitro cultures showed differentiated chondrocytes adhered to scaffold pores. Subcutaneous transplantation of these constructs to a nude mouse produced cartilage, confirmed by histological study. Experimental cartilage repair in five NZr showed cartilaginous tissue repairing the defects, mixed with calcified areas of bone formation. It is possible to produce cartilaginous tissue in vivo and to repair experimental auricular defects by means of chondrocyte cultures and the novel plasma-derived scaffold. Further studies are needed to determine the significance of bone formation in the samples. Copyright © 2016 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

  11. [Feasibility of using connective tissue prosthesis for autoplastic repair of urinary bladder wall defects (an experimental study)].

    Science.gov (United States)

    Tyumentseva, N V; Yushkov, B G; Medvedeva, S Y; Kovalenko, R Y; Uzbekov, O K; Zhuravlev, V N

    2016-12-01

    Experiments on laboratory rats have shown the feasibility of autoplastic repair of urinary bladder wall defects using a connective-tissue capsule formed as the result of an inflammatory response to the presence of a foreign body. The formation of connective tissue prosthesis is characterized by developing fibrous connective tissue, ordering of collagen fibers, reducing the number of cells per unit area with a predominance of more mature cells - fibroblasts. With increasing time of observation, connective tissue prostheses were found to acquire a morphological structure similar to that of the urinary bladder wall. By month 12, the mucosa, the longitudinal and circular muscle layers were formed. The proposed method of partial autoplastic repair of urinary bladder wall is promising, has good long-term results, but requires further experimental studies.

  12. DNA repair processes and their impairment in some human diseases

    International Nuclear Information System (INIS)

    Cleaver, J.E.

    1977-01-01

    Some human diseases show enhanced sensitivity to the action of environmental mutagens, and among these several are known which are defective in the repair of damaged DNA. Xeroderma pigmentosum (XP) is mainly defective in excision repair of a large variety of damaged DNA bases caused by ultraviolet light and chemical mutagens. XP involves at least 6 distinct groups, some of which may lack cofactors required for excising damage from chromatin. As a result of these defects the sensitivity of XP cells to many mutagens is increased 5- to 10-fold. Ataxia telangiectasia and Fanconi's anemia may similarly involve defects in repair of certain DNA base damage or cross-links, respectively. But most of these and other mutagen-sensitive diseases only show increases of about 2-fold in sensitivity to mutagens, and the biochemical defects in the diseases may be more complex and less directly involved in DNA repair than in XP. (Auth.)

  13. Regulation of DNA repair processes in mammalian cell

    International Nuclear Information System (INIS)

    Bil'din, V.N.; Sergina, T.B.; Zhestyanikov, V.D.

    1992-01-01

    A study was made of the repair of ionizing radiation-induced DNA single-strand breaks (SSB) in proliferating and quiescent mouse Swiss 3T6 cells and in those stimulated from the quiet status by epidermal growth factor in combination with insulin, in the presence of specific inhibitors of DNA polymerase α and β (aphidicolin) and DNA polymerase β (2', 3'-dideoxythjymidine-5'-triphosphate). The repair of DNA SSB induced by X-ray-irradiation (10 Gy) or by γ-ray irradiation (150 Gy) is more sensitive to aphidicolin and mitogen-simulated cells three times stronger than in proliferating cells. The influence of 2', 3'-dideoxythymidine-5'-triphosphate on the rate of DNA SSB repair in cells of all the three types does not differ. Thus, the decrease in DNA repair efficiency in quiescent cells is connected with a decrease in the activity of aphidicolin-sensitive DNA polymerase, apparently DNA polymerase α

  14. Human diseases with genetically altered DNA repair processes

    International Nuclear Information System (INIS)

    Cleaver, J.E.; Bootsma, D.; Friedberg, E.

    1975-01-01

    DNA repair of single-strand breaks (produced by ionizing radiation) and of base damage (produced by ultraviolet (uv) light) are two repair mechanisms that most mammalian cells possess. Genetic defects in these repair mechanisms are exemplified by cells from the human premature-aging disease, progeria, which fail to rejoin single-strand breaks, and the skin disease, xeroderma pigmentosum (XP), which exhibits high actinic carcinogenesis and involves failure to repair base damage. In terms of the response of XP cells, many chemical carcinogens can be classified as either x-ray-like (i.e., they cause damage that XP cells can repair) or uv-like (i.e., they cause damage that XP cells cannot repair). The first group contains some of the more strongly carcinogenic chemicals (e.g., alkylating agents). XP occurs in at least two clinical forms, and somatic cell hybridization indicates at least three complementation groups. In order to identify cell lines from various different laboratories unambiguously, a modified nomenclature of XP lines is proposed. (U.S.)

  15. Human diseases with genetically altered DNA repair processes

    International Nuclear Information System (INIS)

    Cleaver, J.E.; Bootsma, D.; Friedberg, E.

    1975-01-01

    DNA repair of single-strand breaks (produced by ionizing radiation) and of base damage (produced by ultraviolet (UV) light) are two repair mechanisms that most mammalian cells possess. Genetic defects in these repair mechanisms are exemplified by cells from the human premature-aging disease, progeria, which fail to rejoin single-strand breaks, and the skin disease, xeroderma pigmentosum (XP), which exhibits high actinic carcinogenesis and involves failure to repair base damage. In terms of the response of XP cells, many chemical carcinogens can be classified as either X-ray-like (i.e., they cause damage that XP cells can repair) or UV-like (i.e., they cause damage that XP cells cannot repair). The first group contains some of the more strongly carcinogenic chemicals (e.g., alkylating agents). XP occurs in at least two clinical forms, and somatic cell hybridization indicates at least three complementation groups. In order to identify cell lines from various different laboratories unambiguously, a modified nomenclature of XP lines is proposed

  16. Time-course expression of CNS inflammatory, neurodegenerative tissue repair markers and metallothioneins during experimental autoimmune encephalomyelitis

    DEFF Research Database (Denmark)

    Espejo, C; Penkowa, M; Demestre, M

    2005-01-01

    -inflammatory, neuroprotective, antioxidant proteins expressed during EAE and MS, in which they might play a protective role. The present study aimed to describe the expression profile of a group of inflammatory, neurodegenerative and tissue repair markers as well as metallothioneins during proteolipid protein-induced EAE...

  17. Biocompatibility Evaluation of EndoSequence Root Repair Paste in the Connective Tissue of Rats.

    Science.gov (United States)

    Taha, Nessrin A; Safadi, Rima A; Alwedaie, Manal S

    2016-10-01

    The aim of this study was to evaluate the subcutaneous connective tissue response to EndoSequence root repair paste (Brasseler, Savannah, GA) compared with mineral trioxide aggregate (MTA). Thirty-six Wistar rats each received 3 sterile tubes, containing 1 of the tested materials and control. The animals were killed 1, 3 and 6 weeks after implantation. The specimens were evaluated histologically for type of inflammation, intensity and extent of inflammatory cells, foreign body reaction, fibrous capsule thickness, perivascular fragments, calcific deposits and vascular congestion. EndoSequence provoked severe inflammation after 1 week, which was significantly different from MTA and control (P ˂ .05), with fragmented particles and foreign body reaction. MTA showed tissue-tolerance features almost comparable to control. EndoSequence was significantly more irritating than MTA and control at 1 and 3 weeks in terms of severity and extent of inflammation. After 6 weeks it displayed more biocompatible characteristics. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  18. Novel Stem Cell Therapies for Applications to Wound Healing and Tissue Repair.

    Science.gov (United States)

    Grada, Ayman; Falanga, Vincent

    2016-10-26

    The number of individuals with chronic cutaneous wounds has been increasing worldwide due to an aging population, diabetes, obesity, and cardiovascular disease. In the United States, almost seven million Americans have chronic skin ulcers. Many therapeutic approaches have been used. However, the treatment outcomes are not always ideal because of failure to achieve complete wound closure in around 60% of cases, scarring, and high rate of recurrence. Therefore, there is a need for more effective therapies. Stem cells offer promising possibilities. Pre-clinical studies have shown that bone- or adipose tissue-derived mesenchymal stem cells (MSCs) have a competitive advantage over other types of stem cells due to their better defined multipotent differentiating potential, paracrine effects, immunomodulatory properties, and safety. However, large controlled clinical trials are needed to examine the capabilities of MSCs in humans and to assess their safety profile. In this review, we highlight emerging treatments in tissue regeneration and repair and provide some perspectives on how to translate current knowledge about stem cells-both multipotent and pluripotent-into viable clinical approaches for treating patients with difficult to heal wounds.

  19. Neural crest stem cell population in craniomaxillofacial development and tissue repair

    Directory of Open Access Journals (Sweden)

    M La Noce

    2014-10-01

    Full Text Available Neural crest cells, delaminating from the neural tube during migration, undergo an epithelial-mesenchymal transition and differentiate into several cell types strongly reinforcing the mesoderm of the craniofacial body area – giving rise to bone, cartilage and other tissues and cells of this human body area. Recent studies on craniomaxillofacial neural crest-derived cells have provided evidence for the tremendous plasticity of these cells. Actually, neural crest cells can respond and adapt to the environment in which they migrate and the cranial mesoderm plays an important role toward patterning the identity of the migrating neural crest cells. In our experience, neural crest-derived stem cells, such as dental pulp stem cells, can actively proliferate, repair bone and give rise to other tissues and cytotypes, including blood vessels, smooth muscle, adipocytes and melanocytes, highlighting that their use in tissue engineering is successful. In this review, we provide an overview of the main pathways involved in neural crest formation, delamination, migration and differentiation; and, in particular, we concentrate our attention on the translatability of the latest scientific progress. Here we try to suggest new ideas and strategies that are needed to fully develop the clinical use of these cells. This effort should involve both researchers/clinicians and improvements in good manufacturing practice procedures. It is important to address studies towards clinical application or take into consideration that studies must have an effective therapeutic prospect for humans. New approaches and ideas must be concentrated also toward stem cell recruitment and activation within the human body, overcoming the classical grafting.

  20. AVACOM-ETAP, Availability and Element Transient and Asymptotic Repair Process

    International Nuclear Information System (INIS)

    Reina, G.

    1987-01-01

    1 - Description of program or function: In reliability theory, the term 'availability' generally indicates the probability of the proper functioning of a system or of a component at a general time t when various possible replacement or repair policies are considered. AVACOM-ETARP calculates the transient and asymptotic availability of a component subject to a repair process with generic failure and repair laws. Five of the most commonly used distributions have been included as options: exponential, normal; lognormal; gamma; Weibull. 2 - Method of solution: The used mathematical model considers the failure-restoration process as a 2-state non-homogeneous Markov process containing the homogeneous Markov one as a particular case

  1. Brazing and diffusion bonding processes as available repair techniques for gas turbine blades and nozzles

    International Nuclear Information System (INIS)

    Mazur, Z.

    1997-01-01

    The conventionally welding methods are not useful for repair of heavily damaged gas turbine blades and nozzles. It includes thermal fatigue and craze cracks, corrosion, erosion and foreign object damage, which extend to the large areas. Because of required extensive heat input and couponing, it can cause severe distortion of the parts and cracks in the heat affected zone, and can made the repair costs high. For these cases, the available repair methods of gas turbine blades and nozzles, include brazing and diffusion bonding techniques are presented. Detailed analysis of the brazing and diffusion bonding processes applied for gas turbine blades repair with all elements which presented. Detailed analysis of the brazing and diffusion bonding processes applied for gas turbine blades repair with all elements which have influence to get sound joint is carried out. Depend of kind of blades and nozzle damage or deterioration registered a different methods of brazing and diffusion bonding applicability is presented. (Author) 65 refs

  2. Potential of Osteoblastic Cells Derived from Bone Marrow and Adipose Tissue Associated with a Polymer/Ceramic Composite to Repair Bone Tissue.

    Science.gov (United States)

    Freitas, Gileade P; Lopes, Helena B; Almeida, Adriana L G; Abuna, Rodrigo P F; Gimenes, Rossano; Souza, Lucas E B; Covas, Dimas T; Beloti, Marcio M; Rosa, Adalberto L

    2017-09-01

    One of the tissue engineering strategies to promote bone regeneration is the association of cells and biomaterials. In this context, the aim of this study was to evaluate if cell source, either from bone marrow or adipose tissue, affects bone repair induced by osteoblastic cells associated with a membrane of poly(vinylidene-trifluoroethylene)/barium titanate (PVDF-TrFE/BT). Mesenchymal stem cells (MSC) were isolated from rat bone marrow and adipose tissue and characterized by detection of several surface markers. Also, both cell populations were cultured under osteogenic conditions and it was observed that MSC from bone marrow were more osteogenic than MSC from adipose tissue. The bone repair was evaluated in rat calvarial defects implanted with PVDF-TrFE/BT membrane and locally injected with (1) osteoblastic cells differentiated from MSC from bone marrow, (2) osteoblastic cells differentiated from MSC from adipose tissue or (3) phosphate-buffered saline. Luciferase-expressing osteoblastic cells derived from bone marrow and adipose tissue were detected in bone defects after cell injection during 25 days without difference in luciferin signal between cells from both sources. Corroborating the in vitro findings, osteoblastic cells from bone marrow combined with the PVDF-TrFE/BT membrane increased the bone formation, whereas osteoblastic cells from adipose tissue did not enhance the bone repair induced by the membrane itself. Based on these findings, it is possible to conclude that, by combining a membrane with cells in this rat model, cell source matters and that bone marrow could be a more suitable source of cells for therapies to engineer bone.

  3. Tissue engineering and the use of stem/progenitor cells for airway epithelium repair

    Directory of Open Access Journals (Sweden)

    GM Roomans

    2010-06-01

    Full Text Available Stem/progenitor cells can be used to repair defects in the airway wall, resulting from e.g., tumors, trauma, tissue reactions following long-time intubations, or diseases that are associated with epithelial damage. Several potential sources of cells for airway epithelium have been identified. These can be divided into two groups. The first group consists of endogenous progenitor cells present in the respiratory tract. This group can be subdivided according to location into (a a ductal cell type in the submucosal glands of the proximal trachea, (b basal cells in the intercartilaginous zones of the lower trachea and bronchi, (c variant Clara cells (Clarav-cells in the bronchioles and (d at the junctions between the bronchioles and the alveolar ducts, and (e alveolar type II cells. This classification of progenitor cell niches is, however, controversial. The second group consists of exogenous stem cells derived from other tissues in the body. This second group can be subdivided into: (a embryonic stem (ES cells, induced pluripotent stem (iPS cells, or amniotic fluid stem cells, (b side-population cells from bone marrow or epithelial stem cells present in bone marrow or circulation and (c fat-derived mesenchymal cells. Airway epithelial cells can be co-cultured in a system that includes a basal lamina equivalent, extracellular factors from mesenchymal fibroblasts, and in an air-liquid interface system. Recently, spheroid-based culture systems have been developed. Several clinical applications have been suggested: cystic fibrosis, acute respiratory distress syndrome, chronic obstructive lung disease, pulmonary fibrosis, pulmonary edema, and pulmonary hypertension. Clinical applications so far are few, but include subglottic stenosis, tracheomalacia, bronchiomalacia, and emphysema.

  4. Immuno-modulatory effect of local rhEGF treatment during tissue repair in diabetic ulcers.

    Science.gov (United States)

    García-Honduvilla, Natalio; Cifuentes, Alberto; Ortega, Miguel A; Pastor, Marta; Gainza, Garazi; Gainza, Eusebio; Buján, Julia; Álvarez-Mon, Melchor

    2018-04-01

    Wound healing is a complex process that can be severely impaired due to pathological situations such as diabetes mellitus. Diabetic foot ulcers are a common complication of this pathology and are characterized by an excessive inflammatory response. In this work, the effects of local treatment with recombinant human epidermal growth factor (rhEGF) were studied using a full-thickness wound healing model in streptozotocin-induced diabetic rats. Wound healing process was assessed with different concentrations of rhEGF (0.1, 0.5, 2.0 and 8.0 µg/mL), placebo and both diabetic and non-diabetic controls ( n  = 53). The macroscopic healing observed in treated diabetic rats was affected by rhEGF concentration. Histologically, we also observed an improvement in the epithelialization, granulation tissue formation and maturation in treated groups, finding again the best response at doses of 0.5 and 2.0 µg/mL. Afterwards, the tissue immune response over time was assessed in diabetic rats using the most effective concentrations of rhEGF (0.5 and 2.0 µg/mL), compared to controls. The presence of macrophages, CD4 + T lymphocytes and CD8 + T lymphocytes, in the reparative tissue was quantified, and cytokine expression was measured by quantitative real-time PCR. rhEGF treatment caused a reduction in the number of infiltrating macrophages in the healing tissue of diabetic, as well as diminished activation of these leukocytes. These findings show that local administration of rhEGF improves the healing process of excisional wounds and the quality of the neoformed tissue in a dose-dependent manner. Besides, this treatment reduces the local inflammation associated with diabetic healing, indicating immuno-modulatory properties. © 2018 The authors.

  5. Prospective study of single-stage repair of contaminated hernias using a biologic porcine tissue matrix: the RICH Study.

    Science.gov (United States)

    Itani, Kamal M F; Rosen, Michael; Vargo, Daniel; Awad, Samir S; Denoto, George; Butler, Charles E

    2012-09-01

    In the presence of contamination, the repair of a ventral incisional hernia (VIH) is challenging. The presence of comorbidities poses an additional risk for postoperative wound events and hernia recurrence. To date, very few studies describe the outcomes of VIH repair in this high-risk population. A prospective, multicenter, single-arm, the Repair of Infected or Contaminated Hernias study was performed to study the clinical outcomes of open VIH repair of contaminated abdominal defects with a non-cross-linked, porcine, acellular dermal matrix, Strattice. Of 85 patients who consented to participate, 80 underwent open VIH repair with Strattice. Hernia defects were 'clean-contaminated' (n = 39), 'contaminated' (n = 39), or 'dirty' (n = 2), and the defects were classified as grade 3 (n = 60) or grade 4 (n = 20). The midline was restored, and primary closure was achieved in 64 patients; the defect was bridged in 16 patients. At 24 months, 53 patients (66%) experienced 95 wound events. There were 28 unique, infection-related events in 24 patients. Twenty-two patients experienced seromas, all but 5 of which were transient and required no intervention. No unanticipated adverse events occurred, and no tissue matrix required complete excision. There were 22 hernia (28%) recurrences by month 24. There was no correlation between infection-related events and hernia recurrence. The use of the intact, non-cross-linked, porcine, acellular dermal matrix, Strattice, in the repair of contaminated VIH in high-risk patients allowed for successful, single-stage reconstruction in >70% of patients followed for 24 months after repair. Published by Mosby, Inc.

  6. Changes in tissue morphology and collagen composition during the repair of cortical bone in the adult chicken.

    Science.gov (United States)

    Glimcher, M J; Shapiro, F; Ellis, R D; Eyre, D R

    1980-09-01

    An animal model was developed to study the histology and collagen chemistry of healing cortical bone. A hole was cut through the cortex of the mid-shaft of the humerus of the adult chicken, which allowed for repair at a mechanically stable site. After one to two weeks the collagen of the repair tissue, which consisted principally of woven bone, contained almost three times as much hydroxylysine as the collagen of normal adult bone and thus resembled the collagen of embryonic long bones. By eight weeks, when lamellar one predominated, the hydroxylysine content had fallen to normal levels. Type I was the major genetic type of collagen present throughout. No type-II collagen, characteristic of cartilage, was detected; this was consistent with the histological findings. The results established that hydroxylysine-rich type-I collagen can be made by osteoblasts of adult animals as well as by those of embryos and early postnates. In order to understand the biological characteristics of fracture healing, it is vital to study not only the macroscopic organization of the repair tissue but also the chemical properties of its molecular components. The strength of healing fractured bone, and indeed of normal bone, depends largely on the properties of the structural protein collagen. To date, it is not known whether the collagen in healing fractures is the same as that in normal bone, or whether it has distinct chemical features that may suit it for bone repair.

  7. Effects of "second-hand" smoke on structure and function of fibroblasts, cells that are critical for tissue repair and remodeling

    Directory of Open Access Journals (Sweden)

    Yadav Madhav

    2004-04-01

    Full Text Available Abstract Background It is known that "second-hand" cigarette smoke leads to abnormal tissue repair and remodelling but the cellular mechanisms involved in these adverse effects are not well understood. Fibroblasts play a major role in repair and remodelling. They orchestrate these processes by proliferating, migrating, and secreting proteins such as, cytokines, growth factors and extracellular matrix molecules. Therefore, we focus our studies on the effects of "second-hand" cigarette smoke on the structure and function of these cells. Results We used sidestream whole (SSW smoke, a major component of "second-hand" smoke, primary embryonic fibroblasts, cells that behave very much like wound fibroblasts, and a variety of cellular and molecular approaches. We show that doses of smoke similar to those found in tissues cause cytoskeletal changes in the fibroblasts that may lead to a decrease in cell migration. In addition, we also show that these levels of cigarette smoke stimulate an increase in cell survival that is reflected in an increase and/or activation of stress/survival proteins such as cIL-8, grp78, PKB/Akt, p53, and p21. We further show that SSW affects the endomembrane system and that this effect is also accomplished by nicotine alone. Conclusions Taken together, our results suggest that: (i SSW may delay wound repair because of the inability of the fibroblasts to migrate into the wounded area, leading to an accumulation of these cells at the edge of the wound, thus preventing the formation of the healing tissue; (ii the increase in cell survival coupled to the decrease in cell migration can lead to a build-up of connective tissue, thereby causing fibrosis and excess scarring.

  8. Emergency repair of upper extremity large soft tissue and vascular injuries with flow-through anterolateral thigh free flaps.

    Science.gov (United States)

    Zhan, Yi; Fu, Guo; Zhou, Xiang; He, Bo; Yan, Li-Wei; Zhu, Qing-Tang; Gu, Li-Qiang; Liu, Xiao-Lin; Qi, Jian

    2017-12-01

    Complex extremity trauma commonly involves both soft tissue and vascular injuries. Traditional two-stage surgical repair may delay rehabilitation and functional recovery, as well as increase the risk of infections. We report a single-stage reconstructive surgical method that repairs soft tissue defects and vascular injuries with flow-through free flaps to improve functional outcomes. Between March 2010 and December 2016 in our hospital, 5 patients with severe upper extremity trauma received single-stage reconstructive surgery, in which a flow-through anterolateral thigh free flap was applied to repair soft tissue defects and vascular injuries simultaneously. Cases of injured artery were reconstructed with the distal trunk of the descending branch of the lateral circumflex femoral artery. A segment of adjacent vein was used if there was a second artery injury. Patients were followed to evaluate their functional recoveries, and received computed tomography angiography examinations to assess peripheral circulation. Two patients had post-operative thumb necrosis; one required amputation, and the other was healed after debridement and abdominal pedicle flap repair. The other 3 patients had no major complications (infection, necrosis) to the recipient or donor sites after surgery. All the patients had achieved satisfactory functional recovery by the end of the follow-up period. Computed tomography angiography showed adequate circulation in the peripheral vessels. The success of these cases shows that one-step reconstructive surgery with flow-through anterolateral thigh free flaps can be a safe and effective treatment option for patients with complex upper extremity trauma with soft tissue defects and vascular injuries. Copyright © 2017. Published by Elsevier Ltd.

  9. Microsurgical head and neck tissue repair by visceral mini-autografting

    Directory of Open Access Journals (Sweden)

    A. D. Kaprin

    2015-01-01

    Full Text Available Objective. To minimize surgical trauma in patients with head and neck tumors during microsurgical plasty with visceral autografts.Subjects and methods. Clinical experience has been gained in the treatment of 53 patients with locally advanced craniofascial (n = 27 and oropharyngeal (n = 36 cancers. Abdominal organs were used for plastic closure of extensive defects after surgical resection. Paraumbilical incision allowing for an adequate approach into the abdominal cavity with minimal external trauma in the anterior abdominal wall was chosen as an access procedure. Video-assisted techniques were used to excise the midline aponeurosis. Donor organs, such as the omentum, greater curvature of the stomach, transverse colon, small intestine were taken through a mini-laparotomic incision to the anterior abdominal wall, then the vascular pedicle was exposed and a visceral autograft was made. After forming and cutting off the autograft, organ anastomoses were created extracorporeally.Results. Mini-access surgery could be completed in 50 of the 53 cases (4 patients had previously undergone abdominal interventions. Omental (n = 26, colo-omental (n = 15, gastro-omental (n = 7, and entero-omental (n = 5 flaps were made and prepared for autografting. No intra- or postoperative abdominal complications were found.Conclusion. Minimally invasive technologies used to create visceral authografts for head and neck tissue repair can minimize surgical trauma and reduce treatment duration. The indications for this access are the debilitating state of a cancer patient or the young age of a patient who does not wish to have an additional scar in the donor region.

  10. Can We Fix This? Parent-Child Repair Processes and Preschoolers' Regulatory Skills.

    Science.gov (United States)

    Kemp, Christine J; Lunkenheimer, Erika; Albrecht, Erin C; Chen, Deborah

    2016-10-01

    The repair of difficult parent-child interactions is a marker of healthy functioning in infancy, but less is known about repair processes during early childhood. We used dynamic systems methods to investigate dyadic repair in mothers and their 3-year-old children ( N = 96) and its prediction of children's emotion regulation and behavior problems at a four-month follow-up. Mothers and children completed free play and challenging puzzle tasks. Repair was operationalized as the conditional probability of moving into a dyadic adaptive behavior region after individual or dyadic maladaptive behavior (e.g., child noncompliance, parental criticism). Overall, dyads repaired approximately half their maladaptive behaviors. A greater likelihood of repair during the puzzle task predicted better child emotion regulation and fewer behavior problems in preschool. Results suggest dyadic repair is an important process in early childhood and provide further evidence for the connection between parent-child coregulation and children's developing regulatory capacities. Implications for family-based interventions are discussed.

  11. Analysis and Modeling of Friction Stir Processing-Based Crack Repairing in 2024 Aluminum Alloy

    Institute of Scientific and Technical Information of China (English)

    Jun-Gang Ren; Lei Wang; Dao-Kui Xu; Li-Yang Xie; Zhan-Chang Zhang

    2017-01-01

    A friction stir processing-based method was used to repair cracks in the 2024 aluminum alloy plates.The temperature field and plastic material flow pattern were analyzed on the basis of experimental and finite element simulation results.Microstructure and tensile properties of the repaired specimens were studied.The results showed that the entire crack repairing was a solid-phase process and plastic materials tended to flow toward the shoulder center and then resulted in the repairing of cracks.Meanwhile,the coarse grain structures were refined in repaired zone (RZ),while the grains in thermal-mechanically affected zone and heat-affected zone were elongated and driven to grow up.Meanwhile,large phases are crushed into small particles and dispersed inside the RZ.Finally,the strength of the repaired specimens can be restored dramatically and their ductility can be partially restored.After heat treatment,the tensile properties of the repaired specimens can be further enhanced.

  12. DNA double-strand break repair of blood lymphocytes and normal tissues analysed in a preclinical mouse model: implications for radiosensitivity testing.

    Science.gov (United States)

    Rübe, Claudia E; Grudzenski, Saskia; Kühne, Martin; Dong, Xiaorong; Rief, Nicole; Löbrich, Markus; Rübe, Christian

    2008-10-15

    Radiotherapy is an effective cancer treatment, but a few patients suffer severe radiation toxicities in neighboring normal tissues. There is increasing evidence that the variable susceptibility to radiation toxicities is caused by the individual genetic predisposition, by subtle mutations, or polymorphisms in genes involved in cellular responses to ionizing radiation. Double-strand breaks (DSB) are the most deleterious form of radiation-induced DNA damage, and DSB repair deficiencies lead to pronounced radiosensitivity. Using a preclinical mouse model, the highly sensitive gammaH2AX-foci approach was tested to verify even subtle, genetically determined DSB repair deficiencies known to be associated with increased normal tissue radiosensitivity. By enumerating gammaH2AX-foci in blood lymphocytes and normal tissues (brain, lung, heart, and intestine), the induction and repair of DSBs after irradiation with therapeutic doses (0.1-2 Gy) was investigated in repair-proficient and repair-deficient mouse strains in vivo and blood samples irradiated ex vivo. gammaH2AX-foci analysis allowed to verify the different DSB repair deficiencies; even slight impairments caused by single polymorphisms were detected similarly in both blood lymphocytes and solid tissues, indicating that DSB repair measured in lymphocytes is valid for different and complex organs. Moreover, gammaH2AX-foci analysis of blood samples irradiated ex vivo was found to reflect repair kinetics measured in vivo and, thus, give reliable information about the individual DSB repair capacity. gammaH2AX analysis of blood and tissue samples allows to detect even minor genetically defined DSB repair deficiencies, affecting normal tissue radiosensitivity. Future studies will have to evaluate the clinical potential to identify patients more susceptible to radiation toxicities before radiotherapy.

  13. Mesh complications and failure rates after transvaginal mesh repair compared with abdominal or laparoscopic sacrocolpopexy and to native tissue repair in treating apical prolapse.

    Science.gov (United States)

    Dandolu, Vani; Akiyama, Megumi; Allenback, Gayle; Pathak, Prathamesh

    2017-02-01

    Our objective was to quantitate the extent of complications and failure rate for apical prolapse repair with transvaginal mesh (TVM) use versus sacrocolpopexy over a minimum of 2 years of follow-up. Truven CCAE and Medicare Supplemental databases 2008-2013 were used for analysis. Patients with apical prolapse repair via transvaginal mesh (TVMR), abdominal sacrocolpopexy (ASCP), laparoscopic sacrocolpopexy (LSCP), or native tissue repair (NTR) and continuously enrolled for years were in the study cohort. Surgical failures were identified by reoperation for any prolapse or subsequent use of pessary. SAS® 9.3 was used for analysis. Mesh removal/revision was reported highest in TVMR (5.1 %), followed by LSCP (1.7 %) and ASCP (1.2 %). In those with concomitant sling, combined rates for mesh/sling revision were high, at 9.0 % in TVMR + sling, 5.6 % in ASCP + sling, and 4.5 % LSCP + sling. Sling-alone cases reported a 3.5 % revision rate. Pelvic pain (16.4-22.7 %) and dyspareunia (5.6-7.5 %) were high in all three approaches for apical prolapse repairs. Reoperation for apical prolapse was more common for TVMR (2.9 %) compared with NTR (2.3 %) [odds ratio (OR) 1.27; confidence interval (CI) 1.1-1.47; p 0.002]. Both ASCP and LSCP were superior to NTR (ASCP 1.5 %, OR 0.63, CI 0.46-0.86; p 0.003) and LSCP 1.8 % (OR 0.79, CI 0.62-1.01; p 0.07). Overall prolapse recurrence, as indicated by any compartment surgery for prolapse and/or pessary use, was also noted highest in TVMR (5.9 % OR 1.23, CI 1.11-1.36; p mesh is used for repair, mesh revision is highest with TVMR and lowest with ASCP.

  14. Self-Repair and Language Selection in Bilingual Speech Processing

    Directory of Open Access Journals (Sweden)

    Inga Hennecke

    2013-07-01

    Full Text Available In psycholinguistic research the exact level of language selection in bilingual lexical access is still controversial and current models of bilingual speech production offer conflicting statements about the mechanisms and location of language selection. This paper aims to provide a corpus analysis of self-repair mechanisms in code-switching contexts of highly fluent bilingual speakers in order to gain further insights into bilingual speech production. The present paper follows the assumptions of the Selection by Proficiency model, which claims that language proficiency and lexical robustness determine the mechanism and level of language selection. In accordance with this hypothesis, highly fluent bilinguals select languages at a prelexical level, which should influence the occurrence of self-repairs in bilingual speech. A corpus of natural speech data of highly fluent and balanced bilingual French-English speakers of the Canadian French variety Franco-Manitoban serves as the basis for a detailed analysis of different self-repair mechanisms in code-switching environments. Although the speech data contain a large amount of code-switching, results reveal that only a few speech errors and self-repairs occur in direct code-switching environments. A detailed analysis of the respective starting point of code-switching and the different repair mechanisms supports the hypothesis that highly proficient bilinguals do not select languages at the lexical level.Le niveau exact de la sélection des langues lors de l’accès lexical chez le bilingue reste une question controversée dans la recherche psycholinguistique. Les modèles actuels de la production verbale bilingue proposent des arguments contradictoires concernant le mécanisme et le lieu de la sélection des langues. La présente recherche vise à fournir une analyse de corpus mettant l’accent sur les mécanismes d’autoréparation dans le contexte d’alternance codique dans la production verbale

  15. The importance of establishing an international network of tissue banks and regional tissue processing centers.

    Science.gov (United States)

    Morales Pedraza, Jorge

    2014-03-01

    During the past four decades, many tissue banks have been established across the world with the aim of supplying sterilized tissues for clinical use and research purposes. Between 1972 and 2005, the International Atomic Energy Agency supported the establishment of more than sixty of these tissue banks in Latin America and the Caribbean, Asia and the Pacific, Africa and Eastern Europe; promoted the use of the ionizing radiation technique for the sterilization of the processed tissues; and encouraged cooperation between the established tissue banks during the implementation of its program on radiation and tissue banking at national, regional and international levels. Taking into account that several of the established tissue banks have gained a rich experience in the procurement, processing, sterilization, storage, and medical use of sterilized tissues, it is time now to strengthen further international and regional cooperation among interested tissue banks located in different countries. The purpose of this cooperation is to share the experience gained by these banks in the procurement, processing, sterilization, storage, and used of different types of tissues in certain medical treatments and research activities. This could be done through the establishment of a network of tissue banks and a limited number of regional tissue processing centers in different regions of the world.

  16. The optimal fraction size in high-dose-rate brachytherapy: dependency on tissue repair kinetics and low-dose rate

    International Nuclear Information System (INIS)

    Sminia, Peter; Schneider, Christoph J.; Fowler, Jack F.

    2002-01-01

    Background and Purpose: Indications of the existence of long repair half-times on the order of 2-4 h for late-responding human normal tissues have been obtained from continuous hyperfractionated accelerated radiotherapy (CHART). Recently, these data were used to explain, on the basis of the biologically effective dose (BED), the potential superiority of fractionated high-dose rate (HDR) with large fraction sizes of 5-7 Gy over continuous low-dose rate (LDR) irradiation at 0.5 Gy/h in cervical carcinoma. We investigated the optimal fraction size in HDR brachytherapy and its dependency on treatment choices (overall treatment time, number of HDR fractions, and time interval between fractions) and treatment conditions (reference low-dose rate, tissue repair characteristics). Methods and Materials: Radiobiologic model calculations were performed using the linear-quadratic model for incomplete mono-exponential repair. An irradiation dose of 20 Gy was assumed to be applied either with HDR in 2-12 fractions or continuously with LDR for a range of dose rates. HDR and LDR treatment regimens were compared on the basis of the BED and BED ratio of normal tissue and tumor, assuming repair half-times between 1 h and 4 h. Results: With the assumption that the repair half-time of normal tissue was three times longer than that of the tumor, hypofractionation in HDR relative to LDR could result in relative normal tissue sparing if the optimum fraction size is selected. By dose reduction while keeping the tumor BED constant, absolute normal tissue sparing might therefore be achieved. This optimum HDR fraction size was found to be largely dependent on the LDR dose rate. On the basis of the BED NT/TUM ratio of HDR over LDR, 3 x 6.7 Gy would be the optimal HDR fractionation scheme for replacement of an LDR scheme of 20 Gy in 10-30 h (dose rate 2-0.67 Gy/h), while at a lower dose rate of 0.5 Gy/h, four fractions of 5 Gy would be preferential, still assuming large differences between tumor

  17. Effects of chronic severe pulmonary regurgitation and percutaneous valve repair on right ventricular geometry and contractility assessed by tissue Doppler echocardiography

    DEFF Research Database (Denmark)

    Kjaergaard, Jesper; Iversen, Kasper K; Vejlstrup, Niels G

    2010-01-01

    Pulmonary regurgitation (PR) following repair of right ventricular (RV) outflow obstruction is related to slowly progressive RV dilatation and heart failure and will eventually require surgical intervention, but optimal timing of pulmonary valve replacement is challenging. Tissue Doppler based...

  18. Translational Research in Pediatrics IV: Solid Tissue Collection and Processing.

    Science.gov (United States)

    Gillio-Meina, Carolina; Zielke, H Ronald; Fraser, Douglas D

    2016-01-01

    Solid tissues are critical for child-health research. Specimens are commonly obtained at the time of biopsy/surgery or postmortem. Research tissues can also be obtained at the time of organ retrieval for donation or from tissue that would otherwise have been discarded. Navigating the ethics of solid tissue collection from children is challenging, and optimal handling practices are imperative to maximize tissue quality. Fresh biopsy/surgical specimens can be affected by a variety of factors, including age, gender, BMI, relative humidity, freeze/thaw steps, and tissue fixation solutions. Postmortem tissues are also vulnerable to agonal factors, body storage temperature, and postmortem intervals. Nonoptimal tissue handling practices result in nucleotide degradation, decreased protein stability, artificial posttranslational protein modifications, and altered lipid concentrations. Tissue pH and tryptophan levels are 2 methods to judge the quality of solid tissue collected for research purposes; however, the RNA integrity number, together with analyses of housekeeping genes, is the new standard. A comprehensive clinical data set accompanying all tissue samples is imperative. In this review, we examined: the ethical standards relating to solid tissue procurement from children; potential sources of solid tissues; optimal practices for solid tissue processing, handling, and storage; and reliable markers of solid tissue quality. Copyright © 2016 by the American Academy of Pediatrics.

  19. 18.2.3 Current Concepts on Tissue Engineering for Meniscus Repair

    OpenAIRE

    Mandelbaum, B.; Roos, H.; Shive, M.S.; Hambly, K.; Mithoefer, K.; Della Villa, S.; Silvers, H.J.; Hambly, K.; Fontana, A.; Dalemans, W.; Celis, P.; Brittberg, M.; Marcacci, M.; Kon, E.; Delcogliano, M.

    2009-01-01

    Introduction Articular cartilage lesions are a common pathology of the knee joint and many patients could benefit from cartilage repair. Untreated, however, cartilage defects may lead to osteoarthritis (OA). Thus, surgical treatment options may offer a possibility for patients with cartilage defects to avoid OA or to delay the progression of OA. Therefore, cartilage repair techniques require sophisticated follow-up, if possible non-invasively. Although clinical findings are the primary criter...

  20. The self-assembling process and applications in tissue engineering

    Science.gov (United States)

    Lee, Jennifer K.; Link, Jarrett M.; Hu, Jerry C. Y.; Athanasiou, Kyriacos A.

    2018-01-01

    Tissue engineering strives to create neotissues capable of restoring function. Scaffold-free technologies have emerged that can recapitulate native tissue function without the use of an exogenous scaffold. This chapter will survey, in particular, the self-assembling and self-organization processes as scaffold-free techniques. Characteristics and benefits of each process are described, and key examples of tissues created using these scaffold-free processes are examined to provide guidance for future tissue engineering developments. This chapter aims to explore the potential of self-assembly and self-organization scaffold-free approaches, detailing the recent progress in the in vitro tissue engineering of biomimetic tissues with these methods, toward generating functional tissue replacements. PMID:28348174

  1. Disrupted G1 to S phase clearance via cyclin signaling impairs liver tissue repair in thioacetamide-treated type 1 diabetic rats

    International Nuclear Information System (INIS)

    Devi, Sachin S.; Mehendale, Harihara M.

    2005-01-01

    Previously we reported that a nonlethal dose of thioacetamide (TA, 300 mg/kg) causes 90% mortality in type 1 diabetic (DB) rats because of irreversible acute liver injury owing to inhibited hepatic tissue repair, primarily due to blockage of G 0 to S phase progression of cell division cycle. On the other hand, DB rats receiving 30 mg TA/kg exhibited equal initial liver injury and delayed tissue repair compared to nondiabetic (NDB) rats receiving 300 mg TA/kg, resulting in a delay in recovery from liver injury and survival. The objective of the present study was to test the hypothesis that impaired cyclin-regulated progression of G 1 to S phase of the cell cycle may explain inhibited liver tissue repair, hepatic failure, and death, contrasted with delayed liver tissue repair but survival observed in the DB rats receiving 300 in contrast to 30 mg TA/kg. In the TA-treated NDB rats sustained MAPKs and cyclin expression resulted in higher phosphorylation of retinoblastoma (pRb), explaining prompt tissue repair and survival. In contrast, DB rats receiving the same dose of TA (300 mg/kg) exhibited suppressed MAPKs and cyclin expression that led to inhibition of pRb, inhibited tissue repair, and death. On the other hand, DB rats receiving 30 mg TA/kg exhibited delayed up regulation of MAPK signaling that delayed the expression of CD1 and pRb, explaining delayed stimulation of tissue repair observed in this group. In conclusion, the hepatotoxicant TA has a dose-dependent adverse effect on cyclin-regulated pRb signaling: the lower dose causes a recoverable delay, whereas the higher dose inhibits it with corresponding effect on the ultimate outcomes on hepatic tissue repair; this dose-dependent adverse effect is substantially shifted to the left of the dose response curve in diabetes

  2. Incomplete excision repair process after UV-irradiation in MUT-mutants of Proteus mirabillis

    International Nuclear Information System (INIS)

    Stoerl, K.

    1977-01-01

    MUT-mutants of P. mirabilis seem to be able to perform the incision step in the course of excision repair. In contrast to the corresponding wildtype strains with MUT-mutants the number of single-strand breaks formed after UV-irradiation is independent of the UV-dose up to about 720 erg/mm 2 . Incubation in minimal medium over a longer time does not result in completion of excision repair; about 3-6 single-strand breaks in the DNA of these mutants remain open. Likewise, the low molecular weight of the newly synthesized daughter DNA confirms an incompletely proceeding or delayed repair process. As a possible reason for the mutator phenotype an alteration of the DNA-polymerase playing a role in excision and resynthesis steps of excision repair is discussed. (author)

  3. Molecular dynamics of formation of TD lesioned DNA complexed with repair enzyme - onset of the enzymatic repair process

    Energy Technology Data Exchange (ETDEWEB)

    Pinak, Miroslav [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1999-12-01

    To describe the first step of the enzymatic repair process (formation of complex enzyme-DNA), in which the thymine dimer (TD) part is removed from DNA, the 500 picosecond (ps) molecular dynamics (MD) simulation of TD lesioned DNA and part of repair enzyme cell (inclusive of catalytic center - Arg-22, Glu-23, Arg-26 and Thr-2) was performed. TD is UV originated lesion in DNA and T4 Endonuclease V is TD specific repair enzyme. Both molecules were located in the same simulation cell and their relative movement was examined. During the simulation the research was focused on the role of electrostatic energy in formation of complex enzyme-DNA. It is found, that during the first 100 ps of MD, the part of enzyme approaches the DNA surface at the TD lesion, interacts extensively by electrostatic and van der Walls interactions with TD part of DNA and forms complex that lasts stabile for 500 ps of MD. In the beginning of MD, the positive electrostatic interaction energy between part of enzyme and TD ({approx} +10 kcal/mol) drives enzyme towards the DNA molecule. Water-mediated hydrogen bonds between enzyme and DNA help to keep complex stabile. As a reference, the MD simulation of the identical system with native DNA molecule (two native thymines (TT) instead of TD) was performed. In this system the negative electrostatic interaction energy between part of enzyme and TT ({approx} -11 kcal/mol), in contrary to the positive one in the system with TD, doesn't drive enzyme towards DNA and complex is not formed. (author)

  4. Molecular dynamics of formation of TD lesioned DNA complexed with repair enzyme - onset of the enzymatic repair process

    International Nuclear Information System (INIS)

    Pinak, Miroslav

    1999-12-01

    To describe the first step of the enzymatic repair process (formation of complex enzyme-DNA), in which the thymine dimer (TD) part is removed from DNA, the 500 picosecond (ps) molecular dynamics (MD) simulation of TD lesioned DNA and part of repair enzyme cell (inclusive of catalytic center - Arg-22, Glu-23, Arg-26 and Thr-2) was performed. TD is UV originated lesion in DNA and T4 Endonuclease V is TD specific repair enzyme. Both molecules were located in the same simulation cell and their relative movement was examined. During the simulation the research was focused on the role of electrostatic energy in formation of complex enzyme-DNA. It is found, that during the first 100 ps of MD, the part of enzyme approaches the DNA surface at the TD lesion, interacts extensively by electrostatic and van der Walls interactions with TD part of DNA and forms complex that lasts stabile for 500 ps of MD. In the beginning of MD, the positive electrostatic interaction energy between part of enzyme and TD (∼ +10 kcal/mol) drives enzyme towards the DNA molecule. Water-mediated hydrogen bonds between enzyme and DNA help to keep complex stabile. As a reference, the MD simulation of the identical system with native DNA molecule (two native thymines (TT) instead of TD) was performed. In this system the negative electrostatic interaction energy between part of enzyme and TT (∼ -11 kcal/mol), in contrary to the positive one in the system with TD, doesn't drive enzyme towards DNA and complex is not formed. (author)

  5. The role of allofibroblasts transplantation in cartilaginous tissue regeneration process

    OpenAIRE

    Khadjibaev Аbdukhakim Muminovich; Tilyakov Akbar Buriyevich; Magrupov Bokhodir Asadullaevich; Urazmetova Maisa Dmitriyevna; Ubaydullaev Bobur Sabirovich

    2017-01-01

    Aim of investigation. Ground of embryonal allofibroblasts in the process of cartilaginous tissue regeneration. Material and methods. Investigation is based on the study the results of stimulation cartilaginous tissue regeneration process in the conditions of embryonal allofibroblasts application in 24 experimental sexually mature rabbits in which the model of symphysis pubis rupture with its following recovery have been used. Pieces of cartilaginous tissue have been fixed in 10% neutral forma...

  6. Native tissue repair or transvaginal mesh for recurrent vaginal prolapse: what are the long-term outcomes?

    Science.gov (United States)

    Ow, Lin Li; Lim, Yik N; Dwyer, Peter L; Karmakar, Debjyoti; Murray, Christine; Thomas, Elizabeth; Rosamilia, Anna

    2016-09-01

    The objective of this study was to assess outcomes in native tissue (NT) and transvaginal mesh (TVM) repair in women with recurrent prolapse. A retrospective two-group observational study of 237 women who underwent prolapse repair after failed NT repair in two tertiary hospitals. A primary outcome of "success" was defined using a composite outcome of no vaginal bulge symptoms, no anatomical recurrence in the same compartment beyond the hymen (0 cm on POPQ) and no surgical re-treatment for prolapse in the same compartment. Secondary outcomes assessed included re-operation for prolapse in the same compartment, dyspareunia and mesh-related complications. Of a total of 336 repairs, 196 were performed in the anterior compartment and 140 in the posterior compartment. Compared with the TVM groups, women undergoing repeat NT repair were more likely to experience anatomical recurrence (anterior 40.9 % vs 25 %, p = 0.02, posterior 25.3 % vs 7.5 %, p = 0.01), report vaginal bulge (anterior 34.1 % vs 12 %, p mesh exposure were 9.3 % anteriorly and 15.1 % posteriorly. Although the number of women requiring a prolapse re-operation is lower in the TVM group, the overall re-operation rate was not significantly different when procedures to correct mesh complications were included. Although the success rate is better with the use of TVM for recurrent prolapse, the total re-operation rates are similar when mesh complication-related surgeries are included.

