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Sample records for biological repair

  1. Biologics for tendon repair.

    Science.gov (United States)

    Docheva, Denitsa; Müller, Sebastian A; Majewski, Martin; Evans, Christopher H

    2015-04-01

    Tendon injuries are common and present a clinical challenge to orthopedic surgery mainly because these injuries often respond poorly to treatment and require prolonged rehabilitation. Therapeutic options used to repair ruptured tendons have consisted of suture, autografts, allografts, and synthetic prostheses. To date, none of these alternatives has provided a successful long-term solution, and often the restored tendons do not recover their complete strength and functionality. Unfortunately, our understanding of tendon biology lags far behind that of other musculoskeletal tissues, thus impeding the development of new treatment options for tendon conditions. Hence, in this review, after introducing the clinical significance of tendon diseases and the present understanding of tendon biology, we describe and critically assess the current strategies for enhancing tendon repair by biological means. These consist mainly of applying growth factors, stem cells, natural biomaterials and genes, alone or in combination, to the site of tendon damage. A deeper understanding of how tendon tissue and cells operate, combined with practical applications of modern molecular and cellular tools could provide the long awaited breakthrough in designing effective tendon-specific therapeutics and overall improvement of tendon disease management.

  2. Biology of biological meshes used in hernia repair.

    Science.gov (United States)

    Novitsky, Yuri W

    2013-10-01

    Successful repair of most hernias requires the use of a prosthetic implant for reinforcement of the defect. Because of the need for prosthetic implants to resist infections as well to support repairs in contaminated or potentially contaminated fields, biological meshes have been developed to take the place of nondegradable synthetic meshes in cases where mesh infection is of high concern. The ideal is a biological matrix that resists infection while providing durable reinforcement of a hernia repair. This article reviews the validity of assumptions that support the purported notion of the biological behavior of biological meshes.

  3. Biologics for tendon repair

    OpenAIRE

    2014-01-01

    Tendon injuries are common and present a clinical challenge to orthopedic surgery mainly because these injuries often respond poorly to treatment and require prolonged rehabilitation. Therapeutic options used to repair ruptured tendons have consisted of suture, autografts, allografts, and synthetic prostheses. To date, none of these alternatives has provided a successful long-term solution, and often the restored tendons do not recover their complete strength and functionality. Unfortunately,...

  4. Biological and artificial nerve conduit for repairing peripheral nerve defect

    Institute of Scientific and Technical Information of China (English)

    Xuetao Xie; Changqing Zhang

    2006-01-01

    OBJECTIVE: Recently, with the development of biological and artificial materials, the experimental and clinical studies on application of this new material-type nerve conduit for treatment of peripheral nerve defect have become the hotspot topics for professorial physicians.DATA SOURCES: Using the terms "nerve conduits, peripheral nerve, nerve regeneration and nerve transplantation" in English, we searched Pubmed database, which was published during January 2000 to June 2006, for the literatures related to repairing peripheral nerve defect with various materials. At the same time, we also searched Chinese Technical Scientific Periodical Database at the same time period by inputting" peripheral nerve defect, nerve repair, nerve regeneration and nerve graft" in Chinese.STUDY SELECTION: The materials were firstly selected, and literatures about study on various materials for repairing peripheral nerve defect and their full texts were also searched. Inclusive criteria: nerve conduits related animal experiments and clinical studies. Exclusive criteria: review or repetitive studies.DATA EXTRACTION: Seventy-nine relevant literatures were collected and 30 of them met inclusive criteria and were cited.DATA SYNTHESTS: Peripheral nerve defect, a commonly seen problem in clinic, is difficult to be solved. Autogenous nerve grafting is still the gold standard for repairing peripheral nerve defect, but because of its application limitation and possible complications, people studied nerve conduits to repair nerve defect. Nerve conduits consist of biological and artificial materials.CONCLUSION: There have been numerous reports about animal experimental and clinical studies of various nerve conduits, but nerve conduit, which is more ideal than autogenous nerve grafting, needs further clinical observation and investigation.

  5. Stem cell-based biological tooth repair and regeneration.

    Science.gov (United States)

    Volponi, Ana Angelova; Pang, Yvonne; Sharpe, Paul T

    2010-12-01

    Teeth exhibit limited repair in response to damage, and dental pulp stem cells probably provide a source of cells to replace those damaged and to facilitate repair. Stem cells in other parts of the tooth, such as the periodontal ligament and growing roots, play more dynamic roles in tooth function and development. Dental stem cells can be obtained with ease, making them an attractive source of autologous stem cells for use in restoring vital pulp tissue removed because of infection, in regeneration of periodontal ligament lost in periodontal disease, and for generation of complete or partial tooth structures to form biological implants. As dental stem cells share properties with mesenchymal stem cells, there is also considerable interest in their wider potential to treat disorders involving mesenchymal (or indeed non-mesenchymal) cell derivatives, such as in Parkinson's disease.

  6. Eukaryotic nucleotide excision repair: from understanding mechanisms to influencing biology

    Institute of Scientific and Technical Information of China (English)

    Sarah C Shuck; Emily A Short; John J Turchi

    2008-01-01

    Repair of bulky DNA adducts by the nucleotide excision repair (NER) pathway is one of the more versatile DNA repair pathways for the removal of DNA lesions. There are two subsets of the NER pathway, global genomic-NER (GG-NER) and transcription-coupled NER (TC-NER), which differ only in the step involving recognition of the DNA lesion. Following recognition of the damage, the sub-pathways then converge for the incision/excision steps and subsequent gap filling and ligation steps. This review will focus on the GGR sub-pathway of NER while the TCR sub-pathway will be covered in another article in this issue. The ability of the NER pathway to repair a wide array of adducts stems, in part, from the mechanisms involved in the initial recognition step of the damaged DNA and results in NER impacting an equally wide array of human physiological responses and events. In this review, the impact of NER on carcinogenesis, neurological function, sensitivity to environmental factors and sensitivity to cancer therapeutics will be discussed. The knowledge generated in our understanding of the NER pathway over the past 40 years has resulted from advances in the fields of animal model systems, mammalian genetics and in vitro biochemistry, as well as from reconstitution studies and structural analyses of the proteins and enzymes that participate in this pathway. Each of these avenues of research has contributed significantly to our understanding of how the NER pathway works and how alterations in NER activity, both positive and negative, influence human biology.

  7. Biology and augmentation of tendon-bone insertion repair

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    Lui PPY

    2010-08-01

    Full Text Available 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 paid to augment tendon to bone insertion (TBI healing. Apart from surgical fixation, biological and biophysical interventions have been studied aiming at regeneration of TBI healing complex, especially the regeneration of interpositioned fibrocartilage and new bone at the healing junction. This paper described the biology and the factors influencing TBI healing using patella-patellar tendon (PPT healing and tendon graft to bone tunnel healing in ACL reconstruction as examples. Recent development in the improvement of TBI healing and directions for future studies were also reviewed and discussed.