  7. Degradability of injectable calcium sulfate/mineralized collagen-based bone repair material and its effect on bone tissue regeneration

    International Nuclear Information System (INIS)

    Chen, Zonggang; Kang, Lingzhi; Meng, Qing-Yuan; Liu, Huanye; Wang, Zhaoliang; Guo, Zhongwu; Cui, Fu-Zhai

    2014-01-01

    The nHAC/CSH composite is an injectable bone repair material with controllable injectability and self-setting properties prepared by introducing calcium sulfate hemihydrate (CSH) into mineralized collagen (nHAC). When mixed with water, the nHAC/CSH composites can be transformed into mineralized collagen/calcium sulfate dihydrate (nHAC/CSD) composites. The nHAC/CSD composites have good biocompatibility and osteogenic capability. Considering that the degradation behavior of bone repair material is another important factor for its clinical applications, the degradability of nHAC/CSD composites was studied. The results showed that the degradation ratio of the nHAC/CSD composites with lower nHAC content increased with the L/S ratio increase of injectable materials, but the variety of L/S ratio had no significant effect on the degradation ratio of the nHAC/CSD composites with higher nHAC content. Increasing nHAC content in the composites could slow down the degradation of nHAC/CSD composite. Setting accelerator had no significant effect on the degradability of nHAC/CSD composites. In vivo histological analysis suggests that the degradation rate of materials can match the growth rate of new mandibular bone tissues in the implanted site of rabbit. The regulable degradability of materials resulting from the special prescriptions of injectable nHAC/CSH composites will further improve the workability of nHAC/CSD composites. - Highlights: • The nHAC/CSH composite can be as an injectable bone repair material. • The L/S ratio and nHAC content have a significant effect on material degradability. • The degradability of bone materials can be regulated to match tissue repair. • The regulable degradability will further improve the workability of bone materials

  8. Degradability of injectable calcium sulfate/mineralized collagen-based bone repair material and its effect on bone tissue regeneration

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Zonggang, E-mail: chenzg@sdu.edu.cn [National Glycoengineering Research Center, Shandong University, Jinan 250100 (China); Department of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Kang, Lingzhi [National Glycoengineering Research Center, Shandong University, Jinan 250100 (China); Meng, Qing-Yuan [Department of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Liu, Huanye [Department of Prosthodontics, School of Stomatology, China Medical University, Shenyang 110001 (China); Wang, Zhaoliang [Jinan Military General Hospital of PLA, Jinan 250031 (China); Guo, Zhongwu, E-mail: zwguo@sdu.edu.cn [National Glycoengineering Research Center, Shandong University, Jinan 250100 (China); Cui, Fu-Zhai, E-mail: cuifz@mail.tsinghua.edu.cn [Department of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China)

    2014-12-01

    The nHAC/CSH composite is an injectable bone repair material with controllable injectability and self-setting properties prepared by introducing calcium sulfate hemihydrate (CSH) into mineralized collagen (nHAC). When mixed with water, the nHAC/CSH composites can be transformed into mineralized collagen/calcium sulfate dihydrate (nHAC/CSD) composites. The nHAC/CSD composites have good biocompatibility and osteogenic capability. Considering that the degradation behavior of bone repair material is another important factor for its clinical applications, the degradability of nHAC/CSD composites was studied. The results showed that the degradation ratio of the nHAC/CSD composites with lower nHAC content increased with the L/S ratio increase of injectable materials, but the variety of L/S ratio had no significant effect on the degradation ratio of the nHAC/CSD composites with higher nHAC content. Increasing nHAC content in the composites could slow down the degradation of nHAC/CSD composite. Setting accelerator had no significant effect on the degradability of nHAC/CSD composites. In vivo histological analysis suggests that the degradation rate of materials can match the growth rate of new mandibular bone tissues in the implanted site of rabbit. The regulable degradability of materials resulting from the special prescriptions of injectable nHAC/CSH composites will further improve the workability of nHAC/CSD composites. - Highlights: • The nHAC/CSH composite can be as an injectable bone repair material. • The L/S ratio and nHAC content have a significant effect on material degradability. • The degradability of bone materials can be regulated to match tissue repair. • The regulable degradability will further improve the workability of bone materials.

  9. Endovascular Repair of Thoracoabdominal and Arch Aneurysms in Patients with Connective Tissue Disease Using Branched and Fenestrated Devices.

    Science.gov (United States)

    Clough, Rachel E; Martin-Gonzalez, Teresa; Van Calster, Katrien; Hertault, Adrien; Spear, Rafaëlle; Azzaoui, Richard; Sobocinski, Jonathan; Haulon, Stéphan

    2017-10-01

    Prophylactic open surgery is the standard practice in patients with connective tissue and thoracoabdominal aortic aneurysm (TAAA) and aortic arch disease. Branched and fenestrated devices offer a less invasive alternative but there are concerns regarding the durability of the repair and the effect of the stent graft on the fragile aortic wall. The aim of this study is to evaluate mid-term outcomes of fenestrated and/or branched endografting in patients with connective tissue disease. All patients with connective tissue disease who underwent TAAA or arch aneurysm repair using a fenestrated and/or branched endograft in a single, high-volume center between 2004 and 2015 were included. Ruptured aneurysms and acute aortic dissections were excluded from this study, but not chronic aortic dissections. In total, 427 (403 pararenal and TAAAs, and 24 arch aneurysms) endovascular interventions were performed during the study period. Of these, 17 patients (4%) (16 TAAAs, 1 arch) had connective tissue disease. All patients were classified as unfit for open repair. The mean age was 51 ± 8 years. Thirteen patients with TAAA were treated with a fenestrated, 1 with a branched, and 2 with a combined fenestrated/branch device. A double inner branch device was used to treat the arch aneurysm. The technical success rate was 100% with no incidence of early mortality, spinal cord ischemia, stroke, or further dissection. Postoperative deterioration in renal function was seen in 3 patients (18.8%) and no hemodialysis was required. The mean follow-up was 3.4 years (0.3-7.4). Aneurysm sac shrinkage was seen in 35% of patients (6/17) and the sac diameter remained stable in 65% of patients (11/17). No sac or sealing zone enlargement was observed in any of the patients and there were no conversions to open repair. Reintervention was required in 1 patient at 2 years for bilateral renal artery occlusion (successful fibrinolysis). One type II endoleak (lumbar) is under surveillance and 1 type

  10. Cell sensitivity to irradiation and DNA repair processes. II

    International Nuclear Information System (INIS)

    Kozubek, S.; Krasavin, E.A.

    1984-01-01

    A new model of DNA single-strand break (SSB) and double-strand break (DSB) induction by radiations of different linear energy transfer (LET) has been developed. Utilizing quadratic dependence of the dose that delta-electrons depart in the track of heavy particles the fraction of heavy particle energy deposited in the target of DNA dimensions has been calculated. SSBs arise from energy depositions in one strand of DNA, direct DSBs arise from two SSBs on opposite strands of DNA in the track of one particle. It is concluded that DSB's induced by γ-radiation are mostly of enzymatic origin, meanwhile DSB's induced by high-LET radiation are direct DSB's. The dependence of radiosensitivity D 0 -1 on LET (L) for isogenic mutants of E. coli with different sensitivity to γ-radiation has been determined on the bases of the model and considering microscopic energy fluctuations. The shape of D 0 -1 (L) function is formed both by physical characteristics of radiation and by the ability of cells to repair some types of DNA damage. The model provides a basis for further investigation. (author)

  11. Selection, processing and clinical application of muscle-skeletal tissue

    International Nuclear Information System (INIS)

    Luna Z, D.; Reyes F, M.L.; Lavalley E, C.; Castaneda J, G.

    2007-01-01

    Due to the increase in the average of the world population's life, people die each time to more age, this makes that the tissues of support of the human body, as those muscle-skeletal tissues, when increasing the individual's age go weakening, this in turn leads to the increment of the illnesses like the osteoporosis and the arthritis, that undoubtedly gives as a result more injure of the muscle-skeletal tissues joined a greater number of traffic accidents where particularly these tissues are affected, for that the demand of tissues muscle-skeletal for transplant every day will be bigger. The production of these tissues in the Bank of Radio sterilized Tissues, besides helping people to improve its quality of life saved foreign currencies because most of the muscle-skeletal tissues transplanted in Mexico are of import. The use of the irradiation to sterilize tissues for transplant has shown to be one of the best techniques with that purpose for what the International Atomic Energy Agency believes a Technical cooperation program to establish banks of tissues using the nuclear energy, helping mainly to countries in development. In this work the stages that follows the bank of radio sterilized tissues of the National Institute of Nuclear Research for the cadaverous donor's of muscle-skeletal tissue selection are described, as well as the processing and the clinical application of these tissues. (Author)

  12. Non-Immunogenic Structurally and Biologically Intact Tissue Matrix Grafts for the Immediate Repair of Ballistic-Induced Vascular and Nerve Tissue Injury in Combat Casualty Care

    National Research Council Canada - National Science Library

    Bachrach, Nathaniel

    2003-01-01

    .... This past year the source of he defects was determined to be the freeze-drying process. Ongoing efforts toward process optimization and design modifications that will provide undamaged tissue grafts are presented in this report...

  13. Using radionuclide imaging for monitoring repairment of bone defect with tissue-engineered bone graft in rabbits

    International Nuclear Information System (INIS)

    Xia Changsuo; Ye Fagang; Zou Yunwen; Ji Shixiang; Wang Dengchun

    2004-01-01

    Objective: To observe the effect of tissue-engineered bone grafts in repairing bone defect in rabbits, and assess the value of radionuclide for monitoring the therapeutic effect of this approach. Methods: Bilateral radial defects of 15 mm in length in 24 rabbits were made. The tissue-engineered bone grafts (composite graft) contained bone marrow stromal cells (BMSCs) of rabbits and calcium phosphate cement (CPC) were grafted in left side defects, CPC only grafts (artificial bone graft) in right defects. After the operation, radionuclide was used to monitor the therapeutic effects at 4, 8 and 12 weeks. Results: 99 Tc m -methylene diphosphonic acid (MDP) radionuclide bone imaging indicated that there was more radionuclide accumulation in grafting region of composite than that of CPC. There was significant difference between 99 Tc m -MDP uptake of the region of interest (ROI) and scintillant counts of composite bone and the artificial bone (P<0.01). Conclusion: Tissue-engineered bone grafts is eligible for repairing radial bone defects, and radionuclide imaging may accurately monitor the revascularization and bone regeneration after the bone graft implantation. (authors)

  14. Investigations on the mechanism of DNA excision repair in tissue culture cells

    International Nuclear Information System (INIS)

    Wawra, E.; Dolejs, I.; Ott, E.

    1976-12-01

    Semiconservative DNA- synthesis and repair- synthesis was measured in HeLa cells and spleen cells under different conditions (i.e. different temperatures, addition of p-chloromercuribenzoate or cytosine-arabinoside). In order to obtain more information about the enzymatic background of these steps of DNA metabolism, parallel in vitro experiments were done with two different types of DNA polymerase, which had been isolated from pig spleen. At least the experiments at different temperatures are showing some correlations of α-polymerase with semiconservative synthesis and of β-polymerase with repair synthesis. (author)

  15. Honey can repairing damage of liver tissue due to protein energy malnutrition through induction of endogenous stem cells

    Directory of Open Access Journals (Sweden)

    R. Heru Prasetyo

    2017-06-01

    Full Text Available Aim: This study was to evaluate effect of honey in repairing damage of liver tissue due to energy protein malnutrition and in mobilization of endogenous stem cells. Materials and Methods: Male mice model of degenerative liver was obtained through food fasting but still have drinking water for 5 days. It caused energy protein malnutrition and damage of liver tissue. The administration of 50% (v/v honey was performed for 10 consecutive days, while the positive control group was fasted and not given honey and the negative control not fasted and without honey. Observations of regeneration the liver tissue based on histologically examination, observation of Hsp70 expression, and homing signal based on vascular endothelial growth factor-1 (VEGF-1 expression using immunohistochemistry technique. Observation on expression of CD34 and CD45 as the marker of auto mobilization of hematopoietic stem cells using flow cytometry technique. Results: There is regeneration of the liver tissue due to protein energy malnutrition, decrease of Hsp70 expression, increase of VEGF-1 expression, and high expression of CD34 and CD45. Conclusion: Honey can improve the liver tissue based on: (1 Mobilization of endogenous stem cells (CD34 and CD45; (2 Hsp70 and VEGF-1 expressions as regeneration marker of improvement, and (3 regeneration histologically of liver tissue.

  16. Honey can repairing damage of liver tissue due to protein energy malnutrition through induction of endogenous stem cells.

    Science.gov (United States)

    Prasetyo, R Heru; Hestianah, Eka Pramyrtha

    2017-06-01

    This study was to evaluate effect of honey in repairing damage of liver tissue due to energy protein malnutrition and in mobilization of endogenous stem cells. Male mice model of degenerative liver was obtained through food fasting but still have drinking water for 5 days. It caused energy protein malnutrition and damage of liver tissue. The administration of 50% (v/v) honey was performed for 10 consecutive days, while the positive control group was fasted and not given honey and the negative control not fasted and without honey. Observations of regeneration the liver tissue based on histologically examination, observation of Hsp70 expression, and homing signal based on vascular endothelial growth factor-1 (VEGF-1) expression using immunohistochemistry technique. Observation on expression of CD34 and CD45 as the marker of auto mobilization of hematopoietic stem cells using flow cytometry technique. There is regeneration of the liver tissue due to protein energy malnutrition, decrease of Hsp70 expression, increase of VEGF-1 expression, and high expression of CD34 and CD45. Honey can improve the liver tissue based on: (1) Mobilization of endogenous stem cells (CD34 and CD45); (2) Hsp70 and VEGF-1 expressions as regeneration marker of improvement, and (3) regeneration histologically of liver tissue.

  17. Cellular response of healing tissue to DegraPol tube implantation in rabbit Achilles tendon rupture repair: an in vivo histomorphometric study.

    Science.gov (United States)

    Buschmann, Johanna; Meier-Bürgisser, Gabriella; Bonavoglia, Eliana; Neuenschwander, Peter; Milleret, Vincent; Giovanoli, Pietro; Calcagni, Maurizio

    2013-05-01

    In tendon rupture repair, improvements such as higher primary repair strength, anti-adhesion and accelerated healing are needed. We developed a potential carrier system of an electrospun DegraPol tube, which was tightly implanted around a transected and conventionally sutured rabbit Achilles tendon. Histomorphometric analysis of the tendon tissue 12 weeks postoperation showed that the tenocyte density, tenocyte morphology and number of inflammation zones were statistically equivalent, whether or not DegraPol tube was implanted; only the collagen fibres were slightly less parallelly orientated in the tube-treated case. Comparison of rabbits that were operated on both hind legs with ones that were operated on only one hind leg showed that there were significantly more inflammation zones in the two-leg cases compared to the one-leg cases, while the implantation of a DegraPol tube had no such adverse effects. These findings are a prerequisite for using DegraPol tube as a carrier system for growth factors, cytokines or stem cells in order to accelerate the healing process of tendon tissue. Copyright © 2012 John Wiley & Sons, Ltd.

  18. Repair of full-thickness tendon injury using connective tissue progenitors efficiently derived from human embryonic stem cells and fetal tissues.

    Science.gov (United States)

    Cohen, Shahar; Leshansky, Lucy; Zussman, Eyal; Burman, Michael; Srouji, Samer; Livne, Erella; Abramov, Natalie; Itskovitz-Eldor, Joseph

    2010-10-01

    The use of stem cells for tissue engineering (TE) encourages scientists to design new platforms in the field of regenerative and reconstructive medicine. Human embryonic stem cells (hESC) have been proposed to be an important cell source for cell-based TE applications as well as an exciting tool for investigating the fundamentals of human development. Here, we describe the efficient derivation of connective tissue progenitors (CTPs) from hESC lines and fetal tissues. The CTPs were significantly expanded and induced to generate tendon tissues in vitro, with ultrastructural characteristics and biomechanical properties typical of mature tendons. We describe a simple method for engineering tendon grafts that can successfully repair injured Achilles tendons and restore the ankle joint extension movement in mice. We also show the CTP's ability to differentiate into bone, cartilage, and fat both in vitro and in vivo. This study offers evidence for the possibility of using stem cell-derived engineered grafts to replace missing tissues, and sets a basic platform for future cell-based TE applications in the fields of orthopedics and reconstructive surgery.

  19. Fine structural observation on repair processes in experimental ulcer of the rat gastric mucosa

    International Nuclear Information System (INIS)

    Saito, Takiko

    1982-01-01

    Experimental stomach ulcer of the rat was produced by clamping method. Repair processes of the epithelial and glandular cells were examined by LM, SEM, TEM and autoradiograph with 3 H-thymidine at various times after removal of the clamp. The epithelial cells in the vicinity of the defect consisted of the surface cells with a few mucous granuls, parietal cells, endocrine cells and fibrillovesicular cells of Hammond and LaDuer during repair processes. The chief cells appeared after 12 days. After 5 weeks, the defect was completely covered with the epithelium. All kind of the epithelial cells except fibrillovesicular cells can incorporate thymidine precursor during regeneration. (author)

  20. Adult Bone Marrow Mesenchymal Stem Cells Primed for fhe Repair of Damaged Cardiac Tissue After Myocardial Infarction

    Science.gov (United States)

    Marks, Edward D.

    The burden of cardiovascular disease around the world is growing, despite improvements in hospital care and time to treatment. As more people survive an initial myocardial infarction (MI), the decompensated heart tissue is strained, leading to heart failure (HF) and an increased risk for a second MI. While extensive progress has been made in treating the symptoms after MI, including HF and angina, little success has come from repairing the damaged heart tissue to alleviate the progression to these end- stage symptoms. One promising area of regenerative research has been the use of adult stem cells, particularly from the bone marrow (BMSCs). These cells can differentiate towards the cardiac cell lineage in vitro while producing trophic factors that can repair damaged tissue. When placed in the heart after MI though, BMSCs have mixed results, producing profound changes in some patients but zero or even negative effects in others. In this report, we used BMSCs as a stem cell base for a regenerative medicine system for the repair of damaged cardiac tissue. These cells are seeded on a polycaprolactone nanoscaffolding support system, which provides a growth substrate for in vitro work, as well as a housing system for protected in vivo delivery. When the nanoscaffold is pre-coated with a novel combination of a cardiac protein, thymosin beta4 (Tbeta4), and a small molecule effector of the WNT protein pathway, IWP-2, BMSCs differentiated towards the cardiac lineage in as little as 24hours. When injected into rat hearts that have been given an ischemic MI, the nanoscaffolding system slowly dissolves, leaving the cells in place of the damaged cardiac tissue. After two weeks of monitoring, BMSCs are present within the damaged hearts, as evidenced by immunofluorescence and nanoparticle tracking. Injections of the nanoscaffolding/cell system led to robust healing of the rat hearts that had been given small- and medium- damage heart attacks, outperforming PBS sham and cell

  1. The influence of Cellular Interactions in Tissue Engineering for Cartilage Repair

    NARCIS (Netherlands)

    Hendriks, J.A.A.

    2006-01-01

    Tissues are complex 3-dimensional structures with a highly organized architecture made up of cells and matrix. The cells and matrix in a tissue are continuously interacting with each other and (cells from) their surrounding tissues to maintain their form and function. Interactions of cells with

  2. Repairing business process models as retrieved from source code

    NARCIS (Netherlands)

    Fernández-Ropero, M.; Reijers, H.A.; Pérez-Castillo, R.; Piattini, M.; Nurcan, S.; Proper, H.A.; Soffer, P.; Krogstie, J.; Schmidt, R.; Halpin, T.; Bider, I.

    2013-01-01

    The static analysis of source code has become a feasible solution to obtain underlying business process models from existing information systems. Due to the fact that not all information can be automatically derived from source code (e.g., consider manual activities), such business process models

  3. Mimicking Bone Healing Process to Self Repair Concrete Structure Novel Approach Using Porous Network Concrete

    NARCIS (Netherlands)

    Sangadji, S.; Schlangen, H.E.J.G.

    2013-01-01

    To repair concrete cracks in difficult or dangerous conditions such as underground structures or hazardous liquid containers, self healing mechanism is a promising alternative method. This research aims to imitate the bone self healing process by putting porous concrete internally in the concrete

  4. Tissue engineering for urinary tract reconstruction and repair: Progress and prospect in China.

    Science.gov (United States)

    Zou, Qingsong; Fu, Qiang

    2018-04-01

    Several urinary tract pathologic conditions, such as strictures, cancer, and obliterations, require reconstructive plastic surgery. Reconstruction of the urinary tract is an intractable task for urologists due to insufficient autologous tissue. Limitations of autologous tissue application prompted urologists to investigate ideal substitutes. Tissue engineering is a new direction in these cases. Advances in tissue engineering over the last 2 decades may offer alternative approaches for the urinary tract reconstruction. The main components of tissue engineering include biomaterials and cells. Biomaterials can be used with or without cultured cells. This paper focuses on cell sources, biomaterials, and existing methods of tissue engineering for urinary tract reconstruction in China. The paper also details challenges and perspectives involved in urinary tract reconstruction.

  5. Point-of-care instrument for monitoring tissue health during skin graft repair

    Science.gov (United States)

    Gurjar, R. S.; Seetamraju, M.; Zhang, J.; Feinberg, S. E.; Wolf, D. E.

    2011-06-01

    We have developed the necessary theoretical framework and the basic instrumental design parameters to enable mapping of subsurface blood dynamics and tissue oxygenation for patients undergoing skin graft procedures. This analysis forms the basis for developing a simple patch geometry, which can be used to map by diffuse optical techniques blood flow velocity and tissue oxygenation as a function of depth in subsurface tissue.skin graft, diffuse correlation analysis, oxygen saturation.

  6. Photobiomodulation laser improves the early repair process of hypothyroid rats

    Science.gov (United States)

    Uzêda e Silva, V. D.; Rodriguez, T. T.; Xavier, F. C. A.; dos Santos, J. N.; Vasconcelos, R. M.; Ramalho, L. M. P.

    2018-04-01

    Delay in wound healing has been observed in the hypothyroidism disfunction. Laser light can modulate various biological phenomena acting on different cell types. However, there are few reports in the literature regarding the effects of laser on wound healing of hypothyroid models. This study aimed to evaluate the differences in reepithelialization process of cutaneous wounds on hypothyroid and euthyroid rats treated with laser phototherapy. Forty-eight rats were divided into two main groups: euthyroid (EU) and hypothyroid (HYPO). Hypothyroidism was induced by Thyroidectomy. Each group was divided into subgroups: control (without laser) and laser groups. Standard surgical wound was created on the dorsum of each rat. The irradiation protocols (λ660 nm, 40 mW, CW; 10 J/cm2) was carried out immediately after wounding and repeated every 24h during 3 and 7 days. After animal death, specimens were taken, routinely processed, cut, stained with hematoxylin-eosin, and underwent histological analysis. Three days after the surgery, it was possible to observe initial reepithelialization in more advanced stages in the wound area of the irradiated hypothyroid group when compared to control hypothyroid group (p<0.05). No significant difference was found in the experimental period of 7 days among the groups. It was concluded that the laser light did influence reepithelialization process on hypothyroid rats in early stages of healing process.

  7. Evaluation and comparison of cartilage repair tissue of the patella and medial femoral condyle by using morphological MRI and biochemical zonal T2 mapping

    International Nuclear Information System (INIS)

    Welsch, Goetz H.; Mamisch, Tallal C.; Quirbach, Sebastian; Trattnig, Siegfried; Zak, Lukas; Marlovits, Stefan

    2009-01-01

    The objective of this study was to use advanced MR techniques to evaluate and compare cartilage repair tissue after matrix-associated autologous chondrocyte transplantation (MACT) in the patella and medial femoral condyle (MFC). Thirty-four patients treated with MACT underwent 3-T MRI of the knee. Patients were treated on either patella (n = 17) or MFC (n = 17) cartilage and were matched by age and postoperative interval. For morphological evaluation, the MR observation of cartilage repair tissue (MOCART) score was used, with a 3D-True-FISP sequence. For biochemical assessment, T2 mapping was prepared by using a multiecho spin-echo approach with particular attention to the cartilage zonal structure. Statistical evaluation was done by analyses of variance. The MOCART score showed no significant differences between the patella and MFC (p ≥ 0.05). With regard to biochemical T2 relaxation, higher T2 values were found throughout the MFC (p < 0.05). The zonal increase in T2 values from deep to superficial was significant for control cartilage (p < 0.001) and cartilage repair tissue (p < 0.05), with an earlier onset in the repair tissue of the patella. The assessment of cartilage repair tissue of the patella and MFC afforded comparable morphological results, whereas biochemical T2 values showed differences, possibly due to dissimilar biomechanical loading conditions. (orig.)

  8. Recovery process of wall condition in KSTAR vacuum vessel after temporal machine-vent for repair

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kwang Pyo, E-mail: kpkim@nfri.er.ke; Hong, Suk-Ho; Lee, Hyunmyung; Song, Jae-in; Jung, Nam-Yong; Lee, Kunsu; Chu, Yong; Kim, Hakkun; Park, Kaprai; Oh, Yeong-Kook

    2015-10-15

    Highlights: • Efforts have been made to obtain vacuum condition that is essential for the plasma experiments. • For example, the vacuum vessel should be vented to repair in-vessel components such as diagnostic shutter, and PFC damaged by high energy plasma. • Here, we present the recovery process of wall condition in KSTAR after temporal machine-vent for repair. • It is found that an acceptable vacuum condition has been achieved only by plasma based wall conditioning techniques such as baking, GDC, and boronization. • This study was that the proper recovering method of the vacuum condition should be developed according to the severity of the accident. - Abstract: Efforts have been made to obtain vacuum condition that is essential for the plasma experiments. Under certain situations, for example, the vacuum vessel should be vented to repair in-vessel components such as diagnostic shutter, exchange of window for diagnostic equipment, and PFC damaged by high energy plasma. For the quick restart of the campaign, a recovery process was established to make the vacuum condition acceptable for the plasma experiment. In this paper, we present the recovery process of wall condition in KSTAR after temporal machine-vent for repair. It is found that an acceptable vacuum condition has been achieved only by plasma based wall conditioning techniques such as baking, GDC, and boronization. This study was that the proper recovering method of the vacuum condition should be developed according to the severity of the accident.

  9. Evaluation of the Low Heat Input Process for Weld Repair of Nickel-Base Superalloys

    Science.gov (United States)

    Durocher, J.; Richards, N. L.

    2011-10-01

    The repair of turbine blades and vanes commonly involves gas tungsten arc welding or an equivalent process, but unfortunately these components are often susceptible to heat-affected zone (HAZ) cracking during the weld repair process. This is a major problem especially in cast alloys due to their coarse-grain size and where the (Al + Ti) contents is in excess of 3-4%; vacuum brazing is also used but mainly on low stress non-rotating components such as vanes. Micro-welding has the potential to deposit small amounts of filler at low heat input levels with minimum HAZ and thus is an attractive process for depositing a quality weld. As with conventional fusion processes, the filler alloy is deposited by the generation of a low power arc between a consumable electrode and the substrate. The low heat input of this process offers unique advantages over more common welding processes such as gas tungsten arc, plasma arc, laser, and electron beam welding. In this study, the low heat input characteristic of micro-welding has been used to simulate weld repair using Inconel (IN) (Inconel and IN are trademarks of INCO Alloys International) 625, Rene (Rene is a trademark of General Electric Company) 41, Nimonic (Nimonic is a trademark of INCO Alloys International) 105 and Inconel 738LC filler alloys, to a cast Inconel 738LC substrate. The effect of micro-welding process parameters on the deposition rate, coating quality, and substrate has been investigated.

  10. Prediction of radiotherapy induced normal tissue adverse reactions: the role of double-strand break repair

    International Nuclear Information System (INIS)

    Rao, B.S. Satish; Mumbrekar, K.D.; Goutham, H.V.; Donald, J.F.; Vadhiraja, M.B.; Satyamoorthy, K.

    2016-01-01

    We aimed at evaluating the predictive potential of DSB repair kinetics (using γH2AX foci assay) in lymphocytes and analysed the genetic variants in the selected radioresponsive candidate genes like XRCC3, LIG4, NBN, CD44, RAD9A, LIG3, SH3GL1, BAXS, XRCC1, MAD2L2 on the individual susceptibility to radiotherapy (RT) induced acute skin reactions among the head and neck cancer (HNC), and breast cancer (BC) patients. All the 183 HNC and 132 BC patients were treated by a 3-dimensional conformal RT technique

  11. Use of Processed Nerve Allografts to Repair Nerve Injuries Greater Than 25 mm in the Hand.

    Science.gov (United States)

    Rinker, Brian; Zoldos, Jozef; Weber, Renata V; Ko, Jason; Thayer, Wesley; Greenberg, Jeffrey; Leversedge, Fraser J; Safa, Bauback; Buncke, Gregory

    2017-06-01

    Processed nerve allografts (PNAs) have been demonstrated to have improved clinical results compared with hollow conduits for reconstruction of digital nerve gaps less than 25 mm; however, the use of PNAs for longer gaps warrants further clinical investigation. Long nerve gaps have been traditionally hard to study because of low incidence. The advent of the RANGER registry, a large, institutional review board-approved, active database for PNA (Avance Nerve Graft; AxoGen, Inc, Alachua, FL) has allowed evaluation of lower incidence subsets. The RANGER database was queried for digital nerve repairs of 25 mm or greater. Demographics, injury, treatment, and functional outcomes were recorded on standardized forms. Patients younger than 18 and those lacking quantitative follow-up data were excluded. Recovery was graded according to the Medical Research Council Classification for sensory function, with meaningful recovery defined as S3 or greater level. Fifty digital nerve injuries in 28 subjects were included. There were 22 male and 6 female subjects, and the mean age was 45. Three patients gave a previous history of diabetes, and there were 6 active smokers. The most commonly reported mechanisms of injury were saw injuries (n = 13), crushing injuries (n = 9), resection of neuroma (n = 9), amputation/avulsions (n = 8), sharp lacerations (n = 7), and blast/gunshots (n = 4). The average gap length was 35 ± 8 mm (range, 25-50 mm). Recovery to the S3 or greater level was reported in 86% of repairs. Static 2-point discrimination (s2PD) and Semmes-Weinstein monofilament (SWF) were the most common completed assessments. Mean s2PD in 24 repairs reporting 2PD data was 9 ± 4 mm. For the 38 repairs with SWF data, protective sensation was reported in 33 repairs, deep pressure in 2, and no recovery in 3. These data compared favorably with historical data for nerve autograft repairs, with reported levels of meaningful recovery of 60% to 88%. There were no reported adverse effects

  12. Processing closely spaced lesions during Nucleotide Excision Repair triggers mutagenesis in E. coli

    Science.gov (United States)

    Isogawa, Asako; Fujii, Shingo

    2017-01-01

    It is generally assumed that most point mutations are fixed when damage containing template DNA undergoes replication, either right at the fork or behind the fork during gap filling. Here we provide genetic evidence for a pathway, dependent on Nucleotide Excision Repair, that induces mutations when processing closely spaced lesions. This pathway, referred to as Nucleotide Excision Repair-induced Mutagenesis (NERiM), exhibits several characteristics distinct from mutations that occur within the course of replication: i) following UV irradiation, NER-induced mutations are fixed much more rapidly (t ½ ≈ 30 min) than replication dependent mutations (t ½ ≈ 80–100 min) ii) NERiM specifically requires DNA Pol IV in addition to Pol V iii) NERiM exhibits a two-hit dose-response curve that suggests processing of closely spaced lesions. A mathematical model let us define the geometry (infer the structure) of the toxic intermediate as being formed when NER incises a lesion that resides in close proximity of another lesion in the complementary strand. This critical NER intermediate requires Pol IV / Pol II for repair, it is either lethal if left unrepaired or mutation-prone when repaired. Finally, NERiM is found to operate in stationary phase cells providing an intriguing possibility for ongoing evolution in the absence of replication. PMID:28686598

  13. An application of modulated poisson processes to the reliability analysis of repairable systems

    Energy Technology Data Exchange (ETDEWEB)

    Saldanha, Pedro L.C. [Comissao Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil). Coordenacao de Reatores]. E-mail: saldanha@cnen.gov.br; Melo, P.F. Frutuoso e [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia. Programa de Engenharia Nuclear]. E-mail: frutuoso@con.ufrj.br; Noriega, Hector C. [Universidad Austral de Chile (UACh), Valdivia (Chile). Faculdad de Ciencias de la Ingeniaria]. E-mail: hnoriega@uach.cl

    2005-07-01

    This paper discusses the application of the modulated power law process (MPLP) model to the rate of occurrence of failures of active repairable systems in reliability engineering. Traditionally, two ways of modeling repairable systems, in what concerns maintenance policies, are: a pessimistic approach (non-homogeneous process - NHPP), and a very optimistic approach (renewal processes - RP). It is important to build a generalized model that might consider characteristics and properties both of the NHPP and of the RP models as particular cases. In practice, by considering the pattern of times between failures, the MPLP appears to be more realistic to represent the occurrence of failures of repairable systems in order to define whether they can be modeled by a homogeneous or a non-homogeneous process. The study has shown that the model can be used to make decisions concerning the evaluation of the qualified life of plant equipment. By controlling and monitoring two of the three parameters of the MPLP model during the equipment operation, it is possible to check whether and how the equipment is following the basis of its qualification process, and so identify how the effects of time, degradation and operation modes are influencing the equipment performance. The discussion is illustrated by an application to the service water pumps of a typical PWR plant. (author)

  14. CO II laser free-form processing of hard tissue

    Science.gov (United States)

    Werner, Martin; Klasing, Manfred; Ivanenko, Mikhail; Harbecke, Daniela; Steigerwald, Hendrik; Hering, Peter

    2007-07-01

    Drilling and surface processing of bone and tooth tissue belongs to standard medical procedures (bores and embeddings for implants, trepanation etc.). Small circular bores can be generally quickly produced with mechanical drills. However problems arise at angled drilling, the need to execute drilling procedures without damaging of sensitive soft tissue structures underneath the bone or the attempt to mill small non-circular cavities in hard tissue with high precision. We present investigations on laser hard tissue "milling", which can be advantageous for solving these problems. The processing of bone is done with a CO II laser (10.6 μm) with pulse durations of 50 - 100 μs, combined with a PC-controlled fast galvanic laser beam scanner and a fine water-spray, which helps keeping the ablation process effective and without thermal side-effects. Laser "milling" of non-circular cavities with 1 - 4 mm width and about 10 mm depth can be especially interesting for dental implantology. In ex-vivo investigations we found conditions for fast laser processing of these cavities without thermal damage and with minimised tapering. It included the exploration of different filling patterns (concentric rings, crosshatch, parallel lines, etc.), definition of maximal pulse duration, repetition rate and laser power, and optimal water spray position. The optimised results give evidence for the applicability of pulsed CO II lasers for biologically tolerable effective processing of deep cavities in hard tissue.

  15. Generalized renewal process for repairable systems based on finite Weibull mixture

    International Nuclear Information System (INIS)

    Veber, B.; Nagode, M.; Fajdiga, M.

    2008-01-01

    Repairable systems can be brought to one of possible states following a repair. These states are: 'as good as new', 'as bad as old' and 'better than old but worse than new'. The probabilistic models traditionally used to estimate the expected number of failures account for the first two states, but they do not properly apply to the last one, which is more realistic in practice. In this paper, a probabilistic model that is applicable to all of the three after-repair states, called generalized renewal process (GRP), is applied. Simplistically, GRP addresses the repair assumption by introducing the concept of virtual age into the stochastic point processes to enable them to represent the full spectrum of repair assumptions. The shape of measured or design life distributions of systems can vary considerably, and therefore frequently cannot be approximated by simple distribution functions. The scope of the paper is to prove that a finite Weibull mixture, with positive component weights only, can be used as underlying distribution of the time to first failure (TTFF) of the GRP model, on condition that the unknown parameters can be estimated. To support the main idea, three examples are presented. In order to estimate the unknown parameters of the GRP model with m-fold Weibull mixture, the EM algorithm is applied. The GRP model with m mixture components distributions is compared to the standard GRP model based on two-parameter Weibull distribution by calculating the expected number of failures. It can be concluded that the suggested GRP model with Weibull mixture with an arbitrary but finite number of components is suitable for predicting failures based on the past performance of the system

  16. Tissue Engineering-based Therapeutic Strategies for Vocal Fold Repair and Regeneration

    Science.gov (United States)

    Li, Linqing; Stiadle, Jeanna M.; Lau, Hang K.; Zerdoum, Aidan B.; Jia, Xinqiao; L.Thibeault, Susan; Kiick, Kristi L.

    2016-01-01

    Vocal folds are soft laryngeal connective tissues with distinct layered structures and complex multicomponent matrix compositions that endow phonatory and respiratory functions. This delicate tissue is easily damaged by various environmental factors and pathological conditions, altering vocal biomechanics and causing debilitating vocal disorders that detrimentally affect the daily lives of suffering individuals. Modern techniques and advanced knowledge of regenerative medicine have led to a deeper understanding of the microstructure, microphysiology, and micropathophysiology of vocal fold tissues. State-of-the-art materials ranging from extracecullar-matrix (ECM)-derived biomaterials to synthetic polymer scaffolds have been proposed for the prevention and treatment of voice disorders including vocal fold scarring and fibrosis. This review intends to provide a thorough overview of current achievements in the field of vocal fold tissue engineering, including the fabrication of injectable biomaterials to mimic in vitro cell microenvironments, novel designs of bioreactors that capture in vivo tissue biomechanics, and establishment of various animal models to characterize the in vivo biocompatibility of these materials. The combination of polymeric scaffolds, cell transplantation, biomechanical stimulation, and delivery of antifibrotic growth factors will lead to successful restoration of functional vocal folds and improved vocal recovery in animal models, facilitating the application of these materials and related methodologies in clinical practice. PMID:27619243

  17. AVARIS. An innovative process to repair seal seat surfaces in gate and check valves

    International Nuclear Information System (INIS)

    Herzing, Karl-Heinz; Breitenberger, Ulf; Grieser, Armin

    2011-01-01

    AREVA Valve Repair in situ - AVARIS in short - is an innovative process for valve repair developed by AREVA. Its main benefit is that valves no longer need to be cut out but can be machined in situ, i.e. within the piping system. AVARIS saves the plant operators time and money, as complete exchanges of valves and the ensuing complex measures become dispensable. AVARIS is of high interest in the worldwide maintenance market, as it can be applied in both nuclear and conventional power plants. Moreover, AVARIS retrofits valves in the secondary and primary circuit which even saves complex nuclear transports. AVARIS fulfills the quality requirements of 3. party authorities in national and international markets. Valves repaired with AVARIS correspond to their original condition with regard to the sealing function. The successful first application on 2 gate valves in a German nuclear power plant proves that this repair technology is very reliable and flexible. Follow-up orders for AVARIS will be realized in several nuclear power plants in 2011. (orig.)

  18. Photographic-Based Optical Evaluation of Tissues and Biomaterials Used for Corneal Surface Repair: A New Easy-Applied Method.

    Directory of Open Access Journals (Sweden)

    Miguel Gonzalez-Andrades

    Full Text Available Tissues and biomaterials used for corneal surface repair require fulfilling specific optical standards prior to implantation in the patient. However, there is not a feasible evaluation method to be applied in clinical or Good Manufacturing Practice settings. In this study, we describe and assess an innovative easy-applied photographic-based method (PBM for measuring functional optical blurring and transparency in corneal surface grafts.Plastic compressed collagen scaffolds (PCCS and multilayered amniotic membranes (AM samples were optically and histologically evaluated. Transparency and image blurring measures were obtained by PBM, analyzing photographic images of a standardized band pattern taken through the samples. These measures were compared and correlated to those obtained applying the Inverse Adding-Doubling (IAD technique, which is the gold standard method.All the samples used for optical evaluation by PBM or IAD were histological suitable. PCCS samples presented transmittance values higher than 60%, values that increased with increasing wavelength as determined by IAD. The PBM indicated that PCCS had a transparency ratio (TR value of 80.3 ± 2.8%, with a blurring index (BI of 50.6 ± 4.2%. TR and BI obtained from the PBM showed a high correlation (ρ>|0.6| with the diffuse transmittance and the diffuse reflectance, both determined using the IAD (p<0.005. The AM optical properties showed that there was a largely linear relationship between the blurring and the number of amnion layers, with more layers producing greater blurring.This innovative proposed method represents an easy-applied technique for evaluating transparency and blurriness of tissues and biomaterials used for corneal surface repair.

  19. Osteochondral Biopsy Analysis Demonstrates That BST-CarGel Treatment Improves Structural and Cellular Characteristics of Cartilage Repair Tissue Compared With Microfracture

    Science.gov (United States)

    Méthot, Stéphane; Changoor, Adele; Tran-Khanh, Nicolas; Hoemann, Caroline D.; Stanish, William D.; Restrepo, Alberto; Shive, Matthew S.; Buschmann, Michael D.

    2016-01-01

    Objective The efficacy and safety of BST-CarGel, a chitosan-based medical device for cartilage repair, was compared with microfracture alone at 1 year during a multicenter randomized controlled trial (RCT) in the knee. The quality of repair tissue of osteochondral biopsies collected from a subset of patients was compared using blinded histological assessments. Methods The international RCT evaluated repair tissue quantity and quality by 3-dimensional quantitative magnetic resonance imaging as co-primary endpoints at 12 months. At an average of 13 months posttreatment, 21/41 BST-CarGel and 17/39 microfracture patients underwent elective second look arthroscopies as a tertiary endpoint, during which ICRS (International Cartilage Repair Society) macroscopic scoring was carried out, and osteochondral biopsies were collected. Stained histological sections were evaluated by blinded readers using ICRS I and II histological scoring systems. Collagen organization was evaluated using a polarized light microscopy score. Results BST-CarGel treatment resulted in significantly better ICRS macroscopic scores (P = 0.0002) compared with microfracture alone, indicating better filling, integration, and tissue appearance. Histologically, BST-CarGel resulted in a significant improvement of structural parameters—Surface Architecture (P = 0.007) and Surface/Superficial Assessment (P = 0.042)—as well as cellular parameters—Cell Viability (P = 0.006) and Cell Distribution (P = 0.032). No histological parameters were significantly better for the microfracture group. BST-CarGel treatment also resulted in a more organized repair tissue with collagen stratification more similar to native hyaline cartilage, as measured by polarized light microscopy scoring (P = 0.0003). Conclusion Multiple and independent analyses in this biopsy substudy demonstrated that BST-CarGel treatment results in improved structural and cellular characteristics of repair tissue at 1 year posttreatment compared with

  20. Interleukin-22-producing innate immune cells: new players in mucosal immunity and tissue repair?

    NARCIS (Netherlands)

    Vivier, Eric; Spits, Hergen; Cupedo, Tom

    2009-01-01

    Mucosal tissues, lying at the interface with the external environment, are constantly challenged by microbial, physical and chemical assaults. To provide the necessary immune defence to such challenges, lymph nodes and Peyer's patches are formed in utero in response to inductive signals from

  1. Repair of extensive radionecrosis of the thoracic wall using soft tissues from the paralyzed upper limb

    Energy Technology Data Exchange (ETDEWEB)

    Delacroix, R; Wallaert, C; Soulier, A; Delepoulle, E; Francois, C; Grignet, J P

    1975-04-01

    The authors report one case of extensive radionecrosis after postoperative radiotherapy for breast cancer, with overt pyothorax, deep axillary ulceration, and brachial paralysis. The plastic use of the musculo-aponeutrotic tissues of the paralysed upper limb resulted in spectacular success, complicated only by empyema of the hemithoracic cavity, for which treatment with neomycin is recommended.

  2. A generalised formulation of the 'incomplete-repair' model for cell survival and tissue response to fractionated low dose-rate irradiation

    International Nuclear Information System (INIS)

    Nilsson, P.; Joiner, M.C.

    1990-01-01

    A generalized equation for cell survival or tissue effects after fractionated low dose-rate irradiations, when there is incomplete repair between fractions and significant repair during fractions, is derived in terms of the h- and g-functions of the 'incomplete-repair' (IR) model. The model is critically dependent on α/β, repair half-time, treatment time and interfraction interval, and should therefore be regarded primarily as a tool for the analysis of fractionation and dose-rate effects in carefully designed radiobiological experiments, although it should also be useful in exploring, in a general way, the feasibility of clinical treatment protocols using fractionated low dose-rate treatments. (author)

  3. A decision dependent stochastic process model for repairable systems with applications

    Directory of Open Access Journals (Sweden)

    Paul F. Zantek

    2015-12-01

    This paper mathematically formalizes the notion of how management actions impact the functioning of a repairable system over time by developing a new stochastic process model for such systems. The proposed model is illustrated using both simulated and real data. The proposed model compares favorably to other models for well-known data on Boeing airplanes. The model is further illustrated and compared to other models on failure time and maintenance data stemming from the South Texas Project nuclear power plant.

  4. Evaporation process in histological tissue sections for neutron autoradiography.

    Science.gov (United States)

    Espector, Natalia M; Portu, Agustina; Santa Cruz, Gustavo A; Saint Martin, Gisela

    2018-05-01

    The analysis of the distribution and density of nuclear tracks forming an autoradiography in a nuclear track detector (NTD) allows the determination of 10 B atoms concentration and location in tissue samples from Boron Neutron Capture Therapy (BNCT) protocols. This knowledge is of great importance for BNCT dosimetry and treatment planning. Tissue sections studied with this technique are obtained by cryosectioning frozen tissue specimens. After the slicing procedure, the tissue section is put on the NTD and the sample starts drying. The thickness varies from its original value allowing more particles to reach the detector and, as the mass of the sample decreases, the boron concentration in the sample increases. So in order to determine the concentration present in the hydrated tissue, the application of corrective coefficients is required. Evaporation mechanisms as well as various factors that could affect the process of mass variation are outlined in this work. Mass evolution for tissue samples coming from BDIX rats was registered with a semimicro analytical scale and measurements were analyzed with software developed to that end. Ambient conditions were simultaneously recorded, obtaining reproducible evaporation curves. Mathematical models found in the literature were applied for the first time to this type of samples and the best fit of the experimental data was determined. The correlation coefficients and the variability of the parameters were evaluated, pointing to Page's model as the one that best represented the evaporation curves. These studies will contribute to a more precise assessment of boron concentration in tissue samples by the Neutron Autoradiography technique.

  5. Relationship between DNA repair and cell recovery: Importance of competing biochemical and metabolic processes

    International Nuclear Information System (INIS)

    Van Ankeren, S.C.; Wheeler, K.T.; Kansas Univ., Lawrence

    1985-01-01

    The relationship between the inhibition of repair of radiation-induced DNA damage and the inhibition of recovery from radiation-induced potentially lethal damage (PLD) by hypertonic treatment was compared in 9L/Ro rat brain tumor cells. Fed plateau phase cultures were γ-irradiated with 1500 rad and then immediately treated for 20 min with a 37 0 C isotonic (0.15 M) or hypertonic (0.50 M) salt solution. The kinetics of repair of radiation-induced DNA damage as assayed using alkaline filter elution were compared to those of recovery from radiation-induced PLD as assayed by colony formation. hypertonic treatment of unirradiated cells produced neither DNA damage nor cell kill. Post-irradiation hypertonic treatment inhibited both DNA repair and PLD recovery, while post-irradiation istonic treatment inhibited neither phenomenon. However, by 2 h after irradiation, the amount of DNA damage remaining after a 20 min hypertonic treatment was equivalent to that remaining after a 20 min isotonic treatment. In contrast, cell survival after hypertonic treatment remained 2 logs lower than after isotonic treatment even at times up to 24 h. These results suggest that the repair of radiation-induced DNA damage per per se is not causally related to recovery from radiation-induced PLD. However, the data are consistent with the time of DNA repair as an important parameter in determining cell survival and, therefore, tend to support the hypothesis that imbalances in sets of competing biochemical or metabolic processes determine survival rather than the presence of a single class of unrepaired DNA lesions. (orig.)

  6. TC17 titanium alloy laser melting deposition repair process and properties

    Science.gov (United States)

    Liu, Qi; Wang, Yudai; Zheng, Hang; Tang, Kang; Li, Huaixue; Gong, Shuili

    2016-08-01

    Due to the high manufacturing cost of titanium compressor blisks, aero engine repairing process research has important engineering significance and economic value. TC17 titanium alloy is a rich β stable element dual α+β phase alloy whose nominal composition is Ti-5Al-2Sn-2Zr-4Mo-4Cr. It has high mechanical strength, good fracture toughness, high hardenability and a wide forging-temperature range. Through a surface response experiment with different laser powers, scanning speeds and powder feeding speeds, the coaxial powder feeding laser melting deposition repair process is studied for the surface circular groove defects. In this paper, the tensile properties, relative density, microhardness, elemental composition, internal defects and microstructure of the laser-repaired TC17 forging plate are analyzed. The results show that the laser melting deposition process could realize the form restoration of groove defect; tensile strength and elongation could reach 1100 MPa and 10%, which could reach 91-98% that of original TC17 wrought material; with the optimal parameters (1000 W-25 V-8 mm/s), the microhardness of the additive zone, the heat-affected zone and base material is evenly distributed at 370-390 HV500. The element content difference between the additive zone and base material is less than ±0.15%. Due to the existence of the pores 10 μm in diameter, the relative density could reach 99%, which is mainly inversely proportional to the powder feeding speed. The repaired zone is typically columnar and dendrite crystal, and the 0.5-1.5 mm-deep heat-affected zone in the groove interface is coarse equiaxial crystal.