  8. Hiatal hernia repair with biologic mesh reinforcement reduces recurrence rate in small hiatal hernias.

    Science.gov (United States)

    Schmidt, E; Shaligram, A; Reynoso, J F; Kothari, V; Oleynikov, D

    2014-01-01

    The utility of mesh reinforcement for small hiatal hernia found especially during antireflux surgery is unknown. Initial reports for the use of biological mesh for crural reinforcement during repair for defects greater than 5 cm have been shown to decrease recurrence rates. This study compares patients with small hiatal hernias who underwent onlay biologic mesh buttress repair versus those with suture cruroplasty alone. This is a single-institution retrospective review of all patients undergoing repair of hiatal hernia measuring 1-5 cm between 2002 and 2009. The patients were evaluated based on surgical repair: one group undergoing crural reinforcement with onlay biologic mesh and other group with suture cruroplasty only. Seventy patients with hiatal hernia measuring 1-5 cm were identified. Thirty-eight patients had hernia repair with biologic mesh, and 32 patients had repair with suture cruroplasty only. Recurrence rate at 1 year was 16% (5/32) in patients who had suture cruroplasty only and 0% (0/38) in the group with crural reinforcement with absorbable mesh (statistically significant, P = 0.017). Suture cruroplasty alone appears to be inadequate for hiatal hernias measuring 1-5 cm with significant recurrence rate and failure of antireflux surgery. Crural reinforcement with absorbable mesh may reduce hiatal hernia recurrence rate in small hiatal hernias.

  9. Biological effects of exposure to intermediate neutron and repair mechanism

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    Utsumi, Hiroshi; Sasaki, Masao [Kyoto Univ. (Japan); Onishi, Takeo; Onizuka, Masahiko

    2000-01-01

    An investigation was made on cytotoxic effects of neutron capture using chicken B-cell line mutants, DT40, KURO{sup -/-}, RAD54 {sup -/-} and KU70{sup -/-} / RAD54{sup -/-}. Suspensions of these cells were exposed to two times X-radiation at various doses and the cell surviving was evaluated. The sensitivity to radiation was highest in the double defective mutant, KU70{sup -/-} / RAD54{sup -/-} and followed by that of RAD54 {sup -/-}, a homologous recombination mutant, whereas KURO {sup -/-} cell, a non-homologous end-joining mutant showed a peculiar surviving curve composed of two phases and the cell was highly sensitive to a low-dose radiation. This indicates that there are two different DNA repair systems for double-strand breaks and the system for non-homologous end-joining repair can be involved in all phases of cell cycle, but the system for the homologous one is involved only in S-phase. Therefore, it was thought that variation of sensitivity to radiation exposure depending to the phase of cell cycle might explain the alternation of repair system depending to the phase progressing of cell cycle. It was thus likely that the recovery from radiation injury, which is still a black box might be explained with the double strand breaks of DNA. (M.N.)

  10. Apical External Root Resorption and Repair in Orthodontic Tooth Movement: Biological Events

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    Liviu Feller

    2016-01-01

    Full Text Available Some degree of external root resorption is a frequent, unpredictable, and unavoidable consequence of orthodontic tooth movement mediated by odontoclasts/cementoclasts originating from circulating precursor cells in the periodontal ligament. Its pathogenesis involves mechanical forces initiating complex interactions between signalling pathways activated by various biological agents. Resorption of cementum is regulated by mechanisms similar to those controlling osteoclastogenesis and bone resorption. Following root resorption there is repair by cellular cementum, but factors mediating the transition from resorption to repair are not clear. In this paper we review some of the biological events associated with orthodontically induced external root resorption.

  11. Biological Glue Application in Repair of Atrioventricular Groove Rupture: A Case Report

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    Ahmet Baris-Durukan

    2015-10-01

    Full Text Available Atrioventricular groove rupture is a rare, albeit mortal, complication following mitral valve surgery. Avoidance is the best strategy but it cannot fully prevent the occurrence of this complication. Several repair techniques have been described with varying success rates; however, the rarity of the complication precludes consensus about the safest technique.Here we report two cases of posterior atrioventricular groove rupture. Both cases were diagnosed immediately after the cessation of cardiopulmonary bypass. Repair was performed successfully with a technique involving the use of biological glue. The postoperative course was uneventful for both of them. Both cases are well with normally functioning mitral prostheses; one with a follow-up time of 5.5 years and the other 10 months. We believe that the glue provides additional hemostasis and support to the repaired area.

  12. Focus on research: Which disc is a candidate for biological repair?

    Institute of Scientific and Technical Information of China (English)

    彭宝淦

    2007-01-01

      Low back pain affects the majority of population at some point in their lives.Disc degeneration of lumbar spine has been considered as a main contributor to low back pain.Considering the high prevalence of low back pain in the population, treatment that aims to repair or regenerate the disc degeneration biologically appears promising as a future treatment option in humans.……

  13. Biology of anterior cruciate ligament injury and repair: Kappa delta ann doner vaughn award paper 2013.

    Science.gov (United States)

    Murray, Martha Meaney; Fleming, Braden C

    2013-10-01

    Anterior cruciate ligament (ACL) injuries are currently treated by removing the injured ligament and replacing it with a tendon graft. Recent studies have examined alternative treatment methods, including repair and regeneration of the injured ligament. In order to make such an approach feasible, a basic understanding of ACL biology and its response to injury is needed. Identification of obstacles to native ACL healing can then be identified and potentially resolved using tissue engineering strategies-first, with in vitro screening assays, and then with in vivo models of efficacy and safety. This Perspectives paper outlines this path of discovery for optimizing ACL healing using a bio-enhanced repair technique. This journey required constructing indices of the functional tissue response, pioneering physiologically based methods of biomechanical testing, developing, and validating clinically relevant animal models, and creating and optimizing translationally feasible scaffolds, surgical techniques, and biologic additives. Using this systematic translational approach, "bio-enhanced" ACL repair has been advanced to the point where it may become an option for future treatment of acute ACL injuries and the prevention of subsequent post-traumatic osteoarthritis associated with this injury.

  14. Chemotherapy-induced enterocutaneous fistula after perineal hernia repair using a biological mesh: a case report

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    Eriksen MH

    2014-01-01

    Full Text Available MH Eriksen, O Bulut Department of Surgical Gastroenterology, Hvidovre University Hospital, University of Copenhagen, Copenhagen, Denmark Abstract: This is the first reported case of an enterocutaneous fistula as a late complication to reconstruction of the pelvic floor with a Permacol™ mesh after a perineal hernia. A 70-year-old man had a reconstruction of the pelvic floor with a biological mesh because of a perineal hernia after laparoscopic abdominoperineal resection. Nine months after the perineal hernia operation, the patient had multiple metastases in both lungs and liver. The patient underwent chemotherapy, including bevacizumab, irinotecan, calcium folinate, and fluorouracil. Six weeks into chemotherapy, the patient developed signs of sepsis and complained of pain from the right buttock. Ultrasound examination revealed an abscess, which was drained, guided by ultrasound. A computed tomography scan showed a subcutaneous abscess cavity located in the right buttock with communication to the small bowel. Operative findings confirmed a perineal fistula from the distal ileum to perineum. A resection of the small bowel with primary anastomosis was performed. The postoperative course was complicated by fluid and electrolyte disturbances, but the patient was stabilized and finally discharged to a hospice for terminal care after 28 days of hospital stay. It seems that hernia repairs with biological meshes have lower erosion and infection rates compared with synthetic meshes, and so far, evidence suggests that biological grafts are safe and effective in the treatment of pelvic floor reconstruction. There have been no reports of enteric fistulas after pelvic reconstruction with biological meshes. However, the development of intestinal fistulas after chemotherapy with bevacizumab has been described in the literature. Our case report supports this association between bevacizumab and fistula formation among rectal cancer patients, as symptoms of a