  7. Five-Year Follow-up of Knee Joint Distraction: Clinical Benefit and Cartilaginous Tissue Repair in an Open Uncontrolled Prospective Study.

    Science.gov (United States)

    van der Woude, Jan-Ton A D; Wiegant, Karen; van Roermund, Peter M; Intema, Femke; Custers, Roel J H; Eckstein, Felix; van Laar, Jaap M; Mastbergen, Simon C; Lafeber, Floris P J G

    2017-07-01

    Objective In end-stage knee osteoarthritis, total knee arthroplasty (TKA) may finally become inevitable. At a relatively young age, this comes with the risk of future revision surgery. Therefore, in these cases, joint preserving surgery such as knee joint distraction (KJD) is preferred. Here we present 5-year follow-up data of KJD. Design Patients ( n = 20; age cartilaginous tissue repair that provides a long-term tissue structure benefit as compared to natural progression. Level of evidence, II.

  8. Repair of articular cartilage defects by tissue-engineered cartilage constructed with adipose-derived stem cells and acellular cartilaginous matrix in rabbits.

    Science.gov (United States)

    Wang, Z J; An, R Z; Zhao, J Y; Zhang, Q; Yang, J; Wang, J B; Wen, G Y; Yuan, X H; Qi, X W; Li, S J; Ye, X C

    2014-06-18

    After injury, inflammation, or degeneration, articular cartilage has limited self-repair ability. We aimed to explore the feasibility of repair of articular cartilage defects with tissue-engineered cartilage constructed by acellular cartilage matrices (ACMs) seeded with adipose-derived stem cells (ADSCs). The ADSCs were isolated from 3-month-old New Zealand albino rabbit by using collagenase and cultured and amplified in vitro. Fresh cartilage isolated from adult New Zealand albino rabbit were freeze-dried for 12 h and treated with Triton X-100, DNase, and RNase to obtain ACMs. ADSCs were seeded in the acellular cartilaginous matrix at 2x10(7)/mL, and cultured in chondrogenic differentiation medium for 2 weeks to construct tissue-engineered cartilage. Twenty-four New Zealand white rabbits were randomly divided into A, B, and C groups. Engineered cartilage was transplanted into cartilage defect position of rabbits in group A, group B obtained ACMs, and group C did not receive any transplants. The rabbits were sacrificed in week 12. The restored tissue was evaluated using macroscopy, histology, immunohistochemistry, and transmission electron microscopy (TEM). In the tissue-engineered cartilage group (group A), articular cartilage defects of the rabbits were filled with chondrocyte-like tissue with smooth surface. Immunohistochemistry showed type II-collagen expression and Alcian blue staining was positive. TEM showed chondrocytes in the recesses, with plenty of secretary matrix particles. In the scaffold group (group B), the defect was filled with fibrous tissue. No repaired tissue was found in the blank group (group C). Tissue-engineered cartilage using ACM seeded with ADSCs can help repair articular cartilage defects in rabbits.

  9. An update-tissue engineered nerve grafts for the repair of peripheral nerve injuries.

    Science.gov (United States)

    Patel, Nitesh P; Lyon, Kristopher A; Huang, Jason H

    2018-05-01

    Peripheral nerve injuries (PNI) are caused by a range of etiologies and result in a broad spectrum of disability. While nerve autografts are the current gold standard for the reconstruction of extensive nerve damage, the limited supply of autologous nerve and complications associated with harvesting nerve from a second surgical site has driven groups from multiple disciplines, including biomedical engineering, neurosurgery, plastic surgery, and orthopedic surgery, to develop a suitable or superior alternative to autografting. Over the last couple of decades, various types of scaffolds, such as acellular nerve grafts (ANGs), nerve guidance conduits, and non-nervous tissues, have been filled with Schwann cells, stem cells, and/or neurotrophic factors to develop tissue engineered nerve grafts (TENGs). Although these have shown promising effects on peripheral nerve regeneration in experimental models, the autograft has remained the gold standard for large nerve gaps. This review provides a discussion of recent advances in the development of TENGs and their efficacy in experimental models. Specifically, TENGs have been enhanced via incorporation of genetically engineered cells, methods to improve stem cell survival and differentiation, optimized delivery of neurotrophic factors via drug delivery systems (DDS), co-administration of platelet-rich plasma (PRP), and pretreatment with chondroitinase ABC (Ch-ABC). Other notable advancements include conduits that have been bioengineered to mimic native nerve structure via cell-derived extracellular matrix (ECM) deposition, and the development of transplantable living nervous tissue constructs from rat and human dorsal root ganglia (DRG) neurons. Grafts composed of non-nervous tissues, such as vein, artery, and muscle, will be briefly discussed.

  10. Biopolymer-based hydrogels as injectable materials for tissue repair scaffolds

    International Nuclear Information System (INIS)

    Fiejdasz, Sylwia; Szczubiałka, Krzysztof; Lewandowska-Łańcucka, Joanna; Nowakowska, Maria; Osyczka, Anna M

    2013-01-01

    The progress in tissue regeneration is strongly dependent on the development of biocompatible materials with properties resembling those of a native tissue. Also, the application of noninvasive methods of delivering the scaffold into the tissue defect is of great importance. In this study we present a group of biopolymer-based materials as potential injectable scaffolds. In contrast to other studies involving collagen neutralization or additional incubation of gel in genipin solution, we propose collagen and collagen–chitosan gels crosslinked in situ with genipin. Since some parameters of the cells should be considered in the microscale, the steady-state fluorescence anisotropy was applied to study the microenvironment of the gels. To our knowledge we are the first to report on microrheological properties, such as gel time and microviscosity, for this group of hydrogels. Rapid gelation at physiological temperatures found makes these materials of special interest in applications requiring gel injectability. Physico-chemical investigation showed the influence of the crosslinking agent concentration and chitosan addition on the crosslinking degree, swelling ratio, gel microviscosity, and the degradation rate. Strong correlation was revealed between the surface wettability and the viability of cultured mesenchymal stem cells. Cytotoxicity studies indicated that the collagen–chitosan hydrogels showed the best biocompatibility. (paper)

  11. Drug-Loadable Calcium Alginate Hydrogel System for Use in Oral Bone Tissue Repair.

    Science.gov (United States)

    Chen, Luyuan; Shen, Renze; Komasa, Satoshi; Xue, Yanxiang; Jin, Bingyu; Hou, Yepo; Okazaki, Joji; Gao, Jie

    2017-05-06

    This study developed a drug-loadable hydrogel system with high plasticity and favorable biological properties to enhance oral bone tissue regeneration. Hydrogels of different calcium alginate concentrations were prepared. Their swelling ratio, degradation time, and bovine serum albumin (BSA) release rate were measured. Human periodontal ligament cells (hPDLCs) and bone marrow stromal cells (BMSCs) were cultured with both calcium alginate hydrogels and polylactic acid (PLA), and then we examined the proliferation of cells. Inflammatory-related factor gene expressions of hPDLCs and osteogenesis-related gene expressions of BMSCs were observed. Materials were implanted into the subcutaneous tissue of rabbits to determine the biosecurity properties of the materials. The materials were also implanted in mandibular bone defects and then scanned using micro-CT. The calcium alginate hydrogels caused less inflammation than the PLA. The number of mineralized nodules and the expression of osteoblast-related genes were significantly higher in the hydrogel group compared with the control group. When the materials were implanted in subcutaneous tissue, materials showed favorable biocompatibility. The calcium alginate hydrogels had superior osteoinductive bone ability to the PLA. The drug-loadable calcium alginate hydrogel system is a potential bone defect reparation material for clinical dental application.

  12. Histological and MR quantitative analysis of repaired tissue following microfracture treatment for knee joint osteochondritis dissecans in rabbit models

    International Nuclear Information System (INIS)

    Tao Hongyue; Chen Shuang; Feng Xiaoyuan; Wang Zhan; Li Hong; Hua Yinghui; Chen Zhongqing

    2013-01-01

    Objective: To quantitatively analyze the histological and MR images of repaired tissue (RT) following microfracture for knee joint osteochondritis dissecans (OCD) in rabbit models at different time points, make comparisons with the RT performances of joint debridement, explore the efficiency of the microfracture treatment for OCD. Methods: Twenty-seven New Zealand rabbits were randomly assigned into 3 groups (sacrificed at the end of 3, 5 and 7 weeks post-operation respectively), with 9 in each group. For each rabbit, one knee joint was made into an OCD model. In each group, 6 were for microfracture treatment, and the other 3 were for joint debridement as control. MR scan, which mainly included sequences of 3D double echo steady state sequence (3D-DESS) and T_2-mapping, was taken at 3, 5 and 7 weeks postoperation. The thickness index and T_2 value index of RT were calculated and T_2-mapping of repaired region was drafted. Then the operation sites were removed to make histological sections of HE and Masson staining. The modified O'Driscoll score system was employed to make semi-quantitative evaluation for the histological performance of RT. Comparisons were made with respect to MR and histological findings between two treatments at each time point using unpaired Student t test. Effects of two treatments were evaluated longitudinally by comparing the results of three time points using one-way ANOVA. Results: The post-operation thickness indexes of two groups increased gradually (F = 33.940, 28.841, P < 0.05), T_2 value indexes decreased (F = 80.183, 206.206, P < 0.05), and O'driscoll scores increased gradually (F = 29.867, 17.167, P < 0.05). At each time point, the thickness index of microfracture was higher than that of debridement group (3-week: 0.743 ± 0.048 vs 0.624 ± 0.013, t = 4.077; 5-week: 0.813 ± 0.031 vs 0.734 ± 0.015, t = 4.107; 7-week: 0.972 ± 0.064 vs 0.777 ± 0.039, t = 4.782; P < 0.05), and the defects of microfracture in 7-week group were almost

  13. 21 CFR 864.3010 - Tissue processing equipment.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Tissue processing equipment. 864.3010 Section 864.3010 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Pathology Instrumentation and Accessories § 864.3010...

  14. Method for Processing Liver Spheroids Using an Automatic Tissue Processor

    Science.gov (United States)

    2016-05-01

    alcohol dehydration and hot liquid wax infiltration. After the water in the tissue is replaced with wax and cooled, it then becomes possible to cut...effective for processing and preparing microscopy slides of liver spheroids. The general process involved formalin fixation, dehydration in a...DPBS);  formalin (37% neutral buffer formaldehyde);  series of alcohol solutions: 70, 80, 95, and 100% ethanol in water; 2  xylene

  15. 21 CFR 876.5885 - Tissue culture media for human ex vivo tissue and cell culture processing applications.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Tissue culture media for human ex vivo tissue and cell culture processing applications. 876.5885 Section 876.5885 Food and Drugs FOOD AND DRUG... DEVICES Therapeutic Devices § 876.5885 Tissue culture media for human ex vivo tissue and cell culture...

  16. Repair of segmental bone defect using Totally Vitalized tissue engineered bone graft by a combined perfusion seeding and culture system.

    Directory of Open Access Journals (Sweden)

    Lin Wang

    Full Text Available BACKGROUND: The basic strategy to construct tissue engineered bone graft (TEBG is to combine osteoblastic cells with three dimensional (3D scaffold. Based on this strategy, we proposed the "Totally Vitalized TEBG" (TV-TEBG which was characterized by abundant and homogenously distributed cells with enhanced cell proliferation and differentiation and further investigated its biological performance in repairing segmental bone defect. METHODS: In this study, we constructed the TV-TEBG with the combination of customized flow perfusion seeding/culture system and β-tricalcium phosphate (β-TCP scaffold fabricated by Rapid Prototyping (RP technique. We systemically compared three kinds of TEBG constructed by perfusion seeding and perfusion culture (PSPC method, static seeding and perfusion culture (SSPC method, and static seeding and static culture (SSSC method for their in vitro performance and bone defect healing efficacy with a rabbit model. RESULTS: Our study has demonstrated that TEBG constructed by PSPC method exhibited better biological properties with higher daily D-glucose consumption, increased cell proliferation and differentiation, and better cell distribution, indicating the successful construction of TV-TEBG. After implanted into rabbit radius defects for 12 weeks, PSPC group exerted higher X-ray score close to autograft, much greater mechanical property evidenced by the biomechanical testing and significantly higher new bone formation as shown by histological analysis compared with the other two groups, and eventually obtained favorable healing efficacy of the segmental bone defect that was the closest to autograft transplantation. CONCLUSION: This study demonstrated the feasibility of TV-TEBG construction with combination of perfusion seeding, perfusion culture and RP technique which exerted excellent biological properties. The application of TV-TEBG may become a preferred candidate for segmental bone defect repair in orthopedic and

  17. Biomechanical regulation of in vitro cardiogenesis for tissue-engineered heart repair.

    Science.gov (United States)

    Zimmermann, Wolfram-Hubertus

    2013-01-01

    The heart is a continuously pumping organ with an average lifespan of eight decades. It develops from the onset of embryonic cardiogenesis under biomechanical load, performs optimally within a defined range of hemodynamic load, and fails if acutely or chronically overloaded. Unloading of the heart leads to defective cardiogenesis in utero, but can also lead to a desired therapeutic outcome (for example, in patients with heart failure under left ventricular assist device therapy). In light of the well-documented relevance of mechanical loading for cardiac physiology and pathology, it is plausible that tissue engineers have integrated mechanical stimulation regimens into protocols for heart muscle construction. To achieve optimal results, physiological principles of beat-to-beat myocardial loading and unloading should be simulated. In addition, heart muscle engineering, in particular if based on pluripotent stem cell-derived cardiomyocytes, may benefit from staggered tonic loading protocols to simulate viscoelastic properties of the prenatal and postnatal myocardial stroma. This review will provide an overview of heart muscle mechanics, summarize observations on the role of mechanical loading for heart development and postnatal performance, and discuss how physiological loading regimens can be exploited to advance myocardial tissue engineering towards a therapeutic application.

  18. Vaginal native tissue repair versus transvaginal mesh repair for apical prolapse: how utilizing different methods of analysis affects the estimated trade-off between reoperation for mesh exposure/erosion and reoperation for recurrent prolapse.

    Science.gov (United States)

    Dieter, Alexis A; Willis-Gray, Marcella G; Weidner, Alison C; Visco, Anthony G; Myers, Evan R

    2015-05-01

    Informed decision-making about optimal surgical repair of apical prolapse with vaginal native tissue (NT) versus transvaginal mesh (TVM) requires understanding the balance between the potential "harm" of mesh-related complications and the potential "benefit" of reducing prolapse recurrence. Synthesis of data from observational studies is required and the current literature shows that the average follow-up for NT repair is significantly longer than for TVM repair. We examined this harm/benefit balance. We hypothesized that using different methods of analysis to incorporate follow-up time would affect the balance of outcomes. We used a Markov state transition model to estimate the cumulative 24-month probabilities of reoperation for mesh exposure/erosion or for recurrent prolapse after either NT or TVM repair. We used four different analytic approaches to estimate probability distributions ranging from simple pooled proportions to a random effects meta-analysis using study-specific events per patient-time. As variability in follow-up time was accounted for better, the balance of outcomes became more uncertain. For TVM repair, the incremental ratio of number of operations for mesh exposure/erosion per single reoperation for recurrent prolapse prevented increased progressively from 1.4 to over 100 with more rigorous analysis methods. The most rigorous analysis showed a 70% probability that TVM would result in more operations for recurrent prolapse repair than NT. Based on the best available evidence, there is considerable uncertainty about the harm/benefit trade-off between NT and TVM for apical prolapse repair. Future studies should incorporate time-to-event analyses, with greater standardization of reporting, in order to better inform decision-making.

  19. Evaluation of a steam generator tube repair process using an explosive expansion techniuqe at TMI-1

    International Nuclear Information System (INIS)

    Rajan, J.; Shook, T.A.; Leonard, L.

    1983-01-01

    After a planned shutdown of Unit No. 1 at Three Mile Island, cracks were discovered in the primary side of steam generator tubes in the vicinity of the upper surface of the upper tubesheet. The nature of these cracks was later characterized as intergranular stress corrosion. The licensee, General Public Utilities Nuclear (GPUN), proposed to form a new tube-to-tubesheet seal below the cracks using a repair process wherein a detonating cord and polyethylene cartridge assembly inserted into the tube explosively expand the tube against the tubesheet. The explosive expansion process has had numerous applications over the years in the initial fabrication of heat exchanger tube-to-tubesheet assemblies and in repair processes using sleeving. However, this is the first use of this process in a steam generator to expand a previously rolled tube and to form a new seal between it and the tubesheet below a defective region in the tube. The seal obtained between the tube and tubesheet depends on the magnitude of explosive energy released in the detonating process. In this application, it is desired to obtain a mechanical bond rather than a metallurgical welding of the tube and tubesheet. A number of critical variables must be taken into account in order to obtain a successful mechanical seal. These include the explosive power of the detonating cord, the number of expansion shots used, the length of tube which is expanded, cartridge and tube diameters, the diameter of the tubesheet hole, the materials of the tube and tubesheet, and the condition of the surfaces at the time of repair. (orig./GL)

  20. Tissue photoablation process with short-pulsed lasers

    Science.gov (United States)

    Mueller, Gerhard J.; Doerschel, Klaus; Kar, Hasan

    1992-03-01

    Since Hippocrates, physicians have three weapons to fight malignant diseases of the human body: Quae medicamenta non sanat, ferrum sanat; quae ferrum non sanat, ignis sanat; and quae vero ignis non sanat, insanabilia reputari oportet. Today there are various possibilities to use the ''fire'': electrical and optical cauterization; mono- and bipolar rf-surgery; ionizing radiation for tumor treatment; and last but not least, the laser of laser tissue interactions, all can be used to remove malignant tissue either by biological digestion or immediate ablation, i.e., photovaporization or photodecomposition. This paper will discuss a semiempirical theory of the so-called photoablation process and the thermal side effects of the surrounding tissue. The term ''Photoablation; has to be well differentiated with the terms photovaporization, photodisruption and photofragmentation. As will be shown in this paper, photoablation is a microscale fast thermal explosion.

  1. Development of a fast curing tissue adhesive for meniscus tear repair.

    Science.gov (United States)

    Bochyńska, Agnieszka Izabela; Hannink, Gerjon; Janssen, Dennis; Buma, Pieter; Grijpma, Dirk W

    2017-01-01

    Isocyanate-terminated adhesive amphiphilic block copolymers are attractive materials to treat meniscus tears due to their tuneable mechanical properties and good adhesive characteristics. However, a drawback of this class of materials is their relatively long curing time. In this study, we evaluate the use of an amine cross-linker and addition of catalysts as two strategies to accelerate the curing rates of a recently developed biodegradable reactive isocyanate-terminated hyper-branched adhesive block copolymer prepared from polyethylene glycol (PEG), trimethylene carbonate, citric acid and hexamethylene diisocyanate. The curing kinetics of the hyper-branched adhesive alone and in combination with different concentrations of spermidine solutions, and after addition of 2,2-dimorpholinodiethylether (DMDEE) or 1,4-diazabicyclo [2.2.2] octane (DABCO) were determined using FTIR. Additionally, lap-shear adhesion tests using all compositions at various time points were performed. The two most promising compositions of the fast curing adhesives were evaluated in a meniscus bucket handle lesion model and their performance was compared with that of fibrin glue. The results showed that addition of both spermidine and catalysts to the adhesive copolymer can accelerate the curing rate and that firm adhesion can already be achieved after 2 h. The adhesive strength to meniscus tissue of 3.2-3.7 N was considerably higher for the newly developed compositions than for fibrin glue (0.3 N). The proposed combination of an adhesive component and a cross-linking component or catalyst is a promising way to accelerate curing rates of isocyanate-terminated tissue adhesives.

  2. DNA double strand break repair pathway plays a significant role in determining the radiotherapy induced normal tissue toxicity among head-and-neck and breast cancer

    International Nuclear Information System (INIS)

    Sadashiva, Satish Rao Bola; Mumbrekar, Kamalesh Dattaram; Venkatesh, Goutham Hassan; Fernandes, Donald Jerard; Bejadi, Vadhiraja Manjunath; Kapaettu, Satyamoorthy

    2014-01-01

    The ability to predict individual risk of radiotherapy induced normal tissue complications prior to the therapy may give an opportunity to personalize the treatment aiming improved therapeutic effect and quality of life. Therefore, predicting the risk of developing acute reactions before the initiation of radiation therapy may serve as a potential biomarker. DNA double-strand break (DSB) induction and its repair kinetics in lymphocytes of Head-and-Neck (n = 183) and Breast cancer (n = 132) patients undergoing chemoradiation or radiation therapy alone were analyzed by performing γ-H2AX foci, neutral comet and a modified neutral filter elution assay. Candidate radioresponsive genes like DNA repair, antioxidant pathway, profibrotic cytokine genes were screened for the common variants for their association with normal tissue toxicity outcome. Patients were stratified as non-over responders (NOR) and over responders (OR) based on their Radiation Therapy Oncology Group grading for normal tissue adverse reactions. Our results suggest that DSB repair plays a major role in the development of normal tissue adverse reactions in H and N and Breast cancer patients. The cellular (γ-H2AX analysis) and SNP analysis may have the potential to be developed into a clinically useful predictive assay for identifying the normal tissue over reactors

  3. Cartilage T2 assessment: differentiation of normal hyaline cartilage and reparative tissue after arthroscopic cartilage repair in equine subjects.

    Science.gov (United States)

    White, Lawrence M; Sussman, Marshall S; Hurtig, Mark; Probyn, Linda; Tomlinson, George; Kandel, Rita

    2006-11-01

    To prospectively assess T2 mapping characteristics of normal articular cartilage and of cartilage at sites of arthroscopic repair, including comparison with histologic results and collagen organization assessed at polarized light microscopy (PLM). Study protocol was compliant with the Canadian Council on Animal Care Guidelines and approved by the institutional animal care committee. Arthroscopic osteochondral autograft transplantation (OAT) and microfracture arthroplasty (MFx) were performed in knees of 10 equine subjects (seven female, three male; age range, 3-5 years). A site of arthroscopically normal cartilage was documented in each joint as a control site. Joints were harvested at 12 (n = 5) and 24 (n = 5) weeks postoperatively and were imaged at 1.5-T magnetic resonance (MR) with a 10-echo sagittal fast spin-echo acquisition. T2 maps of each site (21 OAT harvest, 10 MFx, 12 OAT plug, and 10 control sites) were calculated with linear least-squares curve fitting. Cartilage T2 maps were qualitatively graded as "organized" (normal transition of low-to-high T2 signal from deep to superficial cartilage zones) or "disorganized." Quantitative mean T2 values were calculated for deep, middle, and superficial cartilage at each location. Results were compared with histologic and PLM assessments by using kappa analysis. T2 maps were qualitatively graded as organized at 20 of 53 sites and as disorganized at 33 sites. Perfect agreement was seen between organized T2 and histologic findings of hyaline cartilage and between disorganized T2 and histologic findings of fibrous reparative tissue (kappa = 1.0). Strong agreement was seen between organized T2 and normal PLM findings and between disorganized T2 and abnormal PLM findings (kappa = .92). Quantitative assessment of the deep, middle, and superficial cartilage, respectively, showed mean T2 values of 53.3, 58.6, and 54.9 msec at reparative fibrous tissue sites and 40.7, 53.6, and 61.6 msec at hyaline cartilage sites. A

  4. Effect of laser wavelength and protein solder concentration on acute tissue repair using laser welding: initial results in a canine ureter model.

    Science.gov (United States)

    Wright, E J; Poppas, D P

    1997-01-01

    Successful tissue approximation can be performed using low power laser energy combined with human albumin solder. In vitro studies were undertaken to investigate the acute repair strengths achieved using different laser wavelengths. Furthermore, we evaluated the change in repair strength with that resulted from changes in protein solder concentration. Intraluminal bursting pressure following ureterotomy repair was measured for the following laser wavelengths: 532, 808, 1,320, 2,100, and 10,600 nm. The tissue absorption characteristics of the 808-nm diode and the KTP-532-nm lasers required the addition of the exogenous chromophores indocyanine green and fluorescein, respectively. A 40% human albumin solder was incorporated in the repair of a 1.0-cm longitudinal defect in the canine ureter. Following determination of an optimal welding wavelength, human albumin solder of varying concentrations (25%, 38%, 45%, and 50%) were prepared and tested. The 1,320-nm YAG laser achieved the highest acute bursting pressure and was the most effective in this model. Of the concentrations of albumin tested, 50% human albumin yielded the greatest bursting pressures. We conclude that of the laser wavelengths evaluated, the 1,320-nm YAG achieves the strongest tissue weld in the acute ex vivo dog ureter model. In addition, when this laser system is used, the acute strength of a photothermal weld appears to be directly proportional to the concentration of human albumin solder in the range of 25 to 50%.

  5. Assessment of DNA quality in processed tuna muscle tissues

    Directory of Open Access Journals (Sweden)

    Zora Piskatá

    2016-06-01

    Full Text Available Authentication of tuna fish products is necessary to assure consumers of accurate labelling of food products. The quality of species specific DNA crucially affects the efficiency of amplification during the subsequent PCR. The problem in DNA detection in canned products lies in the possibility of the fragmentation of DNA during the processing technologies and the use of ingredients (oil, salt, spice, that may inhibit the PCR reaction. In this study three DNA extraction methods were compared: DNeasy Blood and Tissue Kit, DNeasy mericon Food Kit and Chemagic DNA tissue 10 Kit. The quantity and quality of DNA were evaluated by measuring DNA concentration and ratios A260/A280. Several parameters were estimated: the effect of whole and mechanically treated muscle, sterilization procedure used in canned process (high temperature in combination with high pressure and addition of raw materials. The highest DNA concentrations were observed in non-processed muscle that is not influenced by the sterilization process. Canned whole muscle demonstrated lower DNA yield, and furthermore, the mechanical treatment (canned ground resulted in lower values of DNA concentration that was registered by using all three types of DNA extraction kits. DNeasy mericon Food Kit produced DNA of higher concentration in non-processed sample, Chemagic DNA tissue 10 Kit delivered higher DNA yields than kits DNeasy Blood and Tissue Kit and DNeasy mericon Food Kit in canned samples, although the purity was lower, but still within the range 1.7 - 2.0. DNA was considered to be satisfactorily pure in all three types of samples and using all three types of DNA isolation. In case of the samples enriched of ingredients and treated with sterilization process as whole or ground muscle Chemagic DNA tissue 10 Kit produced in all samples (whole and ground muscle the highest values of DNA concentration, but almost all values of A260/A280 were lower than 1.7. Therefore DNeasy mericon Food Kit

  6. Magnetic resonance observation of cartilage repair tissue (MOCART) for the evaluation of autologous chondrocyte transplantation: Determination of interobserver variability and correlation to clinical outcome after 2 years

    International Nuclear Information System (INIS)

    Marlovits, Stefan; Singer, Philipp; Zeller, Philip; Mandl, Irena; Haller, Joerg; Trattnig, Siegfried

    2006-01-01

    In an observational study, the validity and reliability of magnetic resonance imaging (MRI) for the assessment of autologous chondrocyte transplantation (ACT) in the knee joint was determined. Two years after implantation, high-resolution MRI was used to analyze the repair tissue with nine pertinent variables. A complete filling of the defect was found in 61.5%, and a complete integration of the border zone to the adjacent cartilage in 76.9%. An intact subchondral lamina was present in 84.6% and an intact subchondral bone was present in 61.5%. Isointense signal intensities of the repair tissue compared to the adjacent native cartilage were seen in 92.3%. To evaluate interobserver variability, a reliability analysis with the determination of the intraclass correlation coefficient (ICC) was calculated. An 'almost perfect' agreement, with an ICC value >0.81, was calculated in 8 of 9 variables. The clinical outcome after 2 years showed the visual analog score (VAS) at 2.62 (S.D. ±0.65). The values for the knee injury and osteoarthritis outcome score (KOOS) subgroups were 68.29 (±23.90) for pain, 62.09 (±14.62) for symptoms, 75.45 (±21.91) for ADL function, 52.69 (±28.77) for sport and 70.19 (±22.41) for knee-related quality of life. The clinical scores were correlated with the MRI variables. A statistically significant correlation was found for the variables 'filling of the defect,' 'structure of the repair tissue,' 'changes in the subchondral bone,' and 'signal intensities of the repair issue'. High resolution MRI and well-defined MRI variables are a reliable, reproducible and accurate tool for assessing cartilage repair tissue

  7. Magnetic resonance observation of cartilage repair tissue (MOCART) for the evaluation of autologous chondrocyte transplantation: Determination of interobserver variability and correlation to clinical outcome after 2 years

    Energy Technology Data Exchange (ETDEWEB)

    Marlovits, Stefan [Department of Traumatology, Center for Joint and Cartilage, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna (Austria)]. E-mail: stefan.marlovits@meduniwien.ac.at; Singer, Philipp [Department of Traumatology, Center for Joint and Cartilage, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna (Austria); Zeller, Philip [Department of Traumatology, Center for Joint and Cartilage, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna (Austria); Mandl, Irena [Department of Traumatology, Center for Joint and Cartilage, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna (Austria); Haller, Joerg [Department of Radiology, Hanusch Hospital, Heinrich-Collin-Strasse, A-1140 Vienna (Austria); Trattnig, Siegfried [Department of Radiology, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna (Austria)

    2006-01-15

    In an observational study, the validity and reliability of magnetic resonance imaging (MRI) for the assessment of autologous chondrocyte transplantation (ACT) in the knee joint was determined. Two years after implantation, high-resolution MRI was used to analyze the repair tissue with nine pertinent variables. A complete filling of the defect was found in 61.5%, and a complete integration of the border zone to the adjacent cartilage in 76.9%. An intact subchondral lamina was present in 84.6% and an intact subchondral bone was present in 61.5%. Isointense signal intensities of the repair tissue compared to the adjacent native cartilage were seen in 92.3%. To evaluate interobserver variability, a reliability analysis with the determination of the intraclass correlation coefficient (ICC) was calculated. An 'almost perfect' agreement, with an ICC value >0.81, was calculated in 8 of 9 variables. The clinical outcome after 2 years showed the visual analog score (VAS) at 2.62 (S.D. {+-}0.65). The values for the knee injury and osteoarthritis outcome score (KOOS) subgroups were 68.29 ({+-}23.90) for pain, 62.09 ({+-}14.62) for symptoms, 75.45 ({+-}21.91) for ADL function, 52.69 ({+-}28.77) for sport and 70.19 ({+-}22.41) for knee-related quality of life. The clinical scores were correlated with the MRI variables. A statistically significant correlation was found for the variables 'filling of the defect,' 'structure of the repair tissue,' 'changes in the subchondral bone,' and 'signal intensities of the repair issue'. High resolution MRI and well-defined MRI variables are a reliable, reproducible and accurate tool for assessing cartilage repair tissue.

  8. A Dirichlet process mixture model for brain MRI tissue classification.

    Science.gov (United States)

    Ferreira da Silva, Adelino R

    2007-04-01

    Accurate classification of magnetic resonance images according to tissue type or region of interest has become a critical requirement in diagnosis, treatment planning, and cognitive neuroscience. Several authors have shown that finite mixture models give excellent results in the automated segmentation of MR images of the human normal brain. However, performance and robustness of finite mixture models deteriorate when the models have to deal with a variety of anatomical structures. In this paper, we propose a nonparametric Bayesian model for tissue classification of MR images of the brain. The model, known as Dirichlet process mixture model, uses Dirichlet process priors to overcome the limitations of current parametric finite mixture models. To validate the accuracy and robustness of our method we present the results of experiments carried out on simulated MR brain scans, as well as on real MR image data. The results are compared with similar results from other well-known MRI segmentation methods.

  9. Repair of Cartilage injuries using in vitro engineered 3D cartilage tissue- Preliminary Results of Our Animal Studies.

    Science.gov (United States)

    Arumugam, S; Manjunath, S; Senthilkumar, R; Rajendiran, S; Yoshioka, H; Mori, Y; Abraham, S

    2011-01-01

    The cartilage injuries demand novel therapeutic approaches as the success rates of the current conventional strategies for the repair of injured articular cartilages are not that encouraging. Earlier we have reported that the Thermoreversible Gelation Polymer (TGP) is an ideal scaffold for human chondrocyte expansion in vitro. In this study, we report the preliminary results of the in vitro expansion, characterization and experimental in vivo transplantation of chondrocytes in a rabbit model of cartilage injury. Nine rabbits were included in this study scheduled for two years, after approval by the ethics committee. In the first animal, Chondrocytes were isolated from the weight bearing area of patellar groove in the left hindlimb and cultured in TGP Scaffold and maintained at 37°C in 5% carbon dioxide incubator for 64 days without growth factors. Then the TGP-Chondrocyte construct was transplanted into an experimental defect created in the knee of the right forelimb of the same rabbit. After a period of 10 weeks, a biopsy was taken from the transplanted region and subjected to morphological analysis, characterization by histopathology (H&E stain) and Immunohistochemistry (S-100 staining). The chondrocytes in the 3D TGP culture had round to oval shaped morphology without any de-differentiation which is otherwise observed in Conventional 2D cultures. A macroscopic structure which resembled cartilage was appreciated in the TGP construct in vitro after 64 days which was then transplanted to the rabbit. The H&E and Immunohistochemistry studies confirmed the presence of chondrocytes in the biopsy tissue. Based on the results, we conclude that the TGP significantly supports the in vitro expansion of chondrocytes for a longer period and the 3D culture using TGP preserves the phenotype of the articular chondrocytes. The tissue thus grown when implanted with the TGP has engrafted well without any adverse reactions and upon confirmation of safety following completion of the

  10. Preparation and characterization of gelatin–hydroxyapatite composite microspheres for hard tissue repair

    International Nuclear Information System (INIS)

    Chao, Shao Ching; Wang, Ming-Jia; Pai, Nai-Su; Yen, Shiow-Kang

    2015-01-01

    Gelatin–hydroxyapatite composite microspheres composed of 21% gelatin (G) and 79% hydroxyapatite (HA) with uniform morphology and controllable size were synthesized from a mixed solution of Ca(NO 3 ) 2 , NH 4 H 2 PO 4 and gelatin by a wet-chemical method. Material analyses such as X-ray diffraction (XRD), scanning/transmission electron microscopy examination (SEM/TEM) and inductively coupled plasma-mass spectroscopy (ICP-MS) were used to characterize G–HA microspheres by analyzing their crystalline phase, microstructure, morphology and composition. HA crystals precipitate along G fibers to form nano-rods with diameters of 6–10 nm and tangle into porous microspheres after blending. The cell culture indicates that G–HA composite microspheres without any toxicity could enhance the proliferation and differentiation of osteoblast-like cells. In a rat calvarial defect model, G–HA bioactive scaffolds were compared with fibrin glue (F) and Osteoset® Bone Graft Substitute (OS) for their capacity of regenerating bone. Four weeks post-implantation, new bone, mineralization, and expanded blood vessel area were found in G–HA scaffolds, indicating greater osteoconductivity and bioactivity than F and OS. - Highlights: • G–HA composite microspheres were prepared by hydroxyapatite and gelatin. • In vitro tests indicated that the G–HA microspheres were biocompatible and bioactive. • In in vitro tests, G–HA microspheres could be applied in hard tissue engineering. • G–HA had healed the bone defect and provides a high proportion of surface area to open space

  11. Preparation and characterization of gelatin–hydroxyapatite composite microspheres for hard tissue repair

    Energy Technology Data Exchange (ETDEWEB)

    Chao, Shao Ching [Department of Materials Science and Engineering, National Chung Hsing University, 250 Kuo-Kuang Road, Taichung 40227, Taiwan (China); Department of Minimally Invasive Skull Neurosurgery, Neurological Institute, Taichung Veterans General Hospital, 1650 Taiwan Boulevard, Sect. 4, Taichung, Taiwan (China); Department of Neurosurgery, ChangHua Hospital, Ministry of Health and Welfare, 80 Chung Cheng Road, Sect. 2 Chiu Kuan Village, Changhua 500, Taiwan (China); Wang, Ming-Jia; Pai, Nai-Su [Department of Materials Science and Engineering, National Chung Hsing University, 250 Kuo-Kuang Road, Taichung 40227, Taiwan (China); Yen, Shiow-Kang, E-mail: skyen@dragon.nchu.edu.tw [Department of Materials Science and Engineering, National Chung Hsing University, 250 Kuo-Kuang Road, Taichung 40227, Taiwan (China)

    2015-12-01

    Gelatin–hydroxyapatite composite microspheres composed of 21% gelatin (G) and 79% hydroxyapatite (HA) with uniform morphology and controllable size were synthesized from a mixed solution of Ca(NO{sub 3}){sub 2}, NH{sub 4}H{sub 2}PO{sub 4} and gelatin by a wet-chemical method. Material analyses such as X-ray diffraction (XRD), scanning/transmission electron microscopy examination (SEM/TEM) and inductively coupled plasma-mass spectroscopy (ICP-MS) were used to characterize G–HA microspheres by analyzing their crystalline phase, microstructure, morphology and composition. HA crystals precipitate along G fibers to form nano-rods with diameters of 6–10 nm and tangle into porous microspheres after blending. The cell culture indicates that G–HA composite microspheres without any toxicity could enhance the proliferation and differentiation of osteoblast-like cells. In a rat calvarial defect model, G–HA bioactive scaffolds were compared with fibrin glue (F) and Osteoset® Bone Graft Substitute (OS) for their capacity of regenerating bone. Four weeks post-implantation, new bone, mineralization, and expanded blood vessel area were found in G–HA scaffolds, indicating greater osteoconductivity and bioactivity than F and OS. - Highlights: • G–HA composite microspheres were prepared by hydroxyapatite and gelatin. • In vitro tests indicated that the G–HA microspheres were biocompatible and bioactive. • In in vitro tests, G–HA microspheres could be applied in hard tissue engineering. • G–HA had healed the bone defect and provides a high proportion of surface area to open space.

  12. AVARIS - AREVA Valve Repair in-Situ. Innovative technology and processes

    International Nuclear Information System (INIS)

    Schultz, Ch.

    2012-01-01

    Concept of in-situ welding and turning machine is explained. The AVARIS processes are: Disassembly Evaluation Turning Welding Finish turning Penetration test Grinding Reassembly Result - The seats are within the dimensional and hardness tolerances. The repaired valves with AVARIS as in the case of Isar 2 in 2010 did not show any indications after one year in operation Advantages: Development based on an approved and safe technology; Capability for improving and/or modification of the hardfacing material according to specific system conditions; Minimization of dose exposure (ALARA)

  13. Left ventricular regional myocardial motion and twist function in repaired tetralogy of Fallot evaluated by magnetic resonance tissue phase mapping

    International Nuclear Information System (INIS)

    Chang, Meng-Chu; Peng, Hsu-Hsia; Wu, Ming-Ting; Weng, Ken-Pen; Su, Mao-Yuan; Menza, Marius; Huang, Hung-Chieh

    2018-01-01

    We aimed to characterise regional myocardial motion and twist function in the left ventricles (LV) in patients with repaired tetralogy of Fallot (rTOF) and preserved LV global function. We recruited 47 rTOF patients and 38 age-matched normal volunteers. Tissue phase mapping (TPM) was performed for evaluating the LV myocardial velocity in longitudinal, radial, and circumferential (Vz, Vr, and VOe) directions in basal, middle, and apical slices. The VOe peak-to-peak (PTP) during systolic phases, the rotation angle of each slice, and VOe inconsistency were computed for evaluating LV twist function and VOe dyssynchrony. As compared to the controls, the rTOF patients presented decreased RV ejection fraction (RVEF) (p = 0.002) and preserved global LV ejection fraction (LVEF). They also demonstrated decreased systolic and diastolic Vz in several LV segments and higher diastolic Vr in the septum (all p < 0.05). A lower VOe PTP, higher VOe inconsistency, and reduced peak net rotation angle (all p < 0.05) were observed. The aforementioned indices demonstrated an altered LV twist function in rTOF patients in an early disease stage. MR TPM could provide information about early abnormalities of LV regional motion and twist function in rTOF patients with preserved LV global function. (orig.)

  14. Left ventricular regional myocardial motion and twist function in repaired tetralogy of Fallot evaluated by magnetic resonance tissue phase mapping

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Meng-Chu; Peng, Hsu-Hsia [National Tsing Hua University, Department of Biomedical Engineering and Environmental Sciences, Hsinchu (China); Wu, Ming-Ting [Kaohsiung Veterans General Hospital, Department of Radiology, Kaohsiung (China); National Yang-Ming University, Faculty of Medicine, Taipei (China); Weng, Ken-Pen [National Yang-Ming University, Faculty of Medicine, Taipei (China); Kaohsiung Veterans General Hospital, Department of Pediatrics, Kaohsiung (China); Shu-Zen Junior College of Medicine and Management, Department of Physical Therapy, Kaohsiung (China); Su, Mao-Yuan [National Taiwan University Hospital, Department of Medical Imaging, Taipei (China); Menza, Marius [Medical Center University of Freiburg, Faculty of Medicine, University of Freiburg, Department of Radiology, Medical Physics, Freiburg (Germany); Huang, Hung-Chieh [Kaohsiung Veterans General Hospital, Department of Radiology, Kaohsiung (China)

    2018-01-15

    We aimed to characterise regional myocardial motion and twist function in the left ventricles (LV) in patients with repaired tetralogy of Fallot (rTOF) and preserved LV global function. We recruited 47 rTOF patients and 38 age-matched normal volunteers. Tissue phase mapping (TPM) was performed for evaluating the LV myocardial velocity in longitudinal, radial, and circumferential (Vz, Vr, and VOe) directions in basal, middle, and apical slices. The VOe peak-to-peak (PTP) during systolic phases, the rotation angle of each slice, and VOe inconsistency were computed for evaluating LV twist function and VOe dyssynchrony. As compared to the controls, the rTOF patients presented decreased RV ejection fraction (RVEF) (p = 0.002) and preserved global LV ejection fraction (LVEF). They also demonstrated decreased systolic and diastolic Vz in several LV segments and higher diastolic Vr in the septum (all p < 0.05). A lower VOe PTP, higher VOe inconsistency, and reduced peak net rotation angle (all p < 0.05) were observed. The aforementioned indices demonstrated an altered LV twist function in rTOF patients in an early disease stage. MR TPM could provide information about early abnormalities of LV regional motion and twist function in rTOF patients with preserved LV global function. (orig.)

  15. Comparison of international guidelines for regenerative medicine: Knee cartilage repair and replacement using human-derived cells and tissues.

    Science.gov (United States)

    Itoh, Kuni; Kano, Shingo

    2016-07-01

    Regenerative medicine (RM) is an emerging field using human-derived cells and tissues (HCT). Due to the complexity and diversity of HCT products, each country has its own regulations for authorization and no common method has been applied to date. Individual regulations were previously clarified at the level of statutes but no direct comparison has been reported at the level of guidelines. Here, we generated a new analytical framework that allows comparison of guidelines independent from local definitions of RM, using 2 indicators, product type and information type. The guidelines for products for repair and replacement of knee cartilage in Japan, the United States of America, and Europe were compared and differences were detected in both product type and information type by the proposed analytical framework. Those findings will be critical not only for the product developers to determine the region to initiate the clinical trials but also for the regulators to assess and build their regulations. This analytical framework is potentially expandable to other RM guidelines to identify gaps, leading to trigger discussion of global harmonization in RM regulations. Copyright © 2016 International Alliance for Biological Standardization. Published by Elsevier Ltd. All rights reserved.

  16. Potential Role of Dentin Sialoprotein by Inducing Dental Pulp Mesenchymal Stem Cell Differentiation and Mineralization for Dental Tissue Repair

    Directory of Open Access Journals (Sweden)

    Zhi Chen

    2010-09-01

    Full Text Available Introduction: Dentin sialoprotein (DSP is a dentin extracellular matrix protein, a unique marker of dentinogenesis and plays a vital role in odontoblast differentiation and dentin mineralization. Recently, studies have shown that DSP induces differentiation and mineralization of periodontal ligament stem cells and dental papilla mesenchymal cells in vitro and rescues dentin deficiency and increases enamel mineralization in animal models.The hypothesis: DSP as a nature therapeutic agent stimulates dental tissue repair by inducing endogenous dental pulp mesenchymal stem/progenitor cells into odontoblast-like cells to synthesize and to secrete dentin extracellular matrix forming new tertiary dentin as well as to regenerate a functional dentin-pulp complex. As DSP is a nature protein, and clinical procedure for DSP therapy is easy and simple, application of DSP may provide a new avenue for dentists with additional option for the treatment of substantially damaged vital teeth.Evaluation of the hypothesis: Dental caries is the most common dental disease. Deep caries and pulp exposure have been treated by various restorative materials with limited success. One promising approach is dental pulp stem/progenitor-based therapies to regenerate dentin-pulp complex and restore its functions by DSP induction in vivo.

  17. Potential Role of Dentin Sialoprotein by Inducing Dental Pulp Mesenchymal Stem Cell Differentiation and Mineralization for Dental Tissue Repair.

    Science.gov (United States)

    Yuan, Guo-Hua; Yang, Guo-Bin; Wu, Li-An; Chen, Zhi; Chen, Shuo

    2010-01-01

    INTRODUCTION: Dentin sialoprotein (DSP) is a dentin extracellular matrix protein, a unique marker of dentinogenesis and plays a vital role in odontoblast differentiation and dentin mineralization. Recently, studies have shown that DSP induces differentiation and mineralization of periodontal ligament stem cells and dental papilla mesenchymal cells in vitro and rescues dentin deficiency and increases enamel mineralization in animal models. THE HYPOTHESIS: DSP as a nature therapeutic agent stimulates dental tissue repair by inducing endogenous dental pulp mesenchymal stem/progenitor cells into odontoblast-like cells to synthesize and to secrete dentin extracellular matrix forming new tertiary dentin as well as to regenerate a functional dentin-pulp complex. As DSP is a nature protein, and clinical procedure for DSP therapy is easy and simple, application of DSP may provide a new avenue for dentists with additional option for the treatment of substantially damaged vital teeth. EVALUATION OF THE HYPOTHESIS: Dental caries is the most common dental disease. Deep caries and pulp exposure have been treated by various restorative materials with limited success. One promising approach is dental pulp stem/progenitor-based therapies to regenerate dentin-pulp complex and restore its functions by DSP induction in vivo.

  18. Humeral repair in birds by guided tissue regeneration and external and internal associated fixation techniques

    International Nuclear Information System (INIS)

    Delogu, M.

    1993-01-01

    Ten pigeons (Columba livia domestic form) with humeral diaphyseal fracture were treated with external and internal fixation techniques (Boston technique and intamedullary pin). Longitudinal space was intentionally left between fracture surfaces during osteosynthesis. This space was filled with bovine lyophilized collagen, set around an intramedullary pin, in five samples. Ossification process was checked by radiography every seven days. Results show the utility of this technique in pneumatic bird bones. In fact, shortening control and callus formation facility were observed [it

  19. Inspection indications, stress corrosion cracks and repair of process piping in nuclear materials production reactors

    International Nuclear Information System (INIS)

    Louthan, M.R. Jr.; West, S.L.; Nelson, D.Z.