  15. Prosthetic abdominal wall hernia repair in emergency surgery: from polypropylene to biological meshes

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    Campanelli G

    2008-12-01

    Full Text Available Abstract The use of nonabsorbable prosthetic materials such as polypropylene, polyester, and ePTFE, have expanded and are now widely used in reparative surgery for abdominal wall hernias. There are still difficulties to find correct indication for prosthetic implant in emergency hernia surgery: as a matter of fact there is still a great debate if to use non-absorbable prostheses in potentially or truly infected operating fields [e.g. after intestinal resections]. All these problems can be avoided with the use of absorbable prosthetic materials such as those composed of lactic acid polymers or lactic and glycolic acid copolymers: however, the use of these absorbable prosthesis exposes the patient to a rapid and inevitable hernia recurrence. It is important to remember that prosthetic repair has been proven to have a significant less risk of recurrence than repair with direct sutures. Recently, new "biologic" prosthetic materials have been developed and proposed for the clinical use in infected fields. These materials can be called "remodeling" for the way by which they are replaced after their placement within the patient. The "remodeling" process is made possible through a process of incorporation, where a reproduction of a site-specific tissue similar to the original host tissue is created.

  16. Functional results after repair of large hiatal hernia by use of a biologic mesh

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    Filimon eAntonakis

    2016-03-01

    Full Text Available Background: The aim of this observational study is to analyze the results of patients with large hiatal hernia and upside-down stomach after surgical closure with a biologic mesh (Permacol®, Covidien, Neustadt an der Donau, Germany. Biologic mesh is used to prevent long-term detrimental effects of artificial meshes and to reduce recurrence rates. Methods: A total of 13 patients with a large hiatal hernia and endothoracic stomach, who underwent surgery between 2010 and 2014, were included. Interviews and upper endoscopy were conducted to determine recurrence, lifestyle restrictions and current complaints. Results: After a mean follow-up of 26+18 months (range 3-58 months 10 patients (three men, mean age 73+13, range 26-81 years were evaluated. A small recurrent axial hernia was found in one patient postoperatively. Dysphagia was the most common complaint (four cases, while in one case the problem was solved after endoscopic dilatation. In three cases bloat and postprandial pain were documented. In one case explantation of the mesh was necessary due to mesh migration and painful adhesions. In one further case with gastroparesis pyloroplasty was performed without success.Conclusion: Recurrence was rare after hernia repair with the biologic mesh Permacol®. Dysphagia, gas bloat and intraabdominal pain were frequent complaints. Despite the small number of patients it can be concluded that a biologic mesh may be an alternative to synthetic meshes to reduce recurrences. Long-term results should be studied in the future in order to assess the potential of biologic meshes to preserve esophageal function as well. This is important since artificial meshes are known to erode the esophagus after 5–10 years.

  17. DNA Mismatch Repair and Oxidative DNA Damage: Implications for Cancer Biology and Treatment

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    Bridge, Gemma; Rashid, Sukaina; Martin, Sarah A., E-mail: sarah.martin@qmul.ac.uk [Centre for Molecular Oncology, Barts Cancer Institute, Queen Mary University of London, Charterhouse Square, London EC1M 6BQ (United Kingdom)

    2014-08-05

    Many components of the cell, including lipids, proteins and both nuclear and mitochondrial DNA, are vulnerable to deleterious modifications caused by reactive oxygen species. If not repaired, oxidative DNA damage can lead to disease-causing mutations, such as in cancer. Base excision repair and nucleotide excision repair are the two DNA repair pathways believed to orchestrate the removal of oxidative lesions. However, recent findings suggest that the mismatch repair pathway may also be important for the response to oxidative DNA damage. This is particularly relevant in cancer where mismatch repair genes are frequently mutated or epigenetically silenced. In this review we explore how the regulation of oxidative DNA damage by mismatch repair proteins may impact on carcinogenesis. We discuss recent studies that identify potential new treatments for mismatch repair deficient tumours, which exploit this non-canonical role of mismatch repair using synthetic lethal targeting.

  18. Maintaining Genetic Integrity Under Extreme Conditions: Novel DNA Damage Repair Biology in the Archaea

    Science.gov (United States)

    2013-11-23

    11/23/2013 Final Report DISTRIBUTION A: Distribution approved for public release. AIR FORCE RESEARCH LABORATORY AF OFFICE OF SCIENTIFIC RESEARCH...damaging agents, the genetic interactions with known DNA repair pathways and, crucially, the observed delay in DSB repair visualised by PFGE confirm the

  19. Lineage plasticity and cell biology of fibrocartilage and hyaline cartilage: Its significance in cartilage repair and replacement

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    Freemont, Anthony J. [Regenerative Medicine Research Group, University of Manchester, England (United Kingdom)]. E-mail: Tony.freemont@man.ac.uk; Hoyland, Judith [Regenerative Medicine Research Group, University of Manchester, England (United Kingdom)

    2006-01-15

    Cartilage repair is a major goal of modern tissue engineering. To produce novel engineered implants requires a knowledge of the basic biology of the tissues that are to be replaced or reproduced. Hyaline articular cartilage and meniscal fibrocartilage are two tissues that have excited attention because of the frequency with which they are damaged. A basic strategy is to re-engineer these tissues ex vivo by stimulating stem cells to differentiate into the cells of the mature tissue capable of producing an intact functional matrix. In this brief review, the sources of cells for tissue engineering cartilage and the culture conditions that have promoted differentiation are discussed within the context of natural cartilage repair. In particular, the role of cell density, cytokines, load, matrices and oxygen tension are discussed.

  20. Skin appendage-derived stem cells: cell biology and potential for wound repair.

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    Xie, Jiangfan; Yao, Bin; Han, Yutong; Huang, Sha; Fu, Xiaobing

    2016-01-01

    Stem cells residing in the epidermis and skin appendages are imperative for skin homeostasis and regeneration. These stem cells also participate in the repair of the epidermis after injuries, inducing restoration of tissue integrity and function of damaged tissue. Unlike epidermis-derived stem cells, comprehensive knowledge about skin appendage-derived stem cells remains limited. In this review, we summarize the current knowledge of skin appendage-derived stem cells, including their fundamental characteristics, their preferentially expressed biomarkers, and their potential contribution involved in wound repair. Finally, we will also discuss current strategies, future applications, and limitations of these stem cells, attempting to provide some perspectives on optimizing the available therapy in cutaneous repair and regeneration.