    1991-01-01

    Ultrasonic inspection of Schedule 40 Type 304 stainless steel piping in the process water system of the Savannah River Site reactors has provided indications of discontinuities in less than 10% of the weld heat affected zones. Pipe sections containing significant indications are replaced with Type 304L components. Post removal metallurgical evaluation showed that the indications resulted from stress corrosion cracking in weld heat-affected zones and that the overall weld quality was excellent. The evaluation also revealed weld fusion zone discontinuities such as incomplete penetration, incomplete fusion, inclusions, underfill at weld roots and hot cracks. Service induced extension of these discontinuities was generally not significant although stress corrosion cracking in one weld fusion zone was noted. One set of UT indications was caused by metallurgical discontinuities at the fusion boundary of an extra weld. This extra weld, not apparent on the outer pipe surface, was slightly overlapping and approximately parallel to the weld being inspected. This extra weld was made during a pipe repair, probably associated with initial construction processes. The two nearly parallel welds made accurate assessment of the UT signal difficult. The implications of these observations to the inspection and repair of process water systems of nuclear reactors is discussed

  20. Generation of human secondary cardiospheres as a potent cell processing strategy for cell-based cardiac repair.

    Science.gov (United States)

    Cho, Hyun-Jai; Lee, Ho-Jae; Chung, Yeon-Ju; Kim, Ju-Young; Cho, Hyun-Ju; Yang, Han-Mo; Kwon, Yoo-Wook; Lee, Hae-Young; Oh, Byung-Hee; Park, Young-Bae; Kim, Hyo-Soo

    2013-01-01

    Cell therapy is a promising approach for repairing damaged heart. However, there are large rooms to be improved in therapeutic efficacy. We cultured a small quantity (5-10 mg) of heart biopsy tissues from 16 patients who received heart transplantation. We produced primary and secondary cardiospheres (CSs) using repeated three-dimensional culture strategy and characterized the cells. Approximately 5000 secondary CSs were acquired after 45 days. Genetic analysis confirmed that the progenitor cells in the secondary CSs originated from the innate heart, but not from extra-cardiac organs. The expressions of Oct4 and Nanog were significantly induced in secondary CSs compared with adherent cells derived from primary CSs. Those expressions in secondary CSs were higher in a cytokine-deprived medium than in a cytokine-supplemented one, suggesting that formation of the three-dimensional structure was important to enhance stemness whereas supplementation with various cytokines was not essential. Signal blocking experiments showed that the ERK and VEGF pathways are indispensable for sphere formation. To optimize cell processing, we compared four different methods of generating spheres. Method based on the hanging-drop or AggreWell™ was superior to that based on the poly-d-lysine-coated dish or Petri dish with respect to homogeneity of the product, cellular potency and overall simplicity of the process. When transplanted into the ischemic myocardium of immunocompromised mice, human secondary CSs differentiated into cardiomyocytes and endothelial cells. These results demonstrate that generation of secondary CSs from a small quantity of adult human cardiac tissue is a feasible and effective cell processing strategy to improve the therapeutic efficacy of cell therapy. Copyright © 2012 Elsevier Ltd. All rights reserved.

  1. Actualities on molecular pathogenesis and repairing processes of cerebral damage in perinatal hypoxic-ischemic encephalopathy

    Directory of Open Access Journals (Sweden)

    Praticò Andrea D

    2010-09-01

    Full Text Available Abstract Hypoxic-ischemic encephalopathy (HIE is the most important cause of cerebral damage and long-term neurological sequelae in the perinatal period both in term and preterm infant. Hypoxic-ischemic (H-I injuries develop in two phases: the ischemic phase, dominated by necrotic processes, and the reperfusion phase, dominated by apoptotic processes extending beyond ischemic areas. Due to selective ischemic vulnerability, cerebral damage affects gray matter in term newborns and white matter in preterm newborns with the typical neuropathological aspects of laminar cortical necrosis in the former and periventricular leukomalacia in the latter. This article summarises the principal physiopathological and biochemical processes leading to necrosis and/or apoptosis of neuronal and glial cells and reports recent insights into some endogenous and exogenous cellular and molecular mechanisms aimed at repairing H-I cerebral damage.

  2. Wound repair in Pocillopora

    Science.gov (United States)

    Rodríguez-Villalobos, Jenny Carolina; Work, Thierry M.; Calderon-Aguileraa, Luis Eduardo

    2016-01-01

    Corals routinely lose tissue due to causes ranging from predation to disease. Tissue healing and regeneration are fundamental to the normal functioning of corals, yet we know little about this process. We described the microscopic morphology of wound repair in Pocillopora damicornis. Tissue was removed by airbrushing fragments from three healthy colonies, and these were monitored daily at the gross and microscopic level for 40 days. Grossly, corals healed by Day 30, but repigmentation was not evident at the end of the study (40 d). On histology, from Day 8 onwards, tissues at the lesion site were microscopically indistinguishable from adjacent normal tissues with evidence of zooxanthellae in gastrodermis. Inflammation was not evident. P. damicornis manifested a unique mode of regeneration involving projections of cell-covered mesoglea from the surface body wall that anastomosed to form gastrovascular canals.

  3. Biology and augmentation of tendon-bone insertion repair

    OpenAIRE

    Lui, PPY; Zhang, P; Chan, KM; Qin, L

    2010-01-01

    Abstract Surgical reattachment of tendon and bone such as in rotator cuff repair, patellar-patella tendon repair and anterior cruciate ligament (ACL) reconstruction often fails due to the failure of regeneration of the specialized tissue ("enthesis") which connects tendon to bone. Tendon-to-bone healing taking place between inhomogenous tissues is a slow process compared to healing within homogenous tissue, such as tendon to tendon or bone to bone healing. Therefore special attention must be ...

  4. Diabetic mice are protected from normally lethal nephrotoxicity of S-1,2-dichlorovinyl-L-cysteine (DCVC): role of nephrogenic tissue repair

    International Nuclear Information System (INIS)

    Dnyanmote, Ankur V.; Sawant, Sharmilee P.; Lock, Edward A.; Latendresse, John R.; Warbritton, Alan A.; Mehendale, Harihara M.

    2006-01-01

    Streptozotocin (STZ)-induced diabetic (DB) rats are protected from nephrotoxicity of gentamicin, cisplatin and mercuric chloride, although the mechanisms remain unclear. Ninety percent of DB mice receiving a LD90 dose (75 mg/kg, ip) of S-1,2-dichlorovinyl-L-cysteine (DCVC) survived in contrast to only 10% of the nondiabetic (NDB) mice surviving the same dose. We tested the hypothesis that the mechanism of protection is upregulated tissue repair. In the NDB mice, DCVC produced steep temporal increases in blood urea nitrogen (BUN) and plasma creatinine, which were associated with proximal tubular cell (PTC) necrosis, acute renal failure (ARF), and death within 48 h. In contrast, in the DB mice, BUN and creatinine increased less steeply, declining after 36 h to completely resolve by 96 h. HPLC analysis of plasma and urine revealed that DB did not alter the toxicokinetics of DCVC. Furthermore, activity of renal cysteine conjugate β-lyase, the enzyme that bioactivates DCVC, was unaltered in DB mice, undermining the possibility of lower bioactivation of DCVC leading to lower injury. [3H]-thymidine pulse labeling and PCNA analysis indicated an early onset and sustained nephrogenic tissue repair in DCVC-treated DB mice. BRDU immunohistochemistry revealed a fourfold increase in the number of cells in S-phase in the DB kidneys even without exposure to DCVC. Blocking the entry of cells into S-phase by antimitotic intervention using colchicine abolished stimulated nephrogenic tissue repair and nephroprotection. These findings suggest that preplacement of S-phase cells in the kidney due to diabetes is critical in mitigating the progression of DCVC-initiated renal injury by upregulation of tissue repair, leading to survival of the DB mice by avoiding acute renal failure

  5. Proteolytic processing of connective tissue growth factor in normal ocular tissues and during corneal wound healing.

    Science.gov (United States)

    Robinson, Paulette M; Smith, Tyler S; Patel, Dilan; Dave, Meera; Lewin, Alfred S; Pi, Liya; Scott, Edward W; Tuli, Sonal S; Schultz, Gregory S

    2012-12-13

    Connective tissue growth factor (CTGF) is a fibrogenic cytokine that is up-regulated by TGF-β and mediates most key fibrotic actions of TGF-β, including stimulation of synthesis of extracellular matrix and differentiation of fibroblasts into myofibroblasts. This study addresses the role of proteolytic processing of CTGF in human corneal fibroblasts (HCF) stimulated with TGF-β, normal ocular tissues and wounded corneas. Proteolytic processing of CTGF in HCF cultures, normal animal eyes, and excimer laser wounded rat corneas were examined by Western blot. The identity of a 21-kDa band was determined by tandem mass spectrometry, and possible alternative splice variants of CTGF were assessed by 5' Rapid Amplification of cDNA Ends (RACE). HCF stimulated by TGF-β contained full length 38-kDa CTGF and fragments of 25, 21, 18, and 13 kDa, while conditioned medium contained full length 38- and a 21-kDa fragment of CTGF that contained the middle "hinge" region of CTGF. Fragmentation of recombinant CTGF incubated in HCF extracts was blocked by the aspartate protease inhibitor, pepstatin. Normal mouse, rat, and rabbit whole eyes and rabbit ocular tissues contained abundant amounts of C-terminal 25- and 21-kDa fragments and trace amounts of 38-kDa CTGF, although no alternative transcripts were detected. All forms of CTGF (38, 25, and 21 kDa) were detected during healing of excimer ablated rat corneas, peaking on day 11. Proteolytic processing of 38-kDa CTGF occurs during corneal wound healing, which may have important implications in regulation of corneal scar formation.

  6. Chapter 10 the primary cilium coordinates signaling pathways in cell cycle control and migration during development and tissue repair

    DEFF Research Database (Denmark)

    Christensen, Søren T; Pedersen, Stine F; Satir, Peter

    2008-01-01

    Cell cycle control and migration are critical processes during development and maintenance of tissue functions. Recently, primary cilia were shown to take part in coordination of the signaling pathways that control these cellular processes in human health and disease. In this review, we present...... an overview of the function of primary cilia and the centrosome in the signaling pathways that regulate cell cycle control and migration with focus on ciliary signaling via platelet-derived growth factor receptor alpha (PDGFRalpha). We also consider how the primary cilium and the centrosome interact...... with the extracellular matrix, coordinate Wnt signaling, and modulate cytoskeletal changes that impinge on both cell cycle control and cell migration....

  7. Solid emulsion gel as a vehicle for delivery of polyunsaturated fatty acids: implications for tissue repair, dermal angiogenesis and wound healing.

    Science.gov (United States)

    Shingel, Kirill I; Faure, Marie-Pierre; Azoulay, Laurent; Roberge, Christophe; Deckelbaum, Richard J

    2008-10-01

    The paper describes preparation and biological characterization of the solid hybrid biomaterial that was designed for cell-targeted lipid delivery in healing tissues. The material referred to as 'solid emulsion gel' combines a protein-stabilized lipid emulsion and a hydrogel structure in a single compartment. The potential of the omega-3 (n-3)-fatty acids rich solid emulsion gel for tissue repair applications was investigated at the macro-, micro-, molecular and gene expression levels, using human fibroblasts and endothelial cells and a porcine model of full-thickness wounds. Being non-cytotoxic in vitro and in vivo, the biomaterial was found to affect cell metabolism, modulate expression of certain genes, stimulate early angiogenesis and promote wound repair in vivo. The neovascular response in vivo was correlated with upregulated expression of the genes involved in lipid transport (e.g. adipophilin), anti-apoptosis (e.g. heat shock proteins, haem oxygenase 1) and angiogenesis (vascular endothelial growth factor, placental growth factor). Collectively, the results of this study provide first evidence that the angiogenic response provided by solid emulsion gel-mediated delivery of n-3 fatty acids is an alternative to the topical administration of exogenous growth factors or gene therapy, and can be advantageously used for the stimulation of tissue repair in complex wounds. Copyright (c) 2008 John Wiley & Sons, Ltd.

  8. Treatment of non-vital primary molar using lesion sterilization and tissue repair (LSTR 3Mix-MP

    Directory of Open Access Journals (Sweden)

    Tania Saskianti

    2013-06-01

    Full Text Available Background: Root canal preparation and anatomic variations of deciduous teeth often cause the child patient uncooperative and sometimes the treatment failure. the non-threatening treatment and non-invasive approaches is needed to obtain a good cooperation from child patient. Purpose: The study was aimed to clinically evaluate the use of 3Mix-MP- a combination of antibacterial drugs, i.e. metronidazole, minocycline and ciprofloxacin (3Mix, and macrogol and propylene glycol (MP - as pulp medicament on a necroses primary molar. Methods: Subject were the children patients of Pediatric Dental Clinic Universitas Airlangga Dental Hospital. Eight primary molars with pulp necroses due to dental caries were selected as samples. The treatment was done based on the concept of lesion sterilization and tissue repair (LSTR therapy. A slice of 3 Mix-MP pastes was placed in the cavity and then sealed with glassionomer cement. Subjects were asked for recall visit in 1, 3 and 6 months post treatment, for clinical and radiographic evaluation. The antibacterial effect of 3 Mix-MP was compared with tempophore on mixed bacteria of pulp cavity which was isolated prior to therapy. The antibacterial effect was determined by measuring the inhibition zone after 24 hours anaerobe incubation. Results: Seven out of 8 subjects on recall visit showed no acute or chronic clinical symptoms, such as fistulae, abscess, purulent exudates, swelling or feel any pain during mastication. Microbiological test result showed LSTR 3Mix-MP had antibacterial effect higher than tempophore (p<0.001. Conclusion: The study revealed that 3Mix-MP treatment showed clinical and radiographic positive response on necrose primary molar.Latar belakang: Preparasi saluran akar dan variasi anatomi gigi sulung seringkali menyebabkan pasien anak tidak kooperatif dan kadang menyebabkan kegagalan perawatan. Perawatan yang tidak menakutkan dan non-invasif diperlukan untuk mendapatkan kerjasama yang baik dari

  9. An international eDelphi study identifying the research and education priorities in wound management and tissue repair.

    Science.gov (United States)

    Cowman, Seamus; Gethin, Georgina; Clarke, Eric; Moore, Zena; Craig, Gerardine; Jordan-O'Brien, Julie; McLain, Niamh; Strapp, Helen

    2012-02-01

    To incorporate an international and multidisciplinary consensus in the determination of the research and education priorities for wound healing and tissue repair. A compelling reason for the study is the lack of an agreed list of priorities for wound care research and education. Furthermore, there is a growth in the prevalence of chronic wounds, a growth in wound care products and marketing, and an increase in clinician attendance at conferences and education programmes. The study used a survey method. A four-round eDelphi technique was used to collect responses from an international population of health professionals across 24 countries. Responses were obtained from 360 professionals representing many health care settings. The top education priorities related to the standardisation of all foundation education programmes in wound care, the inclusion of wound care in all professional undergraduate and postgraduate education programmes, selecting dressings and the prevention of pressure ulcers. The top research priorities related to the dressing selection, pressure ulcer prevention and wound infection. conclusion: Professionals from different backgrounds and countries who are engaged in wound management share a common set of priorities for research and education. Most notably, the priorities identified relate to long-established clinical challenges in wound care and underpin the principles of good patient care practices. The priorities are closely allied to an ageing population and identify many challenges ahead for practitioners engaged in wound management services. The provision of wound care is a major investment of health service resources and remains a clinical challenge today. Research is essential to building evidence-based practice and fundamental to development of quality in standards of practice; education is central to achieving competence to deliver effective care. The determination of research and education priorities is therefore an absolute requirement

  10. Multifunctional bioactive glass and glass-ceramic biomaterials with antibacterial properties for repair and regeneration of bone tissue.

    Science.gov (United States)

    Fernandes, João S; Gentile, Piergiorgio; Pires, Ricardo A; Reis, Rui L; Hatton, Paul V

    2017-09-01

    Bioactive glasses (BGs) and related glass-ceramic biomaterials have been used in bone tissue repair for over 30years. Previous work in this field was comprehensively reviewed including by their inventor Larry Hench, and the key features and properties of BGs are well understood. More recently, attention has focused on their modification to further enhance the osteogenic behaviour, or further compositional changes that may introduce additional properties, such as antimicrobial activity. Evidence is emerging that BGs and related glass-ceramics may be modified in such a way as to simultaneously introduce more than one desirable property. The aim of this review is therefore to consider the evidence that these more recent inorganic modifications to glass and glass-ceramic biomaterials are effective, and whether or not these new compositions represent sufficiently versatile systems to underpin the development of a new generation of truly multifunctional biomaterials to address pressing clinical needs in orthopaedic and dental surgery. Indeed, a number of classical glass compositions exhibited antimicrobial activity, however the structural design and the addition of specific ions, i.e. Ag + , Cu + , and Sr 2+ , are able to impart a multifunctional character to these systems, through the combination of, for example, bioactivity with bactericidal activity. In this review we demonstrate the multifunctional potential of bioactive glasses and related glass-ceramics as biomaterials for orthopaedic and craniofacial/dental applications. Therefore, it considers the evidence that the more recent inorganic modifications to glass and glass-ceramic biomaterials are able to impart antimicrobial properties alongside the more classical bone bonding and osteoconduction. These properties are attracting a special attention nowadays that bacterial infections are an increasing challenge in orthopaedics. We also focus the manuscript on the versatility of these systems as a basis to underpin

  11. An international eDelphi study identifying the research and education priorities in wound management and tissue repair.

    LENUS (Irish Health Repository)

    2012-02-01

    Aim. To incorporate an international and multidisciplinary consensus in the determination of the research and education priorities for wound healing and tissue repair. Background. A compelling reason for the study is the lack of an agreed list of priorities for wound care research and education. Furthermore, there is a growth in the prevalence of chronic wounds, a growth in wound care products and marketing, and an increase in clinician attendance at conferences and education programmes. Design. The study used a survey method. Methods. A four-round eDelphi technique was used to collect responses from an international population of health professionals across 24 countries. Results. Responses were obtained from 360 professionals representing many health care settings. The top education priorities related to the standardisation of all foundation education programmes in wound care, the inclusion of wound care in all professional undergraduate and postgraduate education programmes, selecting dressings and the prevention of pressure ulcers. The top research priorities related to the dressing selection, pressure ulcer prevention and wound infection. Conclusion. Professionals from different backgrounds and countries who are engaged in wound management share a common set of priorities for research and education. Most notably, the priorities identified relate to long-established clinical challenges in wound care and underpin the principles of good patient care practices. The priorities are closely allied to an ageing population and identify many challenges ahead for practitioners engaged in wound management services. Relevance to clinical practice. The provision of wound care is a major investment of health service resources and remains a clinical challenge today. Research is essential to building evidence-based practice and fundamental to development of quality in standards of practice; education is central to achieving competence to deliver effective care. The

  12. Repair of Cartilage injuries using in vitro engineered 3D cartilage tissue- Preliminary Results of Our Animal Studies

    Directory of Open Access Journals (Sweden)

    Arumugam S

    2011-01-01

    Full Text Available Introduction: The cartilage injuries demand novel therapeutic approaches as the success rates of the current conventional strategies for the repair of injured articular cartilages are not that encouraging. Earlier we have reported that the Thermoreversible Gelation Polymer (TGP is an ideal scaffold for human chondrocyte expansion in vitro. In this study, we report the preliminary results of the in vitro expansion, characterization and experimental in vivo transplantation of chondrocytes in a rabbit model of cartilage injury Materials & Methods: Nine rabbits were included in this study scheduled for two years, after approval by the ethics committee. In the first animal, Chondrocytes were isolated from the weight bearing area of patellar groove in the left hindlimb and cultured in TGP Scaffold and maintained at 37°C in 5% carbon dioxide incubator for 64 days without growth factors. Then the TGP-Chondrocyte construct was transplanted into an experimental defect created in the knee of the right forelimb of the same rabbit. After a period of 10 weeks, a biopsy was taken from the transplanted region and subjected to morphological analysis, characterization by histopathology (H&E stain and Immunohistochemistry (S-100 staining.Results: The chondrocytes in the 3D TGP culture had round to oval shaped morphology without any de-differentiation which is otherwise observed in Conventional 2D cultures. A macroscopic structure which resembled cartilage was appreciated in the TGP construct in vitro after 64 days which was then transplanted to the rabbit. The H&E and Immunohistochemistry studies confirmed the presence of chondrocytes in the biopsy tissue. Conclusion: Based on the results, we conclude that the TGP significantly supports the in vitro expansion of chondrocytes for a longer period and the 3D culture using TGP preserves the phenotype of the articular chondrocytes. The tissue thus grown when implanted with the TGP has engrafted well without any

  13. BIOCHEMICAL MECHANISM OF AUTOLYTIC PROCESSES OF MUSCULAR TISSUE OF FISHES

    Directory of Open Access Journals (Sweden)

    L. V. Antipova

    2015-01-01

    Full Text Available The conducted researches allowed to establish that intensive disintegration of a muscular glycogen leads to sharp decrease in size рН muscular tissue in the sour party that in turn affects a chemical composition and physic-colloidal structure of proteins therefore: resistance of meat of fish to action of putrefactive microorganisms increases; solubility of muscle proteins, level of their hydration which is water connecting abilities decreases; there is a swelling of collagen of connecting fabric; activity of the cathepsin (an optimum рН 5,3 causing hydrolysis of proteins at later stages of an autolysis increases; the bicarbonate system of muscular tissue with release of carbon dioxide collapses; predecessors of taste and aroma of meat are formed; process of oxidation of lipids becomes more active. As a result of accumulation dairy, phosphoric and other acids in meat of fish concentration of hydrogen ions of that decrease рН is result increases. Sharply shown sour environment and availability of inorganic phosphorus is considered the reason of disintegration of an actin-myosin complex on actin and a myosin which begins after 8 hours of storage, i.e. there comes the period of relaxation of muscle fibers and the period of permission of an numbness, and then the last stage of maturing of meat – deep autolysis. Thus, on the basis of classical ideas of biochemical changes of meat of land animals and summarizing the obtained data on posthumous changes in muscular tissue of fishes, it is possible to draw a conclusion that they have similar nature of regularity in comparison with muscular tissue of land animals, but their main difference is higher speed of course of autolytic transformations. It in turn leads to faster change of FTS of meat of fishes who are the defining indicators when developing assortment groups of products taking into account stages of an autolysis in meat.

  14. Biomechanical validation of load-sharing rip-stop fixation for the repair of tissue-deficient rotator cuff tears.

    Science.gov (United States)

    Burkhart, Stephen S; Denard, Patrick J; Konicek, John; Hanypsiak, Bryan T

    2014-02-01

    Poor-quality tendon is one of the most difficult problems the surgeon must overcome in achieving secure fixation during rotator cuff repair. A load-sharing rip-stop construct (LSRS) has recently been proposed as a method for improving fixation strength, but the biomechanical properties of this construct have not yet been examined. To compare the strength of the LSRS construct to that of single-row fixation for rotator cuff repair. Controlled laboratory study. Rotator cuff tears were created in 6 cadaveric matched-pair specimens and repaired with a single row or an LSRS. In the LSRS repair, a 2-mm suture tape was placed as an inverted mattress stitch in the rotator cuff, and sutures from 2 anchors were placed as simple stitches that passed medial to the suture tape. The suture tape limbs were secured with knotless anchors laterally before sutures were tied from the medial anchors. Displacement was observed with video tracking after cyclic loading, and specimens were loaded to failure. The mean load to failure was 371 ± 102 N in single-row repairs compared with 616 ± 185 N in LSRS repairs (P = .031). There was no difference in displacement with cyclic loading between the groups (3.3 ± 0.8 mm vs. 3.5 ± 1.1 mm; P = .561). In the single-row group, 4 of 6 failures occurred at the suture-tendon interface. In the LSRS group, only 1 failure occurred at the suture-tendon interface. The ultimate failure load of the LSRS construct for rotator cuff repair was 1.7 times that of a single-row construct in a cadaveric model. The LSRS rotator cuff repair construct may be useful in the repair of difficult tears such as massive tears, medial tears, and tears with tendon loss.

  15. Variance of [sup 99m]Tc-MDP bone imaging among the repairing process after experimental femoral head necrosis

    Energy Technology Data Exchange (ETDEWEB)

    Shibiao, Sang; Yimin, Jiang; Jinxi, Wang [Suzhou Medical Coll., Suzhou, JS (China). First Affiliated Hospital

    1993-05-01

    Six of 26 adult mongrel dogs were used as controls. Avascular necrosis of the left femoral head was induced by freezing method with liquid nitrogen and the right side being used as a self-control. The 20 dogs were divided into four groups, 5 dogs each which was sacrificed successively at 1/2, 2,2 and 6 months after operation. All of the femoral heads were studied by radionuclide bone imaging, radiological, histological and biochemical examinations. The results were as follows: [sup 99m]Tc-MDP bone imaging showed a decreased uptake at the early stage, and was gradually increased later, and reached its peak values at precollape stage at four months. Hypermetabolism state was still maintained at collapsed stage. Above changes was in coincidence with the bone imaging. As for the repairing process after necrosis, the hypermetabolic reaction in bone imaging of the femoral head correlates well with the proliferation of vessels and bone marrow cells and also the activity of tissue collagenase. Therefore, a poor bony reconstruction in the weight-bearing portion could be an important cause for late segmental collapse.

  16. Efeitos bioestimulantes do laser de baixa potência no processo de reparo Biostimulation effects of low-power laser in the repair process

    Directory of Open Access Journals (Sweden)

    Ruthinéia Diógenes Alves Uchôa Lins

    2010-12-01

    Full Text Available Os lasers de baixa potência promovem efeitos biológicos benéficos, de caráter analgésico, antiinflamatório e cicatrizante, por meio de um fenômeno de bioestimulação. A radiação emitida pelo laser terapêutico afeta os processos metabólicos das células-alvo, produzindo efeitos bioestimulantes que resultam na ocorrência de eventos celulares e vasculares, os quais parecem interferir diretamente no processo de reparo. Este trabalho visa estudar o fenômeno da bioestimulação e destacar os principais efeitos bioestimulantes do laser de baixa potência na reparação tecidual.The wound healing process has always been an excellent subject for researchers. The use of low-power laser on wounds during the postoperative phase has increased the speed of the healing process. It has been implied that low power radiation affects cellular metabolic processes and promotes beneficial biological effects (analgesic, anti-inflammatory, and healing. Laser biostimulation appears to influence the behavior of the repair process. This paper aims at reviewing the most interesting aspects of the use of low-power laser in the tissue-repair process.

  17. Biological effect of pulsed dose rate brachytherapy with stepping sources if short half-times of repair are present in tissues

    International Nuclear Information System (INIS)

    Fowler, Jack F.; Limbergen, Erik F.M. van

    1997-01-01

    Purpose: To explore the possible increase of radiation effect in tissues irradiated by pulsed brachytherapy (PDR) for local tissue dose rates between those 'averaged over the whole pulse' and the instantaneous high dose rates close to the dwell positions. Increased effect is more likely for tissues with short half-times of repair of the order of a few minutes, similar to pulse durations. Methods and Materials: Calculations were done assuming the linear quadratic formula for radiation damage, in which only the dose-squared term is subject to exponential repair. The situation with two components of T (1(2)) is addressed. A constant overall time of 140 h and a constant total dose of 70 Gy were assumed throughout, the continuous low dose rate of 0.5 Gy/h (CLDR) providing the unitary standard effects for each PDR condition. Effects of dose rates ranging from 4 Gy/h to 120 Gy/h (HDR at 2 Gy/min) were studied, covering the gap in an earlier publication. Four schedules were examined: doses per pulse of 0.5, 1, 1.5, and 2 Gy given at repetition frequencies of 1, 2, 3, and 4 h, respectively, each with a range of assumed half-times of repair of 4 min to 1.5 h. Results are presented for late-responding tissues, the differences from CLDR being two or three times greater than for early-responding tissues and most tumors. Results: Curves are presented relating the ratio of increased biological effect (proportional to log cell kill) calculated for PDR relative to CLDR. Ratios as high as 1.5 can be found for large doses per pulse (2 Gy) if the half-time of repair in tissues is as short as a few minutes. The major influences on effect are dose per pulse, half-time of repair in tissue, and--when T (1(2)) is short--the instantaneous dose rate. Maximum ratios of PDR/CLDR occur when the dose rate is such that pulse duration is approximately equal to T (1(2)) . As dose rate in the pulse is increased, a plateau of effect is reached, for most T (1(2)) s, above 10 to 20 Gy/h, which is

  18. Biological effects of radiation and chemical agents with special regard to repair processes

    International Nuclear Information System (INIS)

    Altmann, H.; Wottawa, A.

    1980-01-01

    It is reasonably certain that the introduction or increase of pollutants in the environment can augment mutagenic and carcinogenic effects. These effects are operationally definable, but the genetic organization and the underlying mechanisms of DNA repair, mutagenesis and carcinogenesis are so complex as to make the extrapolation of results from mutagenicity test data to carcinogenicity somewhat uncertain. The subject is reviewed. Recent discoveries in gene organization and expression include overlapping genes in bacteriophages, split genes, processing of RNA and splicing, translocation of genes in eukaryotes, inactivation of the X-chromosome in mammals, etc. Apart from the genetic regulation, plasmids, insertion sequences and mutators can additionally affect mutation frequency. Cancers due to gene mutations, viruses, chemicals and physical agents are known. However, little is known about the epigenetic mechanisms involved. The value of mutagenicity test data is beyond question, but in view of the extraordinary complexities encountered our extrapolations will be more sound if the data have the underpinning of basic information. (author)

  19. Detoxification and repair process of ozone injury: From O3 uptake to gene expression adjustment

    International Nuclear Information System (INIS)

    Castagna, A.; Ranieri, A.

    2009-01-01

    Plants react to O 3 threat by setting up a variety of defensive strategies involving the co-ordinated modulation of stress perception, signalling and metabolic responses. Although stomata largely controls O 3 uptake, differences in O 3 tolerance cannot always be ascribed to changes in stomatal conductance but cell protective and repair processes should be taken into account. O 3 -driven ROS production in the apoplast induces a secondary, active, self-propagating generation of ROS, whose levels must be finely tuned, by many enzymatic and non-enzymatic antioxidant systems, to induce gene activation without determining uncontrolled cell death. Additional signalling molecules, as ethylene, jasmonic and salicylic acid are also crucial to determine the spreading and the containment of leaf lesions. The main recent results obtained on O 3 sensing, signal transduction, ROS formation and detoxification mechanisms are here discussed. - A dissection of the complex network of interacting mechanisms which determine the cell fate under ozone stress.

  20. Post-irradiation repairing processes of glucose-6-phosphate dehydrogenase and catalase from Hansenula Polymorpha yeast

    International Nuclear Information System (INIS)

    Postolache, Carmen; Postolache, Cristian; Dinu, Diana; Dinischiotu, Anca; Sahini, Victor Emanuel

    2002-01-01

    The post-irradiation repairing mechanisms of two Hansenula Polymorpha yeast enzymes, glucose-6-phosphate dehydrogenase and catalase, were studied. The kinetic parameters of the selected enzymes were investigated over one month since the moment of γ-irradiation with different doses in the presence of oxygen. Dose dependent decrease of initial reaction rates was noticed for both enzymes. Small variation of initial reaction rate was recorded for glucose-6-phosphate dehydrogenase over one month, with a decreasing tendency. No significant electrophoretic changes of molecular forms of this enzyme were observed after irradiation. Continuous strong decrease of catalase activity was evident for the first 20 days after irradiation. Partial recovery process of the catalytic activity was revealed by this study. (authors)

  1. HGF-transgenic MSCs can improve the effects of tissue self-repair in a rabbit model of traumatic osteonecrosis of the femoral head.

    Directory of Open Access Journals (Sweden)

    Qian Wen

    Full Text Available BACKGROUND: Osteonecrosis of the femoral head (ONFH is generally characterized as an irreversible disease and tends to cause permanent disability. Therefore, understanding the pathogenesis and molecular mechanisms of ONFH and developing effective therapeutic methods is critical for slowing the progress of the disease. METHODOLOGY/PRINCIPAL FINDINGS: In this study, an experimental rabbit model of early stage traumatic ONFH was established, validated, and used for an evaluation of therapy. Computed tomography (CT and magnetic resonance (MR imaging confirmed that this model represents clinical Association Research Circulation Osseous (ARCO phase I or II ONFH, which was also confirmed by the presence of significant tissue damage in osseous tissue and vasculature. Pathological examination detected obvious self-repair of bone tissue up to 2 weeks after trauma, as indicated by revascularization (marked by CD105 and expression of collagen type I (Col I, osteocalcin, and proliferating cell nuclear antigen. Transplantation of hepatocyte growth factor (HGF-transgenic mesenchymal stem cells (MSCs 1 week after trauma promoted recovery from ONFH, as evidenced by a reversed pattern of Col I expression compared with animals receiving no therapeutic treatment, as well as increased expression of vascular endothelial growth factor. CONCLUSIONS/SIGNIFICANCE: These results indicate that the transplantation of HGF-transgenic MSCs is a promising method for the treatment for ONFH and suggest that appropriate interference therapy during the tissue self-repair stage contributes to the positive outcomes. This study also provides a model for the further study of the ONFH etiology and therapeutic interventions.

  2. Nasal chondrocyte-based engineered autologous cartilage tissue for repair of articular cartilage defects: an observational first-in-human trial.

    Science.gov (United States)

    Mumme, Marcus; Barbero, Andrea; Miot, Sylvie; Wixmerten, Anke; Feliciano, Sandra; Wolf, Francine; Asnaghi, Adelaide M; Baumhoer, Daniel; Bieri, Oliver; Kretzschmar, Martin; Pagenstert, Geert; Haug, Martin; Schaefer, Dirk J; Martin, Ivan; Jakob, Marcel

    2016-10-22

    Articular cartilage injuries have poor repair capacity, leading to progressive joint damage, and cannot be restored predictably by either conventional treatments or advanced therapies based on implantation of articular chondrocytes. Compared with articular chondrocytes, chondrocytes derived from the nasal septum have superior and more reproducible capacity to generate hyaline-like cartilage tissues, with the plasticity to adapt to a joint environment. We aimed to assess whether engineered autologous nasal chondrocyte-based cartilage grafts allow safe and functional restoration of knee cartilage defects. In a first-in-human trial, ten patients with symptomatic, post-traumatic, full-thickness cartilage lesions (2-6 cm 2 ) on the femoral condyle or trochlea were treated at University Hospital Basel in Switzerland. Chondrocytes isolated from a 6 mm nasal septum biopsy specimen were expanded and cultured onto collagen membranes to engineer cartilage grafts (30 × 40 × 2 mm). The engineered tissues were implanted into the femoral defects via mini-arthrotomy and assessed up to 24 months after surgery. Primary outcomes were feasibility and safety of the procedure. Secondary outcomes included self-assessed clinical scores and MRI-based estimation of morphological and compositional quality of the repair tissue. This study is registered with ClinicalTrials.gov, number NCT01605201. The study is ongoing, with an approved extension to 25 patients. For every patient, it was feasible to manufacture cartilaginous grafts with nasal chondrocytes embedded in an extracellular matrix rich in glycosaminoglycan and type II collagen. Engineered tissues were stable through handling with forceps and could be secured in the injured joints. No adverse reactions were recorded and self-assessed clinical scores for pain, knee function, and quality of life were improved significantly from before surgery to 24 months after surgery. Radiological assessments indicated variable degrees of

  3. Tissue Factor and Tissue Factor Pathway Inhibitor in the Wound-Healing Process After Neurosurgery.

    Science.gov (United States)

    Ślusarz, Robert; Głowacka, Mariola; Biercewicz, Monika; Barczykowska, Ewa; Haor, Beata; Rość, Danuta; Gadomska, Grażyna

    2016-03-01

    The aim of the study was to assess the concentrations of tissue factor (TF) and tissue factor pathway inhibitor (TFPI) in the blood of patients with a postoperative wound after neurosurgery. Participants included 20 adult patients who underwent neurosurgery because of degenerative spine changes. The concentration of TF and TFPI in the patients' blood serum was measured 3 times: before surgery, during the first 24 hr after surgery, and between the 5th and 7th days after surgery. The control group comprised 20 healthy volunteers similar to the patient group with respect to gender and age. A statistically significant difference was observed between TF concentration at all three measurement time points in the research group and TF concentration in the control group (p = .018, p = .010, p = .001). A statistically significant difference was found between TFPI concentration at the second time point in the research group and TFPI concentration in the control group (p = .041). No statistically significant within-subject difference was found between TF concentrations before and after surgery. A statistically significant within-subject difference was found between TFPI concentrations within 24 hr after surgery and 5-7 days after surgery (p = .004). High perioperative concentrations of TF indicate not only the presence of thrombophilia but also the importance of TF in the wound-healing process. Perioperative changes in TFPI concentrations are related to its compensatory influence on hemostasis in thrombophilic conditions. © The Author(s) 2015.

  4. Effects of low dose radiation on repair processes in human lymphocytes

    International Nuclear Information System (INIS)

    Tuschl, H.; Altmann, H.; Kovac, R.; Topaloglou, A.; Egg, D.; Guenther, R.

    1978-10-01

    DNA excision repair was investigated in lymphocytes of persons occupationally exposed to low dose radiation of 222 Rn. Autoradiographic studies of unscheduled DNA synthesis and measurement of 3 H-thymidine incorporation by repair replication into double stranded and single-strand containing DNA fractions obtained by BND cellulose chromatography seem to indicate a stimulatory effect of repeated low dose radiation on repair enzymes. (author)

  5. DNA repair and cancer

    International Nuclear Information System (INIS)

    Rathore, Shakuntla; Joshi, Pankaj Kumar; Gaur, Sudha

    2012-01-01

    DNA repair refers to a collection of processes by which a cell identifies and corrects damage to the DNA molecule that encode it's genome. In human cells, both normal metabolic activities and environmental factors such as UV light and radiation can cause DNA damage, resulting in as many one million individual molecular lesions per day. Many of these lesions cause structural damage to the DNA molecule and can alter or eliminate the cell's ability to transcribe the gene that the affected DNA encodes. Other lesions include potentially harmful mutation in cell's genome which affect the survival of it's daughter cells after it undergoes mitosis. As a consequence, the DNA repair process is constantly active as it responds to damage in the DNA structure. Inherited mutation that affect DNA repair genes are strongly associated with high cancer risks in humans. Hereditary non polyposis colorectal cancer (HNPCC) is strongly associated with specific mutation in the DNA mismatch repair pathway. BRCA1, BRCA2 two famous mutation conferring a hugely increased risk of breast cancer on carrier, are both associated with a large number of DNA repair pathway, especially NHEJ and homologous recombination. Cancer therapy procedures such as chemotherapy and radiotherapy work by overwhelming the capacity of the cell to repair DNA damage, resulting in cell death. Cells that are most rapidly dividing most typically cancer cells are preferentially affected. The side effect is that other non-cancerous but rapidly dividing cells such as stem cells in the bone marrow are also affected. Modern cancer treatment attempt to localize the DNA damage to cells and tissue only associated with cancer, either by physical means (concentrating the therapeutic agent in the region of the tumor) or by biochemical means (exploiting a feature unique to cancer cells in the body). (author)

  6. The influence of combined treatment of Cd, and γ-irradiation on DNA damage and repair in lymphoid tissues of mice

    International Nuclear Information System (INIS)

    Privezentsev, K.V.; Sirota, N.P.; Gaziev, A.I.

    1996-01-01

    The effect of combined treatment of Cd and γ-irradiation on DNA damage and repair was studied in lymphoid tissues of mice using single-cell gel assay. Single i.p. injection of CdCl 2 (1 mg Cd/kg body wt), 2 h prior to irradiation resulted in increasing of DNA lesions in peripheral blood lymphocytes (PBL) when compared to non-injected animals. However, the same treatment, 48 h prior to irradiation is shown to decrease DNA damage in PBL and splenocytes in comparison with untreated mice. In thymocytes maximal protective effect of Cd was determined when mice were irradiated in 24 h after injection. The protective effect observed is due to decreasing of initial level of DNA damage in thymocytes as well as acceleration of DNA repair in PBL and splenocytes. 28 refs.; 2 figs

  7. Staged abdominal closure with intramuscular tissue expanders and modified components separation technique of a giant incisional hernia after repair of a ruptured omphalocele

    Directory of Open Access Journals (Sweden)

    Yukihiro Tatekawa

    2016-07-01

    Full Text Available In patients with omphalocele, several different techniques are performed for repair of the abdominal wall defect. We present the case of a staged abdominal closure of a giant incisional hernia after repair of a ruptured omphalocele. At birth, skin flap coverage associated with silo formation occurred, but the abdominal wall defect remained, resulting in a giant abdominal hernia. To expand the layers of the abdominal wall, tissue expanders were placed between the bilateral internal oblique and transverses abdominis muscles. Postoperatively, a modified components separation technique was performed. The abdominal wall was closed in the midline. Upon closure of the skin in the midline, bilateral relaxing incisions were performed, covering the remaining defect with artificial dermis. At the age of one year and 7 months, the patient had no recurrent incisional hernia nor any wound complications.

  8. Solid state crack repair by friction stir processing in 304L stainless steel

    Institute of Scientific and Technical Information of China (English)

    C.Gunter; M.P.Miles; F.C.Liu; T.W Nelson

    2018-01-01

    Friction stir processing (FSP) was investigated as a method of repairing cracks in 12mm thick 304L stainless steel plate.Healing feasibility was demonstrated by processing a tapered crack using a PCBN/WRe tool with a 25 mm diameter shoulder and a pin length of 6.4 mm.The experiment showed that it was possible to heal a crack that begins narrow and then progressively grows up to a width of 2 mm.Bead on plate experiments were used to find the best parameters for creating a consolidated stir zone with the least amount of hardness difference compared to the base metal.Grain refinement in some specimens resulted in much higher stir zone hardness,compared to base metal.A plot of grain size versus microhardness showed a very strong inverse correlation between grain size and hardness,as expected from the HallPetch relationship.Corrosion testing was carried out in order to evaluate the effect of FSP on potential sensitization of the stir zone.After 1000h of intermittent immersion in 3.5% saline solution at room temperature it was found that no corrosion products formed on the base material controls or on any of the friction stir processed specimens.

  9. Preparation and application of an innovative thrombocyte/leukocyte-enriched plasma to promote tissue repair in chelonians.

    Directory of Open Access Journals (Sweden)

    Francesco Di Ianni

    healing process of both soft and hard tissue injuries in chelonians.

  10. Preparation and Application of an Innovative Thrombocyte/Leukocyte-Enriched Plasma to Promote Tissue Repair in Chelonians

    Science.gov (United States)

    Di Ianni, Francesco; Merli, Elisa; Burtini, Francesca; Conti, Virna; Pelizzone, Igor; Di Lecce, Rosanna; Parmigiani, Enrico; Squassino, Gian Paolo; Del Bue, Maurizio; Lucarelli, Enrico; Ramoni, Roberto; Grolli, Stefano

    2015-01-01

    Platelet concentrates are widely used in mammalian regenerative medicine to improve tissue healing. Chelonians (Testudines) would benefit from the application of thrombocyte preparations to regenerate damaged tissues, since traumatic injuries are leading causes of morbidity and mortality for both wild-living and domesticated animals. The aim of this study was to establish a protocol that optimized the recovery of the thrombocytes from blood samples and to show the efficacy of thrombocyte-enriched plasma in chelonians. Peripheral blood samples were obtained from Testudo spp. (n = 12) and Trachemys scripta elegans (n = 10). Blood cells were fractionated by sodium diatrizoate-sodium polysucrose density gradient using a two-step centrifugation protocol. Thrombocytes and leukocytes were isolated and resuspended to obtain thrombocyte-leucocyte rich plasma (TLRP). The mean recovery of leukocytes and thrombocytes was 48.9% (±4.0 SEM, n = 22) of the whole blood cell content. No statistically significant difference was observed between blood samples collected from different turtle species. The ability of TLRP to form a gel was evaluated by adding variable concentrations of calcium gluconate at room temperature and at 37°C. A reliable and consistent clotting of the TLRP was obtained in glass tubes and dishes by adding 5-20% v/v of a 100 mg/ml solution of calcium gluconate. Furthermore, in order to test the clinical efficacy of TLRP, a preliminary evaluation was performed on four turtles (Testudo spp.) with traumatic injuries. In all the four animals, a successful clinical outcome was observed. The results demonstrated that a thrombocyte-enriched plasma, comparable to mammalian platelet rich plasma, can be prepared from chelonian blood samples. Furthermore, although the low number of cases presented does not allow definitive conclusions from a clinical point of view, their outcome suggests that TLRP application could be further investigated to improve the healing process of

  11. An early approach for the evaluation of repair processes in fish after exposure to sediment contaminated by an oil spill.

    Science.gov (United States)

    Salamanca, Maria J; Jimenez-Tenorio, Natalia; Reguera, Diana F; Morales-Caselles, Carmen; Delvalls, T Angel

    2008-12-01

    A chronic bioassay was carried out under laboratory conditions using juvenile Solea senegalensis to determine the toxicity of contaminants from an oil spill(Prestige). Also, the repair processes in fish affected by contaminants due to oil exposure were evaluated. Over 30 days individuals were exposed to clean sediment (control) and to sediment contaminated by a mixture of polyaromatic hydrocarbons (PAHs) and other substances. The physicochemical parameters of the tanks (salinity, temperature, pH and dissolved oxygen) were controlled during the exposure period. Clean sediment from the Bay of Cadiz (Spain) was used as negative control and was mixed with fuel oil to prepare the dilution (0.5% w:w dry-weight). After the exposure period, fish were labeled and transferred to "clean tanks" (tanks without sediment) in order to study the recovery and the repair processes in the exposed organisms. A biomarker of exposure (ethoxyresorufin-O-deethylase activity - EROD activity) and a biomarker of effect (histopathology) were analyzed during the exposure and recovery period. After 10, 20 and 30 days of exposure, individuals showed significant induction (P tank", enabled a first evaluation of the repair process of the induced damages due to the fuel oil exposure. After the recovery phase, control individuals showed a more significant decrease (P repair processes probably need longer recovery periods to observe significant improvement of the affected organs. This will be further investigated in the future.

  12. DNA hybrids suggesting a recombination process repairing radiation-induced DNA double-strand breaks in Ehrlich Ascites tumor cells

    International Nuclear Information System (INIS)

    Barthel, H.R.

    1984-01-01

    The results presented suggest the possibility of repair of DNA double-strand breaks by recombination, at least in the S and G 2 -phases of the cell cycle, in mammalian cells. Further experiments with synchronized cell cultures will have to show whether this process may also occur in the G 1 -phase of the cell cycle. (orig./AJ) [de

  13. Biomaterial-mediated strategies targeting vascularization for bone repair.

    Science.gov (United States)

    García, José R; García, Andrés J

    2016-04-01

    Repair of non-healing bone defects through tissue engineering strategies remains a challenging feat in the clinic due to the aversive microenvironment surrounding the injured tissue. The vascular damage that occurs following a bone injury causes extreme ischemia and a loss of circulating cells that contribute to regeneration. Tissue-engineered constructs aimed at regenerating the injured bone suffer from complications based on the slow progression of endogenous vascular repair and often fail at bridging the bone defect. To that end, various strategies have been explored to increase blood vessel regeneration within defects to facilitate both tissue-engineered and natural repair processes. Developments that induce robust vascularization will need to consolidate various parameters including optimization of embedded therapeutics, scaffold characteristics, and successful integration between the construct and the biological tissue. This review provides an overview of current strategies as well as new developments in engineering biomaterials to induce reparation of a functional vascular supply in the context of bone repair.

  14. Inherited DNA repair defects in H. sapiens: their relation to uv-associated processes in xeroderma pigmentosum

    International Nuclear Information System (INIS)

    Robbins, J.H.; Kraemer, K.H.; Andrews, A.D.

    1976-01-01

    Xeroderma pigmentosum (XP) is an autosomal recessive disease in which patients develop pigmentation abnormalities and numerous malignancies on areas of skin exposed to sunlight. Some XP patients have neurological abnormalities in addition to their cutaneous pathology. Genetic defects in DNA repair have now been found in all studied XP patients. Here, we shall review and present studies relating the different inherited DNA repair defects of XP to several uv-associated processes. Peripheral blood lymphocytes and skin fibroblasts obtained from patients were cultured and the uv-induced thymidine incorporation in DNA was measured by autoradiography or by scintillation spectroscopy

  15. Effects of in vitro low oxygen tension preconditioning of adipose stromal cells on their in vivo chondrogenic potential: application in cartilage tissue repair.

    Directory of Open Access Journals (Sweden)

    Sophie Portron

    Full Text Available PURPOSE: Multipotent stromal cell (MSC-based regenerative strategy has shown promise for the repair of cartilage, an avascular tissue in which cells experience hypoxia. Hypoxia is known to promote the early chondrogenic differentiation of MSC. The aim of our study was therefore to determine whether low oxygen tension could be used to enhance the regenerative potential of MSC for cartilage repair. METHODS: MSC from rabbit or human adipose stromal cells (ASC were preconditioned in vitro in control or chondrogenic (ITS and TGF-β medium and in 21 or 5% O2. Chondrogenic commitment was monitored by measuring COL2A1 and ACAN expression (real-time PCR. Preconditioned rabbit and human ASC were then incorporated into an Si-HPMC hydrogel and injected (i into rabbit articular cartilage defects for 18 weeks or (ii subcutaneously into nude mice for five weeks. The newly formed tissue was qualitatively and quantitatively evaluated by cartilage-specific immunohistological staining and scoring. The phenotype of ASC cultured in a monolayer or within Si-HPMC in control or chondrogenic medium and in 21 or 5% O2 was finally evaluated using real-time PCR. RESULTS/CONCLUSIONS: 5% O2 increased the in vitro expression of chondrogenic markers in ASC cultured in induction medium. Cells implanted within Si-HPMC hydrogel and preconditioned in chondrogenic medium formed a cartilaginous tissue, regardless of the level of oxygen. In addition, the 3D in vitro culture of ASC within Si-HPMC hydrogel was found to reinforce the pro-chondrogenic effects of the induction medium and 5% O2. These data together indicate that although 5% O2 enhances the in vitro chondrogenic differentiation of ASC, it does not enhance their in vivo chondrogenesis. These results also highlight the in vivo chondrogenic potential of ASC and their potential value in cartilage repair.