  1. Transcription-coupled nucleotide excision repair in mammalian cells: molecular mechanisms and biological effects

    Institute of Scientific and Technical Information of China (English)

    Mafia Fousteri; Leon HF Mullenders

    2008-01-01

    The encounter of elongating RNA polymerase Ⅱ (RNAPIIo) with DNA lesions has severe consequences for the cell as this event provides a strong signal for P53-dependent apoptosis and cell cycle arrest. To counteract prolonged blockage of transcription, the cell removes the RNAPllo-hlocking DNA lesions by transcription-coupled repair (TC-NER), a specialized subpathway of nucleotide excision repair (NER). Exposure of mice to UVB light or chemicals has elucidated that TC-NER is a critical survival pathway protecting against acute toxic and long-term effects (cancer) of genotoxic exposure. Deficiency in TC-NER is associated with mutations in the CSA and CSB genes giving rise to the rare hu-man disorder Cockayne syndrome (CS). Recent data suggest that CSA and CSB play differential roles in mammalian TC-NER: CSB as a repair coupling factor to attract NER proteins, chromatin remodellers and the CSA- E3-ubiquitin iigase complex to the stalled RNAPI io. CSA is dispensable for attraction of NER proteins, yet in cooperation with CSB is required to recruit XAB2, the nucleosomal binding protein HMGNl and TFIIS. The emerging picture of TC-NER is complex: repair of transcription-blocking lesions occurs without displacement of the DNA damage-stalled RNAPIIo, and requires at least two essential assembly factors (CSA and CSB), the core NER factors (except for XPC-RAD23B), and TC-NER specific factors. These and yet unidentified proteins will accomplish not only efficient repair of transcrip-tion-blocking lesions, but are also likely to contribute to DNA damage signalling events.

  2. Open and laparo-endoscopic repair of incarcerated abdominal wall hernias by the use of biological and biosynthetic meshes

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    René H Fortelny

    2016-02-01

    Full Text Available Introduction: Although recently published guidelines recommend against the use of synthetic non-absorbable materials in cases of potentially contaminated or contaminated surgical fields due to the increased risk of infection [1, 2], the use of bio-prosthetic meshes for abdominal wall or ventral hernia repair is still controversially discussed in such cases. Bio-prosthetic meshes have been recommended due to less susceptibility for infection and the decreased risk of subsequent mesh explantation. The purpose of this review is to elucidate if there are any indications for the use of biological and biosynthetic meshes in incarcerated abdominal wall hernias based on the recently published literature.Methods: A literature search of the Medline database using the PubMed search engine, using the keywords returned 486 articles up to June 2015. The full text of 486 articles was assessed and 13 relevant papers were identified including 5 retrospective case cohort studies, 2 case controlled studies, 6 case series.Results: The results of Franklin et al [23, 24, 25] included the highest number of biological mesh repairs (Surgisis® by laparoscopic IPOM in infected fields which demonstrated a very low incidence of infection and recurrence (0,7% and 5,2%. Han et al [26] reported in his retrospective study the highest number of treated patients due to incarcerated hernias by open approach using acellular dermal matrix (ADM® with very low rate of infection as well as recurrences (1,6% and 15,9. Both studies achieved acceptable outcome in a follow up of at least 3,5 years compared to the use of synthetic mesh in this high-risk population [3]Conclusion:Currently there is a very limited evidence for the use of biological and biosynthetic meshes in strangulated hernias in either open or laparo-endoscopic repair. Finally, there is an urgent need to start with randomized controlled comparative trials as well as to support registries with data to achieve more

  3. Biological evaluation of human hair keratin scaffolds for skin wound repair and regeneration

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    Xu, Songmei; Sang, Lin [National Engineering Research Center for Biomaterials, Sichuan University, Chengdu 610064 (China); Zhang, Yaping [Engineering Research Center of Biomass Materials, School of Materials Science and Engineering, Southwest University of Science and Technology, Mianyang 621010 (China); Wang, Xiaoliang [National Engineering Research Center for Biomaterials, Sichuan University, Chengdu 610064 (China); Li, Xudong, E-mail: xli20004@yahoo.com [National Engineering Research Center for Biomaterials, Sichuan University, Chengdu 610064 (China)

    2013-03-01

    The cytocompatibility, in vivo biodegradation and wound healing of keratin biomaterials were investigated. For the purposes, three groups of keratin scaffolds were fabricated by freeze-drying reduced solutions at 2 wt.%, 4 wt.% and 8 wt.% keratins extracted from human hairs. These scaffolds exhibited evenly distributed high porous structures with pore size of 120-220 {mu}m and the porosity > 90%. NIH3T3 cells proliferated well on these scaffolds in culture lasting up to 22 days. Confocal micrographs stained with AO visually revealed cell attachment and infiltration as well as scaffold architectural stability. In vivo animal experiments were conducted with 4 wt.% keratin scaffolds. Early degradation of subcutaneously implanted scaffolds occurred at 3 weeks in the outermost surface, in concomitant with inflammatory response. At 5 weeks, the overall porous structure of scaffolds severely deteriorated while the early inflammatory response in the outermost surface obviously subsided. A faster keratin biodegradation was observed in repairing full-thickness skin defects. Compared with the blank control, keratin scaffolds gave rise to more blood vessels at 2 weeks and better complete wound repair at 3 weeks with a thicker epidermis, less contraction and newly formed hair follicles. These preliminary results suggest that human hair keratin scaffolds are promising dermal substitutes for skin regeneration. - Highlights: Black-Right-Pointing-Pointer Preparation of highly-interconnected human hair keratin scaffolds. Black-Right-Pointing-Pointer Long-term cell culturing and in vivo animal experiments with keratin scaffolds. Black-Right-Pointing-Pointer Biodegradation is dependent on implantation site and function Black-Right-Pointing-Pointer Early vascularization and better repair in treating full-thickness skin wounds. Black-Right-Pointing-Pointer A thicker epidermis, less contraction and newly formed hair follicles are observed.

  4. Cartilage Repair in the Inflamed Joint: Considerations for Biological Augmentation Toward Tissue Regeneration.

    Science.gov (United States)

    Scotti, Celeste; Gobbi, Alberto; Karnatzikos, Georgios; Martin, Ivan; Shimomura, Kazunori; Lane, John G; Peretti, Giuseppe Michele; Nakamura, Norimasa

    2016-04-01

    Cartilage repair/regeneration procedures (e.g., microfracture, autologous chondrocyte implantation [ACI]) typically result in a satisfactory outcome in selected patients. However, the vast majority of patients with chronic symptoms and, in general, a more diseased joint, do not benefit from these surgical techniques. The aims of this work were to (1) review factors negatively influencing the joint environment; (2) review current adjuvant therapies that can be used to improve results of cartilage repair/regeneration procedures in patients with more diseased joints, (3) outline future lines of research and promising experimental approaches. Chronicity of symptoms and advancing patient age appear to be the most relevant factors negatively affecting clinical outcome of cartilage repair/regeneration. Preliminary experience with hyaluronic acid, platelet-rich plasma, and mesenchymal stem cell has been positive but there is no strong evidence supporting the use of these products and this requires further assessment with high-quality, prospective clinical trials. The use of a Tissue Therapy strategy, based on more mature engineered tissues, holds promise to tackle limitations of standard ACI procedures. Current research has highlighted the need for more targeted therapies, and (1) induction of tolerance with granulocyte colony-stimulating factor (G-CSF) or by preventing IL-6 downregulation; (2) combined IL-4 and IL-10 local release; and (3) selective activation of the prostaglandin E2 (PGE2) signaling appear to be the most promising innovative strategies. For older patients and for those with chronic symptoms, adjuvant therapies are needed in combination with microfracture and ACI.