  16. Analysis of weld-cracking and improvement of the weld-repair process of superplastic forming tools

    International Nuclear Information System (INIS)

    Duchosal, A.; Deschaux-Beaume, F.; Lours, P.; Haro, S.; Fras, G.

    2013-01-01

    Highlights: ► Characterisation of the microstructure of a heat-resistant austenitic cast steel. ► Failure analysis using in situ tensile tests and isothermal fatigue tests. ► Analyses of weld cracking mechanism during shielded metal arc welding process. ► Improvement of weld-repair method by re-melting of the base material surface with GTAW process. - Abstract: Superplastic forming (SPF) dies are generally made of using heat resistant cast steels, which are very sensitive to weld cracking. In order to improve the weld-repair process of such dies to prevent weld-cracking, the microstructure and the mechanical behaviour of a typical heat-resistant cast steel was first studied, using isothermal low-cycle fatigue tests and in situ tensile tests. The welding behaviour of such steel was also investigated, using a shielded metal arc welding (SMAW) process and welding conditions similar to those employed for weld repair industrial dies. The comparison of the aspect of weld-cracking with the fracture mechanisms observed at room temperature or during isothermal low-cycle fatigue tests suggests a similar brittle failure mechanism, due to the presence of large interdendritic carbides in the cast steel. The melting of the cast steel surface using a gas tungsten arc welding (GTAW) process allowed to refine the primary carbides, and then to reduce the weld-cracking sensitivity. The refining method with GTAW before welding has been successfully tested to weld-repair a sample representative of SPF dies, and is recommended for subsequent repairs of such dies

  17. Molecular Mechanisms of Soft Tissue Regeneration and Bone Formation in Mice: Implications in Fracture Repair and Wound Healing in Humans

    National Research Council Canada - National Science Library

    Baylink, David

    2003-01-01

    The primary goal of the project funded by the U.S. Army is to identify genes which play an anabolic role in bone tissue and soft tissue function, particularly during regeneration, and to clarify the function of these genes...

  18. Wound repair and regeneration: Mechanisms, signaling, and translation

    Science.gov (United States)

    Eming, Sabine A.; Martin, Paul; Tomic-Canic, Marjana

    2015-01-01

    The cellular and molecular mechanisms underpinning tissue repair and its failure to heal are still poorly understood, and current therapies are limited. Poor wound healing after trauma, surgery, acute illness, or chronic disease conditions affects millions of people worldwide each year and is the consequence of poorly regulated elements of the healthy tissue repair response, including inflammation, angiogenesis, matrix deposition, and cell recruitment. Failure of one or several of these cellular processes is generally linked to an underlying clinical condition, such as vascular disease, diabetes, or aging, which are all frequently associated with healing pathologies. The search for clinical strategies that might improve the body’s natural repair mechanisms will need to be based on a thorough understanding of the basic biology of repair and regeneration. In this review, we highlight emerging concepts in tissue regeneration and repair, and provide some perspectives on how to translate current knowledge into viable clinical approaches for treating patients with wound-healing pathologies. PMID:25473038

  19. Tissue-engineered rhesus monkey nerve grafts for the repair of long ulnar nerve defects: similar outcomes to autologous nerve grafts

    Directory of Open Access Journals (Sweden)

    Chang-qing Jiang

    2016-01-01

    Full Text Available Acellular nerve allografts can help preserve normal nerve structure and extracellular matrix composition. These allografts have low immunogenicity and are more readily available than autologous nerves for the repair of long-segment peripheral nerve defects. In this study, we repaired a 40-mm ulnar nerve defect in rhesus monkeys with tissue-engineered peripheral nerve, and compared the outcome with that of autograft. The graft was prepared using a chemical extract from adult rhesus monkeys and seeded with allogeneic Schwann cells. Pathomorphology, electromyogram and immunohistochemistry findings revealed the absence of palmar erosion or ulcers, and that the morphology and elasticity of the hypothenar eminence were normal 5 months postoperatively. There were no significant differences in the mean peak compound muscle action potential, the mean nerve conduction velocity, or the number of neurofilaments between the experimental and control groups. However, outcome was significantly better in the experimental group than in the blank group. These findings suggest that chemically extracted allogeneic nerve seeded with autologous Schwann cells can repair 40-mm ulnar nerve defects in the rhesus monkey. The outcomes are similar to those obtained with autologous nerve graft.

  20. Tissue-engineered rhesus monkey nerve gratfs for the repair of long ulnar nerve defects:similar outcomes to autologous nerve gratfs

    Institute of Scientific and Technical Information of China (English)

    Chang-qing Jiang; Jun Hu; Jian-ping Xiang; Jia-kai Zhu; Xiao-lin Liu; Peng Luo

    2016-01-01

    Acellular nerve allogratfs can help preserve normal nerve structure and extracellular matrix composition. These allogratfs have low immu-nogenicity and are more readily available than autologous nerves for the repair of long-segment peripheral nerve defects. In this study, we repaired a 40-mm ulnar nerve defect in rhesus monkeys with tissue-engineered peripheral nerve, and compared the outcome with that of autogratf. The gratf was prepared using a chemical extract from adult rhesus monkeys and seeded with allogeneic Schwann cells. Pathomo-rphology, electromyogram and immunohistochemistry ifndings revealed the absence of palmar erosion or ulcers, and that the morphology and elasticity of the hypothenar eminence were normal 5 months postoperatively. There were no signiifcant differences in the mean peak compound muscle action potential, the mean nerve conduction velocity, or the number of neuroiflaments between the experimental and control groups. However, outcome was signiifcantly better in the experimental group than in the blank group. These ifndings suggest that chemically extracted allogeneic nerve seeded with autologous Schwann cells can repair 40-mm ulnar nerve defects in the rhesus monkey. The outcomes are similar to those obtained with autologous nerve gratf.

  1. A portrait of tissue phosphoprotein stability in the clinical tissue procurement process.

    Science.gov (United States)

    Espina, Virginia; Edmiston, Kirsten H; Heiby, Michael; Pierobon, Mariaelena; Sciro, Manuela; Merritt, Barbara; Banks, Stacey; Deng, Jianghong; VanMeter, Amy J; Geho, David H; Pastore, Lucia; Sennesh, Joel; Petricoin, Emanuel F; Liotta, Lance A

    2008-10-01

    Little is known about the preanalytical fluctuations of phosphoproteins during tissue procurement for molecular profiling. This information is crucial to establish guidelines for the reliable measurement of these analytes. To develop phosphoprotein profiles of tissue subjected to the trauma of excision, we measured the fidelity of 53 signal pathway phosphoproteins over time in tissue specimens procured in a community clinical practice. This information provides strategies for potential surrogate markers of stability and the design of phosphoprotein preservative/fixation solutions. Eleven different specimen collection time course experiments revealed augmentation (+/-20% from the time 0 sample) of signal pathway phosphoprotein levels as well as decreases over time independent of tissue type, post-translational modification, and protein subcellular location (tissues included breast, colon, lung, ovary, and uterus (endometrium/myometrium) and metastatic melanoma). Comparison across tissue specimens showed an >20% decrease of protein kinase B (AKT) Ser-473 (p 20% increases within 90-min postprocurement. Endothelial nitric-oxide synthase Ser-1177 did not change over the time period evaluated with breast or leiomyoma tissue. Treatment with phosphatase or kinase inhibitors alone revealed that tissue kinase pathways are active ex vivo. Combinations of kinase and phosphatase inhibitors appeared to stabilize proteins that exhibited increases in the presence of phosphatase inhibitors alone (ATF-2 Thr-71, SAPK/JNK Thr-183/Tyr-185, STAT1 Tyr-701, JAK1 Tyr-1022/1023, and PAK1/PAK2 Ser-199/204/192/197). This time course study 1) establishes the dynamic nature of specific phosphoproteins in excised tissue, 2) demonstrates augmented phosphorylation in the presence of phosphatase inhibitors, 3) shows that kinase inhibitors block the upsurge in phosphorylation of phosphoproteins, 4) provides a rational strategy for room temperature preservation of proteins, and 5) constitutes a

  2. Development and validation of predictive simulation model of multi-layer repair welding process by temper bead technique

    International Nuclear Information System (INIS)

    Okano, Shigetaka; Miyasaka, Fumikazu; Mochizuki, Masahito; Tanaka, Manabu

    2015-01-01

    Stress corrosion cracking (SCC) has recently been observed in the nickel base alloy weld metal of dissimilar pipe joint used in pressurized water reactor (PWR) . Temper bead technique has been developed as one of repair procedures against SCC applicable in case that post weld heat treatment (PWHT) is difficult to carry out. In this regard, however it is essential to pass the property and performance qualification test to confirm the effect of tempering on the mechanical properties at repair welds before temper bead technique is actually used in practice. Thus the appropriate welding procedure conditions in temper bead technique are determined on the basis of the property and performance qualification testing. It is necessary for certifying the structural soundness and reliability at repair welds but takes a lot of work and time in the present circumstances. Therefore it is desirable to establish the reasonable alternatives for qualifying the property and performance at repair welds. In this study, mathematical modeling and numerical simulation procedures were developed for predicting weld bead configuration and temperature distribution during multi-layer repair welding process by temper bead technique. In the developed simulation technique, characteristics of heat source in temper bead welding are calculated from weld heat input conditions through the arc plasma simulation and then weld bead configuration and temperature distribution during temper bead welding are calculated from characteristics of heat source obtained through the coupling analysis between bead surface shape and thermal conduction. The simulation results were compared with the experimental results under the same welding heat input conditions. As the results, the bead surface shape and temperature distribution, such as A cl lines, were in good agreement between simulation and experimental results. It was concluded that the developed simulation technique has the potential to become useful for

  3. Changing perspective on tissue processing - comparison of microwave histoprocessing method with the conventional method

    Directory of Open Access Journals (Sweden)

    G Shrestha

    2015-09-01

    Full Text Available Background: Histopathological examination of tissues requires sliver of formalin fixed tissue that has been chemically processed and then stained with Haematoxylin and Eosin. The time honored conventional method of tissue processing, which requires 12 to 13 hours for completion, is employed at majority of laboratories but is now seeing the

  4. [Ru(bipy)3]2+ nanoparticle-incorporate dental light cure resin to promote photobiomodulation therapy for enhanced vital pulp tissue repair

    Science.gov (United States)

    Mosca, Rodrigo C.; Young, Nicholas; Zeituni, Carlos A.; Arany, Praveen R.

    2018-02-01

    The use of nanoparticle on dental light cure resin is not new, currently several compounds (nanoadditives) are used to promote better communication between the restorative material and biological tissues. The interest for this application is growing up to enhance mechanical proprieties to dental tissue cells regeneration. Bioactive nanoparticles and complex compounds with multiple functions are the major target for optimizing the restorative materials. In this work, we incorporate [Ru(bipy)3]2+ nanoparticles, that absorbs energy at 450 nm (blue-light) and emits strongly at 620 nm (red-light), in PLGA Microspheres and insert it in Dental Light Cure Resin to promote the Photobiomodulation Therapy (PBM) effects to accelerate dental pulp repair by in vitro using cytotoxicity and proliferation assay.

  5. Axolotl cells and tissues enhances cutaneous wound healing in mice

    OpenAIRE

    DEMIRCAN, Turan; KESKIN, Ilknur; GUNAL, Yalcin; ILHAN, Ayse Elif; KOLBASI, Bircan; OZTURK, Gurkan

    2017-01-01

    Adult mammalian skin wound repair is defective due to loss of the regulation in balancing the complete epithelial regeneration and excessive connective tissue production, and this repair process commonly results in scar tissue formation. However, unlike mammals, adult salamanders repair the wounds by regeneration compared to scarring. To elucidate the healing capability of a salamander, Axolotl, in a different species, here we addressed this question by treating the wounds in mice with Axolot...

  6. Optimal molecular profiling of tissue and tissue components: defining the best processing and microdissection methods for biomedical applications.

    Science.gov (United States)

    Rodriguez-Canales, Jaime; Hanson, Jeffrey C; Hipp, Jason D; Balis, Ulysses J; Tangrea, Michael A; Emmert-Buck, Michael R; Bova, G Steven

    2013-01-01

    Isolation of well-preserved pure cell populations is a prerequisite for sound studies of the molecular basis of any tissue-based biological phenomenon. This updated chapter reviews current methods for obtaining anatomically specific signals from molecules isolated from tissues, a basic requirement for productive linking of phenotype and genotype. The quality of samples isolated from tissue and used for molecular analysis is often glossed over or omitted from publications, making interpretation and replication of data difficult or impossible. Fortunately, recently developed techniques allow life scientists to better document and control the quality of samples used for a given assay, creating a foundation for improvement in this area. Tissue processing for molecular studies usually involves some or all of the following steps: tissue collection, gross dissection/identification, fixation, processing/embedding, storage/archiving, sectioning, staining, microdissection/annotation, and pure analyte labeling/identification and quantification. We provide a detailed comparison of some current tissue microdissection technologies and provide detailed example protocols for tissue component handling upstream and downstream from microdissection. We also discuss some of the physical and chemical issues related to optimal tissue processing and include methods specific to cytology specimens. We encourage each laboratory to use these as a starting point for optimization of their overall process of moving from collected tissue to high-quality, appropriately anatomically tagged scientific results. Improvement in this area will significantly increase life science quality and productivity. The chapter is divided into introduction, materials, protocols, and notes subheadings. Because many protocols are covered in each of these sections, information relating to a single protocol is not contiguous. To get the greatest benefit from this chapter, readers are advised to read through the entire

  7. Improvement in the repair of defects in maxillofacial soft tissue in irradiated minipigs by a mixture of adipose-derived stem cells and platelet-rich fibrin.

    Science.gov (United States)

    Chen, Yuanzheng; Niu, Zhanguo; Xue, Yan; Yuan, Fukang; Fu, Yanjie; Bai, Nan

    2014-10-01

    To find out if adipose-derived stem cells (ASC) and platelet-rich fibrin (PRF), alone or combined, had any effect on the repair of maxillofacial soft tissue defects in irradiated minipigs, ASC were isolated, characterised, and expanded. Twenty female minipigs, the right parotid glands of which had been irradiated, were randomly divided into 4 groups of 5 each: those in the first group were injected with both ASC and PRF (combined group), the second group was injected with ASC alone (ASC group), the third group with PRF alone (PRF group), and the fourth group with phosphate buffer saline (PBS) (control group). Six months after the last injection, the size and depth of each defect were assessed, and subcutaneous tissues were harvested, stained with haematoxylin and eosin, and examined immunohistologically and for apoptosis. Expanded cells were successfully isolated and identified. Six months after injection the defects in the 3 treated groups were significantly smaller (p<0.001) and shallower (p<0.001) than those in the control group. Those in the combined group were the smallest and shallowest. Haematoxylin and eosin showed that the 3 treated groups contained more subcutaneous adipose tissue than the control group, and also had significantly greater vascular density (p<0.001) and fewer apoptotic cells (p<0.001). Both ASC and PRF facilitate the repair of defects in maxillofacial soft tissue in irradiated minipigs, and their combined use is more effective than their use as single agents. Copyright © 2014 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  8. Evaluation of five DNA extraction methods for purification of DNA from atherosclerotic tissue and estimation of prevalence of Chlamydia pneumoniae in tissue from a Danish population undergoing vascular repair

    Directory of Open Access Journals (Sweden)

    Lindholt Jes S

    2003-09-01

    Full Text Available Abstract Background To date PCR detection of Chlamydia pneumoniae DNA in atherosclerotic lesions from Danish patients has been unsuccessful. To establish whether non-detection was caused by a suboptimal DNA extraction method, we tested five different DNA extraction methods for purification of DNA from atherosclerotic tissue. Results The five different DNA extraction methods were tested on homogenate of atherosclerotic tissue spiked with C. pneumoniae DNA or EB, on pure C. pneumoniae DNA samples and on whole C. pneumoniae EB. Recovery of DNA was measured with a C. pneumoniae-specific quantitative real-time PCR. A DNA extraction method based on DNA-binding to spin columns with a silica-gel membrane (DNeasy Tissue kit showed the highest recovery rate for the tissue samples and pure DNA samples. However, an automated extraction method based on magnetic glass particles (MagNA Pure performed best on intact EB and atherosclerotic tissue spiked with EB. The DNeasy Tissue kit and MagNA Pure methods and the highly sensitive real-time PCR were subsequently used on 78 atherosclerotic tissue samples from Danish patients undergoing vascular repair. None of the samples were positive for C. pneumoniae DNA. The atherosclerotic samples were tested for inhibition by spiking with two different, known amounts of C. pneumoniae DNA and no samples showed inhibition. Conclusion As a highly sensitive PCR method and an optimised DNA extraction method were used, non-detection in atherosclerotic tissue from the Danish population was probably not caused by use of inappropriate methods. However, more samples may need to be analysed per patient to be completely certain on this. Possible methodological and epidemiological reasons for non-detection of C. pneumoniae DNA in atherosclerotic tissue from the Danish population are discussed. Further testing of DNA extraction methods is needed as this study has shown considerable intra- and inter-method variation in DNA recovery.

  9. Differentiating normal hyaline cartilage from post-surgical repair tissue using fast gradient echo imaging in delayed gadolinium-enhanced MRI (dGEMRIC) at 3 Tesla

    Energy Technology Data Exchange (ETDEWEB)

    Trattnig, Siegfried; Pinker, Katja; Welsch, Goetz H. [Medical University of Vienna, MR Center-High field MR, Department of Radiology, Vienna (Austria); Mamisch, Tallal C. [Inselspital Bern, Orthopedic Surgery Department, Bern (Switzerland); Domayer, Stephan [Medical University of Vienna, MR Center-High field MR, Department of Radiology, Vienna (Austria); Medical University of Vienna, Department of Orthopaedics, Vienna (Austria); Szomolanyi, Pavol [Medical University of Vienna, MR Center-High field MR, Department of Radiology, Vienna (Austria); Slovak Academy of Sciences, Department of Imaging Methods, Institute of Measurement Science, Bratislava (Slovakia); Marlovits, Stefan; Kutscha-Lissberg, Florian [Medical University of Vienna, Department of Traumatology, Center for Joints and Cartilage, Vienna (Austria)

    2008-06-15

    The purpose was to evaluate the relative glycosaminoglycan (GAG) content of repair tissue in patients after microfracturing (MFX) and matrix-associated autologous chondrocyte transplantation (MACT) of the knee joint with a dGEMRIC technique based on a newly developed short 3D-GRE sequence with two flip angle excitation pulses. Twenty patients treated with MFX or MACT (ten in each group) were enrolled. For comparability, patients from each group were matched by age (MFX: 37.1 {+-} 16.3 years; MACT: 37.4 {+-} 8.2 years) and postoperative interval (MFX: 33.0 {+-} 17.3 months; MACT: 32.0 {+-} 17.2 months). The {delta} relaxation rate ({delta}R1) for repair tissue and normal hyaline cartilage and the relative {delta}R1 were calculated, and mean values were compared between both groups using an analysis of variance. The mean {delta}R1 for MFX was 1.07 {+-} 0.34 versus 0.32 {+-} 0.20 at the intact control site, and for MACT, 1.90 {+-} 0.49 compared to 0.87 {+-} 0.44, which resulted in a relative {delta}R1 of 3.39 for MFX and 2.18 for MACT. The difference between the cartilage repair groups was statistically significant. The new dGEMRIC technique based on dual flip angle excitation pulses showed higher GAG content in patients after MACT compared to MFX at the same postoperative interval and allowed reducing the data acquisition time to 4 min. (orig.)

  10. Composite scaffolds for osteochondral repair obtained by combination of additive manufacturing, leaching processes and hMSC-CM functionalization.

    Science.gov (United States)

    Díaz Lantada, Andrés; Alarcón Iniesta, Hernán; García-Ruíz, Josefa Predestinación

    2016-02-01

    Articular repair is a relevant and challenging area for the emerging fields of tissue engineering and biofabrication. The need of significant gradients of properties, for the promotion of osteochondral repair, has led to the development of several families of composite biomaterials and scaffolds, using different effective approaches, although a perfect solution has not yet been found. In this study we present the design, modeling, rapid manufacturing and in vitro testing of a composite scaffold aimed at osteochondral repair. The presented composite scaffold stands out for having a functional gradient of density and stiffness in the bony phase, obtained in titanium by means of computer-aided design combined with additive manufacture using selective laser sintering. The chondral phase is obtained by sugar leaching, using a PDMS matrix and sugar as porogen, and is joined to the bony phase during the polymerization of PDMS, therefore avoiding the use of supporting adhesives or additional intermediate layers. The mechanical performance of the construct is biomimetic and the stiffness values of the bony and chondral phases can be tuned to the desired applications, by means of controlled modifications of different parameters. A human mesenchymal stem cell (h-MSC) conditioned medium (CM) is used for improving scaffold response. Cell culture results provide relevant information regarding the viability of the composite scaffolds used. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Extracellular matrix and tissue engineering applications

    NARCIS (Netherlands)

    Fernandes, H.A.M.; Moroni, Lorenzo; van Blitterswijk, Clemens; de Boer, Jan

    2009-01-01

    The extracellular matrix is a key component during regeneration and maintenance of tissues and organs, and it therefore plays a critical role in successful tissue engineering as well. Tissue engineers should recognise that engineering technology can be deduced from natural repair processes. Due to

  12. Relationship of DNA repair processes to mutagenesis and carcinogenesis in mammalian cells. Progress report, November 1, 1980-October 31, 1981

    International Nuclear Information System (INIS)

    Evans, H.H.

    1981-10-01

    The isolation of several radiation-sensitive BHK strains following a host-cell viral suicide enrichment procedure has been reported in which mutagenized cells were infected with heavily irradiated Herpes virus (HSV). Six surviving colonies were isolated from 38,000 infected cells. The survivors were not transformed by HSV, as indicated by a lack of reaction with fluorescent HSV antibody. At least two of the strains were shown to be sensitive to the lethal effects of ionizing radiation and methylmethane sulfonate, but not to ethylmethane sulfonate (EMS) or to uv radiation. These two strains showed a small decrease in the ability to repair sublethal damage following a split dose of ionizing radiation. The two strains differed from wild-type BHK cells in EMS-induced mutability; strain VI showed a higher mutation frequency and V2 a lower mutation frequency than did BHK cells following treatment with this agent. When either ionizing radiation or uv radiation was used as the mutagenic agent, however, the comparative mutability patterns were altered: the mutation frequency of both strains was somewhat less than the wild type following ionizing radiation, whereas following uv radiation, strain V1 showed a markedly lower mutation frequency than the wild type. It is possible that the strain V1 is deficient in the repair of an EMS-induced mutagenic lesion, while strain V2 is either efficient in such repair or deficient in an error-prone repair process

  13. Biomechanics and mechanobiology in functional tissue engineering

    Science.gov (United States)

    Guilak, Farshid; Butler, David L.; Goldstein, Steven A.; Baaijens, Frank P.T.

    2014-01-01

    The field of tissue engineering continues to expand and mature, and several products are now in clinical use, with numerous other preclinical and clinical studies underway. However, specific challenges still remain in the repair or regeneration of tissues that serve a predominantly biomechanical function. Furthermore, it is now clear that mechanobiological interactions between cells and scaffolds can critically influence cell behavior, even in tissues and organs that do not serve an overt biomechanical role. Over the past decade, the field of “functional tissue engineering” has grown as a subfield of tissue engineering to address the challenges and questions on the role of biomechanics and mechanobiology in tissue engineering. Originally posed as a set of principles and guidelines for engineering of load-bearing tissues, functional tissue engineering has grown to encompass several related areas that have proven to have important implications for tissue repair and regeneration. These topics include measurement and modeling of the in vivo biomechanical environment; quantitative analysis of the mechanical properties of native tissues, scaffolds, and repair tissues; development of rationale criteria for the design and assessment of engineered tissues; investigation of the effects biomechanical factors on native and repair tissues, in vivo and in vitro; and development and application of computational models of tissue growth and remodeling. Here we further expand this paradigm and provide examples of the numerous advances in the field over the past decade. Consideration of these principles in the design process will hopefully improve the safety, efficacy, and overall success of engineered tissue replacements. PMID:24818797

  14. Energetics of cellular repair processes in a respiratory-deficient mutant of yeast

    International Nuclear Information System (INIS)

    Jain, V.K.; Gupta, I.; Lata, K.

    1982-01-01

    Repair of potentially lethal damage induced by cytoxic agents like UV irradiation (254 nm), psorelen-plus-UVA (365 mn), and methyl methanesulfonate has been studied in the presence of a glucose analog, 2-deoxy-D-glucose, in yeast cells. Simultaneously, effects of 2-deoxy-D-glucose were also investigated on parameters of energy metabolism like glucose utilization, rate of ATP production, and ATP content of cells. The following results were obtained. (i) 2-Deoxy-D-glucose is able to inhibit repair of potentially lethal damage induced by all the cytotoxic agents tested. The 2-deoxy-D-glucose-induced inhibition of repair depends upon the type of lesion and the pattern of cellular energy metabolism, the inhibition being greater in respiratory-deficient mutants than in the wild type. (ii) A continuous energy flow is necessary for repair of potentially lethal damage in yeast cells. Energy may be supplied by the glycolytic and/or the respiratory pathway; respiratory metabolism is not essential for this purpose. (iii) The magnitude of repair correlates with the rate of ATP production in a sigmoid manner

  15. Growth factor and proteinase profile of Vivostat® platelet-rich fibrin linked to tissue repair

    DEFF Research Database (Denmark)

    Ågren, Sven Per Magnus; Rasmussen, Karina; Pakkenberg, Bente

    2014-01-01

    . Leucocyte, erythrocyte and platelet counts in whole blood and fibrin-I were determined by automated haematology analyser. Platelet concentration in PRF was quantified manually by stereologic analysis of Giemsa-stained tissue sections, and the total content of five growth factors and MMP-9 by enzyme......·001]. MMP-9 was reduced 139-fold (P tissue regenerative applications....

  16. Repairing organs: lessons from intestine and liver.

    Science.gov (United States)

    Gehart, Helmuth; Clevers, Hans

    2015-06-01

    The concept of organ regeneration has fascinated humanity from ancient mythology to modern science fiction. Recent advances offer the potential to soon bring such technology within the grasp of clinical medicine. Rapidly expanding insights into the intrinsic repair processes of the intestine and liver have uncovered significant plasticity in epithelial tissues. Harnessing this knowledge, researchers have recently created culture systems that enable the expansion of stem cells into transplantable tissue in vitro. Here we discuss how the growing tool set of stem cell biology can bring organ repair from fictitious narrative to medical practice. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Influence of oxidized purine processing on strand directionality of mismatch repair.

    Science.gov (United States)

    Repmann, Simone; Olivera-Harris, Maite; Jiricny, Josef

    2015-04-17

    Replicative DNA polymerases are high fidelity enzymes that misincorporate nucleotides into nascent DNA with a frequency lower than [1/10(5)], and this precision is improved to about [1/10(7)] by their proofreading activity. Because this fidelity is insufficient to replicate most genomes without error, nature evolved postreplicative mismatch repair (MMR), which improves the fidelity of DNA replication by up to 3 orders of magnitude through correcting biosynthetic errors that escaped proofreading. MMR must be able to recognize non-Watson-Crick base pairs and excise the misincorporated nucleotides from the nascent DNA strand, which carries by definition the erroneous genetic information. In eukaryotes, MMR is believed to be directed to the nascent strand by preexisting discontinuities such as gaps between Okazaki fragments in the lagging strand or breaks in the leading strand generated by the mismatch-activated endonuclease of the MutL homologs PMS1 in yeast and PMS2 in vertebrates. We recently demonstrated that the eukaryotic MMR machinery can make use also of strand breaks arising during excision of uracils or ribonucleotides from DNA. We now show that intermediates of MutY homolog-dependent excision of adenines mispaired with 8-oxoguanine (G(O)) also act as MMR initiation sites in extracts of human cells or Xenopus laevis eggs. Unexpectedly, G(O)/C pairs were not processed in these extracts and failed to affect MMR directionality, but extracts supplemented with exogenous 8-oxoguanine DNA glycosylase (OGG1) did so. Because OGG1-mediated excision of G(O) might misdirect MMR to the template strand, our findings suggest that OGG1 activity might be inhibited during MMR. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  18. High-dose mode of mortality in Tribolium: A model system for study of radiation injury and repair in non-proliferative tissues

    International Nuclear Information System (INIS)

    Cheng, Chihing Christina.

    1989-01-01

    With appropriate doses of ionizing radiation, both the acute, or lethal-midlethal, dose-independent pattern of mortality, and the hyperacute, dose-dependent pattern, were demonstrated within a single insect genus (Tribolium). This demonstration provides resolution of apparently contradictory reports of insect radiation responses in terms of doses required to cause lethality and those based on survival time as a function of dose. A dose-dependent mortality pattern was elicited in adult Tribolium receiving high doses, viz., 300 Gy or greater; its time course was complete in 10 days, before the dose-independent pattern of mortality began. Visual observations of heavily-irradiated Tribolium suggested neural and/or neuromuscular damage, as had been previously proposed by others for lethally-irradiated wasps, flies, and mosquitoes. Results of experiments using fractionated high doses supported the suggestion that the hyperacute or high-dose mode of death is the result of damage to nonproliferative tissues. Relative resistance of a strain to the hyperacute or high-dose mode of death was not correlated with resistance to the midlethal mode, which is believed to be the result of damage to the proliferative cells of the midgut. Using the high-dose mode of death as a model of radiation damage to nonproliferative tissues, the effects of age, and of a moderate priming dose were assessed. Beetles showed age-related increase in sensitivity to the high-dose mode of death, suggesting a decline in capacity to repair radiation damage to postmitotic tissue. This correlated with a decrease (50%) in the amount of repair reflected in the sparing effect of dose-fractionation (SDF) between the age of 1 to 3 months. The age related increase in radiosensitivity was reduced by a moderate priming dose (40 or 65 Gy) given at a young age

  19. Quantitatively characterizing microstructural variations of skin tissues during ultraviolet radiation damaging process based on Mueller matrix polarimetry

    Science.gov (United States)

    Sheng, Wei; He, Honghui; Dong, Yang; Ma, Hui

    2018-02-01

    As one of the most fundamental features of light, polarization can be used to develop imaging techniques which can provide insight into the optical and structural properties of tissues. Especially, the Mueller matrix polarimetry is suitable to detect the changes in collagen and elastic fibres, which are the main compositions of skin tissue. Here we demonstrate a novel quantitative, non-contact and in situ technique to monitor the microstructural variations of skin tissue during ultraviolet radiation (UVR) induced photoaging based on Mueller matrix polarimetry. Specifically, we measure the twodimensional (2D) backscattering Mueller matrices of nude mouse skin samples, then calculate and analyze the Mueller matrix derived parameters during the skin photoaging and self-repairing processes. To induce three-day skin photoaging, the back skin of each mouse is irradiated with UVR (0.05J/cm2) for five minutes per day. After UVR, the microstructures of the nude mouse skin are damaged. During the process of UV damage, we measure the backscattering Mueller matrices of the mouse skin samples and examine the relationship between the Mueller matrix parameters and the microstructural variations of skin tissue quantitatively. The comparisons between the UVR damaged groups with and without sunscreens show that the Mueller matrix derived parameters are potential indicators for fibrous microstructure variation in skin tissue. The pathological examinations and Monte Carlo simulations confirm the relationship between the values of Mueller matrix parameters and the changes of fibrous structures. Combined with smart phones or wearable devices, this technique may have a good application prospect in the fields of cosmetics and dermatological health.

  20. Multi-level repair decision-making process for composite structures

    NARCIS (Netherlands)

    Dhanisetty, V.S.V.; Verhagen, W.J.C.; Curran, R.

    2016-01-01

    This paper details the development of a decision-making model that evaluates the multiple repair levels that a composite structure can undergo, each with its inherent achievable survivability and consequence to operations in terms of availability, costs, and scheduling. The goal of this model is to

  1. Implementation of a new rapid tissue processing method--advantages and challenges

    DEFF Research Database (Denmark)

    Munkholm, Julie; Talman, Maj-Lis; Hasselager, Thomas

    2008-01-01

    Conventional tissue processing of histologic specimens has been carried out in the same manner for many years. It is a time-consuming process involving batch production, resulting in a 1-day delay of the diagnosis. Microwave-assisted tissue processing enables a continuous high flow of histologic...... specimens through the processor with a processing time of as low as 1h. In this article, we present the effects of the automated microwave-assisted tissue processor on the histomorphologic quality and the turnaround time (TAT) for histopathology reports. We present a blind comparative study regarding...... the histomorphologic quality of microwave-processed and conventionally processed tissue samples. A total of 333 specimens were included. The microwave-assisted processing method showed a histomorphologic quality comparable to the conventional method for a number of tissue types, including skin and specimens from...

  2. Towards defect free EUVL reticles: carbon and particle removal by single dry cleaning process and pattern repair by HIM

    Science.gov (United States)

    Koster, N. B.; Molkenboer, F. T.; van Veldhoven, E.; Oostrom, S.

    2011-04-01

    We report on our findings on EUVL reticle contamination removal, inspection and repair. We show that carbon contamination can be removed without damage to the reticle by our plasma process. Also organic particles, simulated by PSL spheres, can be removed from both the surface of the absorber as well as from the bottom of the trenches. The particles shrink in size during the plasma treatment until they are vanished. The determination of the necessary cleaning time for PSL spheres was conducted on Ru coated samples and the final experiment was performed on our dummy reticle. Finally we show that the Helium Ion Microscope in combination with a Gas Injection System is capable of depositing additional lines and squares on the reticle with sufficient resolution for pattern repair.

  3. Non-invasive characterization of polyurethane-based tissue constructs in a rat abdominal repair model using high frequency ultrasound elasticity imaging.

    Science.gov (United States)

    Yu, Jiao; Takanari, Keisuke; Hong, Yi; Lee, Kee-Won; Amoroso, Nicholas J; Wang, Yadong; Wagner, William R; Kim, Kang

    2013-04-01

    The evaluation of candidate materials and designs for soft tissue scaffolds would benefit from the ability to monitor the mechanical remodeling of the implant site without the need for periodic animal sacrifice and explant analysis. Toward this end, the ability of non-invasive ultrasound elasticity imaging (UEI) to assess temporal mechanical property changes in three different types of porous, biodegradable polyurethane scaffolds was evaluated in a rat abdominal wall repair model. The polymers utilized were salt-leached scaffolds of poly(carbonate urethane) urea, poly(ester urethane) urea and poly(ether ester urethane) urea at 85% porosity. A total of 60 scaffolds (20 each type) were implanted in a full thickness muscle wall replacement in the abdomens of 30 rats. The constructs were ultrasonically scanned every 2 weeks and harvested at weeks 4, 8 and 12 for compression testing or histological analysis. UEI demonstrated different temporal stiffness trends among the different scaffold types, while the stiffness of the surrounding native tissue remained unchanged. The changes in average normalized strains developed in the constructs from UEI compared well with the changes of mean compliance from compression tests and histology. The average normalized strains and the compliance for the same sample exhibited a strong linear relationship. The ability of UEI to identify herniation and to characterize the distribution of local tissue in-growth with high resolution was also investigated. In summary, the reported data indicate that UEI may allow tissue engineers to sequentially evaluate the progress of tissue construct mechanical behavior in vivo and in some cases may reduce the need for interim time point animal sacrifice. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Effect of negative pressure therapy on repair of soft tissues of the lower extremities in patients with neuropathic and neuroischaemic forms of diabetic foot syndrome

    Directory of Open Access Journals (Sweden)

    Ekaterina Leonidovna Zaytseva

    2014-06-01

    Full Text Available Aim. To evaluate the efficiency of topical negative pressure wound therapy (NPWT compared with standard therapy for the regeneration of the soft tissues of the lower extremities in patients with diabetic foot syndrome. Materials and Methods. The effects of negative pressure therapy on the clinical (size, tissue oxygenation, histological (light microscopy and immunohistochemical (CD68, MMP-9, TIMP-1 aspects of repair of the soft tissue of the lower extremities in patients with diabetes mellitus were compared with those of standard treatment. Thirty-one patients with diabetic foot ulcers were included in the study from the moment of debridement until the plastic closure of the wound. During the perioperative period, 13 patients received NPWT (-90 to -120 mmHg and 18 patients received standard therapy. Results. A reduction of the wound area (26.6%?17.2% and the depth of the defects (40.5%?25.6% were achieved with negative pressure therapy compared with baseline data. In the control group, the corresponding values were 25.3%?19.4% and 21.8%?21.6%, respectively. The results of transcutaneous oximetry showed a greater increase in the level of local hemodynamics in the study group (p

  5. Development and regeneration of the zebrafish maxillary barbel: a novel study system for vertebrate tissue growth and repair.

    Science.gov (United States)

    LeClair, Elizabeth E; Topczewski, Jacek

    2010-01-15

    Barbels are integumentary sense organs found in fishes, reptiles and amphibians. The zebrafish, Danio rerio, develops paired nasal and maxillary barbels approximately one month post fertilization. Small in diameter and optically clear, these adult appendages offer a window on the development, maintenance and function of multiple cell types including skin cells, neural-crest derived pigment cells, circulatory vessels, taste buds and sensory nerves. Importantly, barbels in other otophysan fishes (e.g., catfish) are known to regenerate; however, this capacity has not been tested in zebrafish. We describe the development of the maxillary barbel in a staged series of wild type and transgenic zebrafish using light microscopy, histology and immunohistochemistry. By imaging transgenic zebrafish containing fluorescently labeled endothelial cells (Tg(fli1a:EGFP)), we demonstrate that the barbel contains a long ( approximately 2-3 mm) closed-end vessel that we interpret as a large lymphatic. The identity of this vessel was further supported by live imaging of the barbel circulation, extending recent descriptions of the lymphatic system in zebrafish. The maxillary barbel can be induced to regenerate by proximal amputation. After more than 750 experimental surgeries in which approximately 85% of the barbel's length was removed, we find that wound healing is complete within hours, followed by blastema formation ( approximately 3 days), epithelial redifferentiation (3-5 days) and appendage elongation. Maximum regrowth occurs within 2 weeks of injury. Although superficially normal, the regenerates are shorter and thicker than the contralateral controls, have abnormally organized mesenchymal cells and extracellular matrix, and contain prominent connective tissue "stumps" at the plane of section--a mode of regeneration more typical of mammalian scarring than other zebrafish appendages. Finally, we show that the maxillary barbel can regenerate after repeated injury and also in

  6. Development and regeneration of the zebrafish maxillary barbel: a novel study system for vertebrate tissue growth and repair.

    Directory of Open Access Journals (Sweden)

    Elizabeth E LeClair

    2010-01-01

    Full Text Available Barbels are integumentary sense organs found in fishes, reptiles and amphibians. The zebrafish, Danio rerio, develops paired nasal and maxillary barbels approximately one month post fertilization. Small in diameter and optically clear, these adult appendages offer a window on the development, maintenance and function of multiple cell types including skin cells, neural-crest derived pigment cells, circulatory vessels, taste buds and sensory nerves. Importantly, barbels in other otophysan fishes (e.g., catfish are known to regenerate; however, this capacity has not been tested in zebrafish.We describe the development of the maxillary barbel in a staged series of wild type and transgenic zebrafish using light microscopy, histology and immunohistochemistry. By imaging transgenic zebrafish containing fluorescently labeled endothelial cells (Tg(fli1a:EGFP, we demonstrate that the barbel contains a long ( approximately 2-3 mm closed-end vessel that we interpret as a large lymphatic. The identity of this vessel was further supported by live imaging of the barbel circulation, extending recent descriptions of the lymphatic system in zebrafish. The maxillary barbel can be induced to regenerate by proximal amputation. After more than 750 experimental surgeries in which approximately 85% of the barbel's length was removed, we find that wound healing is complete within hours, followed by blastema formation ( approximately 3 days, epithelial redifferentiation (3-5 days and appendage elongation. Maximum regrowth occurs within 2 weeks of injury. Although superficially normal, the regenerates are shorter and thicker than the contralateral controls, have abnormally organized mesenchymal cells and extracellular matrix, and contain prominent connective tissue "stumps" at the plane of section--a mode of regeneration more typical of mammalian scarring than other zebrafish appendages. Finally, we show that the maxillary barbel can regenerate after repeated injury and

  7. Nuclear survivin and its relationship to DNA damage repair genes in non-small cell lung cancer investigated using tissue array.

    Directory of Open Access Journals (Sweden)

    Songliu Hu

    Full Text Available To investigate the predictive role and association of nuclear survivin and the DNA double-strand breaks repair genes in non-small cell lung cancer (NSCLC: DNA-dependent protein kinase catalytic subunit (DNA-PKcs, Ku heterodimeric regulatory complex 70-KD subunit (Ku70 and ataxia-telangiectasia mutated (ATM.The protein expression of nuclear survivin, DNA-PKcs, Ku70 and ATM were investigated using immunohistochemistry in tumors from 256 patients with surgically resected NSCLC. Furthermore, we analyzed the correlation between the expression of nuclear survivin, DNA-PKcs, Ku70 and ATM. Univariate and multivariate analyses were performed to determine the prognostic factors that inuenced the overall survival and disease-free survival of NSCLC.The expression of nuclear survivin, DNA-PKcs, Ku70 and ATM was significantly higher in tumor tissues than in normal tissues. By dichotomizing the specimens as expressing low or high levels of nuclear survivin, nuclear survivin correlated significantly with the pathologic stage (P = 0.009 and lymph node status (P = 0.004. The nuclear survivin levels were an independent prognostic factor for both the overall survival and the disease-free survival in univariate and multivariate analyses. Patients with low Ku70 and DNA-PKcs expression had a greater benefit from radiotherapy than patients with high expression of Ku70 (P = 0.012 and DNA-PKcs (P = 0.02. Nuclear survivin expression positively correlated with DNA-PKcs (P<0.001 and Ku70 expression (P<0.001.Nuclear survivin may be a prognostic factor for overall survival in patients with resected stage I-IIIA NSCLC. DNA-PKcs and Ku70 could predict the effect of radiotherapy in patients with NSCLC. Nuclear survivin may also stimulates DNA double-strand breaks repair by its interaction with DNA-PKcs and Ku70.

  8. Six weeks of continuous joint distraction appears sufficient for clinical benefit and cartilaginous tissue repair in the treatment of knee osteoarthritis.

    Science.gov (United States)

    van der Woude, J A D; van Heerwaarden, R J; Spruijt, S; Eckstein, F; Maschek, S; van Roermund, P M; Custers, R J H; van Spil, W E; Mastbergen, S C; Lafeber, F P J G

    2016-10-01

    Knee joint distraction (KJD) is a surgical joint-preserving treatment in which the knee joint is temporarily distracted by an external frame. It is associated with joint tissue repair and clinical improvement. Initially, patients were submitted to an eight-week distraction period, and currently patients are submitted to a six-week distraction period. This study evaluates whether a shorter distraction period influences the outcome. Both groups consisted of 20 patients. Clinical outcome was assessed by WOMAC questionnaires and VAS-pain. Cartilaginous tissue repair was assessed by radiographic joint space width (JSW) and MRI-observed cartilage thickness. Baseline data between both groups were comparable. Both groups showed an increase in total WOMAC score; 24±4 in the six-week group and 32±5 in the eight-week group (both p<0.001). Mean JSW increased 0.9±0.3mm in the six-week group and 1.1±0.3mm in the eight-week group (p=0.729 between groups). The increase in mean cartilage thickness on MRI was 0.6±0.2mm in the eight-week group and 0.4±0.1mm in the six-week group (p=0.277). A shorter distraction period does not influence short-term clinical and structural outcomes statistically significantly, although effect sizes tend to be smaller in six week KJD as compared to eight week KJD. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Injectable Biodegradable Polyurethane Scaffolds with Release of Platelet-derived Growth Factor for Tissue Repair and Regeneration

    Science.gov (United States)

    Hafeman, Andrea E.; Li, Bing; Yoshii, Toshitaka; Zienkiewicz, Katarzyna; Davidson, Jeffrey M.; Guelcher, Scott A.

    2013-01-01

    Purpose The purpose of this work was to investigate the effects of triisocyanate composition on the biological and mechanical properties of biodegradable, injectable polyurethane scaffolds for bone and soft tissue engineering. Methods Scaffolds were synthesized using reactive liquid molding techniques, and were characterized in vivo in a rat subcutaneous model. Porosity, dynamic mechanical properties, degradation rate, and release of growth factors were also measured. Results Polyurethane scaffolds were elastomers with tunable damping properties and degradation rates, and they supported cellular infiltration and generation of new tissue. The scaffolds showed a two-stage release profile of platelet-derived growth factor, characterized by a 75% burst release within the first 24 h and slower release thereafter. Conclusions Biodegradable polyurethanes synthesized from triisocyanates exhibited tunable and superior mechanical properties compared to materials synthesized from lysine diisocyanates. Due to their injectability, biocompatibility, tunable degradation, and potential for release of growth factors, these materials are potentially promising therapies for tissue engineering. PMID:18516665

  10. A Review of Injectable and Implantable Biomaterials for Treatment and Repair of Soft Tissues in Wound Healing

    Directory of Open Access Journals (Sweden)

    Shih-Feng Chou

    2017-01-01

    Full Text Available The two major topics concerning the development of nanomedicine are drug delivery and tissue engineering. With the advance in nanotechnology, scientists and engineers now have the ability to fabricate functional drug carriers and/or biomaterials that deliver and release drugs locally as well as promote tissue regeneration. In this short review, we address the use of nanotechnology in the fabrication of biomaterials (i.e., nanoparticles and nanofibers and their therapeutic function in wound healing as dressing materials. Furthermore, we discuss the use of surface nanofeatures to regulate cell adhesion, migration, proliferation, and differentiation, which is a crucial step in wound healing associated with tissue regeneration. Given that nanotechnology-based biomaterials exhibit superior pharmaceutical performance as compared to the traditional medicine, this short review provides current status and future directions of how nanotechnology is and will be used in biomedical field, especially in wound healing.

  11. Non-Immunogenic Structurally and Biologically Intact Tissue Matrix Grafts for the Immediate Repair of Ballistic-Induced Vascular and Nerve Tissue Injury in Combat

    Science.gov (United States)

    2004-12-01

    the absence of dilatation, aneurysm formation or neointimal hyperplasia . The 2003 report described the failure to provide appropriate carotid grafts...growth of fibrovascular tissue, sometimes accompanied by inflammatory cells and pigment-laden macrophages. Fragmentation of the umbilical vein...were also present within the device interstices. A fibrovascular stroma (all animals, mild to marked) was also noted within the lumen of the ePTFE

  12. A comparative study on microwave and routine tissue processing

    Directory of Open Access Journals (Sweden)

    T Mahesh Babu

    2011-01-01

    Conclusions: The individual scores by different observers regarding the various parameters included in the study were statistically insignificant, the overall quality of microwave-processed and microwave-stained slides appeared slightly better than conventionally processed and stained slides.

  13. Induction of angiogenesis in tissue-engineered scaffolds designed for bone repair: a combined gene therapy-cell transplantation approach.

    Science.gov (United States)

    Jabbarzadeh, Ehsan; Starnes, Trevor; Khan, Yusuf M; Jiang, Tao; Wirtel, Anthony J; Deng, Meng; Lv, Qing; Nair, Lakshmi S; Doty, Steven B; Laurencin, Cato T

    2008-08-12

    One of the fundamental principles underlying tissue engineering approaches is that newly formed tissue must maintain sufficient vascularization to support its growth. Efforts to induce vascular growth into tissue-engineered scaffolds have recently been dedicated to developing novel strategies to deliver specific biological factors that direct the recruitment of endothelial cell (EC) progenitors and their differentiation. The challenge, however, lies in orchestration of the cells, appropriate biological factors, and optimal factor doses. This study reports an approach as a step forward to resolving this dilemma by combining an ex vivo gene transfer strategy and EC transplantation. The utility of this approach was evaluated by using 3D poly(lactide-co-glycolide) (PLAGA) sintered microsphere scaffolds for bone tissue engineering applications. Our goal was achieved by isolation and transfection of adipose-derived stromal cells (ADSCs) with adenovirus encoding the cDNA of VEGF. We demonstrated that the combination of VEGF releasing ADSCs and ECs results in marked vascular growth within PLAGA scaffolds. We thereby delineate the potential of ADSCs to promote vascular growth into biomaterials.

  14. Induction of angiogenesis in tissue-engineered scaffolds designed for bone repair: A combined gene therapy–cell transplantation approach

    Science.gov (United States)

    Jabbarzadeh, Ehsan; Starnes, Trevor; Khan, Yusuf M.; Jiang, Tao; Wirtel, Anthony J.; Deng, Meng; Lv, Qing; Nair, Lakshmi S.; Doty, Steven B.; Laurencin, Cato T.

    2008-01-01

    One of the fundamental principles underlying tissue engineering approaches is that newly formed tissue must maintain sufficient vascularization to support its growth. Efforts to induce vascular growth into tissue-engineered scaffolds have recently been dedicated to developing novel strategies to deliver specific biological factors that direct the recruitment of endothelial cell (EC) progenitors and their differentiation. The challenge, however, lies in orchestration of the cells, appropriate biological factors, and optimal factor doses. This study reports an approach as a step forward to resolving this dilemma by combining an ex vivo gene transfer strategy and EC transplantation. The utility of this approach was evaluated by using 3D poly(lactide-co-glycolide) (PLAGA) sintered microsphere scaffolds for bone tissue engineering applications. Our goal was achieved by isolation and transfection of adipose-derived stromal cells (ADSCs) with adenovirus encoding the cDNA of VEGF. We demonstrated that the combination of VEGF releasing ADSCs and ECs results in marked vascular growth within PLAGA scaffolds. We thereby delineate the potential of ADSCs to promote vascular growth into biomaterials. PMID:18678895

  15. Codes and standards in repair and replacement process. Importance of corrective action in maintenance activities

    International Nuclear Information System (INIS)

    Aoki, Takayuki; Takagi, Toshiyuki

    2015-01-01

    For creating a corrective measure plan for industrial plant components, it is very important to have a well-grounded basis. Therefore, this paper proposes a method for determining the following three elements of such a plan: an equipment to be repaired, a corrective measure method to be adopted, and a timing of its implementation using a rational approach. And the importance of corrective measure in plant maintenance is also discussed. (author)

  16. Thromboxane A{sub 2} receptor signaling promotes liver tissue repair after toxic injury through the enhancement of macrophage recruitment

    Energy Technology Data Exchange (ETDEWEB)

    Minamino, Tsutomu [Departments of Pharmacology, Kitasato University School of Medicine, Kanagawa 252-0374 (Japan); Departments of Gastroenterology, Kitasato University School of Medicine, Kanagawa 252-0374 (Japan); Ito, Yoshiya [Departments of Surgery, Kitasato University School of Medicine, Kanagawa 252-0374 (Japan); Ohkubo, Hirotoki [Departments of Pharmacology, Kitasato University School of Medicine, Kanagawa 252-0374 (Japan); Departments of Surgery, Kitasato University School of Medicine, Kanagawa 252-0374 (Japan); Hosono, Kanako; Suzuki, Tatsunori [Departments of Pharmacology, Kitasato University School of Medicine, Kanagawa 252-0374 (Japan); Sato, Takehito [Departments of Pharmacology, Kitasato University School of Medicine, Kanagawa 252-0374 (Japan); Departments of Gastroenterology, Kitasato University School of Medicine, Kanagawa 252-0374 (Japan); Ae, Takako; Shibuya, Akitaka [Departments of Gastroenterology, Kitasato University School of Medicine, Kanagawa 252-0374 (Japan); Sakagami, Hiroyuki [Departments of Anatomy, Kitasato University School of Medicine, Kanagawa 252-0374 (Japan); Narumiya, Shuh [Department of Pharmacology, Kyoto University School of Medicine, Kyoto, 606-8315 (Japan); Koizumi, Wasaburo [Departments of Gastroenterology, Kitasato University School of Medicine, Kanagawa 252-0374 (Japan); Majima, Masataka, E-mail: mmajima@med.kitasato-u.ac.jp [Departments of Pharmacology, Kitasato University School of Medicine, Kanagawa 252-0374 (Japan)

    2012-02-15

    It is thought that thromboxane A{sub 2} (TxA{sub 2}) contributes to the progression of inflammation during acute hepatic injury; however, it is still unknown whether TxA{sub 2} is involved in liver repair. The objective of the present study was to examine the role of TxA{sub 2} receptor (TP) signaling in liver injury and repair in response to toxic injury. Carbon tetrachloride (CCl{sub 4}) was used to induce liver injury in TP knockout (TP{sup −/−}) mice and wild-type (WT) mice. In WT mice, serum levels of alanine aminotransferase (ALT) and the size of the necrotic area peaked at 24 and 48 h, respectively, and then declined. In TP{sup −/−} mice, the changes in ALT levels were similar to WT mice, but liver regeneration was impaired as evidenced by remained elevated levels of hepatic necrosis and by delayed hepatocyte proliferation, which was associated with the reduced expression of growth factors including interleukin-6 (IL-6), tumor necrosis factor alpha (TNFα), and hepatocyte growth factor (HGF). In TP{sup −/−} mice, the accumulation of hepatic CD11b{sup +}/F4/80{sup +} macrophages in injured livers was attenuated, and the hepatic expression of monocyte chemoattractant protein-1 (MCP-1/CCL2) and its receptor, the C―C chemokine receptor (CCR2), was reduced compared to WT. Additionally, the application of the TP receptor agonist, U-46619, enhanced the expression of MCP-1/CCL2 and CCR2 in peritoneal macrophages, which was associated with increased levels of IL-6, TNFα and HGF. These results suggested that TP receptor signaling facilitates liver recovery following CCl{sub 4}-induced hepatotoxicity by affecting the expression of hepatotrophic growth factors, and through the recruitment of macrophages mediated by MCP-1/CCL2-CCR2 expression. -- Highlights: ► TP enhances liver regeneration by CCl{sub 4}. ► TP accumulates macrophages. ► TP up-regulates MCP-1.

  17. Tissue

    Directory of Open Access Journals (Sweden)

    David Morrissey

    2012-01-01

    Full Text Available Purpose. In vivo gene therapy directed at tissues of mesenchymal origin could potentially augment healing. We aimed to assess the duration and magnitude of transene expression in vivo in mice and ex vivo in human tissues. Methods. Using bioluminescence imaging, plasmid and adenoviral vector-based transgene expression in murine quadriceps in vivo was examined. Temporal control was assessed using a doxycycline-inducible system. An ex vivo model was developed and optimised using murine tissue, and applied in ex vivo human tissue. Results. In vivo plasmid-based transgene expression did not silence in murine muscle, unlike in liver. Although maximum luciferase expression was higher in muscle with adenoviral delivery compared with plasmid, expression reduced over time. The inducible promoter cassette successfully regulated gene expression with maximum levels a factor of 11 greater than baseline. Expression was re-induced to a similar level on a temporal basis. Luciferase expression was readily detected ex vivo in human muscle and tendon. Conclusions. Plasmid constructs resulted in long-term in vivo gene expression in skeletal muscle, in a controllable fashion utilising an inducible promoter in combination with oral agents. Successful plasmid gene transfection in human ex vivo mesenchymal tissue was demonstrated for the first time.

  18. Raman spectroscopic analysis of human skin tissue sections ex-vivo: evaluation of the effects of tissue processing and dewaxing

    Science.gov (United States)

    Ali, Syed M.; Bonnier, Franck; Tfayli, Ali; Lambkin, Helen; Flynn, Kathleen; McDonagh, Vincent; Healy, Claragh; Clive Lee, T.; Lyng, Fiona M.; Byrne, Hugh J.

    2013-06-01

    Raman spectroscopy coupled with K-means clustering analysis (KMCA) is employed to elucidate the biochemical structure of human skin tissue sections and the effects of tissue processing. Both hand and thigh sections of human cadavers were analyzed in their unprocessed and formalin-fixed, paraffin-processed (FFPP), and subsequently dewaxed forms. In unprocessed sections, KMCA reveals clear differentiation of the stratum corneum (SC), intermediate underlying epithelium, and dermal layers for sections from both anatomical sites. The SC is seen to be relatively rich in lipidic content; the spectrum of the subjacent layers is strongly influenced by the presence of melanin, while that of the dermis is dominated by the characteristics of collagen. For a given anatomical site, little difference in layer structure and biochemistry is observed between samples from different cadavers. However, the hand and thigh sections are consistently differentiated for all cadavers, largely based on lipidic profiles. In dewaxed FFPP samples, while the SC, intermediate, and dermal layers are clearly differentiated by KMCA of Raman maps of tissue sections, the lipidic contributions to the spectra are significantly reduced, with the result that respective skin layers from different anatomical sites become indistinguishable. While efficient at removing the fixing wax, the tissue processing also efficiently removes the structurally similar lipidic components of the skin layers. In studies of dermatological processes in which lipids play an important role, such as wound healing, dewaxed samples are therefore not appropriate. Removal of the lipids does however accentuate the spectral features of the cellular and protein components, which may be more appropriate for retrospective analysis of disease progression and biochemical analysis using tissue banks.

  19. Radiation repair models for clinical application.

    Science.gov (United States)

    Dale, Roger G

    2018-02-28

    A number of newly emerging clinical techniques involve non-conventional patterns of radiation delivery which require an appreciation of the role played by radiation repair phenomena. This review outlines the main models of radiation repair, focussing on those which are of greatest clinical usefulness and which may be incorporated into biologically effective dose assessments. The need to account for the apparent "slowing-down" of repair rates observed in some normal tissues is also examined, along with a comparison of the relative merits of the formulations which can be used to account for such phenomena. Jack Fowler brought valuable insight to the understanding of radiation repair processes and this article includes reference to his important contributions in this area.

  20. MENISCAL REPAIR BY FIBROCARTILAGE - AN EXPERIMENTAL-STUDY IN THE DOG

    NARCIS (Netherlands)

    JANSEN, HWB; VETH, RPH; NIELSEN, HKL; DEGROOT, JH; PENNINGS, AJ; KUIJER, R

    Longitudinal lesions in the avascular part of the dog's meniscus were repaired by implantation of a porous polyurethane. Ingrowing repair tissue was characterized by biochemical and immunological analysis. Histologically, repair tissue initially was composed of fibrous tissue containing type I

  1. A network of epigenetic modifiers and DNA repair genes controls tissue-specific copy number alteration preference.

    Science.gov (United States)

    Cramer, Dina; Serrano, Luis; Schaefer, Martin H

    2016-11-10

    Copy number alterations (CNAs) in cancer patients show a large variability in their number, length and position, but the sources of this variability are not known. CNA number and length are linked to patient survival, suggesting clinical relevance. We have identified genes that tend to be mutated in samples that have few or many CNAs, which we term CONIM genes (COpy Number Instability Modulators). CONIM proteins cluster into a densely connected subnetwork of physical interactions and many of them are epigenetic modifiers. Therefore, we investigated how the epigenome of the tissue-of-origin influences the position of CNA breakpoints and the properties of the resulting CNAs. We found that the presence of heterochromatin in the tissue-of-origin contributes to the recurrence and length of CNAs in the respective cancer type.

  2. Proteomics-based network analysis characterizes biological processes and pathways activated by preconditioned mesenchymal stem cells in cardiac repair mechanisms.

    Science.gov (United States)

    Di Silvestre, Dario; Brambilla, Francesca; Scardoni, Giovanni; Brunetti, Pietro; Motta, Sara; Matteucci, Marco; Laudanna, Carlo; Recchia, Fabio A; Lionetti, Vincenzo; Mauri, Pierluigi

    2017-05-01

    We have demonstrated that intramyocardial delivery of human mesenchymal stem cells preconditioned with a hyaluronan mixed ester of butyric and retinoic acid (MSCp + ) is more effective in preventing the decay of regional myocardial contractility in a swine model of myocardial infarction (MI). However, the understanding of the role of MSCp + in proteomic remodeling of cardiac infarcted tissue is not complete. We therefore sought to perform a comprehensive analysis of the proteome of infarct remote (RZ) and border zone (BZ) of pigs treated with MSCp + or unconditioned stem cells. Heart tissues were analyzed by MudPIT and differentially expressed proteins were selected by a label-free approach based on spectral counting. Protein profiles were evaluated by using PPI networks and their topological analysis. The proteomic remodeling was largely prevented in MSCp + group. Extracellular proteins involved in fibrosis were down-regulated, while energetic pathways were globally up-regulated. Cardioprotectant pathways involved in the production of keto acid metabolites were also activated. Additionally, we found that new hub proteins support the cardioprotective phenotype characterizing the left ventricular BZ treated with MSCp + . In fact, the up-regulation of angiogenic proteins NCL and RAC1 can be explained by the increase of capillary density induced by MSCp + . Our results show that angiogenic pathways appear to be uniquely positioned to integrate signaling with energetic pathways involving cardiac repair. Our findings prompt the use of proteomics-based network analysis to optimize new approaches preventing the post-ischemic proteomic remodeling that may underlie the limited self-repair ability of adult heart. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Scratching the surface: the processing of pain from deep tissues.

    Science.gov (United States)

    Sikandar, Shafaq; Aasvang, Eske Kvanner; Dickenson, Anthony H

    2016-04-01

    Although most pain research focuses on skin, muscles, joints and viscerae are major sources of pain. We discuss the mechanisms of deep pains arising from somatic and visceral structures and how this can lead to widespread manifestations and chronification. We include how both altered peripheral and central sensory neurotransmission lead to deep pain states and comment on key areas such as top-down modulation where little is known. It is vital that the clinical characterization of deep pain in patients is improved to allow for back translation to preclinical models so that the missing links can be ascertained. The contribution of deeper somatic and visceral tissues to various chronic pain syndromes is common but there is much we need to know.

  4. Function and repair of dental enamel - Potential role of epithelial transport processes of ameloblasts.

    Science.gov (United States)

    Varga, Gábor; Kerémi, Beáta; Bori, Erzsébet; Földes, Anna

    2015-07-01

    The hardest mammalian tissue, dental enamel is produced by ameloblasts, which are electrolyte-transporting epithelial cells. Although the end product is very different, they show many similarities to transporting epithelia of the pancreas, salivary glands and kidney. Enamel is produced in a multi-step epithelial secretory process that features biomineralization which is an interplay of secreted ameloblast specific proteins and the time-specific transport of minerals, protons and bicarbonate. First, "secretory" ameloblasts form the entire thickness of the enamel layer, but with low mineral content. Then they differentiate into "maturation" ameloblasts, which remove organic matrix from the enamel and in turn further build up hydroxyapatite crystals. The protons generated by hydroxyapatite formation need to be buffered, otherwise enamel will not attain full mineralization. Buffering requires a tight pH regulation and secretion of bicarbonate by ameloblasts. The whole process has been the focus of many immunohistochemical and gene knock-out studies, but, perhaps surprisingly, no functional data existed for mineral ion transport by ameloblasts. However, recent studies including ours provided a better insight for molecular mechanism of mineral formation. The secretory regulation is not completely known as yet, but its significance is crucial. Impairing regulation retards or prevents completion of enamel mineralization and results in the development of hypomineralized enamel that easily erodes after dental eruption. Factors that impair this function are fluoride and disruption of pH regulators. Revealing these factors may eventually lead to the treatment of enamel hypomineralization related to genetic or environmentally induced malformation. Copyright © 2015 IAP and EPC. Published by Elsevier B.V. All rights reserved.

  5. Fixation Strength of Polyetheretherketone Sheath-and-Bullet Device for Soft Tissue Repair in the Foot and Ankle.

    Science.gov (United States)

    Christensen, Jay; Fischer, Brian; Nute, Michael; Rizza, Robert

    Tendon transfers are often performed in the foot and ankle. Recently, interference screws have been a popular choice owing to their ease of use and fixation strength. Considering the benefits, one disadvantage of such devices is laceration of the soft tissues by the implant threads during placement that potentially weaken the structural integrity of the grafts. A shape memory polyetheretherketone bullet-in-sheath tenodesis device uses circumferential compression, eliminating potential damage from thread rotation and maintaining the soft tissue orientation of the graft. The aim of this study was to determine the pullout strength and failure mode for this device in both a synthetic bone analogue and porcine bone models. Thirteen mature bovine extensor tendons were secured into ten 4.0 × 4.0 × 4.0-cm cubes of 15-pound per cubic foot solid rigid polyurethane foam bone analogue models or 3 porcine femoral condyles using the 5 × 20-mm polyetheretherketone soft tissue anchor. The bullet-in-sheath device demonstrated a mean pullout of 280.84 N in the bone analog models and 419.47 N in the porcine bone models. (p = .001). The bullet-in-sheath design preserved the integrity of the tendon graft, and none of the implants dislodged from their original position. Copyright © 2017 The American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

  6. Soft Tissue Repair with Easy-Accessible Autologous Newborn Placenta or Umbilical Cord Blood in Severe Malformations: A Primary Evaluation

    Science.gov (United States)

    2017-01-01

    Disrupted organogenesis leads to permanent malformations that may require surgical correction. Autologous tissue grafts may be needed in severe lack of orthotopic tissue but include donor site morbidity. The placenta is commonly discarded after birth and has a therapeutic potential. The aim of this study was to determine if the amnion from placenta or plasma rich of growth factors (PRGF) with mononuclear cells (MNC) from umbilical cord blood (UCB), collected noninvasively, could be used as bio-constructs for autologous transplantation as an easy-accessible no cell culture-required method. Human amnion and PRGF gel were isolated and kept in culture for up to 21 days with or without small intestine submucosa (SIS). The cells in the constructs showed a robust phenotype without induced increased proliferation (Ki67) or apoptosis (caspase 3), but the constructs showed decreased integrity of the amnion-epithelial layer at the end of culture. Amnion-residing cells in the SIS constructs expressed CD73 or pan-cytokeratin, and cells in the PRGF-SIS constructs expressed CD45 and CD34. This study shows that amnion and UCB are potential sources for production of autologous grafts in the correction of congenital soft tissue defects. The constructs can be made promptly after birth with minimal handling or cell expansion needed. PMID:29403534

  7. Soft Tissue Repair with Easy-Accessible Autologous Newborn Placenta or Umbilical Cord Blood in Severe Malformations: A Primary Evaluation

    Directory of Open Access Journals (Sweden)

    Åsa Ekblad

    2017-01-01

    Full Text Available Disrupted organogenesis leads to permanent malformations that may require surgical correction. Autologous tissue grafts may be needed in severe lack of orthotopic tissue but include donor site morbidity. The placenta is commonly discarded after birth and has a therapeutic potential. The aim of this study was to determine if the amnion from placenta or plasma rich of growth factors (PRGF with mononuclear cells (MNC from umbilical cord blood (UCB, collected noninvasively, could be used as bio-constructs for autologous transplantation as an easy-accessible no cell culture-required method. Human amnion and PRGF gel were isolated and kept in culture for up to 21 days with or without small intestine submucosa (SIS. The cells in the constructs showed a robust phenotype without induced increased proliferation (Ki67 or apoptosis (caspase 3, but the constructs showed decreased integrity of the amnion-epithelial layer at the end of culture. Amnion-residing cells in the SIS constructs expressed CD73 or pan-cytokeratin, and cells in the PRGF-SIS constructs expressed CD45 and CD34. This study shows that amnion and UCB are potential sources for production of autologous grafts in the correction of congenital soft tissue defects. The constructs can be made promptly after birth with minimal handling or cell expansion needed.

  8. Effect of negative pressure therapy on repair of soft tissues of the lower extremities in patients with neuropathic and neuroischaemic forms of diabetic foot syndrome

    Directory of Open Access Journals (Sweden)

    Ekaterina Leonidovna Zaytseva

    2014-06-01

    Full Text Available AimTo evaluate the efficiency of topical negative pressure wound therapy (NPWT compared with standard therapy for the regeneration of the soft tissues of the lower extremities in patients with diabetic foot syndrome.Materials and MethodsThe effects of negative pressure therapy on the clinical (size, tissue oxygenation, histological (light microscopy and immunohistochemical (CD68, MMP-9, TIMP-1 aspects of repair of the soft tissue of the lower extremities in patients with diabetes mellitus were compared with those of standard treatment. Thirty-one patients with diabetic foot ulcers were included in the study from the moment of debridement until the plastic closure of the wound. During the perioperative period, 13 patients received NPWT (-90 to -120 mmHg and 18 patients received standard therapy.ResultsA reduction of the wound area (26.6%±17.2% and the depth of the defects (40.5%±25.6% were achieved with negative pressure therapy compared with baseline data. In the control group, the corresponding values were 25.3%±19.4% and 21.8%±21.6%, respectively. The results of transcutaneous oximetry showed a greater increase in the level of local hemodynamics in the study group (p <0.04. An important criterion for wound preparation for a plastic closure is filling it with granulation tissue by more than 75%. In the study group, 95% of patients had wounds filled with 89.9%±17% of abundant granulation tissue. The histological data of the study group show a significant reduction of oedema by 80% (p <0.05, improved extracellular matrix organization (p <0.05, 90% (p <0.05 dissolution of inflammatory infiltrate and the formation of healthy granulation tissue (p <0.05. Immunohistochemical analysis demonstrated a significant decrease in the number of macrophages in the dermis (CD68 expression (p <0.05. In both groups, the level of MMP-9 was decreased. However, the ratio of MMP-9:TIMP-1 was lower in the study group (p <0.05.ConclusionThe findings suggest that

  9. Mechanical properties of hyaline and repair cartilage studied by nanoindentation.

    Science.gov (United States)

    Franke, O; Durst, K; Maier, V; Göken, M; Birkholz, T; Schneider, H; Hennig, F; Gelse, K

    2007-11-01

    Articular cartilage is a highly organized tissue that is well adapted to the functional demands in joints but difficult to replicate via tissue engineering or regeneration. Its viscoelastic properties allow cartilage to adapt to both slow and rapid mechanical loading. Several cartilage repair strategies that aim to restore tissue and protect it from further degeneration have been introduced. The key to their success is the quality of the newly formed tissue. In this study, periosteal cells loaded on a scaffold were used to repair large partial-thickness cartilage defects in the knee joint of miniature pigs. The repair cartilage was analyzed 26 weeks after surgery and compared both morphologically and mechanically with healthy hyaline cartilage. Contact stiffness, reduced modulus and hardness as key mechanical properties were examined in vitro by nanoindentation in phosphate-buffered saline at room temperature. In addition, the influence of tissue fixation with paraformaldehyde on the biomechanical properties was investigated. Although the repair process resulted in the formation of a stable fibrocartilaginous tissue, its contact stiffness was lower than that of hyaline cartilage by a factor of 10. Fixation with paraformaldehyde significantly increased the stiffness of cartilaginous tissue by one order of magnitude, and therefore, should not be used when studying biomechanical properties of cartilage. Our study suggests a sensitive method for measuring the contact stiffness of articular cartilage and demonstrates the importance of mechanical analysis for proper evaluation of the success of cartilage repair strategies.

  10. Magnetic resonance imaging in the repair of ruptured Achilles tendons. Morphological difference in healing process between conservative and surgical treatment

    International Nuclear Information System (INIS)

    Nakano, Tetsuo; Tsuruta, Takao; Abe, Yasuyuki; Tani, Akifumi; Koga, Toshimitsu; Shimizu, Yasuhiro

    1996-01-01

    We observed the healing process of ruptured Achilles tendons in a series using magnetic resonance imaging. In six cases, tendons were repaired percutaneously with limited skin incisions. Seven cases were treated conservatively using unique functional braces. MR imaging revealed two different modes of conjoining. In the conservatively treated group, tendons inclined to conjoin in a dumbbell shape. In the surgically treated group, they inclined to conjoin in a spindle shape. The diameters of the ruptured part are wider in the spindle shape compared to the dumbbell shape at all stages. These findings suggest that surgical treatment is favorable for acquiring earlier strength. (author)

  11. Effect of unit size on thermal fatigue behavior of hot work steel repaired by a biomimetic laser remelting process

    Science.gov (United States)

    Cong, Dalong; Li, Zhongsheng; He, Qingbing; Chen, Dajun; Chen, Hanbin; Yang, Jiuzhou; Zhang, Peng; Zhou, Hong

    2018-01-01

    AISI H13 hot work steel with fatigue cracks was repaired by a biomimetic laser remelting (BLR) process in the form of lattice units with different sizes. Detailed microstructural studies and microhardness tests were carried out on the units. Studies revealed a mixed microstructure containing martensite, retained austenite and carbide particles with ultrafine grain size in units. BLR samples with defect-free units exhibited superior thermal fatigue resistance due to microstructure strengthening, and mechanisms of crack tip blunting and blocking. In addition, effects of unit size on thermal fatigue resistance of BLR samples were discussed.

  12. Additive Manufacturing of IN100 Superalloy Through Scanning Laser Epitaxy for Turbine Engine Hot-Section Component Repair: Process Development, Modeling, Microstructural Characterization, and Process Control

    Science.gov (United States)

    Acharya, Ranadip; Das, Suman

    2015-09-01

    This article describes additive manufacturing (AM) of IN100, a high gamma-prime nickel-based superalloy, through scanning laser epitaxy (SLE), aimed at the creation of thick deposits onto like-chemistry substrates for enabling repair of turbine engine hot-section components. SLE is a metal powder bed-based laser AM technology developed for nickel-base superalloys with equiaxed, directionally solidified, and single-crystal microstructural morphologies. Here, we combine process modeling, statistical design-of-experiments (DoE), and microstructural characterization to demonstrate fully metallurgically bonded, crack-free and dense deposits exceeding 1000 μm of SLE-processed IN100 powder onto IN100 cast substrates produced in a single pass. A combined thermal-fluid flow-solidification model of the SLE process compliments DoE-based process development. A customized quantitative metallography technique analyzes digital cross-sectional micrographs and extracts various microstructural parameters, enabling process model validation and process parameter optimization. Microindentation measurements show an increase in the hardness by 10 pct in the deposit region compared to the cast substrate due to microstructural refinement. The results illustrate one of the very few successes reported for the crack-free deposition of IN100, a notoriously "non-weldable" hot-section alloy, thus establishing the potential of SLE as an AM method suitable for hot-section component repair and for future new-make components in high gamma-prime containing crack-prone nickel-based superalloys.

  13. Comparative analysis in continuous expansion of bovine and human primary nucleus pulposus cells for tissue repair applications

    Directory of Open Access Journals (Sweden)

    DH Rosenzweig

    2017-03-01

    Full Text Available Autologous NP cell implantation is a potential therapeutic avenue for intervertebral disc (IVD degeneration. However, monolayer expansion of cells isolated from surgical samples may negatively impact matrix production by way of dedifferentiation. Previously, we have used a continuous expansion culture system to successfully preserve a chondrocyte phenotype. In this work, we hypothesised that continuous expansion culture could also preserve nucleus pulposus (NP phenotype. We confirmed that serial passaging drove NP dedifferentiation by significantly decreasing collagen type II, aggrecan and chondroadherin (CHAD gene expression, compared to freshly isolated cells. Proliferation, gene expression profile and matrix production in both culture conditions were compared using primary bovine NP cells. Both standard culture and continuous culture produced clinically relevant cell populations. However, continuous culture cells maintained significantly higher collagen type II, aggrecan and CHAD transcript expression levels. Also, continuous expansion cells generated greater amounts of proteoglycan, collagen type II and aggrecan protein deposition in pellet cultures. To our surprise, continuous expansion of human intervertebral disc cells – isolated from acute herniation tissue – produced less collagen type II, aggrecan and CHAD genes and proteins, compared to standard culture. Also, continuous culture of cells isolated from young non-degenerate tissue did not preserve gene and protein expression, compared to standard culture. These data indicated that primary bovine and human NP cells responded differently to continuous culture, where the positive effects observed for bovine cells did not translate to human cells. Therefore, caution must be exercised when choosing animal models and cell sources for pre-clinical studies.

  14. Growth factor and proteinase profile of Vivostat® platelet-rich fibrin linked to tissue repair.

    Science.gov (United States)

    Agren, M S; Rasmussen, K; Pakkenberg, B; Jørgensen, B

    2014-07-01

    Autologous platelet-rich fibrin (PRF(®)) is prepared by the automatic Vivostat(®) system. Conflicting results with Vivostat PRF in acute wound healing prompted us to examine its cellular and biomolecular composition. Specifically, platelets, selected growth factors and matrix metalloproteinase (MMP)-9 were quantified using novel analytical methods. Ten healthy non-thrombocytopenic volunteers donated blood for generation of intermediate fibrin-I and final PRF. Anticoagulated whole blood and serum procured in parallel served as baseline controls. Leucocyte, erythrocyte and platelet counts in whole blood and fibrin-I were determined by automated haematology analyser. Platelet concentration in PRF was quantified manually by stereologic analysis of Giemsa-stained tissue sections, and the total content of five growth factors and MMP-9 by enzyme-linked immunosorbent assays. The number of leucocytes and erythrocytes was reduced (P platelets increased (P fibrin-I versus whole blood. PRF contained 982 ± 206 × 10(9) platelets/l representing 3·9-fold (P platelet-derived growth factor (PDGF)-AB [2·5-fold, P PDGF-BB [1·6-fold, P vascular endothelial growth factor > basic fibroblast growth factor [75-fold, P platelet enrichment and biomolecular constituents may guide clinicians in their optimal use of Vivostat PRF for tissue regenerative applications. © 2013 International Society of Blood Transfusion.

  15. Self-Organization and the Self-Assembling Process in Tissue Engineering

    Science.gov (United States)

    Eswaramoorthy, Rajalakshmanan; Hadidi, Pasha; Hu, Jerry C.

    2015-01-01

    In recent years, the tissue engineering paradigm has shifted to include a new and growing subfield of scaffoldless techniques which generate self-organizing and self-assembling tissues. This review aims to provide a cogent description of this relatively new research area, with special emphasis on applications toward clinical use and research models. Particular emphasis is placed on providing clear definitions of self-organization and the self-assembling process, as delineated from other scaffoldless techniques in tissue engineering and regenerative medicine. Significantly, during formation, self-organizing and self-assembling tissues display biological processes similar to those that occur in vivo. These help lead to the recapitulation of native tissue morphological structure and organization. Notably, functional properties of these tissues also approach native tissue values; some of these engineered tissues are already in clinical trials. This review aims to provide a cohesive summary of work in this field, and to highlight the potential of self-organization and the self-assembling process to provide cogent solutions to current intractable problems in tissue engineering. PMID:23701238

  16. Protection and repair of post-thrombolytic brain tissue with high-dose human albumin and magnesium sulfate: an experimental study

    International Nuclear Information System (INIS)

    Li Yongdong; Zhao Jungong; Li Minghua; You Xiaofang; Chen Yingsheng

    2008-01-01

    , local exudation of fluorescent materials with a mild microvascular dilation in group C and D comparing with group B. GFAP in group C and D at 6 h after stroke increased. The electron microscopy showed mild swelling of mitochondrion, moderate vacuolation of end-foot process of astrocyte, and no compression of the lumen of vessels of the vascular in group C and group D. Conclusions: Thrombolysis with rt-PA combined with high-dose human albumin and magnesium sulfate can reduce total infarct volume, accelarete the rCBV, promote astrocyte repairment with no increase incidence of cerebral hemorrhage in rats within 6 h after the onset of MCAO. (authors)

  17. Experience of nurses in the process of donation of organs and tissues for transplant.

    Science.gov (United States)

    de Moraes, Edvaldo Leal; dos Santos, Marcelo José; Merighi, Miriam Aparecida Barbosa; Massarollo, Maria Cristina Komatsu Braga

    2014-01-01

    to investigate the meaning of the action of nurses in the donation process to maintain the viability of organs and tissues for transplantation. this qualitative study with a social phenomenological approach was conducted through individual interviews with ten nurses of three Organ and Tissue Procurement Services of the city of São Paulo. the experience of the nurses in the donation process was represented by the categories: obstacles experienced in the donation process, and interventions performed. The meaning of the action to maintain the viability of organs and tissues for transplantation was described by the categories: to change paradigms, to humanize the donation process, to expand the donation, and to save lives. knowledge of the experience of the nurses in this process is important for healthcare professionals who work in different realities, indicating strategies to optimize the procurement of organs and tissues for transplantation.

  18. Experience of nurses in the process of donation of organs and tissues for transplant

    Directory of Open Access Journals (Sweden)

    Edvaldo Leal de Moraes

    2014-04-01

    Full Text Available OBJECTIVE: to investigate the meaning of the action of nurses in the donation process to maintain the viability of organs and tissues for transplantation.METHOD: this qualitative study with a social phenomenological approach was conducted through individual interviews with ten nurses of three Organ and Tissue Procurement Services of the city of São Paulo.RESULTS: the experience of the nurses in the donation process was represented by the categories: obstacles experienced in the donation process, and interventions performed. The meaning of the action to maintain the viability of organs and tissues for transplantation was described by the categories: to change paradigms, to humanize the donation process, to expand the donation, and to save lives.FINAL CONSIDERATIONS: knowledge of the experience of the nurses in this process is important for healthcare professionals who work in different realities, indicating strategies to optimize the procurement of organs and tissues for transplantation.

  19. Research for organism functions by analysis of radiation damage-repair process. Analysis of high order structure in radiosensitive parts

    International Nuclear Information System (INIS)

    Maekawa, Hideaki; Tsuchida, Kozo; Hashido, Kazuo; Takada, Naoko; Kameoka, Yosuke; Hirata, Makoto

    2004-01-01

    Centromere of human chromosome was recognized easily and certainly by fluorescence in situ hybridization (FISH) process. The DNA in plasmid were extracted right after irradiation of 137 Cs before repairs of the damaged DNA. Genes of the damaged DNA were detected by polymerase cycle restoration (PCR) process. Cut off frequency for two chains in the DNA were detected in real time. The cut off frequency in the damaged plasmid DNA detected by the PCR process was compared with simulation calculation. The difference between these cut off frequency values was within the value expected by electrophoretic mobility. It was cleared that the PCR amplification was difficult for the close structure of plasmid, but carried immediately on the nicked plasmid. (M. Suetake)

  20. Epigenomic maintenance through dietary intervention can facilitate DNA repair process to slow down the progress of premature aging.

    Science.gov (United States)

    Ghosh, Shampa; Sinha, Jitendra Kumar; Raghunath, Manchala

    2016-09-01

    DNA damage caused by various sources remains one of the most researched topics in the area of aging and neurodegeneration. Increased DNA damage causes premature aging. Aging is plastic and is characterised by the decline in the ability of a cell/organism to maintain genomic stability. Lifespan can be modulated by various interventions like calorie restriction, a balanced diet of macro and micronutrients or supplementation with nutrients/nutrient formulations such as Amalaki rasayana, docosahexaenoic acid, resveratrol, curcumin, etc. Increased levels of DNA damage in the form of double stranded and single stranded breaks are associated with decreased longevity in animal models like WNIN/Ob obese rats. Erroneous DNA repair can result in accumulation of DNA damage products, which in turn result in premature aging disorders such as Hutchinson-Gilford progeria syndrome. Epigenomic studies of the aging process have opened a completely new arena for research and development of drugs and therapeutic agents. We propose here that agents or interventions that can maintain epigenomic stability and facilitate the DNA repair process can slow down the progress of premature aging, if not completely prevent it. © 2016 IUBMB Life, 68(9):717-721, 2016. © 2016 International Union of Biochemistry and Molecular Biology.

  1. Incorrect modeling of the failure process of minimally repaired systems under random conditions: The effect on the maintenance costs

    International Nuclear Information System (INIS)

    Pulcini, Gianpaolo

    2015-01-01

    This note investigates the effect of the incorrect modeling of the failure process of minimally repaired systems that operates under random environmental conditions on the costs of a periodic replacement maintenance. The motivation of this paper is given by a recently published paper, where a wrong formulation of the expected cost for unit time under a periodic replacement policy is obtained. This wrong formulation is due to the incorrect assumption that the intensity function of minimally repaired systems that operate under random conditions has the same functional form as the failure rate of the first failure time. This produced an incorrect optimization of the replacement maintenance. Thus, in this note the conceptual differences between the intensity function and the failure rate of the first failure time are first highlighted. Then, the correct expressions of the expected cost and of the optimal replacement period are provided. Finally, a real application is used to measure how severe can be the economical consequences caused by the incorrect modeling of the failure process.

  2. Simulation of electrochemical processes in cardiac tissue based on cellular automaton

    International Nuclear Information System (INIS)

    Avdeev, S A; Bogatov, N M

    2014-01-01

    A new class of cellular automata using special accumulative function for nonuniformity distribution is presented. Usage of this automata type for simulation of excitable media applied to electrochemical processes in human cardiac tissue is shown

  3. RAPID PROCESSING OF ARCHIVAL TISSUE SAMPLES FOR PROTEOMIC ANALYSIS USING PRESSURE-CYCLING TECHNOLOGY

    Directory of Open Access Journals (Sweden)

    Vinuth N. Puttamallesh1,2

    2017-06-01

    Full Text Available Advent of mass spectrometry based proteomics has revolutionized our ability to study proteins from biological specimen in a high-throughput manner. Unlike cell line based studies, biomedical research involving tissue specimen is often challenging due to limited sample availability. In addition, investigation of clinically relevant research questions often requires enormous amount of time for sample collection prospectively. Formalin fixed paraffin embedded (FFPE archived tissue samples are a rich source of tissue specimen for biomedical research. However, there are several challenges associated with analysing FFPE samples. Protein cross-linking and degradation of proteins particularly affects proteomic analysis. We demonstrate that barocycler that uses pressure-cycling technology enables efficient protein extraction and processing of small amounts of FFPE tissue samples for proteomic analysis. We identified 3,525 proteins from six 10µm esophageal squamous cell carcinoma (ESCC tissue sections. Barocycler allows efficient protein extraction and proteolytic digestion of proteins from FFPE tissue sections at par with conventional methods.

  4. A functional model for adult stem cells in epithelial tissues.

    NARCIS (Netherlands)

    Verstappen, J.; Katsaros, C.; Torensma, R.; Hoff, J.W. Von den

    2009-01-01

    Tissue turnover, regeneration, and repair take place throughout life. Stem cells are key players in these processes. The characteristics and niches of the stem cell populations in different tissues, and even in related tissues, vary extensively. In this review, stem cell differentiation and stem

  5. Insight on stem cell preconditioning and instructive biomaterials to enhance cell adhesion, retention, and engraftment for tissue repair.

    Science.gov (United States)

    Shafiq, Muhammad; Jung, Youngmee; Kim, Soo Hyun

    2016-06-01

    Stem cells are a promising solution for the treatment of a variety of diseases. However, the limited survival and engraftment of transplanted cells due to a hostile ischemic environment is a bottleneck for effective utilization and commercialization. Within this environment, the majority of transplanted cells undergo apoptosis prior to participating in lineage differentiation and cellular integration. Therefore, in order to maximize the clinical utility of stem/progenitor cells, strategies must be employed to increase their adhesion, retention, and engraftment in vivo. Here, we reviewed key strategies that are being adopted to enhance the survival, retention, and engraftment of transplanted stem cells through the manipulation of both the stem cells and the surrounding environment. We describe how preconditioning of cells or cell manipulations strategies can enhance stem cell survival and engraftment after transplantation. We also discuss how biomaterials can enhance the function of stem cells for effective tissue regeneration. Biomaterials can incorporate or mimic extracellular function (ECM) function and enhance survival or differentiation of transplanted cells in vivo. Biomaterials can also promote angiogenesis, enhance engraftment and differentiation, and accelerate electromechanical integration of transplanted stem cells. Insight gained from this review may direct the development of future investigations and clinical trials. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Experience of nurses in the process of donation of organs and tissues for transplant

    OpenAIRE

    Moraes,Edvaldo Leal de; Santos,Marcelo José dos; Merighi,Miriam Aparecida Barbosa; Massarollo,Maria Cristina Komatsu Braga

    2014-01-01

    OBJECTIVE: to investigate the meaning of the action of nurses in the donation process to maintain the viability of organs and tissues for transplantation.METHOD: this qualitative study with a social phenomenological approach was conducted through individual interviews with ten nurses of three Organ and Tissue Procurement Services of the city of São Paulo.RESULTS: the experience of the nurses in the donation process was represented by the categories: obstacles experienced in the donation proce...

  7. Autologous platelet-rich plasma (PRP) in chronic penile lichen sclerosus: the impact on tissue repair and patient quality of life.

    Science.gov (United States)

    Casabona, Francesco; Gambelli, Ilaria; Casabona, Federica; Santi, Pierluigi; Santori, Gregorio; Baldelli, Ilaria

    2017-04-01

    Lichen sclerosus (LS) is a chronic inflammatory skin condition that frequently involves the anogenital region. Ongoing research is focused on finding more effective treatments for tissue repair and reducing symptoms. The aim of this study is to evaluate the effectiveness of platelet-rich plasma (PRP) local injections in penile LS. Forty-five male patients affected by penile LS underwent injections of autologous PRP in the affected skin areas. Age at diagnosis and at first treatment, number of treatments, clinical conditions (phimosis, splitting, inflammation, synechiae, meatus stenosis), symptoms (pain, burning, itching), and functional impairment were considered. Treatment efficacy was also evaluated through the Investigator's Global Assessment (IGA) on a six-point Likert scale and the Dermatology Life Quality Index (DLQI). The patient age at LS diagnosis was 36.20 ± 9.19 years, while the mean age at the first PRP treatment was 42.96 ± 11.32 years (p PRP injections, it was observed in all patients a significant improvement in clinical conditions, with reduction/disappearance of symptoms. Topical steroid therapy, interrupted before PRP treatment, was not restarted by any patient. Only one patient underwent a later circumcision procedure. Both IGA scale and DLQI score showed a significant difference (p PRP treatment. PRP treatment in penile LS seems to be helpful to regenerate scarring, reduce symptoms, and improve patient quality of life. Further studies are necessary to evaluate long-term results.

  8. Repairing the Osteochondral Defect in Goat with the Tissue-Engineered Osteochondral Graft Preconstructed in a Double-Chamber Stirring Bioreactor

    Directory of Open Access Journals (Sweden)

    Yang Pei

    2014-01-01

    Full Text Available To investigate the reparative efficacy of tissue-engineered osteochondral (TEO graft for repairing the osteochondral defect in goat, we designed a double-chamber stirring bioreactor to construct the bone and cartilage composites simultaneously in one β-TCP scaffold and observed the reparative effect in vivo. The osteochondral defects were created in goats and all the animals were divided into 3 groups randomly. In groups A, the defect was treated with the TEO which was cultured with mechanical stimulation of stir; in group B, the defect was treated with TEO which was cultured without mechanical stimulation of stir; in groups C, the defect was treated without TEO. At 12 weeks and 24 weeks after operation, the reparative effects in different groups were assessed and compared. The results indicated that the reparative effect of the TEO cultured in the bioreactor was better than the control group, and mechanical stimulation of stir could further improve the reparative effect. We provided a feasible and effective method to construct the TEO for treatment of osteochondral defect using autologous BMSCs and the double-chamber bioreactor.

  9. An in vivo study evaluating lesion sterilization and tissue repair 3 MIX-MP noninstrumentation endodontic treatment as an alternative to conventional endodontic retreatment

    Directory of Open Access Journals (Sweden)

    Vaishnavi Dasari

    2016-01-01

    Full Text Available Aim: To alleviate the patient's symptoms and promote periapical healing in teeth with failure of root canal treatment, without the removal of previous obturating material using lesion sterilization and tissue repair (LSTR 3 MIX-MP noninstrumentation endodontic treatment (NIET. Materials and Methods: Fifteen single-rooted teeth with a history of root canal treatment 1–2 years previously, requiring retreatment, with pain, sinus tract, swelling and periapical lesions, and having acceptable obturation were included in the study. The previous coronal restoration was removed, and a medication cavity was prepared for placement of 3MIX MP; this was followed by lining with Glass ionomer cement and a coronal restoration with composite resin. Results: At 8 weeks, all patients did not have either pain, tenderness on vertical percussion, pain on biting, or swelling (asymptomatic. Radiographically, the periapical lesions had reduced by 1 mm in five cases. In six patients, the lesion size remained unchanged. Conclusion: LSTR NIET is an excellent, inexpensive, less traumatic, and least time-consuming alternative to treat symptomatic teeth requiring endodontic retreatment.

  10. Apoptotic factors in physiological and pathological processes of teeth and periodontal tissues – literature review

    Directory of Open Access Journals (Sweden)

    Orzedala-Koszel Urszula

    2014-12-01

    Full Text Available Apoptosis is a physiological process that occurs in the human body throughout the entire life span. This process can be seen in the tissues of the stomatognathic system. A disorder in such programmed cell death processes leads to the development of pathological lesions. Among these are inflammation, osteolytic lesions and neoplastic hyperplasia. We put forward that future studies should concentrate on how to use the knowledge of apoptotic processes and their inhibitors in therapeutic processes involving the stomatognathic system.

  11. Applications of a Hybrid Manufacturing Process for Fabrication and Repair of Metallic Structures (Preprint)

    National Research Council Canada - National Science Library

    Liou, Frank; Slattery, Kevin; Kinsella, Mary; Newkirk, Joseph; Chou, Hsin-Nan; Landers, Robert

    2006-01-01

    .... Coupled between the additive and the subtractive processes into a single workstation, the integrated process, or hybrid process, can produce a metal part with machining accuracy and surface finish...

  12. Dynamics of radiation damage and repair processes in coniferous stands in a 10-km region of the Chernobyl nuclear power station

    International Nuclear Information System (INIS)

    Kozubov, G.M.; Taskaev, A.I.

    1995-01-01

    Properties of morphogenesis, growth dynamics, anatomy and ultrastructure of wood and needle, reproductive processes in coniferous plants were studied under different level of radiation effect in the 10-km zone in 1986-1992. It was established that the full drying of pine forests began under absorbed dose 80-100 Gy/year. Threshold doses, after which repair processes were possible, reached to 10-12 Gy/year for Picea abies and 50 Gy/year for Pinus sylvestris. Three maine stages are revealed in dynamics of radiation damage and repair processes in studied conifers and their morphological and functional characteristic is presented. 14 refs., 3 figs., 2 tabs

  13. Comparative study of the application of microcurrent and AsGa 904 nm laser radiation in the process of repair after calvaria bone excision in rats

    International Nuclear Information System (INIS)

    Mendonça, J S; Neves, L M G; Esquisatto, M A M; Mendonça, F A S; Santos, G M T

    2013-01-01

    This study evaluated the effects of microcurrent stimulation (10 μA/5 min) and 904 nm GaAs laser irradiation (3 J cm −2 for 69 s/day) on excisional lesions created in the calvaria bone of Wistar rats. The results showed significant responses in the reduction of inflammatory cells and an increase in the number of new blood vessels, number of fibroblasts and deposition of birefringent collagen fibers when these data were compared with those of samples of the untreated lesions. Both applications, microcurrent and laser at 904 nm, favored tissue repair in the region of bone excisions during the study period and these techniques can be used as coadjuvantes in the repair of bone tissue. (paper)

  14. DNA repair

    International Nuclear Information System (INIS)

    Setlow, R.

    1978-01-01

    Some topics discussed are as follows: difficulty in extrapolating data from E. coli to mammalian systems; mutations caused by UV-induced changes in DNA; mutants deficient in excision repair; other postreplication mechanisms; kinds of excision repair systems; detection of repair by biochemical or biophysical means; human mutants deficient in repair; mutagenic effects of UV on XP cells; and detection of UV-repair defects among XP individuals

  15. Importance of good manufacturing practices in microbiological monitoring in processing human tissues for transplant.

    Science.gov (United States)

    Pianigiani, Elisa; Ierardi, Francesca; Fimiani, Michele

    2013-12-01

    Skin allografts represent an important therapeutic resource in the treatment of severe skin loss. The risk associated with application of processed tissues in humans is very low, however, human material always carries the risk of disease transmission. To minimise the risk of contamination of grafts, processing is carried out in clean rooms where air quality is monitored. Procedures and quality control tests are performed to standardise the production process and to guarantee the final product for human use. Since we only validate and distribute aseptic tissues, we conducted a study to determine what type of quality controls for skin processing are the most suitable for detecting processing errors and intercurrent contamination, and for faithfully mapping the process without unduly increasing production costs. Two different methods for quality control were statistically compared using the Fisher exact test. On the basis of the current study we selected our quality control procedure based on pre- and post-processing tissue controls, operator and environmental controls. Evaluation of the predictability of our control methods showed that tissue control was the most reliable method of revealing microbial contamination of grafts. We obtained 100 % sensitivity by doubling tissue controls, while maintaining high specificity (77 %).