  5. Biological consequences of potential repair intermediates of clustered base damage site in Escherichia coli

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    Shikazono, Naoya, E-mail: shikazono.naoya@jaea.go.jp [Japan Atomic Energy Agency, Advanced Research Science Center, 2-4 Shirakata-Shirane, Tokai-mura, Naka-gun, Ibaraki 319-1195 (Japan); O' Neill, Peter [Gray Institute for Radiation Oncology and Biology, University of Oxford, Roosevelt Drive, Oxford OX3 7DQ (United Kingdom)

    2009-10-02

    Clustered DNA damage induced by a single radiation track is a unique feature of ionizing radiation. Using a plasmid-based assay in Escherichia coli, we previously found significantly higher mutation frequencies for bistranded clusters containing 7,8-dihydro-8-oxoguanine (8-oxoG) and 5,6-dihydrothymine (DHT) than for either a single 8-oxoG or a single DHT in wild type and in glycosylase-deficient strains of E. coli. This indicates that the removal of an 8-oxoG from a clustered damage site is most likely retarded compared to the removal of a single 8-oxoG. To gain further insights into the processing of bistranded base lesions, several potential repair intermediates following 8-oxoG removal were assessed. Clusters, such as DHT + apurinic/apyrimidinic (AP) and DHT + GAP have relatively low mutation frequencies, whereas clusters, such as AP + AP or GAP + AP, significantly reduce the number of transformed colonies, most probably through formation of a lethal double strand break (DSB). Bistranded AP sites placed 3' to each other with various interlesion distances also blocked replication. These results suggest that bistranded base lesions, i.e., single base lesions on each strand, but not clusters containing only AP sites and strand breaks, are repaired in a coordinated manner so that the formation of DSBs is avoided. We propose that, when either base lesion is initially excised from a bistranded base damage site, the remaining base lesion will only rarely be converted into an AP site or a single strand break in vivo.

  6. DNA repair mechanisms and their biological roles in the malaria parasite Plasmodium falciparum.

    Science.gov (United States)

    Lee, Andrew H; Symington, Lorraine S; Fidock, David A

    2014-09-01

    Research into the complex genetic underpinnings of the malaria parasite Plasmodium falciparum is entering a new era with the arrival of site-specific genome engineering. Previously restricted only to model systems but now expanded to most laboratory organisms, and even to humans for experimental gene therapy studies, this technology allows researchers to rapidly generate previously unattainable genetic modifications. This technological advance is dependent on DNA double-strand break repair (DSBR), specifically homologous recombination in the case of Plasmodium. Our understanding of DSBR in malaria parasites, however, is based largely on assumptions and knowledge taken from other model systems, which do not always hold true in Plasmodium. Here we describe the causes of double-strand breaks, the mechanisms of DSBR, and the differences between model systems and P. falciparum. These mechanisms drive basic parasite functions, such as meiosis, antigen diversification, and copy number variation, and allow the parasite to continually evolve in the contexts of host immune pressure and drug selection. Finally, we discuss the new technologies that leverage DSBR mechanisms to accelerate genetic investigations into this global infectious pathogen.

  7. Structural Biology of DNA Repair: Spatial Organisation of the Multicomponent Complexes of Nonhomologous End Joining

    Directory of Open Access Journals (Sweden)

    Takashi Ochi

    2010-01-01

    Full Text Available Nonhomologous end joining (NHEJ plays a major role in double-strand break DNA repair, which involves a series of steps mediated by multiprotein complexes. A ring-shaped Ku70/Ku80 heterodimer forms first at broken DNA ends, DNA-dependent protein kinase catalytic subunit (DNA-PKcs binds to mediate synapsis and nucleases process DNA overhangs. DNA ligase IV (LigIV is recruited as a complex with XRCC4 for ligation, with XLF/Cernunnos, playing a role in enhancing activity of LigIV. We describe how a combination of methods—X-ray crystallography, electron microscopy and small angle X-ray scattering—can give insights into the transient multicomponent complexes that mediate NHEJ. We first consider the organisation of DNA-PKcs/Ku70/Ku80/DNA complex (DNA-PK and then discuss emerging evidence concerning LigIV/XRCC4/XLF/DNA and higher-order complexes. We conclude by discussing roles of multiprotein systems in maintaining high signal-to-noise and the value of structural studies in developing new therapies in oncology and elsewhere.

  8. Porous alumina, zirconia and alumina/zirconia for bone repair: fabrication, mechanical and in vitro biological response.

    Science.gov (United States)

    Hadjicharalambous, Chrystalleni; Buyakov, Ales; Buyakova, Svetlana; Kulkov, Sergey; Chatzinikolaidou, Maria

    2015-04-23

    Zirconia (ZrO2) and alumina (Al2O3) based ceramics are widely used for load-bearing applications in bone repair due to their excellent mechanical properties and biocompatibility. They are often regarded as bioinert since no direct bone-material interface is created unless a porous structure intercedes, leading to better bone bonding. In this regard, investigating interactions between cells and porous ceramics is of great interest. In the present study, we report on the successful fabrication of sintered alumina A-61, zirconia Z-50 and zirconia/alumina composite ZA-60 ceramics with medium porosities of 61, 50 and 60%, respectively, indicating a bimodal pore size distribution and good interconnectivity. They exhibit elastic moduli of 3-10 GPa and compressive strength values of 60-240 MPa, similar to those of human cortical bone.We performed in vitro cell-material investigations comparing the adhesion, proliferation and differentiation of mouse pre-osteoblasts MC3T3-E1 on the three porous materials. While all three ceramics demonstrate a strong cell attachment, better cell spreading is observed on zirconia-containing substrates. Significantly higher cell growth was quantified on the latter ceramics, revealing an increased alkaline phosphatase activity, higher collagen production and increased calcium biomineralization compared to A-61. Hence, these porous zirconia-containing ceramics elicit superior biological responses over porous alumina of similar porosity, promoting enhanced biological interaction, with potential use as non-degradable bone grafts or as implant coatings.

  9. The Viable Mitral Annular Dynamics and Left Ventricular Function after Mitral Valve Repair by Biological Rings

    Directory of Open Access Journals (Sweden)

    Farideh Roshanali

    2012-12-01

    Full Text Available Objective: Considering the importance of annular dynamics in the valvular and ventricular function, we sought to evaluate the effects of treated pericardial annuloplasty rings on mitral annular dynamics and left-ventricular (LV function after mitral valve repair. The results were compared with the mitral annular dynamics and LV function in patients with rigid and flexible rings and also in those without any heart problems. Materials and Methods: One hundred and thirty-six consecutive patients with a myxomatous mitral valve and severe regurgitation were prospectively enrolled in this observational cohort study. The patients underwent comparable surgical mitral valve reconstruction; of these 100 received autologous pericardium rings (Group I, 20 were given flexible prosthetic rings (Group II, and 16 received rigid rings (Group III. Other repair modalities were also performed, depending on the involved segments. The patients were compared with 100 normal subjects in whom an evaluation of the coronary artery was not indicative of valvular or myocardial abnormalities (Group IV. At follow-up, LV systolic indices were assessed via two-dimensional echocardiography at rest and during dobutamine stress echocardiography. Mitral annular motion was examined through mitral annulus systolic excursion (MASE. Peak transmitral flow velocities (TMFV and mitral valve area (MVA were also evaluated by means of continuous-wave Doppler. Results: A postoperative echocardiographic study showed significant mitral regurgitation (>=2+ in one patient in Group I, one patient in Group II, and none in Group III. None of the patients died. There was a noteworthy increase in TMFV with stress in all the groups, the increase being more considerable in the prosthetic ring groups (Group I from 1.10 ± 0.08 to 1.36 ± 0.13 m/s, Group II from 1.30 ± 0.11 to 1.59 ± 0.19 m/s, Group III from 1.33 ± 0.09 to 1.69 ± 0.21 m/s, and Group IV from 1.08 ± 0.08 to 1.21 ± 0.12 m