  16. DNA damage and repair process in earthworm after in-vivo and in vitro exposure to soils irrigated by wastewaters

    International Nuclear Information System (INIS)

    Qiao Min; Chen Ying; Wang Chunxia; Wang Zijian; Zhu Yongguan

    2007-01-01

    In this study, DNA damage to earthworms (Eisenia fetida) after in vivo exposure to contaminated soils was measured by detecting DNA strand breakages (DSBs) and causality was analyzed through fractionation based bioassays. A non-linear dose-response relationship existed between DNA damage and total soil PAHs levels. DNA damage, measured with the comet assay, and its repair process, were observed. To identify the chemical causality, an in vitro comet assay using coelomocytes was subsequently performed on the fractionated organic extracts from soils. The results showed that the PAHs in the soils were responsible for the exerting genotoxic effects on earthworms. When normalized to benzo(a)pyrene toxic equivalent (TEQ BaP ), the saturation dose in the dose-response curve was about 10 ng TEQ BaP g -1 soil (dw). - A non-linear dose-response relationship exists between earthworm DNA damage, measured with comet assay, and total PAHs levels in soils irrigated by wastewaters

  17. Different domains of P21Cip1/waf1 regulate DNA replication and DNA repair-associated processes after UV

    International Nuclear Information System (INIS)

    Soria, Gaston; Speroni, Juliana; Podhajcer, Osvaldo L.; Gottifredi, Vanesa; Prives, Carol

    2007-01-01

    Full text: Many genotoxic insults result in p21 up-regulation and p21-dependent cell cycle arrest but UV irradiation triggers p21 proteolysis. The significance of the increased p21 turnover is unclear and might be associated to DNA repair. While the role of p21 in Nucleotide Excision Repair (NER) remains controversial, two recent reports explore its effect on Translesion DNA Synthesis (TLS), a process that avoids replication blockage during S phase. The first report shows that p21 degradation is required for efficient PCNA ubiquitination, a post transcriptional modification that is relevant for TLS. The second report demonstrates that p21 (-/-) cells have increased TLS-associated mutagenic rates. Herein we analyze the effect of p21 on different PCNA-driven processes including DNA replication, NER and TLS. Whereas only the CDK binding domain of p21 is required for cell cycle arrest in unstressed cells; neither the CDK- nor the PCNA-binding domains of p21 are able to block early and late steps of NER. Intriguingly, through its PCNA binding domain, p21 inhibited recruitment of the TLS-polymerase, polη to PCNA foci after UV. Moreover, this obstruction correlates with accumulation of γH2AX and increased apoptosis. Taking together, our data emphasizes the link between p21 turnover and efficient TLS. This might also suggest a potential effect of p21 on other activities of polζ, a DNA polymerase with central roles in other biological scenarios such as genetic conversion, homologous recombination and modulation of the cellular response to genotoxic agents [es

  18. The solution of the reliability problem in the repair process of the plates of the silica bricks press boxes

    Directory of Open Access Journals (Sweden)

    Nochvai V.М.

    2017-05-01

    Full Text Available The research analyzes recommendations existing in different sources of information for the choice of methods of strengthening and reconditioning of worn machine parts. These methods include: the method of electric arc deposition, chemical-thermal treatment, gas-powder deposition, gas-powder and plasma spraying, electric arc metallization. As a result of studies of wear of the working surfaces of the plates of silicate brick press boxes, we define that the plates wear out unevenly and the thickness of the worn layer varies between 0.3 ... 2 mm. Technological method is chosen as the method of the plate reliability enhancement and maintaining. One of the main technological stages of reliability formation is machine parts strengthening using the methods of strengthening technologies, namely electric arc metallization. Wire models Нп-65Г, ФМИ-2, Нп-40Х13 are used to develop wear-resistant coatings with desired properties. Technological process of the plates repair consists of the following basic operations: plate preparation, wire preparation, plate coating, plate grinding, final checking. Single and complex reliability indicators are determined by testing a set of the plates and registering all the indicators (operating time, failures, faults. The value of the economic reliability index of the plate Kе equals to 0,10. Higher plate reliability is achieved at the expense of extra cost for plate strengthening using wire Нп-40Х13, and the price of Bн plate reliability is 104,83 UAH. Complex indicators of reliability of the reconditioned plate of the silica bricks press boxes are used for more complete reliability assessment. Availability coefficient Kг. equals to 0,995 and characterizes two different properties simultaneously: reliability and maintainability. Coefficient of technical use Kт.в. equals to 0,974 and most fully characterizes the reliability of the plates because it considers time in the process of maintenance, repair and

  19. Characterization of laser-tissue interaction processes by low-boiling emitted substances

    Science.gov (United States)

    Weigmann, Hans-Juergen; Lademann, Juergen; Serfling, Ulrike; Lehnert, W.; Sterry, Wolfram; Meffert, H.

    1996-01-01

    Main point in this study was the investigation of the gaseous and low-boiling substances produced in the laser plume during cw CO2 laser and XeCl laser irradiation of tissue by gas chromatography (GC)/mass spectrometry. The characteristic emitted amounts of chemicals were determined quantitatively using porcine muscular tissue. The produced components were used to determine the character of the chemical reaction conditions inside the interaction zone. It was found that the temperature, and the water content of the tissue are the main parameter determining kind and amount of the emitted substances. The relative intensity of the GC peak of benzene corresponds to a high temperature inside the interaction area while a relative strong methylbutanal peak is connected with a lower temperature which favors Maillard type reaction products. The water content of the tissue determines the extent of oxidation processes during laser tissue interaction. For that reason the moisture in the tissue is the most important parameter to reduce the emission of harmful chemicals in the laser plume. The same methods of investigation are applicable to characterize the interaction of a controlled and an uncontrolled rf electrosurgery device with tissue. The results obtained with model tissue are in agreement with the situation characteristic in laser surgery.

  20. Measurement of DNA base and nucleotide excision repair activities in mammalian cells and tissues using the comet assay - A methodological overview

    Czech Academy of Sciences Publication Activity Database

    Azqueta, A.; Langie, S. A. S.; Slyšková, Jana; Collins, A. R.

    2013-01-01

    Roč. 12, č. 11 (2013), s. 1007-1010 ISSN 1568-7864 Grant - others:EU FP6(XE) LSHB-CT-2006-037575 Institutional support: RVO:68378041 Keywords : comet assay * base excision repair * nucleotide excision repair Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.362, year: 2013

  1. Development of rheological characterization and twin-screw extrusion/spiral winding processing methods for functionally-graded tissue engineering scaffolds and characterization of cell/biomaterial interactions

    Science.gov (United States)

    Ozkan, Seher

    Tissue engineering involves the fabrication of biodegradable scaffolds, on which various types of cells are grown, to provide tissue constructs for tissue repair/regeneration. Native tissues have complex structures, with functions and properties changing spatially and temporally, and require special tailoring of tissue engineering scaffolds to allow mimicking of their complex elegance. The understanding of the rheological behavior of the biodegradable polymer and the thermo-mechanical history that the polymer experiences during processing is critical in fabricating scaffolds with appropriate microstructural distributions. This study has first focused on the rheological material functions of various gel-like fluids including biofluids and hydrogels, which can emulate the viscoelastic behavior of biofluids. Viscoplasticity and wall slip were recognized as key attributes of such systems. Furthermore, a new technology base involving twin-screw extrusion/spiral winding (TSESW) process was developed for the shaping of functionally-graded scaffolds. This novel scaffold fabrication technology was applied to the development of polycaprolactone (PCL) scaffolds, incorporated with tricalcium phosphate nanoparticles and various porogens in graded fashion. The protein encapsulation and controlled release capabilities of the TSESW process was also demonstrated by dispersing bovine serum albumin (BSA) protein into the PCL matrix. Effects of processing conditions and porosity distributions on compressive properties, surface topography, encapsulation efficiency, release profiles and the secondary structure of BSA were investigated. The PCL scaffolds were determined to be biocompatible, with the proliferation rates of human fetal osteoblast cells (hFOB) increasing with increasing porosity and decreasing concentration of TCP. BSA proteins were determined to be denatured to a greater extent with melt extrusion in the 80-100°C range (in comparison to wet extrusion using organic

  2. Considerations of metal joining processes for space fabrication, construction and repair

    Science.gov (United States)

    Russell, C.; Poorman, R.; Jones, C.; Nunes, A.; Hoffman, D.

    1991-01-01

    A comprehensive evaluation is conducted of candidate processes for metalworking in orbital (vacuum-microgravity) conditions. Attention is given to electron-beam welding, brazing, gas-tungsten arc welding, laser welding, plasma arc welding, and gas-metal arc welding. It is established that several of these processes will be required to cover all foreseeable requirements. Microgravity effects are considered minor, and efforts are being concentrated on problems associated with vacuum conditions and with process-operator safety.

  3. A synergistic approach to the design, fabrication and evaluation of 3D printed micro and nano featured scaffolds for vascularized bone tissue repair

    International Nuclear Information System (INIS)

    Holmes, Benjamin; Bulusu, Kartik; Plesniak, Michael; Zhang, Lijie Grace

    2016-01-01

    3D bioprinting has begun to show great promise in advancing the development of functional tissue/organ replacements. However, to realize the true potential of 3D bioprinted tissues for clinical use requires the fabrication of an interconnected and effective vascular network. Solving this challenge is critical, as human tissue relies on an adequate network of blood vessels to transport oxygen, nutrients, other chemicals, biological factors and waste, in and out of the tissue. Here, we have successfully designed and printed a series of novel 3D bone scaffolds with both bone formation supporting structures and highly interconnected 3D microvascular mimicking channels, for efficient and enhanced osteogenic bone regeneration as well as vascular cell growth. Using a chemical functionalization process, we have conjugated our samples with nano hydroxyapatite (nHA), for the creation of novel micro and nano featured devices for vascularized bone growth. We evaluated our scaffolds with mechanical testing, hydrodynamic measurements and in vitro human mesenchymal stem cell (hMSC) adhesion (4 h), proliferation (1, 3 and 5 d) and osteogenic differentiation (1, 2 and 3 weeks). These tests confirmed bone-like physical properties and vascular-like flow profiles, as well as demonstrated enhanced hMSC adhesion, proliferation and osteogenic differentiation. Additional in vitro experiments with human umbilical vein endothelial cells also demonstrated improved vascular cell growth, migration and organization on micro-nano featured scaffolds. (paper)

  4. A synergistic approach to the design, fabrication and evaluation of 3D printed micro and nano featured scaffolds for vascularized bone tissue repair

    Science.gov (United States)

    Holmes, Benjamin; Bulusu, Kartik; Plesniak, Michael; Zhang, Lijie Grace

    2016-02-01

    3D bioprinting has begun to show great promise in advancing the development of functional tissue/organ replacements. However, to realize the true potential of 3D bioprinted tissues for clinical use requires the fabrication of an interconnected and effective vascular network. Solving this challenge is critical, as human tissue relies on an adequate network of blood vessels to transport oxygen, nutrients, other chemicals, biological factors and waste, in and out of the tissue. Here, we have successfully designed and printed a series of novel 3D bone scaffolds with both bone formation supporting structures and highly interconnected 3D microvascular mimicking channels, for efficient and enhanced osteogenic bone regeneration as well as vascular cell growth. Using a chemical functionalization process, we have conjugated our samples with nano hydroxyapatite (nHA), for the creation of novel micro and nano featured devices for vascularized bone growth. We evaluated our scaffolds with mechanical testing, hydrodynamic measurements and in vitro human mesenchymal stem cell (hMSC) adhesion (4 h), proliferation (1, 3 and 5 d) and osteogenic differentiation (1, 2 and 3 weeks). These tests confirmed bone-like physical properties and vascular-like flow profiles, as well as demonstrated enhanced hMSC adhesion, proliferation and osteogenic differentiation. Additional in vitro experiments with human umbilical vein endothelial cells also demonstrated improved vascular cell growth, migration and organization on micro-nano featured scaffolds.

  5. Fresh and Frozen Tissue-Engineered Three-Dimensional Bone–Ligament–Bone Constructs for Sheep Anterior Cruciate Ligament Repair Following a 2-Year Implantation

    Directory of Open Access Journals (Sweden)

    Vasudevan Mahalingam

    2016-10-01

    Full Text Available njuries to the anterior cruciate ligament (ACL often require surgical reconstruction utilizing tendon grafts to restore knee function and stability. Some current graft options for ACL repair are associated with poor long-term outcomes. Our laboratory has fabricated tissue-engineered bone–ligament–bone (BLB constructs that demonstrate native ligament regeneration and advancement toward native ACL mechanical properties in a sheep ACL reconstruction model. Prior work has shown that freezing BLBs as a method of preservation resulted in similar outcomes compared with fresh BLBs after 6-month implantation. The purpose of this study was to evaluate the long-term efficacy of fresh and frozen BLBs. We hypothesized that both fresh and frozen BLBs would show continued regeneration of structural and functional properties toward those of native ACL after a 2-year implantation. Following removal of the native ACL, fresh (n = 2 and frozen (n = 2 BLBs were implanted arthroscopically. After 2 years of recovery, sheep were euthanized and both the experimental and contralateral hindlimbs were removed and radiographs were performed. Explanted knees were initially evaluated for joint laxity and were then further dissected for uniaxial tensile testing of the isolated ACL or BLB. Following mechanical testing, explanted contralateral ACL (C-ACL and BLBs were harvested for histology. Two years post-ACL reconstruction, fresh and frozen BLBs exhibited similar morphological and biomechanical properties as well as more advanced regeneration compared with our 6-month recovery study. These data indicate that an additional 1.5-year regeneration period allows the BLB to continue ligament regeneration in vivo. In addition, freezing the BLBs is a viable option for the preservation of the graft after fabrication.

  6. Repair mechanisms and exposure standards

    International Nuclear Information System (INIS)

    Mills, W.A.

    1978-01-01

    The following topics are discussed; public policy for setting radiation standards; use of linear, nonthreshold theory in setting radiation standards; dose-rate dependence; occupational exposure to radiation; radon inhalation from radium in the soil in the vicinity of the phosphate industry; relation of repair mechanisms for cell survival to cancer induction; application of information on genetic repair to humans and to cancer induction; importance of repair processes in radiation protection standards; corrective factors for repair processes; relation of repair processes to age, sex, and other factors; and population distribution in radiosensitivity

  7. Repairing organs: lessons from intestine and liver

    OpenAIRE

    Gehart Helmuth; Clevers Hans

    2015-01-01

    The concept of organ regeneration has fascinated humanity from ancient mythology to modern science fiction. Recent advances offer the potential to soon bring such technology within the grasp of clinical medicine. Rapidly expanding insights into the intrinsic repair processes of the intestine and liver have uncovered significant plasticity in epithelial tissues. Harnessing this knowledge researchers have recently created culture systems that enable the expansion of stem cells into transplantab...

  8. Different methods of dentin processing for application in bone tissue engineering: A systematic review.

    Science.gov (United States)

    Tabatabaei, Fahimeh Sadat; Tatari, Saeed; Samadi, Ramin; Moharamzadeh, Keyvan

    2016-10-01

    Dentin has become an interesting potential biomaterial for tissue engineering of oral hard tissues. It can be used as a scaffold or as a source of growth factors in bone tissue engineering. Different forms of dentin have been studied for their potential use as bone substitutes. Here, we systematically review different methods of dentin preparation and the efficacy of processed dentin in bone tissue engineering. An electronic search was carried out in PubMed and Scopus databases for articles published from 2000 to 2016. Studies on dentin preparation for application in bone tissue engineering were selected. The initial search yielded a total of 1045 articles, of which 37 were finally selected. Review of studies showed that demineralization was the most commonly used dentin preparation process for use in tissue engineering. Dentin extract, dentin particles (tooth ash), freeze-dried dentin, and denatured dentin are others method of dentin preparation. Based on our literature review, we can conclude that preparation procedure and the size and shape of dentin particles play an important role in its osteoinductive and osteoconductive properties. Standardization of these methods is important to draw a conclusion in this regard. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2616-2627, 2016. © 2016 Wiley Periodicals, Inc.

  9. Combining rhinoplasty with septal perforation repair.

    Science.gov (United States)

    Foda, Hossam M T; Magdy, Emad A

    2006-11-01

    A combined septal perforation repair and rhinoplasty was performed in 80 patients presenting with septal perforations (size 1 to 5 cm) and external nasal deformities. The external rhinoplasty approach was used for all cases and the perforation was repaired using bilateral intranasal mucosal advancement flaps with a connective tissue interposition graft in between. Complete closure of the perforation was achieved in 90% of perforations of size up to 3.5 cm and in only 70% of perforations that were larger than 3.5 cm. Cosmetically, 95% were very satisfied with their aesthetic result. The external rhinoplasty approach proved to be very helpful in the process of septal perforation repair especially in large and posteriorly located perforations and in cases where the caudal septal cartilage was previously resected. Our results show that septal perforation repair can be safely combined with rhinoplasty and that some of the routine rhinoplasty maneuvers, such as medial osteotomies and dorsal lowering, could even facilitate the process of septal perforation repair.

  10. Sensory processing of deep tissue nociception in the rat spinal cord and thalamic ventrobasal complex.

    Science.gov (United States)

    Sikandar, Shafaq; West, Steven J; McMahon, Stephen B; Bennett, David L; Dickenson, Anthony H

    2017-07-01

    Sensory processing of deep somatic tissue constitutes an important component of the nociceptive system, yet associated central processing pathways remain poorly understood. Here, we provide a novel electrophysiological characterization and immunohistochemical analysis of neural activation in the lateral spinal nucleus (LSN). These neurons show evoked activity to deep, but not cutaneous, stimulation. The evoked responses of neurons in the LSN can be sensitized to somatosensory stimulation following intramuscular hypertonic saline, an acute model of muscle pain, suggesting this is an important spinal relay site for the processing of deep tissue nociceptive inputs. Neurons of the thalamic ventrobasal complex (VBC) mediate both cutaneous and deep tissue sensory processing, but in contrast to the lateral spinal nucleus our electrophysiological studies do not suggest the existence of a subgroup of cells that selectively process deep tissue inputs. The sensitization of polymodal and thermospecific VBC neurons to mechanical somatosensory stimulation following acute muscle stimulation with hypertonic saline suggests differential roles of thalamic subpopulations in mediating cutaneous and deep tissue nociception in pathological states. Overall, our studies at both the spinal (lateral spinal nucleus) and supraspinal (thalamic ventrobasal complex) levels suggest a convergence of cutaneous and deep somatosensory inputs onto spinothalamic pathways, which are unmasked by activation of muscle nociceptive afferents to produce consequent phenotypic alterations in spinal and thalamic neural coding of somatosensory stimulation. A better understanding of the sensory pathways involved in deep tissue nociception, as well as the degree of labeled line and convergent pathways for cutaneous and deep somatosensory inputs, is fundamental to developing targeted analgesic therapies for deep pain syndromes. © 2017 University College London. Physiological Reports published by Wiley Periodicals

  11. Reduction in Repair rate of Welding Processes by Determination & Controlling of Critical KPIVs

    Directory of Open Access Journals (Sweden)

    Faheem Yousaf

    2014-01-01

    Full Text Available Six Sigma is being Implemented all over the World as a successful Quality Improvement Methodology. Many Companies are now days are using Six Sigma as an Approach towards zero defects. This article provides a practical case study regarding the implementation of Six Sigma Project in a Welding Facility and discusses the Statistical Analysis performed for bringing the welding processes in the desired sigma Limits.DMAIC was chosen as potential Six Sigma methodology with the help of findings of this Methodology, Six Sigma Team First Identified the critical Factors affecting the Process Yield and then certain Improvement Measures were taken to improve the Capability of Individual welding Processes and also of Overall Welding Facility.   Cost of Quality was also measured to Validate the Improvement results achieved after Conducting the Six Sigma Project.

  12. DNA double-strand-break complexity levels and their possible contributions to the probability for error-prone processing and repair pathway choice.

    Science.gov (United States)

    Schipler, Agnes; Iliakis, George

    2013-09-01

    Although the DNA double-strand break (DSB) is defined as a rupture in the double-stranded DNA molecule that can occur without chemical modification in any of the constituent building blocks, it is recognized that this form is restricted to enzyme-induced DSBs. DSBs generated by physical or chemical agents can include at the break site a spectrum of base alterations (lesions). The nature and number of such chemical alterations define the complexity of the DSB and are considered putative determinants for repair pathway choice and the probability that errors will occur during this processing. As the pathways engaged in DSB processing show distinct and frequently inherent propensities for errors, pathway choice also defines the error-levels cells opt to accept. Here, we present a classification of DSBs on the basis of increasing complexity and discuss how complexity may affect processing, as well as how it may cause lethal or carcinogenic processing errors. By critically analyzing the characteristics of DSB repair pathways, we suggest that all repair pathways can in principle remove lesions clustering at the DSB but are likely to fail when they encounter clusters of DSBs that cause a local form of chromothripsis. In the same framework, we also analyze the rational of DSB repair pathway choice.

  13. A quantitative and non-contact technique to characterise microstructural variations of skin tissues during photo-damaging process based on Mueller matrix polarimetry.

    Science.gov (United States)

    Dong, Yang; He, Honghui; Sheng, Wei; Wu, Jian; Ma, Hui

    2017-10-31

    Skin tissue consists of collagen and elastic fibres, which are highly susceptible to damage when exposed to ultraviolet radiation (UVR), leading to skin aging and cancer. However, a lack of non-invasive detection methods makes determining the degree of UVR damage to skin in real time difficult. As one of the fundamental features of light, polarization can be used to develop imaging techniques capable of providing structural information about tissues. In particular, Mueller matrix polarimetry is suitable for detecting changes in collagen and elastic fibres. Here, we demonstrate a novel, quantitative, non-contact and in situ technique based on Mueller matrix polarimetry for monitoring the microstructural changes of skin tissues during UVR-induced photo-damaging. We measured the Mueller matrices of nude mouse skin samples, then analysed the transformed parameters to characterise microstructural changes during the skin photo-damaging and self-repairing processes. Comparisons between samples with and without the application of a sunscreen showed that the Mueller matrix-derived parameters are potential indicators for fibrous microstructure in skin tissues. Histological examination and Monte Carlo simulations confirmed the relationship between the Mueller matrix parameters and changes to fibrous structures. This technique paves the way for non-contact evaluation of skin structure in cosmetics and dermatological health.

  14. A Tissue Retrieval and Postharvest Processing Regimen for Rodent Reproductive Tissues Compatible with Long-Term Storage on the International Space Station and Postflight Biospecimen Sharing Program

    Directory of Open Access Journals (Sweden)

    Vijayalaxmi Gupta

    2015-01-01

    Full Text Available Collection and processing of tissues to preserve space flight effects from animals after return to Earth is challenging. Specimens must be harvested with minimal time after landing to minimize postflight readaptation alterations in protein expression/translation, posttranslational modifications, and expression, as well as changes in gene expression and tissue histological degradation after euthanasia. We report the development of a widely applicable strategy for determining the window of optimal species-specific and tissue-specific posteuthanasia harvest that can be utilized to integrate into multi-investigator Biospecimen Sharing Programs. We also determined methods for ISS-compatible long-term tissue storage (10 months at −80°C that yield recovery of high quality mRNA and protein for western analysis after sample return. Our focus was reproductive tissues. The time following euthanasia where tissues could be collected and histological integrity was maintained varied with tissue and species ranging between 1 and 3 hours. RNA quality was preserved in key reproductive tissues fixed in RNAlater up to 40 min after euthanasia. Postfixation processing was also standardized for safe shipment back to our laboratory. Our strategy can be adapted for other tissues under NASA’s Biospecimen Sharing Program or similar multi-investigator tissue sharing opportunities.

  15. Aberrant repair and fibrosis development in skeletal muscle

    Directory of Open Access Journals (Sweden)

    Mann Christopher J

    2011-05-01

    Full Text Available Abstract The repair process of damaged tissue involves the coordinated activities of several cell types in response to local and systemic signals. Following acute tissue injury, infiltrating inflammatory cells and resident stem cells orchestrate their activities to restore tissue homeostasis. However, during chronic tissue damage, such as in muscular dystrophies, the inflammatory-cell infiltration and fibroblast activation persists, while the reparative capacity of stem cells (satellite cells is attenuated. Abnormal dystrophic muscle repair and its end stage, fibrosis, represent the final common pathway of virtually all chronic neurodegenerative muscular diseases. As our understanding of the pathogenesis of muscle fibrosis has progressed, it has become evident that the muscle provides a useful model for the regulation of tissue repair by the local microenvironment, showing interplay among muscle-specific stem cells, inflammatory cells, fibroblasts and extracellular matrix components of the mammalian wound-healing response. This article reviews the emerging findings of the mechanisms that underlie normal versus aberrant muscle-tissue repair.

  16. In vivo and in situ investigative results of repair and recovery processes during ontogenesis, after X-ray irradiation of bean seeds

    International Nuclear Information System (INIS)

    Koeroesi, F.; Jezierska-Szabo, E.; Szoeke, P.

    1999-01-01

    When exposing plant organs to high doses of ionizing radiation, disorders in growth and development or even lethality may occur. With the aim of modelling this phenomenon, seeds of bean, variety Echo Elit, were irradiated with a 300 Gy dose of X-ray irradiation (120 kV; 4.5 mA). In order to characterize repair and recovery at plant level, the biological production and photosynthetic pigments of the plants during ontogenesis in vivo and changes in their electric capacitance were continuously monitored and recorded via a computer-aided and -controlled data acquisition system. According to the data obtained, the repair in the biosynthesis of photosynthetic pigments will have been completed by the beginning of flowering. It may be assumed from the capacitance measurements made at 11 a.m. According to this postulation the process of repairing X-ray injuries might be finished by the beginning of pod formation without the plants actually recovering. (author)

  17. Current concepts in repair of extremity venous injury.

    Science.gov (United States)

    Williams, Timothy K; Clouse, W Darrin

    2016-04-01

    Extremity venous injury management remains controversial. The purpose of this communication is to offer perspective as well as experiential and technical insight into extremity venous injury repair. Available literature is reviewed and discussed. Historical context is provided. Indication, the decision process for repair, including technical conduct, is delineated. In particular, the authors' experiences in both civilian and wartime injury are used for perspective. Extremity venous injury repair was championed within data from the Vietnam Vascular Registry. However, patterns of extremity venous injury differ between combat and civilian settings. Since Vietnam, civilian descriptive series opine the benefits and potential complications associated with both venous injury repair and ligation. These surround extremity edema, chronic venous insufficiency, thromboembolism, and limb loss. Whereas no clear superiority in either approach has been identified to date, there appears to be no increased risk of pulmonary embolism or chronic venous changes with repair. Newer data from the wars in Iraq and Afghanistan and meta-analysis have reinforced this and also have suggested limb salvage benefit for extremity venous repair in combined arterial and venous injuries in modern settings. The patient's physiologic state and associated injury drive five triage categories suggesting vein injury management. Vein repair thrombosis occurs in a significant proportion, yet many recanalize and possibly have a positive impact on limb venous return. Further, early decompression favors reduced blood loss, acute edema, and inflammation, supporting collateral development. Large soft tissue injury minimizing collateral capacity increases the importance of repair. Constructs of repair are varied with modest differences in patency. Venous shunting is feasible, but specific roles remain nebulous. An aggressive posture toward extremity venous injury repair seems justified today because of the likely

  18. A Fully Contained Resin Infusion Process for Fiber-Reinforced Polymer Composite Fabrication and Repair

    Science.gov (United States)

    2013-01-01

    Figures iv  Acknowledgments v  1.  Introduction 1  2.  Experimental 2  2.1  Composite Laminate Fabrication...2 Figure 2. Image of fiberglass composite being fabricated using VARTM processing. 2. Experimental 2.1 Composite Laminate Fabrication...style 5 × 5 plain 5 weave prepreg S-2 fiberglass fabric and a honeycomb core cured in an autoclave, much like the composite parts fielded in

  19. Examination of the skin barrier repair/wound healing process using a living skin equivalent model and matrix-assisted laser desorption-ionization-mass spectrometry imaging.

    Science.gov (United States)

    Lewis, E E L; Barrett, M R T; Freeman-Parry, L; Bojar, R A; Clench, M R

    2018-04-01

    Examination of the skin barrier repair/wound healing process using a living skin equivalent (LSE) model and matrix-assisted laser desorption/ionization-mass spectrometry imaging (MALDI-MSI) to identify lipids directly involved as potential biomarkers. These biomarkers may be used to determine whether an in vivo wound is going to heal for example if infected. An in vitro LSE model was wounded with a scalpel blade and assessed at day 4 post-wounding by histology and MALDI-MSI. Samples were sectioned at wound site and were either formalin-fixed paraffin-embedded (FFPE) for histology or snapped frozen (FF) for MSI analysis. The combination of using an in vitro wounded skin model with MSI allowed the identification of lipids involved in the skin barrier repair/wound healing process. The technique was able to highlight lipids directly in the wound site and distinguish differences in lipid distribution between the epidermis and wound site. This novel method of coupling an in vitro LSE with MSI allowed in-depth molecular analysis of the skin barrier repair/wound healing process. The technique allowed the identification of lipids directly involved in the skin barrier repair/wound healing process, indicating these biomarkers may be potentially be used within the clinic. These biomarkers will help to determine, which stage of the skin barrier repair/wound healing process the wound is in to provide the best treatment. © 2018 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

  20. Microstructure alterations in beef intramuscular connective tissue caused by hydrodynamic pressure processing

    Science.gov (United States)

    Scanning electron microscopy (SEM) was utilized to evaluate microstructural changes in intramuscular connective tissue of beef semimembranosus muscle subjected to hydrodynamic pressure processing (HDP). Samples were HDP treated in a plastic container (HDP-PC) or a steel commercial unit (HDP-CU). C...

  1. Photothermal effects of laser tissue soldering

    International Nuclear Information System (INIS)

    McNally, K.M.; Sorg, B.S.; Welch, A.J.; Dawes, J.M.; Owen, E.R.

    1999-01-01

    Low-strength anastomoses and thermal damage of tissue are major concerns in laser tissue welding techniques where laser energy is used to induce thermal changes in the molecular structure of the tissues being joined, hence allowing them to bond together. Laser tissue soldering, on the other hand, is a bonding technique in which a protein solder is applied to the tissue surfaces to be joined, and laser energy is used to bond the solder to the tissue surfaces. The addition of protein solders to augment tissue repair procedures significantly reduces the problems of low strength and thermal damage associated with laser tissue welding techniques. Investigations were conducted to determine optimal solder and laser parameters for tissue repair in terms of tensile strength, temperature rise and damage and the microscopic nature of the bonds formed. An in vitro study was performed using an 808 nm diode laser in conjunction with indocyanine green (ICG)-doped albumin protein solders to repair bovine aorta specimens. Liquid and solid protein solders prepared from 25% and 60% bovine serum albumin (BSA), respectively, were compared. The efficacy of temperature feedback control in enhancing the soldering process was also investigated. Increasing the BSA concentration from 25% to 60% greatly increased the tensile strength of the repairs. A reduction in dye concentration from 2.5mgml -1 to 0.25mgml -1 was also found to result in an increase in tensile strength. Increasing the laser irradiance and thus surface temperature resulted in an increased severity of histological injury. Thermal denaturation of tissue collagen and necrosis of the intimal layer smooth muscle cells increased laterally and in depth with higher temperatures. The strongest repairs were produced with an irradiance of 6.4Wcm -2 using a solid protein solder composed of 60% BSA and 0.25mgml -1 ICG. Using this combination of laser and solder parameters, surface temperatures were observed to reach 85±5 deg. C with a

  2. Reward optimization of a repairable system

    Energy Technology Data Exchange (ETDEWEB)

    Castro, I.T. [Departamento de Matematicas, Facultad de Veterinaria, Universidad de Extremadura, Avenida de la Universidad, s/n. 10071 Caceres (Spain)]. E-mail: inmatorres@unex.es; Perez-Ocon, R. [Departamento de Estadistica e Investigacion Operativa, Facultad de Ciencias, Universidad de Granada, Avenida de Severo Ochoa, s/n. 18071 Granada (Spain)]. E-mail: rperezo@ugr.es

    2006-03-15

    This paper analyzes a system subject to repairable and non-repairable failures. Non-repairable failures lead to replacement of the system. Repairable failures, first lead to repair but they lead to replacement after a fixed number of repairs. Operating and repair times follow phase type distributions (PH-distributions) and the pattern of the operating times is modelled by a geometric process. In this context, the problem is to find the optimal number of repairs, which maximizes the long-run average reward per unit time. To this end, the optimal number is determined and it is obtained by efficient numerical procedures.

  3. Reward optimization of a repairable system

    International Nuclear Information System (INIS)

    Castro, I.T.; Perez-Ocon, R.

    2006-01-01

    This paper analyzes a system subject to repairable and non-repairable failures. Non-repairable failures lead to replacement of the system. Repairable failures, first lead to repair but they lead to replacement after a fixed number of repairs. Operating and repair times follow phase type distributions (PH-distributions) and the pattern of the operating times is modelled by a geometric process. In this context, the problem is to find the optimal number of repairs, which maximizes the long-run average reward per unit time. To this end, the optimal number is determined and it is obtained by efficient numerical procedures

  4. Review on patents for mechanical stimulation of articular cartilage tissue engineering

    NARCIS (Netherlands)

    Donkelaar, van C.C.; Schulz, R.M.

    2008-01-01

    To repair articular cartilage defects in osteoarthritic patients with three-dimensional tissue engineered chondrocyte grafts, requires the formation of new cartilage with sufficient mechanical properties. The premise is that mechanical stimulation during the culturing process is necessary to reach

  5. Effect-independent measures of tissue response to fractionated radiation

    International Nuclear Information System (INIS)

    Thames, H.D.

    1984-01-01

    Tissue repair factors are measures of sparing from dose fractionation, in the absence of proliferation. A desirable feature of any repair factor is that it be independent of the level of injury induced in the tissue, since otherwise the comparison of tissues on the basis of the factor would not be meaningful. The repair factors F/sub R/ and F/sub rec/ are increasing functions of D/sub 1/, and depend on level of skin reaction after fractionated radiation. By contrast, β/α is effect-independent as a measure of repair capacity in skin, gut, and bone marrow. For late fibrotic reactions in the kidney, there was an increase in β/α with increased levels of injury that was statistically insignificant. The halftime, T/sub 1/2/, for intracellular repair processes in tissues is a measure of repair kinetics. Effect-independence is defend for T/sub 1/2/ as independence from size of dose per fraction. T/sub 1/2/ is independent of fraction size in skin, gut, and spinal cord, and is longer (1.5 hours) in the late-reacting tissues (lung and spinal cord) than in those that react acutely (less than 1 hour), with skin as the exception (1.3 hours). Therefore, early and late-responding normal tissues may be distinguished in terms of both repair capacity and repair kinetics: repair is slower in late-responding tissues, which are also more sensitive to changes in dose fractionation

  6. Poorly processed reusable surface disinfection tissue dispensers may be a source of infection.

    Science.gov (United States)

    Kampf, Günter; Degenhardt, Stina; Lackner, Sibylle; Jesse, Katrin; von Baum, Heike; Ostermeyer, Christiane

    2014-01-21

    Reusable surface disinfectant tissue dispensers are used in hospitals in many countries because they allow immediate access to pre-soaked tissues for targeted surface decontamination. On the other hand disinfectant solutions with some active ingredients may get contaminated and cause outbreaks. We determined the frequency of contaminated surface disinfectant solutions in reusable dispensers and the ability of isolates to multiply in different formulations. Reusable tissue dispensers with different surface disinfectants were randomly collected from healthcare facilities. Solutions were investigated for bacterial contamination. The efficacy of two surface disinfectants was determined in suspension tests against two isolated species directly from a contaminated solution or after 5 passages without selection pressure in triplicate. Freshly prepared use solutions were contaminated to determine survival of isolates. 66 dispensers containing disinfectant solutions with surface-active ingredients were collected in 15 healthcare facilities. 28 dispensers from nine healthcare facilities were contaminated with approximately 107 cells per mL of Achromobacter species 3 (9 hospitals), Achromobacter xylosoxidans or Serratia marcescens (1 hospital each). In none of the hospitals dispenser processing had been adequately performed. Isolates regained susceptibility to the disinfectants after five passages without selection pressure but were still able to multiply in different formulations from different manufacturers at room temperature within 7 days. Neglecting adequate processing of surface disinfectant dispensers has contributed to frequent and heavy contamination of use-solutions based on surface active ingredients. Tissue dispenser processing should be taken seriously in clinical practice.

  7. Robust multi-site MR data processing: iterative optimization of bias correction, tissue classification, and registration.

    Science.gov (United States)

    Young Kim, Eun; Johnson, Hans J

    2013-01-01

    A robust multi-modal tool, for automated registration, bias correction, and tissue classification, has been implemented for large-scale heterogeneous multi-site longitudinal MR data analysis. This work focused on improving the an iterative optimization framework between bias-correction, registration, and tissue classification inspired from previous work. The primary contributions are robustness improvements from incorporation of following four elements: (1) utilize multi-modal and repeated scans, (2) incorporate high-deformable registration, (3) use extended set of tissue definitions, and (4) use of multi-modal aware intensity-context priors. The benefits of these enhancements were investigated by a series of experiments with both simulated brain data set (BrainWeb) and by applying to highly-heterogeneous data from a 32 site imaging study with quality assessments through the expert visual inspection. The implementation of this tool is tailored for, but not limited to, large-scale data processing with great data variation with a flexible interface. In this paper, we describe enhancements to a joint registration, bias correction, and the tissue classification, that improve the generalizability and robustness for processing multi-modal longitudinal MR scans collected at multi-sites. The tool was evaluated by using both simulated and simulated and human subject MRI images. With these enhancements, the results showed improved robustness for large-scale heterogeneous MRI processing.

  8. DNA damage and repair process in earthworm after in-vivo and in vitro exposure to soils irrigated by wastewaters

    Energy Technology Data Exchange (ETDEWEB)

    Qiao Min [State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Chen Ying [State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Wang Chunxia [State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Wang Zijian [State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China)]. E-mail: wangzj@rcees.ac.cn; Zhu Yongguan [State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China)

    2007-07-15

    In this study, DNA damage to earthworms (Eisenia fetida) after in vivo exposure to contaminated soils was measured by detecting DNA strand breakages (DSBs) and causality was analyzed through fractionation based bioassays. A non-linear dose-response relationship existed between DNA damage and total soil PAHs levels. DNA damage, measured with the comet assay, and its repair process, were observed. To identify the chemical causality, an in vitro comet assay using coelomocytes was subsequently performed on the fractionated organic extracts from soils. The results showed that the PAHs in the soils were responsible for the exerting genotoxic effects on earthworms. When normalized to benzo(a)pyrene toxic equivalent (TEQ{sub BaP}), the saturation dose in the dose-response curve was about 10 ng TEQ{sub BaP} g{sup -1} soil (dw). - A non-linear dose-response relationship exists between earthworm DNA damage, measured with comet assay, and total PAHs levels in soils irrigated by wastewaters.

  9. Detoxification and repair process of ozone injury: From O{sub 3} uptake to gene expression adjustment

    Energy Technology Data Exchange (ETDEWEB)

    Castagna, A., E-mail: castagna@agr.unipi.i [Department of Agricultural Chemistry and Biotechnology, University of Pisa, Via del Borghetto 80, 56124 Pisa (Italy); Ranieri, A., E-mail: aranieri@agr.unipi.i [Department of Agricultural Chemistry and Biotechnology, University of Pisa, Via del Borghetto 80, 56124 Pisa (Italy)

    2009-05-15

    Plants react to O{sub 3} threat by setting up a variety of defensive strategies involving the co-ordinated modulation of stress perception, signalling and metabolic responses. Although stomata largely controls O{sub 3} uptake, differences in O{sub 3} tolerance cannot always be ascribed to changes in stomatal conductance but cell protective and repair processes should be taken into account. O{sub 3}-driven ROS production in the apoplast induces a secondary, active, self-propagating generation of ROS, whose levels must be finely tuned, by many enzymatic and non-enzymatic antioxidant systems, to induce gene activation without determining uncontrolled cell death. Additional signalling molecules, as ethylene, jasmonic and salicylic acid are also crucial to determine the spreading and the containment of leaf lesions. The main recent results obtained on O{sub 3} sensing, signal transduction, ROS formation and detoxification mechanisms are here discussed. - A dissection of the complex network of interacting mechanisms which determine the cell fate under ozone stress.

  10. Ultraviolet Light Surface Treatment as an Environmentally Benign Process for Production, Maintenance and Repair of Military Composite Structures

    National Research Council Canada - National Science Library

    Drzal, Lawrence T

    2002-01-01

    The principal objective of this work is to develop a low-cost, high-speed, environmentally benign, dry surface treatment method for production, and repair of military composite structures using ultraviolet (UV...

  11. Improving Aviation Depot Level Repairable (AVDLR) Inventory and Repair Management

    National Research Council Canada - National Science Library

    Baird, Dennis

    1997-01-01

    .... Additionally, research was conducted to document the management process for determining repair requirements at the Naval Inventory Control Point Philadelphia and how those requirements are accepted...

  12. Odorants could elicit repair processes in melanized neuronal and skin cells

    Directory of Open Access Journals (Sweden)

    Barbara Pavan

    2017-01-01

    Full Text Available The expression of ectopic olfactory receptors (ORs in melanized cells, such as the human brain nigrostriatal dopaminergic neurons and skin melanocytes, is here pointed out. ORs are recognized to regulate skin melanogenesis, whereas OR expression in the dopaminergic neurons, characterized by accumulation of pigment neuromelanin, is downregulated in Parkinson's disease. Furthermore, the correlation between the pigmentation process and the dopamine pathway through α-synuclein expression is also highlighted. Purposely, these ORs are suggested as therapeutic target for neurodegenerative diseases related to the pigmentation disorders. Based on this evidence, a possible way of turning odorants into drugs, acting on three specific olfactory receptors, OR51E2, OR2AT4 and VN1R1, is thus introduced. Various odorous molecules are shown to interact with these ORs and their therapeutic potential against melanogenic and neurodegenerative dysfunctions, including melanoma and Parkinson's disease, is suggested. Finally, a direct functional link between olfactory and endocrine systems in human brain through VN1R1 is proposed, helping to counteract female susceptibility to Parkinson's disease in quiescent life.

  13. Carboxyl-modified single-wall carbon nanotubes improve bone tissue formation in vitro and repair in an in vivo rat model

    Directory of Open Access Journals (Sweden)

    Barrientos-Durán A

    2014-09-01

    combination of demineralized bone matrix or cartilage particles with SWCNTs were implanted into nude rats, and ectopic bone formation was analyzed. Histological analysis of both types of implants showed high permeability and pore connectivity of the carbon nanotube-soaked implants. Numerous vascularization channels appeared in the formed tissue, additional progenitor cells were recruited, and areas of de novo ossification were found 4 weeks post-implantation. Induction of the expression of bone-related genes and the presence of secreted osteopontin protein were also confirmed by quantitative polymerase chain reaction analysis and immunofluorescence, respectively. In summary, these results are in line with prior contributions that highlight the suitability of SWCNTs as scaffolds with high bone-inducing capabilities both in vitro and in vivo, confirming them as alternatives to current bone-repair therapies. Keywords: human allografts, demineralized bone matrix, cartilage particles, bone regeneration

  14. Genetic variations in DNA repair genes, radiosensitivity to cancer and susceptibility to acute tissue reactions in radiotherapy-treated cancer patients

    International Nuclear Information System (INIS)

    Chistiakov, Dimitry A.; Voronova, Natalia V.; Chistiakov, Pavel A.

    2008-01-01

    Ionizing radiation is a well established carcinogen for human cells. At low doses, radiation exposure mainly results in generation of double strand breaks (DSBs). Radiation-related DSBs could be directly linked to the formation of chromosomal rearrangements as has been proven for radiation-induced thyroid tumors. Repair of DSBs presumably involves two main pathways, non-homologous end joining (NHEJ) and homologous recombination (HR). A number of known inherited syndromes, such as ataxia telangiectasia, ataxia-telangiectasia like-disorder, radiosensitive severe combined immunodeficiency, Nijmegen breakage syndrome, and LIG4 deficiency are associated with increased radiosensitivity and/or cancer risk. Many of them are caused by mutations in DNA repair genes. Recent studies also suggest that variations in the DNA repair capacity in the general population may influence cancer susceptibility. In this paper, we summarize the current status of DNA repair proteins as potential targets for radiation-induced cancer risk. We will focus on genetic alterations in genes involved in HR- and NHEJ-mediated repair of DSBs, which could influence predisposition to radiation-related cancer and thereby explain interindividual differences in radiosensitivity or radioresistance in a general population

  15. Genetic variations in DNA repair genes, radiosensitivity to cancer and susceptibility to acute tissue reactions in radiotherapy-treated cancer patients

    Energy Technology Data Exchange (ETDEWEB)

    Chistiakov, Dimitry A. (Dept. of Pathology, Univ. of Pittsburgh, Pittsburgh (US)); Voronova, Natalia V. (Dept. of Molecular Diagnostics, National Research Center GosNIIgenetika, Moscow (RU)); Chistiakov, Pavel A. (Dept. of Radiology, Cancer Research Center, Moscow (RU))

    2008-06-15

    Ionizing radiation is a well established carcinogen for human cells. At low doses, radiation exposure mainly results in generation of double strand breaks (DSBs). Radiation-related DSBs could be directly linked to the formation of chromosomal rearrangements as has been proven for radiation-induced thyroid tumors. Repair of DSBs presumably involves two main pathways, non-homologous end joining (NHEJ) and homologous recombination (HR). A number of known inherited syndromes, such as ataxia telangiectasia, ataxia-telangiectasia like-disorder, radiosensitive severe combined immunodeficiency, Nijmegen breakage syndrome, and LIG4 deficiency are associated with increased radiosensitivity and/or cancer risk. Many of them are caused by mutations in DNA repair genes. Recent studies also suggest that variations in the DNA repair capacity in the general population may influence cancer susceptibility. In this paper, we summarize the current status of DNA repair proteins as potential targets for radiation-induced cancer risk. We will focus on genetic alterations in genes involved in HR- and NHEJ-mediated repair of DSBs, which could influence predisposition to radiation-related cancer and thereby explain interindividual differences in radiosensitivity or radioresistance in a general population

  16. A new incomplete-repair model based on a ''reciprocal-time'' pattern of sublethal damage repair

    International Nuclear Information System (INIS)

    Dale, R.G.; Fowler, J.F.

    1999-01-01

    A radiobiological model for closely spaced non-instantaneous radiation fractions is presented, based on the premise that the time process of sublethal damage (SLD) repair is 'reciprocal-time' (second order), rather than exponential (first order), in form. The initial clinical implications of such an incomplete-repair model are assessed. A previously derived linear-quadratic-based model was revised to take account of the possibility that SLD may repair with time such that the fraction of an element of initial damage remaining at time t is given as 1/(1+zt), where z is an appropriate rate constant; z is the reciprocal of the first half-time (τ) of repair. The general equation so derived for incomplete repair is applicable to all types of radiotherapy delivered at high, low and medium dose-rate in fractions delivered at regular time intervals. The model allows both the fraction duration and interfraction intervals to vary between zero and infinity. For any given value of z, reciprocal repair is associated with an apparent 'slowing-down' in the SLD repair rate as treatment proceeds. The instantaneous repair rates are not directly governed by total dose or dose per fraction, but are influenced by the treatment duration and individual fraction duration. Instantaneous repair rates of SLD appear to be slower towards the end of a continuous treatment, and are also slower following 'long' fractions than they are following 'short' fractions. The new model, with its single repair-rate parameter, is shown to be capable of providing a degree of quantitative explanation for some enigmas that have been encountered in clinical studies. A single-component reciprocal repair process provides an alternative explanation for the apparent existence of a range of repair rates in human tissues, and which have hitherto been explained by postulating the existence of a multi-exponential repair process. The build-up of SLD over extended treatments is greater than would be inferred using a

  17. Relationship of DNA repair processes to mutagenesis and carcinogenesis in mammalian cells. Progress report, August 1, 1977-October 31, 1980

    International Nuclear Information System (INIS)

    Evans, H.H.