  10. Chemotherapy-induced enterocutaneous fistula after perineal hernia repair using a biological mesh

    DEFF Research Database (Denmark)

    Eriksen, Mh; Bulut, O

    2014-01-01

    This is the first reported case of an enterocutaneous fistula as a late complication to reconstruction of the pelvic floor with a Permacol™ mesh after a perineal hernia. A 70-year-old man had a reconstruction of the pelvic floor with a biological mesh because of a perineal hernia after laparoscopic...... abdominoperineal resection. Nine months after the perineal hernia operation, the patient had multiple metastases in both lungs and liver. The patient underwent chemotherapy, including bevacizumab, irinotecan, calcium folinate, and fluorouracil. Six weeks into chemotherapy, the patient developed signs of sepsis...... from the distal ileum to perineum. A resection of the small bowel with primary anastomosis was performed. The postoperative course was complicated by fluid and electrolyte disturbances, but the patient was stabilized and finally discharged to a hospice for terminal care after 28 days of hospital stay...

  11. Adverse Biological Effect of TiO2 and Hydroxyapatite Nanoparticles Used in Bone Repair and Replacement

    Directory of Open Access Journals (Sweden)

    Jiangxue Wang

    2016-05-01

    Full Text Available The adverse biological effect of nanoparticles is an unavoidable scientific problem because of their small size and high surface activity. In this review, we focus on nano-hydroxyapatite and TiO2 nanoparticles (NPs to clarify the potential systemic toxicological effect and cytotoxic response of wear nanoparticles because they are attractive materials for bone implants and are widely investigated to promote the repair and reconstruction of bone. The wear nanoparticles would be prone to binding with proteins to form protein-particle complexes, to interacting with visible components in the blood including erythrocytes, leukocytes, and platelets, and to being phagocytosed by macrophages or fibroblasts to deposit in the local tissue, leading to the formation of fibrous local pseudocapsules. These particles would also be translocated to and disseminated into the main organs such as the lung, liver and spleen via blood circulation. The inflammatory response, oxidative stress, and signaling pathway are elaborated to analyze the potential toxicological mechanism. Inhibition of the oxidative stress response and signaling transduction may be a new therapeutic strategy for wear debris–mediated osteolysis. Developing biomimetic materials with better biocompatibility is our goal for orthopedic implants.

  12. Application of a molecular biology concept for the detection of DNA damage and repair during UV disinfection.

    Science.gov (United States)

    Süss, Jacqueline; Volz, Sabrina; Obst, Ursula; Schwartz, Thomas

    2009-08-01

    As nucleic acids are major targets in bacteria during standardised UV disinfection (254 nm), inactivation rates also depend on bacterial DNA repair. Due to UV-related DNA modifications, PCR-based approaches allow for a direct detection of DNA damage and repair during UV disinfection. By applying different primer sets, the correlation between amplicon length and PCR amplification became obvious. The longer the targeted DNA fragment was, the more UV-induced DNA lesions inhibited the PCR. Regeneration of Pseudomonas aeruginosa, Enterococcus faecium, and complex wastewater communities was recorded over a time period of 66 h. While phases of intensive repair and proliferation were found for P. aeruginosa, no DNA repair was detected by qPCR in E. faecium. Cultivation experiments verified these results. Despite high UV mediated inactivation rates original wastewater bacteria seem to express an enhanced robustness against irradiation. Regeneration of dominant and proliferation of low-abundant, probably UV-resistant species contributed to a strong post-irradiation recovery accompanied by a selection for beta-Proteobacteria.

  13. Approach to the classical radiation biology. Ionizing radiation effects and repair mechanism of DNA double strand breaks

    Energy Technology Data Exchange (ETDEWEB)

    Utsumi, Hiroshi [Kyoto Univ., Kumatori, Osaka (Japan). Research Reactor Inst

    2000-09-01

    Split-dose recovery has been observed under a variety of experimental conditions in many cell systems and believed to be the recovery of sublethal damage (SLD). It is considered to be one of the most widespread and important cellular responses in clinical radiotherapy. To study the molecular mechanism of this recovery, we analyzed the knockout mutants KU70{sup -/-}, RAD54{sup -/-}, and KU70{sup -/-}/ RAD54{sup -/-} of the chicken B-cell line, DT40. Rad54 participates in the homologous recombinational (HR) repair of DNA double-strand breaks (DSB), while Ku proteins are involved in non-homologous end-joining (NHEJ). Split-dose recovery was observed in the parent DT40 and KU70{sup -/-} cells. Moreover the split-dose survival enhancement had all of the characteristics of SLD recovery that had been demonstrated earlier: e.g., the reappearance of the shoulder of the survival curve with dose fractionation; repair at 25degC; and inhibition by the antibiotic actinomycin D. These results strongly suggest that SLD recovery is due to DSB repair via or mediated by HR, and that these breaks constitute SLD. The tonicity-sensitive potentially lethal damage (PLD) recovery was also found only in DT40 and KU70 {sup -/-} cells. Delayed-plating PLD recovery may be controlled by NHEJ repair that works through the cell cycle. These results lead to the conclusion that the repair of DSBs could explain the classical operational recovery phenomena. We have also investigated RBE/LET using those mutants. (author)

  14. Optimality in DNA repair.

    Science.gov (United States)

    Richard, Morgiane; Fryett, Matthew; Miller, Samantha; Booth, Ian; Grebogi, Celso; Moura, Alessandro

    2012-01-07

    DNA within cells is subject to damage from various sources. Organisms have evolved a number of mechanisms to repair DNA damage. The activity of repair enzymes carries its own risk, however, because the repair of two nearby lesions may lead to the breakup of DNA and result in cell death. We propose a mathematical theory of the damage and repair process in the important scenario where lesions are caused in bursts. We use this model to show that there is an optimum level of repair enzymes within cells which optimises the cell's response to damage. This optimal level is explained as the best trade-off between fast repair and a low probability of causing double-stranded breaks. We derive our results analytically and test them using stochastic simulations, and compare our predictions with current biological knowledge.