    1980-10-01

    The objective of this research is to determine the role of DNA repair in mutagenesis and carcinogenesis in mammalian cells. More specifically, mutant strains will be selected which are deficient in various DNA repair pathways. These strains will be studied with regard to (1) the nature of the defect in repair, and (2) the mutability and transformability of the defective cells by various agents as compared to the wild type parental cells. The results to date include progress in the following areas: (1) determination of optimum conditions for growth and maintenance of cells and for quantitative measurement of various cellular parameters; (2) investigation of the effect of holding mutagenized cells for various periods in a density inhibited state on survival and on mutation and transformation frequencies; (3) examination of the repair capabilities of BHK cells, as compared to repair-proficient and repair-deficient human cells and excision-deficient mouse cells, as measured by the reactivation of Herpes simplex virus (HSV) treated with radiation and ethylmethane sulfonate (EMS); (4) initiation of host cell reactivation viral sucide enrichment and screening of survivors of the enrichment for sensitivity to ionizing radiation; and (5) investigation of the toxicity, mutagenicity, and carcinogenicity of various metabolites of 4-nitroquinoline-1-oxide (4-NQO)

  18. Sampling Strategies and Processing of Biobank Tissue Samples from Porcine Biomedical Models.

    Science.gov (United States)

    Blutke, Andreas; Wanke, Rüdiger

    2018-03-06

    In translational medical research, porcine models have steadily become more popular. Considering the high value of individual animals, particularly of genetically modified pig models, and the often-limited number of available animals of these models, establishment of (biobank) collections of adequately processed tissue samples suited for a broad spectrum of subsequent analyses methods, including analyses not specified at the time point of sampling, represent meaningful approaches to take full advantage of the translational value of the model. With respect to the peculiarities of porcine anatomy, comprehensive guidelines have recently been established for standardized generation of representative, high-quality samples from different porcine organs and tissues. These guidelines are essential prerequisites for the reproducibility of results and their comparability between different studies and investigators. The recording of basic data, such as organ weights and volumes, the determination of the sampling locations and of the numbers of tissue samples to be generated, as well as their orientation, size, processing and trimming directions, are relevant factors determining the generalizability and usability of the specimen for molecular, qualitative, and quantitative morphological analyses. Here, an illustrative, practical, step-by-step demonstration of the most important techniques for generation of representative, multi-purpose biobank specimen from porcine tissues is presented. The methods described here include determination of organ/tissue volumes and densities, the application of a volume-weighted systematic random sampling procedure for parenchymal organs by point-counting, determination of the extent of tissue shrinkage related to histological embedding of samples, and generation of randomly oriented samples for quantitative stereological analyses, such as isotropic uniform random (IUR) sections generated by the "Orientator" and "Isector" methods, and vertical

  19. Modeling of heat transfer in a vascular tissue-like medium during an interstitial hyperthermia process.

    Science.gov (United States)

    Hassanpour, Saeid; Saboonchi, Ahmad

    2016-12-01

    This paper aims to evaluate the role of small vessels in heat transfer mechanisms of a tissue-like medium during local intensive heating processes, for example, an interstitial hyperthermia treatment. To this purpose, a cylindrical tissue with two co- and counter-current vascular networks and a central heat source is introduced. Next, the energy equations of tissue, supply fluid (arterial blood), and return fluid (venous blood) are derived using porous media approach. Then, a 2D computer code is developed to predict the temperature of blood (fluid phase) and tissue (solid phase) by conventional volume averaging method and a more realistic solution method. In latter method, despite the volume averaging the blood of interconnect capillaries is separated from the arterial and venous blood phases. It is found that in addition to blood perfusion rate, the arrangement of vascular network has considerable effects on the pattern and amount of the achieved temperature. In contrast to counter-current network, the co-current network of vessels leads to considerable asymmetric pattern of temperature contours and relocation of heat affected zone along the blood flow direction. However this relocation can be prevented by changing the site of hyperthermia heat source. The results show that the cooling effect of co-current blood vessels during of interstitial heating is more efficient. Despite much anatomical dissimilarities, these findings can be useful in designing of protocols for hyperthermia cancer treatment of living tissue. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. When is cartilage repair successful?

    International Nuclear Information System (INIS)

    Raudner, M.; Roehrich, S.; Zalaudek, M.; Trattnig, S.; Schreiner, M.M.

    2017-01-01

    Focal cartilage lesions are a cause of long-term disability and morbidity. After cartilage repair, it is crucial to evaluate long-term progression or failure in a reproducible, standardized manner. This article provides an overview of the different cartilage repair procedures and important characteristics to look for in cartilage repair imaging. Specifics and pitfalls are pointed out alongside general aspects. After successful cartilage repair, a complete, but not hypertrophic filling of the defect is the primary criterion of treatment success. The repair tissue should also be completely integrated to the surrounding native cartilage. After some months, the transplants signal should be isointense compared to native cartilage. Complications like osteophytes, subchondral defects, cysts, adhesion and chronic bone marrow edema or joint effusion are common and have to be observed via follow-up. Radiological evaluation and interpretation of postoperative changes should always take the repair method into account. (orig.) [de

  1. Experience in procurement and processing of heart valves at the Northwest Tissue Center

    International Nuclear Information System (INIS)

    Strong, M.; O'Neal, P.D.; Gage, H.N.; Moogk, M.

    1999-01-01

    The Northwest Tissue Center established a human heart valve program in 199 1. It is one of four non-profit tissue banks and one for-profit program that recover and process heart valves in the United States. During the eight years in which the Northwest Tissue Center has been involved in heart valve banking, there have been a total of 673 hearts procured for processing. The age of the donors ranged from <1 to 44 years with a mean of 26.2 years, 66% werw male,and 6.5% of the hearts procered were discarded due to a variety of medical and criteria reason. The primary reasons for differal were questions of possible cancer and questions of high risk behavior/social history. Of the 1,264 cardiovascular tissues processed, 6% were lost because of donor history, 17% were lost because of microbiology results, and 5% were lost because of donor serology . There were total a total of 190 aortic valves and 48 pulmonic conduits transplanted over this time period. The mean age of the recipients was 23.4 with a median or 23 years; 102 of the recipients were less than one year of age. Males comprised 62% of the recipients. Since 1993, there has been a clear shift towards more use of pulmonic valves over aortic valves as a results of the acceptance of the Ross procedure. Early in the program, reports were received from surgeons that some heart valves appeared to have cracks in the conduits. Experimentations in the laboratory led to the discovery that thawing too rapidly would result in cracking of these materials. Packaging was designed to reduce the rate of thawing and this has resolved the problem with cracking. The heart valve program at the Northwest Tissue Center has been very successful in providing the necessary valves for patients in the Northwest Region of the United States

  2. Determination of the heating temperature of potholes surface on road pavement in the process of repairs using hot asphalt concrete mixes

    Directory of Open Access Journals (Sweden)

    Giyasov Botir Iminzhonovich

    2014-12-01

    Full Text Available In the process of roads construction the necessary transport and operational characteristics should be achieved, which depend on the quality of the applied, material and technologies. Under the loads of transport means and the influence of weather conditions on the road pavement deformations and destructions occur, which lead to worsening of transport and operational characteristics, decrease of operational life of the road and they are often the reason of road accidents. According to the data of the Strategic Research Center of "Rosgosstrah" more than 20 % of road accidents in Russia occur due to bad quality of road pavement. One of the main directions in traffic security control and prolongation of operational life for road pavement of non-rigid type is road works, as a result of which defects of pavement are eliminated and in case of timely repairs of high quality the operational life of the road increases for several years. The most widely used material for non-rigid pavement repairs is hot road concrete mixes and in case of adherence to specifications they provide high quality of works. The authors investigate the problems of hot asphalt concrete mixes for repairs of road surfaces of non-rigid type. The results of the study hot asphalt concrete mix’s temperature regimes are offered in case of repair works considering the temperature delivered to the work site and the ambient temperature depending on the type of mix and class of bitumen.

  3. 'TISUCROMA': A Software for Color Processing of Biological Tissue's Images

    International Nuclear Information System (INIS)

    Arista Romeu, Eduardo J.; La Rosa Vazquez, Jose Manuel de; Valor, Alma; Stolik, Suren

    2016-01-01

    In this work a software intended to plot and analyze digital image RGB histograms from normal and abnormal regions of biological tissue. The obtained RGB histograms from each zone can be used to show the image in only one color or the mixture of some of them. The Software was developed in Lab View to process the images in a laptop. Some medical application examples are shown. (Author)

  4. Functional assessments and histopathology of hepatorenal tissues of rats treated with raw and processed herbs

    OpenAIRE

    Ojiako, Okey A.; Chikezie, Paul C.; Ukairo, Doris I.; Ibegbulem, Chiedozie O.; Nwaoguikpe, Reginald N.

    2017-01-01

    The present study ascertained the functional integrity of hepatic and renal tissues, concurrently with blood lipid patterns, of Wistar rats infused with CCl4 and treated with raw and hydrothermal processed herbs, namely, Monodora myristica, Chromolaena odorata, Buccholzia coriacea and Sphenostylis stenocarpa. Measurement of phytochemical contents of the herbs was according to standard methods. The rats were randomly designated on the bases of diets and treatments received for 28 consecutive d...

  5. A compact and versatile microfluidic probe for local processing of tissue sections and biological specimens

    Science.gov (United States)

    Cors, J. F.; Lovchik, R. D.; Delamarche, E.; Kaigala, G. V.

    2014-03-01

    The microfluidic probe (MFP) is a non-contact, scanning microfluidic technology for local (bio)chemical processing of surfaces based on hydrodynamically confining nanoliter volumes of liquids over tens of micrometers. We present here a compact MFP (cMFP) that can be used on a standard inverted microscope and assist in the local processing of tissue sections and biological specimens. The cMFP has a footprint of 175 × 100 × 140 mm3 and can scan an area of 45 × 45 mm2 on a surface with an accuracy of ±15 μm. The cMFP is compatible with standard surfaces used in life science laboratories such as microscope slides and Petri dishes. For ease of use, we developed self-aligned mounted MFP heads with standardized "chip-to-world" and "chip-to-platform" interfaces. Switching the processing liquid in the flow confinement is performed within 90 s using a selector valve with a dead-volume of approximately 5 μl. We further implemented height-compensation that allows a cMFP head to follow non-planar surfaces common in tissue and cellular ensembles. This was shown by patterning different macroscopic copper-coated topographies with height differences up to 750 μm. To illustrate the applicability to tissue processing, 5 μm thick M000921 BRAF V600E+ melanoma cell blocks were stained with hematoxylin to create contours, lines, spots, gradients of the chemicals, and multiple spots over larger areas. The local staining was performed in an interactive manner using a joystick and a scripting module. The compactness, user-friendliness, and functionality of the cMFP will enable it to be adapted as a standard tool in research, development and diagnostic laboratories, particularly for the interaction with tissues and cells.

  6. DNA damage repair and radiosensitivity

    International Nuclear Information System (INIS)

    Suzuki, Norio

    2003-01-01

    Tailored treatment is not new in radiotherapy; it has been the major subject for the last 20-30 years. Radiation responses and RBE (relative biological effectiveness) depend on assay systems, endpoints, type of tissues and tumors, radiation quality, dose rate, dose fractionation, physiological and environmental factors etc, Latent times to develop damages also differ among tissues and endpoints depending on doses and radiation quality. Recent progress in clarification of radiation induced cell death, especially of apoptotic cell death, is quite important for understanding radiosensitivity of tumor cure process as well as of tumorigenesis. Apoptotic cell death as well as dormant cells had been unaccounted and missed into a part of reproductive cell death. Another area of major progress has been made in clarifying repair mechanisms of radiation damage, i.e., non-homologous end joining (NHEJ) and homologous recombinational repair (HRR). New approaches and developments such as cDNA or protein micro arrays and so called informatics in addition to basic molecular biological analysis are expected to aid identifying molecules and their roles in signal transduction pathways, which are multi-factorial and interactive each other being involved in radiation responses. (authors)

  7. Evaluation of early tissue reactions after lumbar intertransverse process fusion using CT in a rabbit

    International Nuclear Information System (INIS)

    Shinbo, Jun; Mainil-Varlet, Pierre; Watanabe, Atsuya; Pippig, Suzanne; Koener, Jens; Anderson, Suzanne E.

    2010-01-01

    The objective of the study was to evaluate tissue reactions such as bone genesis, cartilage genesis and graft materials in the early phase of lumbar intertransverse process fusion in a rabbit model using computed tomography (CT) imaging with CT intensity (Hounsfield units) measurement, and to compare these data with histological results. Lumbar intertransverse process fusion was performed on 18 rabbits. Four graft materials were used: autograft bone (n=3); collagen membrane soaked with recombinant human bone morphogenetic protein-2 (rhBMP-2) (n=5); granular calcium phosphate (n=5); and granular calcium phosphate coated with rhBMP-2 (n=5). All rabbits were euthanized 3 weeks post-operatively and lumbar spines were removed for CT imaging and histological examination. Computed tomography imaging demonstrated that each fusion mass component had the appropriate CT intensity range. CT also showed the different distributions and intensities of bone genesis in the fusion masses between the groups. Each component of tissue reactions was identified successfully on CT images using the CT intensity difference. Using CT color mapping, these observations could be easily visualized, and the results correlated well with histological findings. The use of CT intensity is an effective approach for observing and comparing early tissue reactions such as newly synthesized bone, newly synthesized cartilage, and graft materials after lumbar intertransverse process fusion in a rabbit model. (orig.)

  8. The Appropriate Welding Process of Repairing Crack of Converter Supporting Ring%转炉托圈裂纹修复的焊接工艺

    Institute of Scientific and Technical Information of China (English)

    马海超; 刘子龙

    2014-01-01

    The present paper introduces the process for repairing crack of converter supporting ring. Perfect result has been gained by analysing the weldability, selecting the suitable welding material, and making the appropriate welding process. It offers the practical experience for repairing crack of converter supporting ring.%本文介绍了转炉托圈裂纹的焊接修复过程。通过分析材料的焊接性,选择合适的焊接材料并且制定了合适的焊接工艺,取得了比较满意的结果,为托圈裂纹的焊接修复提供了实践经验。

  9. Nucleotide excision repair genes are expressed at low levels and are not detectably inducible in Caenorhabditis elegans somatic tissues, but their function is required for normal adult life after UVC exposure

    International Nuclear Information System (INIS)

    Boyd, Windy A.; Crocker, Tracey L.; Rodriguez, Ana M.; Leung, Maxwell C.K.; Wade Lehmann, D.; Freedman, Jonathan H.; Van Houten, Ben; Meyer, Joel N.

    2010-01-01

    We performed experiments to characterize the inducibility of nucleotide excision repair (NER) in Caenorhabditis elegans, and to examine global gene expression in NER-deficient and -proficient strains as well as germline vs. somatic tissues, with and without genotoxic stress. We also carried out experiments to elucidate the importance of NER in the adult life of C. elegans under genotoxin-stressed and control conditions. Adult lifespan was not detectably different between wild-type and NER-deficient xpa-1 nematodes under control conditions. However, exposure to 6 J/m 2 /day of ultraviolet C radiation (UVC) decreased lifespan in xpa-1 nematodes more than a dose of 100 J/m 2 /day in wild-type. Similar differential sensitivities were observed for adult size and feeding. Remarkably, global gene expression was nearly identical in young adult wild-type and xpa-1 nematodes, both in control conditions and 3 h after exposure to 50 J/m 2 UVC. Neither NER genes nor repair activity were detectably inducible in young adults that lacked germ cells and developing embryos (glp-1 strain). However, expression levels of dozens of NER and other DNA damage response genes were much (5-30-fold) lower in adults lacking germ cells and developing embryos, suggesting that somatic and post-mitotic cells have a much lower DNA repair ability. Finally, we describe a refinement of our DNA damage assay that allows damage measurement in single nematodes.

  10. Nucleotide excision repair genes are expressed at low levels and are not detectably inducible in Caenorhabditis elegans somatic tissues, but their function is required for normal adult life after UVC exposure

    Energy Technology Data Exchange (ETDEWEB)

    Boyd, Windy A. [Biomolecular Screening Branch, National Toxicology Program, National Institute of Environmental Health Sciences, NIH, Research Triangle Park, NC (United States); Crocker, Tracey L. [Nicholas School of the Environment, Duke University, Durham, NC 27708 (United States); Rodriguez, Ana M. [Laboratory of Molecular Genetics, National Institute of Environmental Health Sciences, NIH, Research Triangle Park, NC (United States); Leung, Maxwell C.K. [Nicholas School of the Environment, Duke University, Durham, NC 27708 (United States); Wade Lehmann, D. [Laboratory of Molecular Genetics, National Institute of Environmental Health Sciences, NIH, Research Triangle Park, NC (United States); Freedman, Jonathan H. [Laboratory of Molecular Toxicology, National Institute of Environmental Health Sciences, NIH, Research Triangle Park, NC (United States); Van Houten, Ben [Laboratory of Molecular Genetics, National Institute of Environmental Health Sciences, NIH, Research Triangle Park, NC (United States); Meyer, Joel N., E-mail: joel.meyer@duke.edu [Nicholas School of the Environment, Duke University, Durham, NC 27708 (United States)

    2010-01-05

    We performed experiments to characterize the inducibility of nucleotide excision repair (NER) in Caenorhabditis elegans, and to examine global gene expression in NER-deficient and -proficient strains as well as germline vs. somatic tissues, with and without genotoxic stress. We also carried out experiments to elucidate the importance of NER in the adult life of C. elegans under genotoxin-stressed and control conditions. Adult lifespan was not detectably different between wild-type and NER-deficient xpa-1 nematodes under control conditions. However, exposure to 6 J/m{sup 2}/day of ultraviolet C radiation (UVC) decreased lifespan in xpa-1 nematodes more than a dose of 100 J/m{sup 2}/day in wild-type. Similar differential sensitivities were observed for adult size and feeding. Remarkably, global gene expression was nearly identical in young adult wild-type and xpa-1 nematodes, both in control conditions and 3 h after exposure to 50 J/m{sup 2} UVC. Neither NER genes nor repair activity were detectably inducible in young adults that lacked germ cells and developing embryos (glp-1 strain). However, expression levels of dozens of NER and other DNA damage response genes were much (5-30-fold) lower in adults lacking germ cells and developing embryos, suggesting that somatic and post-mitotic cells have a much lower DNA repair ability. Finally, we describe a refinement of our DNA damage assay that allows damage measurement in single nematodes.

  11. Forager bees (Apis mellifera) highly express immune and detoxification genes in tissues associated with nectar processing.

    Science.gov (United States)

    Vannette, Rachel L; Mohamed, Abbas; Johnson, Brian R

    2015-11-09

    Pollinators, including honey bees, routinely encounter potentially harmful microorganisms and phytochemicals during foraging. However, the mechanisms by which honey bees manage these potential threats are poorly understood. In this study, we examine the expression of antimicrobial, immune and detoxification genes in Apis mellifera and compare between forager and nurse bees using tissue-specific RNA-seq and qPCR. Our analysis revealed extensive tissue-specific expression of antimicrobial, immune signaling, and detoxification genes. Variation in gene expression between worker stages was pronounced in the mandibular and hypopharyngeal gland (HPG), where foragers were enriched in transcripts that encode antimicrobial peptides (AMPs) and immune response. Additionally, forager HPGs and mandibular glands were enriched in transcripts encoding detoxification enzymes, including some associated with xenobiotic metabolism. Using qPCR on an independent dataset, we verified differential expression of three AMP and three P450 genes between foragers and nurses. High expression of AMP genes in nectar-processing tissues suggests that these peptides may contribute to antimicrobial properties of honey or to honey bee defense against environmentally-acquired microorganisms. Together, these results suggest that worker role and tissue-specific expression of AMPs, and immune and detoxification enzymes may contribute to defense against microorganisms and xenobiotic compounds acquired while foraging.

  12. Instrumental and laboratory assessment of stressful remodelling processes in bone tissue at total hip replacement

    Directory of Open Access Journals (Sweden)

    E.V. Karjakina

    2010-06-01

    Full Text Available Research objective is to estimate stressful remodelling features of bone tissue according to the densitometry data and to the level of biochemical markers of bone resorption and formation in total hip replacement (THR. Bone tissue mineral density (BTMD, condition of calcium-phosphoric metabolism and biochemical markers of bone formation (osteocalcin and bone isoenzyme of alkaline phosphatase and resorption (С-terminal bodypeptide of the I type collagen have been determined in 52 patients with coxarthrosis of ll-lll stages with marked joint dysfunction before and after THR. The control group included 24 donors. The data were considered to be reliable when the probability index was р<0,05. The reliable (р<0,05 change of BTMD was determined only in 3-6 months after the operation, whereas the change of biochemical markers of remodeling had already been done after 1,5-3 months, allowing to define the group of patients with obvious negative bone balance: strong predominance of resorption processes without compensation of the subsequent adequate osteogenesis, that subsequently could lead to significant bone tissue deficiency in the area adjacent to the endoprosthesis. Changes of indices of calcium-phosphoric metabolism were not certain during the investigation term. ln conclusion it is to state that biochemical markers of remodeling in comparison with BTMD allow to estimate objectively features of adaptive bone tissue remodeling after THR in earlier periods and to define group of patients with sharp intensification of metabolism and obvious negative bone balance

  13. In situ ultrahigh-resolution optical coherence tomography characterization of eye bank corneal tissue processed for lamellar keratoplasty.

    Science.gov (United States)

    Brown, Jamin S; Wang, Danling; Li, Xiaoli; Baluyot, Florence; Iliakis, Bernie; Lindquist, Thomas D; Shirakawa, Rika; Shen, Tueng T; Li, Xingde

    2008-08-01

    To use optical coherence tomography (OCT) as a noninvasive tool to perform in situ characterization of eye bank corneal tissue processed for lamellar keratoplasty. A custom-built ultrahigh-resolution OCT (UHR-OCT) was used to characterize donor corneal tissue that had been processed for lamellar keratoplasty. Twenty-seven donor corneas were analyzed. Four donor corneas were used as controls, whereas the rest were processed into donor corneal buttons for lamellar transplantation by using hand dissection, a microkeratome, or a femtosecond laser. UHR-OCT was also used to noninvasively characterize and monitor the viable corneal tissue immersed in storage medium over 3 weeks. The UHR-OCT captured high-resolution images of the donor corneal tissue in situ. This noninvasive technique showed the changes in donor corneal tissue morphology with time while in storage medium. The characteristics of the lamellar corneal tissue with each processing modality were clearly visible by UHR-OCT. The in situ characterization of the femtosecond laser-cut corneal tissue was noted to have more interface debris than shown by routine histology. The effects of the femtosecond laser microcavitation bubbles on the corneal tissue were well visualized at the edges of the lamellar flap while in storage medium. The results of our feasibility study show that UHR-OCT can provide superb, in situ microstructural characterization of eye bank corneal tissue noninvasively. The UHR-OCT interface findings and corneal endothelial disc thickness uniformity analysis are valuable information that may be used to optimize the modalities and parameters for lamellar tissue processing. The UHR-OCT is a powerful approach that will allow us to further evaluate the tissue response to different processing techniques for posterior lamellar keratoplasty. It may also provide information that can be used to correlate with postoperative clinical outcomes. UHR-OCT has the potential to become a routine part of tissue

  14. World Endometriosis Research Foundation Endometriosis Phenome and Biobanking Harmonisation Project: IV. Tissue collection, processing, and storage in endometriosis research

    DEFF Research Database (Denmark)

    Fassbender, Amelie; Rahmioglu, Nilufer; Vitonis, Allison F.

    2014-01-01

    ObjectiveTo harmonize standard operating procedures (SOPs) and standardize the recording of associated data for collection, processing, and storage of human tissues relevant to endometriosis.......ObjectiveTo harmonize standard operating procedures (SOPs) and standardize the recording of associated data for collection, processing, and storage of human tissues relevant to endometriosis....

  15. Next Generation Tissue Engineering of Orthopedic Soft Tissue-to-Bone Interfaces

    Science.gov (United States)

    Boys, Alexander J.; McCorry, Mary Clare; Rodeo, Scott; Bonassar, Lawrence J.; Estroff, Lara A.

    2017-01-01

    Soft tissue-to-bone interfaces are complex structures that consist of gradients of extracellular matrix materials, cell phenotypes, and biochemical signals. These interfaces, called entheses for ligaments, tendons, and the meniscus, are crucial to joint function, transferring mechanical loads and stabilizing orthopedic joints. When injuries occur to connected soft tissue, the enthesis must be re-established to restore function, but due to structural complexity, repair has proven challenging. Tissue engineering offers a promising solution for regenerating these tissues. This prospective review discusses methodologies for tissue engineering the enthesis, outlined in three key design inputs: materials processing methods, cellular contributions, and biochemical factors. PMID:29333332

  16. Arthroscopic Hip Labral Repair: The Iberian Suture Technique

    OpenAIRE

    Stubbs, Allston J.; Andersen, Jason S.; Mannava, Sandeep; Wooster, Benjamin M.; Howse, Elizabeth A.; Winter, S. Bradley

    2014-01-01

    Arthroscopic hip labral repair has beneficial short-term outcomes; however, debate exists regarding ideal surgical labral repair technique. This technical note presents an arthroscopic repair technique that uses intrasubstance labral suture passage to restore the chondrolabral interface. This “Iberian suture technique” allows for an anatomic repair while posing minimal risk of damage to the labral and chondral tissues.

  17. The role of nuclear hormone receptors in cutaneous wound repair.

    Science.gov (United States)

    Rieger, Sandra; Zhao, Hengguang; Martin, Paige; Abe, Koichiro; Lisse, Thomas S

    2015-01-01

    The cutaneous wound repair process involves balancing a dynamic series of events ranging from inflammation, oxidative stress, cell migration, proliferation, survival and differentiation. A complex series of secreted trophic factors, cytokines, surface and intracellular proteins are expressed in a temporospatial manner to restore skin integrity after wounding. Impaired initiation, maintenance or termination of the tissue repair processes can lead to perturbed healing, necrosis, fibrosis or even cancer. Nuclear hormone receptors (NHRs) in the cutaneous environment regulate tissue repair processes such as fibroplasia and angiogenesis. Defects in functional NHRs and their ligands are associated with the clinical phenotypes of chronic non-healing wounds and skin endocrine disorders. The functional relationship between NHRs and skin niche cells such as epidermal keratinocytes and dermal fibroblasts is pivotal for successful wound closure and permanent repair. The aim of this review is to delineate the cutaneous effects and cross-talk of various nuclear receptors upon injury towards functional tissue restoration. Copyright © 2014 John Wiley & Sons, Ltd.

  18. Selection, processing and clinical application of muscle-skeletal tissue; Seleccion, Procesamiento y Aplicacion Clinica de Tejido Musculo-Esqueletico

    Energy Technology Data Exchange (ETDEWEB)

    Luna Z, D.; Reyes F, M.L.; Lavalley E, C.; Castaneda J, G. [ININ, Carretera Mexico-Toluca s/n, 52750 La Marquesa, Ocoyoacac, Estado de Mexico (Mexico)]. e-mail: dlz@nuclear.inin. mx

    2007-07-01

    Due to the increase in the average of the world population's life, people die each time to more age, this makes that the tissues of support of the human body, as those muscle-skeletal tissues, when increasing the individual's age go weakening, this in turn leads to the increment of the illnesses like the osteoporosis and the arthritis, that undoubtedly gives as a result more injure of the muscle-skeletal tissues joined a greater number of traffic accidents where particularly these tissues are affected, for that the demand of tissues muscle-skeletal for transplant every day will be bigger. The production of these tissues in the Bank of Radio sterilized Tissues, besides helping people to improve its quality of life saved foreign currencies because most of the muscle-skeletal tissues transplanted in Mexico are of import. The use of the irradiation to sterilize tissues for transplant has shown to be one of the best techniques with that purpose for what the International Atomic Energy Agency believes a Technical cooperation program to establish banks of tissues using the nuclear energy, helping mainly to countries in development. In this work the stages that follows the bank of radio sterilized tissues of the National Institute of Nuclear Research for the cadaverous donor's of muscle-skeletal tissue selection are described, as well as the processing and the clinical application of these tissues. (Author)

  19. Role of isolated and clustered DNA damage and the post-irradiating repair process in the effects of heavy ion beam irradiation

    International Nuclear Information System (INIS)

    Tokuyama, Yuka; Terato, Hiroaki; Furusawa, Yoshiya; Ide, Hiroshi; Yasui, Akira

    2015-01-01

    Clustered DNA damage is a specific type of DNA damage induced by ionizing radiation. Any type of ionizing radiation traverses the target DNA molecule as a beam, inducing damage along its track. Our previous study showed that clustered DNA damage yields decreased with increased linear energy transfer (LET), leading us to investigate the importance of clustered DNA damage in the biological effects of heavy ion beam radiation. In this study, we analyzed the yield of clustered base damage (comprising multiple base lesions) in cultured cells irradiated with various heavy ion beams, and investigated isolated base damage and the repair process in post-irradiation cultured cells. Chinese hamster ovary (CHO) cells were irradiated by carbon, silicon, argon and iron ion beams with LETs of 13, 55, 90 and 200 keV µm -1 , respectively. Agarose gel electrophoresis of the cells with enzymatic treatments indicated that clustered base damage yields decreased as the LET increased. The aldehyde reactive probe procedure showed that isolated base damage yields in the irradiated cells followed the same pattern. To analyze the cellular base damage process, clustered DNA damage repair was investigated using DNA repair mutant cells. DNA double-strand breaks accumulated in CHO mutant cells lacking Xrcc1 after irradiation, and the cell viability decreased. On the other hand, mouse embryonic fibroblast (Mef) cells lacking both Nth1 and Ogg1 became more resistant than the wild type Mef. Thus, clustered base damage seems to be involved in the expression of heavy ion beam biological effects via the repair process. (author)

  20. Development of a computational system for management of risks in radiosterilization processes of biological tissues

    International Nuclear Information System (INIS)

    Montoya, Cynara Viterbo

    2009-01-01

    Risk management can be understood to be a systematic management which aims to identify record and control the risks of a process. Applying risk management becomes a complex activity, due to the variety of professionals involved. In order to execute risk management the following are requirements of paramount importance: the experience, discernment and judgment of a multidisciplinary team, guided by means of quality tools, so as to provide standardization in the process of investigating the cause and effects of risks and dynamism in obtaining the objective desired, i.e. the reduction and control of the risk. This work aims to develop a computational system of risk management (software) which makes it feasible to diagnose the risks of the processes of radiosterilization of biological tissues. The methodology adopted was action-research, according to which the researcher performs an active role in the establishment of the problems found, in the follow-up and in the evaluation of the actions taken owing to the problems. The scenario of this action-research was the Laboratory of Biological Tissues (LTB) in the Radiation Technology Center IPEN/CNEN-SP - Sao Paulo/Brazil. The software developed was executed in PHP and Flash/MySQL language, the server (hosting), the software is available on the Internet (www.vcrisk.com.br), which the user can access from anywhere by means of the login/access password previously sent by email to the team responsible for the tissue to be analyzed. The software presents friendly navigability whereby the user is directed step-by-step in the process of investigating the risk up to the means of reducing it. The software 'makes' the user comply with the term and present the effectiveness of the actions taken to reduce the risk. Applying this system provided the organization (LTB/CTR/IPEN) with dynamic communication, effective between the members of the multidisciplinary team: a) in decision-making; b) in lessons learned; c) in knowing the new risk

  1. Fast method for the detection of transport process in plant tissues by radiotracing

    International Nuclear Information System (INIS)

    Antal, K.; Joo, P.

    1995-01-01

    The efficiency of nutrients, microelements and plant protective agents and additives applied on foliar and various aeriel parts of plants depends on the adsorption of their spray drops and the penetration of agents into tissues, cells and inner caves. The permeability of the cuticular membrane and the mode of entry of above substances through the cuticle and their mobility in other tissues are poorly understood but have been the subject of intensive research. The traditional methods in biological systems are the automicroradiography and sample taking methods. The radioactive tracer method developed by us is suitable for determining the effective diffusion coefficients characterizing the migration process and concentration distributions off these materials in plants by consumption of minimal amount of β-labelled radioactive isotopes in very short time. (author) 9 refs.; 3 figs

  2. Diagnostic Value of Processing Cytologic Aspirates of Renal Tumors in Agar Cell (Tissue) Blocks

    DEFF Research Database (Denmark)

    Smedts, F.; Schrik, M.; Horn, T.

    2010-01-01

    smears were prepared after each aspiration for conventional cytology and the remaining aspirate was processed for the improved agar microbiopsy (AM) method. Conventional cytology slides, AM slides and surgical specimens were diagnosed separately, after which the diagnoses were compared....... Immunohistochemistry was performed as required on the AM sections. Surgical specimens served as the gold standard. Results In 53% of conventional cytologic smears, the cellular yield was sufficient to render a correct diagnosis. In 12% the diagnosis was incorrect, in 21% only a differential diagnosis could be fin......-initiated, and in 14% too few diagnostic cells were present in the conventional smears for cytologic diagnosis. It was, however, possible to correctly diagnose histologic sections from 97% of AM tissue blocks. In 11 cases this was facilitated with immunochemistry. In only 1 case did the AM tissue block contain too few...

  3. Investigation of Overrun-Processed Porous Hyaluronic Acid Carriers in Corneal Endothelial Tissue Engineering.

    Directory of Open Access Journals (Sweden)

    Jui-Yang Lai

    Full Text Available Hyaluronic acid (HA is a linear polysaccharide naturally found in the eye and therefore is one of the most promising biomaterials for corneal endothelial regenerative medicine. This study reports, for the first time, the development of overrun-processed porous HA hydrogels for corneal endothelial cell (CEC sheet transplantation and tissue engineering applications. The hydrogel carriers were characterized to examine their structures and functions. Evaluations of carbodiimide cross-linked air-dried and freeze-dried HA samples were conducted simultaneously for comparison. The results indicated that during the fabrication of freeze-dried HA discs, a technique of introducing gas bubbles in the aqueous biopolymer solutions can be used to enlarge pore structure and prevent dense surface skin formation. Among all the groups studied, the overrun-processed porous HA carriers show the greatest biological stability, the highest freezable water content and glucose permeability, and the minimized adverse effects on ionic pump function of rabbit CECs. After transfer and attachment of bioengineered CEC sheets to the overrun-processed HA hydrogel carriers, the therapeutic efficacy of cell/biopolymer constructs was tested using a rabbit model with corneal endothelial dysfunction. Clinical observations including slit-lamp biomicroscopy, specular microscopy, and corneal thickness measurements showed that the construct implants can regenerate corneal endothelium and restore corneal transparency at 4 weeks postoperatively. Our findings suggest that cell sheet transplantation using overrun-processed porous HA hydrogels offers a new way to reconstruct the posterior corneal surface and improve endothelial tissue function.

  4. Species and tissues specific differentiation of processed animal proteins in aquafeeds using proteomics tools.

    Science.gov (United States)

    Rasinger, J D; Marbaix, H; Dieu, M; Fumière, O; Mauro, S; Palmblad, M; Raes, M; Berntssen, M H G

    2016-09-16

    The rapidly growing aquaculture industry drives the search for sustainable protein sources in fish feed. In the European Union (EU) since 2013 non-ruminant processed animal proteins (PAP) are again permitted to be used in aquafeeds. To ensure that commercial fish feeds do not contain PAP from prohibited species, EU reference methods were established. However, due to the heterogeneous and complex nature of PAP complementary methods are required to guarantee the safe use of this fish feed ingredient. In addition, there is a need for tissue specific PAP detection to identify the sources (i.e. bovine carcass, blood, or meat) of illegal PAP use. In the present study, we investigated and compared different protein extraction, solubilisation and digestion protocols on different proteomics platforms for the detection and differentiation of prohibited PAP. In addition, we assessed if tissue specific PAP detection was feasible using proteomics tools. All work was performed independently in two different laboratories. We found that irrespective of sample preparation gel-based proteomics tools were inappropriate when working with PAP. Gel-free shotgun proteomics approaches in combination with direct spectral comparison were able to provide quality species and tissue specific data to complement and refine current methods of PAP detection and identification. To guarantee the safe use of processed animal protein (PAP) in aquafeeds efficient PAP detection and monitoring tools are required. The present study investigated and compared various proteomics workflows and shows that the application of shotgun proteomics in combination with direct comparison of spectral libraries provides for the desired species and tissue specific classification of this heat sterilized and pressure treated (≥133°C, at 3bar for 20min) protein feed ingredient. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Relationship of DNA repair processes to mutagenesis and carcinogenesis in mammalian cells. Progress report, November 1, 1979-October 31, 1980

    International Nuclear Information System (INIS)

    Evans, H.H.

    1980-10-01

    The objective of this research is to determine the role of DNA repair in mutagenesis and carcinogenesis in mammalian cells. Use of the host-cell reactivation viral suicide enrichment procedure was initiated in the isolation of repair-deficient mutants. Lightly mutagenized BHK cells were infected with irradiated Herpes simplex virus (HSV); several radiation-sensitive strains were isolated among the survivors of the infection. The characterization of these strains is progressing and the enrichments are continuing. That alterations in the frequency of mutation of C3H/10T 1/2 cells, occurring as a result of holding the cells in a confluent state following treatment with ethylmethane sulfonate, parallel the alterations in the frequency of neoplastic transformation was found. The repair capabilities of BHK cells were found to be intermediate in comparison to repair-proficient and -deficient human cells with regard to the reactivation of HSV treated with various inactivating agents. The effect of confluency and of low serum levels on DNA synthesis, as well as the response to the cytotoxic effects of MNNG and acriflavin were determined in BHK cells in preparation for the investigation of the role of DNA repair in mutagenesis and transformation. It was also found that C3H/10T 1/2 cells partially recover from the toxic effects of 4-nitroquinoline-1-oxide if they are held in a confluent state for 6 to 22 hrs following treatment. Addition of catalase did not alleviate the toxic effects of 4-NQO. The cells contain a relatively high endogenous level of this enzyme

  6. Relationship of DNA repair processes to mutagenesis and carcinogenesis in mammalian cells. Progress report, November 1, 1979-October 31, 1980

    Energy Technology Data Exchange (ETDEWEB)

    Evans, H.H.

    1980-10-01

    The objective of this research is to determine the role of DNA repair in mutagenesis and carcinogenesis in mammalian cells. Use of the host-cell reactivation viral suicide enrichment procedure was initiated in the isolation of repair-deficient mutants. Lightly mutagenized BHK cells were infected with irradiated Herpes simplex virus (HSV); several radiation-sensitive strains were isolated among the survivors of the infection. The characterization of these strains is progressing and the enrichments are continuing. That alterations in the frequency of mutation of C3H/10T 1/2 cells, occurring as a result of holding the cells in a confluent state following treatment with ethylmethane sulfonate, parallel the alterations in the frequency of neoplastic transformation was found. The repair capabilities of BHK cells were found to be intermediate in comparison to repair-proficient and -deficient human cells with regard to the reactivation of HSV treated with various inactivating agents. The effect of confluency and of low serum levels on DNA synthesis, as well as the response to the cytotoxic effects of MNNG and acriflavin were determined in BHK cells in preparation for the investigation of the role of DNA repair in mutagenesis and transformation. It was also found that C3H/10T 1/2 cells partially recover from the toxic effects of 4-nitroquinoline-1-oxide if they are held in a confluent state for 6 to 22 hrs following treatment. Addition of catalase did not alleviate the toxic effects of 4-NQO. The cells contain a relatively high endogenous level of this enzyme. (ERB)

  7. Damage to plasmid DNA produced by 60Co-gamma radiation and subsequent repair processes in E. coli with and without SOS induction

    International Nuclear Information System (INIS)

    Bien, M.

    1986-01-01

    This study was carried out to provide information on the question as to whether radiation-induced separation of double-stranded DNA in E. coli is followed by repair processes leading to the formation of replicable material. For the detection of those double-strand breaks, E. coli was first transformed using enzymatically linearised dBR 322-DNA. This served as a reference standard to compare the transformations using radiated DNA. DNA was either exposed to increasing doses of 60 Co-gamma radiation or separated into one oc-fraction and one lin-fraction following exposure to 30 Gy. The DNA samples thus obtained were then used to transform three different strains of E. coli (wild strain, SFX, SFXrecA - ). In order to improve the repair yield, the cells were additionally SOS-induced using ultraviolet radiation. The mutation rates were a measure of the number of errors occurring during the various repair processes. Restriction analysis was carried out to characterise the resulting mutants in greater detail. (orig./MG) [de

  8. Formation of double-strand breaks in DNA of γ-irradiated bacteria depending on the function of fast repair processes of DNA single-strand breaks

    International Nuclear Information System (INIS)

    Petrov, S.I.; Gaziev, A.I.

    1980-01-01

    The formation of double-strand breaks in DNA of γ-irradiated ( 60 Co)Ex coli bacteria depending on the function of fast repair processes of DNA single-strand breaks, is investigated. The profiles of sedimentation of DNA Ex coli cells, irradiated at 0-2 deg C in the salt medium and in EDTA-borate buffer, are presented. It is shown that when irradiating cells in EDTA-borate buffer, the output of single- and double strand breaks in DNA is much higher than in the case of their irradiation in the minimum salt medium. The dependence of output of single-strand and double-strand breaks depending on the radiatier doze of E coli cells in the salt medium and EDTA-borate buffer, is studied. The supposition is made on the presence of a regulative interaction between the accumulation of DNA single-breaks and their repair with the formation of double-strand breaks. The functionating of fast and superfast repair processes considerably affects the formation of double-strand breaks in DNA of a bacterium cell. A considerable amount of double-breaks registered immediately after irradiation forms due to a close position of single-strand breaks on the opposite DNA strands

  9. Processing of novel bioactive polymeric matrixes for tissue engineering using supercritical fluid technology

    Energy Technology Data Exchange (ETDEWEB)

    Duarte, Ana Rita C., E-mail: aduarte@dep.uminho.pt [3B' s Research Group, Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, AvePark, 4806-909 Taipas, Guimaraes (Portugal); IBB, Institute for Biotechnology and Bioengineering, PT Government Associated Laboratory, Guimaraes (Portugal); Caridade, Sofia G.; Mano, Joao F.; Reis, Rui L. [3B' s Research Group, Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, AvePark, 4806-909 Taipas, Guimaraes (Portugal); IBB, Institute for Biotechnology and Bioengineering, PT Government Associated Laboratory, Guimaraes (Portugal)

    2009-08-31

    The aim of this study was to develop a new process for the production of bioactive 3D scaffolds using a clean and environmentally friendly technology. The possibility of preparing composite scaffolds of Bioglass and a polymeric blend of starch and poly(L-lactic acid) (SPLA50) was evaluated. Supercritical phase-inversion technique was used to prepare inorganic particles loaded starch-based porous composite matrixes in a one-step process for bone tissue engineering purposes. Due to their osteoconductive properties some glasses and ceramics are interesting materials to be used for bone tissue engineering purposes; however their poor mechanical properties create the need of a polymeric support where the inorganic fraction can be dispersed. Samples impregnated with different concentrations of Bioglass (10 and 15% wt/wt polymer) were prepared at 200 bar and 55 deg. C. The presence of Bioglass did not affect the porosity or interconnectivity of the polymeric matrixes. Dynamic mechanical analysis has proven that the modulus of the SPLA50 scaffolds increases when glass particles are impregnated within the matrix. In vitro bioactivity studies were carried out using simulated body fluid and the results show that a calcium-phosphate layer started to be formed after only 1 day of immersion. Chemical analysis of the apatite layer formed on the surface of the scaffold was performed by different techniques, namely EDS and FTIR spectroscopy and X-ray diffraction (XRD). The ion concentration in the simulated body fluid was also carried out by ICP analysis. Results suggest that a bone-like apatite layer was formed. This study reports the feasibility of using supercritical fluid technology to process, in one step, a porous matrix loaded with a bioactive material for tissue engineering purposes.

  10. Modification in oxidative processes in muscle tissues exposed to laser- and light-emitting diode radiation.

    Science.gov (United States)

    Monich, Victor A; Bavrina, Anna P; Malinovskaya, Svetlana L

    2018-01-01

    Exposure of living tissues to high-intensity red or near-infrared light can produce the oxidative stress effects both in the target zone and adjacent ones. The protein oxidative modification (POM) products can be used as reliable and early markers of oxidative stress. The contents of modified proteins in the investigated specimens can be evaluated by the 2,4-dinitrophenylhydrazine assay (the DNPH assay). Low-intensity red light is able to decrease the activity of oxidative processes and the DNPH assay data about the POM products in the biological tissues could show both an oxidative stress level and an efficiency of physical agent protection against the oxidative processes. Two control groups of white rats were irradiated by laser light, the first control group by red light and the second one by near-infrared radiation (NIR).Two experimental groups were consequently treated with laser and red low-level light-emitting diode radiation (LED). One of them was exposed to red laser light + LED and the other to NIR + LED. The fifth group was intact. Each group included ten animals. The effect of laser light was studied by methods of protein oxidative modifications. We measured levels of both induced and spontaneous POM products by the DNPH assay. The dramatic increase in levels of POM products in the control group samples when compared with the intact group data as well as the sharp decrease in the POM products in the experimental groups treated with LED low-level light were statistically significant (p ≤ 0.05). Exposure of skeletal muscles to high-intensity red and near-infrared laser light causes oxidative stress that continues not less than 3 days. The method of measurement of POM product contents by the DNPH assay is a reliable test of an oxidative process rate. Red low-intensity LED radiation can provide rehabilitation of skeletal muscle tissues treated with high-intensity laser light.

  11. Meningocele repair

    Science.gov (United States)

    ... is surgery to repair birth defects of the spine and spinal membranes. Meningocele and myelomeningocele ... is covered by a sterile dressing. Your child may then be transferred to a neonatal intensive ...

  12. Application of nonhomogeneous Poisson process to reliability analysis of repairable systems of a nuclear power plant with rates of occurrence of failures time-dependent

    International Nuclear Information System (INIS)

    Saldanha, Pedro L.C.; Simone, Elaine A. de; Melo, Paulo Fernando F.F. e

    1996-01-01

    Aging is used to mean the continuous process which physical characteristics of a system, a structure or an equipment changes with time or use. Their effects are increases in failure probabilities of a system, a structure or an equipment, and their are calculated using time-dependent failure rate models. The purpose of this paper is to present an application of the nonhomogeneous Poisson process as a model to study rates of occurrence of failures when they are time-dependent. To this application, an analysis of reliability of service water pumps of a typical nuclear power plant is made, as long as the pumps are effectively repaired components. (author)

  13. Application of magnetic resonance to the diagnosis of tumorous processes in soft tissues

    International Nuclear Information System (INIS)

    Kreuzberg, B.

    1998-01-01

    The methodology and results of MR examination of 22 patients with soft tissue tumors (STT) are summarized, and the findings of nine histologically confirmed results are demonstrated. Discussion of the results concentrates on the reliability of the specific diagnosis (which is relatively low) and reliability of discrimination between non-malignant and malignant processes (which is relatively high). The reliability of the examination is enhanced by the intravenous administration of the paramagnetic contrast substance. It is concluded that the examination is of great value for the surgeon and his decision making, in particular with respect to staging. MR completes the set of imaging methods in the diagnosis of STT

  14. Numerical simulation of fluid field and in vitro three-dimensional fabrication of tissue-engineered bones in a rotating bioreactor and in vivo implantation for repairing segmental bone defects.

    Science.gov (United States)

    Song, Kedong; Wang, Hai; Zhang, Bowen; Lim, Mayasari; Liu, Yingchao; Liu, Tianqing

    2013-03-01

    In this paper, two-dimensional flow field simulation was conducted to determine shear stresses and velocity profiles for bone tissue engineering in a rotating wall vessel bioreactor (RWVB). In addition, in vitro three-dimensional fabrication of tissue-engineered bones was carried out in optimized bioreactor conditions, and in vivo implantation using fabricated bones was performed for segmental bone defects of Zelanian rabbits. The distribution of dynamic pressure, total pressure, shear stress, and velocity within the culture chamber was calculated for different scaffold locations. According to the simulation results, the dynamic pressure, velocity, and shear stress around the surface of cell-scaffold construction periodically changed at different locations of the RWVB, which could result in periodical stress stimulation for fabricated tissue constructs. However, overall shear stresses were relatively low, and the fluid velocities were uniform in the bioreactor. Our in vitro experiments showed that the number of cells cultured in the RWVB was five times higher than those cultured in a T-flask. The tissue-engineered bones grew very well in the RWVB. This study demonstrates that stress stimulation in an RWVB can be beneficial for cell/bio-derived bone constructs fabricated in an RWVB, with an application for repairing segmental bone de