  15. Integration of principles of systems biology and radiation biology: toward development of in silico models to optimize IUdR-mediated radiosensitization of DNA mismatch repair-deficient (damage tolerant human cancers

    Directory of Open Access Journals (Sweden)

    Timothy James Kinsella

    2011-08-01

    Full Text Available Over the last 7 years, we have focused our experimental and computational research efforts on improving our understanding of the biochemical, molecular, and cellular processing of iododeoxyuridine (IUdR and ionizing radiation (IR induced DNA base damage by DNA mismatch repair (MMR. These coordinated research efforts, sponsored by the National Cancer Institute Integrative Cancer Biology Program (ICBP, brought together system scientists with expertise in engineering, mathematics, and complex systems theory and translational cancer researchers with expertise in radiation biology. Our overall goal was to begin to develop computational models of IUdR- and/or IR- induced base damage processing by MMR that may provide new clinical strategies to optimize IUdR-mediated radiosensitiztion in MMR deficient (MMR- damage tolerant human cancers. Using multiple scales of experimental testing, ranging from purified protein systems to in vitro (cellular and to in vivo (human tumor xenografts in athymic mice models, we have begun to integrate and interpolate these experimental data with hybrid stochastic biochemical models of MMR damage processing and probabilistic cell cycle regulation models through a systems biology approach. In this article, we highlight the results and current status of our integration of radiation biology approaches and computational modeling to enhance IUdR-mediated radiosensitization in MMR- damage tolerant cancers.

  16. DNA repair protocols

    DEFF Research Database (Denmark)

    Bjergbæk, Lotte

    In its 3rd edition, this Methods in Molecular Biology(TM) book covers the eukaryotic response to genomic insult including advanced protocols and standard techniques in the field of DNA repair. Offers expert guidance for DNA repair, recombination, and replication. Current knowledge of the mechanisms...... that regulate DNA repair has grown significantly over the past years with technology advances such as RNA interference, advanced proteomics and microscopy as well as high throughput screens. The third edition of DNA Repair Protocols covers various aspects of the eukaryotic response to genomic insult including...... recent advanced protocols as well as standard techniques used in the field of DNA repair. Both mammalian and non-mammalian model organisms are covered in the book, and many of the techniques can be applied with only minor modifications to other systems than the one described. Written in the highly...

  17. Repair mechanisms inducible to the DNA in I.M.M.S. biological systems; Mecanismos de reparacion inducible del ADN en sistemas biologicos I.M.M.S

    Energy Technology Data Exchange (ETDEWEB)

    Guzman, J.; Arceo, C.; Cortinas, C.; Rosa, M.E. De la; Olvera, O.; Cruces, M.; Pimentel, E

    1990-03-15

    Given the characteristics of the MMS and the relative antecedents to the repair mechanisms in eucariontes are sought to determine the effect of the MMS on the genetic material and their repair in Drosophila melanogaster. (Author)

  18. Structural biology of disease-associated repetitive DNA sequences and protein-DNA complexes involved in DNA damage and repair

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, G.; Santhana Mariappan, S.V.; Chen, X.; Catasti, P.; Silks, L.A. III; Moyzis, R.K.; Bradbury, E.M.; Garcia, A.E.

    1997-07-01

    This project is aimed at formulating the sequence-structure-function correlations of various microsatellites in the human (and other eukaryotic) genomes. Here the authors have been able to develop and apply structure biology tools to understand the following: the molecular mechanism of length polymorphism microsatellites; the molecular mechanism by which the microsatellites in the noncoding regions alter the regulation of the associated gene; and finally, the molecular mechanism by which the expansion of these microsatellites impairs gene expression and causes the disease. Their multidisciplinary structural biology approach is quantitative and can be applied to all coding and noncoding DNA sequences associated with any gene. Both NIH and DOE are interested in developing quantitative tools for understanding the function of various human genes for prevention against diseases caused by genetic and environmental effects.

  19. A symphony on C : orchestrating DNA repair for gene expression via cytosine modification The 2012 IMB Conference: DNA Demethylation, Repair and Beyond Institute of Molecular Biology, Mainz, Germany, 18-21 October 2012

    NARCIS (Netherlands)

    Rots, Marianne G.; Petersen-Mahrt, Svend K.

    2013-01-01

    Headline-grabbing attention has been given to DNA demethylation pathways as new epigenetic mechanisms, with reviews and hypotheses outnumbering research papers. As candidate proteins for DNA demethylation include well-known DNA repair enzymes, it was timely to join epigenetics and DNA repair experts

  20. Tendon repair

    Science.gov (United States)

    Repair of tendon ... Tendon repair can be performed using: Local anesthesia (the immediate area of the surgery is pain-free) ... a cut on the skin over the injured tendon. The damaged or torn ends of the tendon ...

  1. Embryological origin of the endocardium and derived valve progenitor cells: from developmental biology to stem cell-based valve repair.

    Science.gov (United States)

    Pucéat, Michel

    2013-04-01

    The cardiac valves are targets of both congenital and acquired diseases. The formation of valves during embryogenesis (i.e., valvulogenesis) originates from endocardial cells lining the myocardium. These cells undergo an endothelial-mesenchymal transition, proliferate and migrate within an extracellular matrix. This leads to the formation of bilateral cardiac cushions in both the atrioventricular canal and the outflow tract. The embryonic origin of both the endocardium and prospective valve cells is still elusive. Endocardial and myocardial lineages are segregated early during embryogenesis and such a cell fate decision can be recapitulated in vitro by embryonic stem cells (ESC). Besides genetically modified mice and ex vivo heart explants, ESCs provide a cellular model to study the early steps of valve development and might constitute a human therapeutic cell source for decellularized tissue-engineered valves. This article is part of a Special Issue entitled: Cardiomyocyte Biology: Cardiac Pathways of Differentiation, Metabolism and Contraction.

  2. Biologic characteristic studies of DNA mismatch—repair enzyme hMSH2—deficient cell strain

    Institute of Scientific and Technical Information of China (English)

    HeY; ZhuaZX

    2002-01-01

    The effect of hMSH2 enzyme-deficiency on the cell growing phenotypes,cell ultrastructure,growth character and cell cycle were observed with electronic microscopy examination,cell counting and flow cytometry.hMSH2-deficient cell strain was constructed by transfecting hMSH2 recombination plasmid of antisense RNA into human embryo lung fibroblasts(HLF).In hMSH2-deficient cells,there were a lot of morphological changes under electronic microscopy,such as irregular shape,a lot of protuberances on the surface of cell,the enlarged nuclei.The average time of double increment of HLF and hMSH2-deficient cells were 1.0d and 0.78d,respectively.This suggested that the cell proliferation of hMSH2-deficient cells was greater than that of HLF.The distribution of HLF and hMSH2-deficient cells in G1,G2 and S phases was different.A large part of hMSH2-deficient cells was blocked in G1 phase.hMSH2-deficient cells increased,but it is still not a typical malignant cells.Thus,this cell strain could be used as biologic material to detect mutagenesis of environmental chemicals.

  3. Effect of different hydroxyapatite incorporation methods on the structural and biological properties of porous collagen scaffolds for bone repair.

    Science.gov (United States)

    Ryan, Alan J; Gleeson, John P; Matsiko, Amos; Thompson, Emmet M; O'Brien, Fergal J

    2015-12-01

    Scaffolds which aim to provide an optimised environment to regenerate bone tissue require a balance between mechanical properties and architecture known to be conducive to enable tissue regeneration, such as a high porosity and a suitable pore size. Using freeze-dried collagen-based scaffolds as an analogue of native ECM, we sought to improve the mechanical properties by incorporating hydroxyapatite (HA) in different ways while maintaining a pore architecture sufficient to allow cell infiltration, vascularisation and effective bone regeneration. Specifically we sought to elucidate the effect of different hydroxyapatite incorporation methods on the mechanical, morphological, and cellular response of the resultant collagen-HA scaffolds. The results demonstrated that incorporating either micron-sized (CHA scaffolds) or nano-sized HA particles (CnHA scaffolds) prior to freeze-drying resulted in moderate increases in stiffness (2.2-fold and 6.2-fold, respectively, vs. collagen-glycosaminoglycan scaffolds, P collagen scaffolds with a hydroxyapatite precipitate after freeze-drying (CpHA scaffolds) has been shown to be a highly effective method to increase the compressive modulus (26-fold vs. CG controls, P collagen structure results in a lower cell attachment level (P temperature. It was found that the addition of HA prior to freeze-drying generally reduced the pore size and so the CpHA scaffold fabrication method offered increased control over the resulting scaffolds microstructure. These findings will help guide future design considerations for composite biomaterials and demonstrate that the method of HA incorporation can have profound effects on the resulting scaffold structural and biological response.

  4. Bladder exstrophy repair

    Science.gov (United States)

    Bladder birth defect repair; Everted bladder repair; Exposed bladder repair; Repair of bladder exstrophy ... Bladder exstrophy repair involves two surgeries. The first surgery is to repair the bladder and the second one is to attach ...

  5. 脂肪干细胞和生物支架应用于牙槽骨修复%Adipose stem cells and biological scaffolds used in alveolar bone repair

    Institute of Scientific and Technical Information of China (English)

    曹娜; 裴路; 张微

    2014-01-01

      结果与结论:脂肪干细胞具有与骨髓基质干细胞相似的分化潜能,因其来源广、易采集、易培养低衰老,成骨分化好和风险小等特点被广泛关注,尤其和生物支架应用于骨修复表现出更好的成骨效果。随着有关各科学的发展牙槽骨缺损的修复有关问题都可以解决,脂肪干细胞和生物支架构建工程骨将是实现真正意义上牙槽骨再生的发展趋势且具有良好的发展前景。%BACKGROUND:Alveolar bone absorption and defect caused by various physiological or pathological factors is a common problem in oral clinical medicine, but the most commonly used methods to repair alveolar bone defects cannot ful y meet clinical needs. The emergence of bone tissue engineering for bone defect repair has become a research hotspot. OBJECTIVE:To review the source and application of adipose stem cells, the types and characteristics of biological scaffolds, the effect of biological scaffold on seed cells and the application of adipose stem cells composite scaffolds in animal experiment research. METHODS:A computer-based search of CNKI and PubMed (1995-01/2013-04) was performed to retrieve the related articles about adipose stem cells, biological scaffold and bone repair. The keywords were“adipose stem cells, differentiation, proliferation and osteogenesis, biological scaffold, alveolar bone, bone tissue engineering”in Chinese and English, respectively. Articles published recently or in authorized journals were preferred. There were163 articles after the initial survey. Then, 40 articles were included in result analysis. RESULTS AND CONCLUSION:Adipose stem cells have a differentiating potential similar to bone marrow stromal stem cells. Adipose stem cells have been widely drawn by variety of sources, easy col ection, easy to cultivate and low aging, good osteogenetic differentiation and low risk. Especial y, adipose stem cells and biological scaffolds used in bone repair

  6. 骨缺损修复生物工程研究进展%Research progress of biological engineering on bone defect repairing

    Institute of Scientific and Technical Information of China (English)

    郭宜姣; 李文华

    2014-01-01

    临床上对于骨缺损的治疗从截肢,自体骨、异体骨移植,到目前的生物活性材料、骨组织工程、基因工程治疗,依然没有能够彻底进行骨缺损修复的方法,这也一直是医学界关注和研究的热点。究其原因一方面是因为各种方法的技术水平还不完善如手术时间和方法掌握,生物活性材料的制作等,另一方面是因为骨缺损的局部反应较复杂如骨髓损伤较重,血运较差,断端存在的硬化反应等以及传统治疗后的并发症较多如免疫排斥较重,成骨作用不良,骨折不愈合,神经损伤长期引发的疼痛等,这些原因都在不同程度的制约骨缺损研究的前进。只有从骨的修复与生长机制出发,联合应用多种方法,相互补其不足,从中找到突破点,才能完善骨缺损修复,缩短治疗时间,提高病人的生活质量。本文简要描述自体和异体骨移植在治疗骨缺损时的优缺点,着重叙述骨组织工程与基因工程近年来的研究热点,包括生物材料的更新换代、目的细胞的种类增加、生长因子与基因载体的研究进展等,这其中探讨了生物修复骨缺损工程中两种方法各自的利弊,阐述两种工程联合应用的优缺互补,最后提出骨缺损治疗研究方向上的新思路与新问题。%The treatment for bone defect in clinic varies from amputation, autogenous bone graft, and allograft.Up to now, the biological activity material, bone tissue engineering, and gene engineering treatment are still not able to completely repair the bone defect.It has been a hot spot in medical field.One of the reasons is the limitation of technology, such as the mastery of operation time and method and the manufacture of bioactive materials.On the other hand, the local reactions of bone defect are complicated, such as serous bone marrow damage, poor blood supply, the hardening reaction in the cutting ends, and more

  7. Biologic

    CERN Document Server

    Kauffman, L H

    2002-01-01

    In this paper we explore the boundary between biology and the study of formal systems (logic). In the end, we arrive at a summary formalism, a chapter in "boundary mathematics" where there are not only containers but also extainers ><, entities open to interaction and distinguishing the space that they are not. The boundary algebra of containers and extainers is to biologic what boolean algebra is to classical logic. We show how this formalism encompasses significant parts of the logic of DNA replication, the Dirac formalism for quantum mechanics, formalisms for protein folding and the basic structure of the Temperley Lieb algebra at the foundations of topological invariants of knots and links.

  8. DNA repair genotypes and phenotypes and cancer susceptibility

    Institute of Scientific and Technical Information of China (English)

    Qingyi Wei

    2008-01-01

    @@ The role of DNA repair in the etiology of cancers has been well illustrated in several hereditary syndromes, in which an inherited defect in DNA repair and related biological processes is associated with extraordinarily high incidence of cancer.

  9. Femoral hernia repair

    Science.gov (United States)

    Femorocele repair; Herniorrhaphy; Hernioplasty - femoral ... During surgery to repair the hernia, the bulging tissue is pushed back in. The weakened area is sewn closed or strengthened. This repair ...

  10. Undescended testicle repair

    Science.gov (United States)

    Orchidopexy; Inguinal orchidopexy; Orchiopexy; Repair of undescended testicle; Cryptorchidism repair ... first year of life without treatment. Undescended testicle repair surgery is recommended for patients whose testicles do ...

  11. 经EX-810处理的食管用修补材料%Esophageal repairing acellular biological tissues fixed by EX-810

    Institute of Scientific and Technical Information of China (English)

    李莉; 顾志鹏; 陈健; 余喜讯

    2011-01-01

    BACKGROUND: Natural biological tissue materials can be gradually absorbed, and can induce tissue-specific remodeling, whichare ideal esophageal repair materials.OBJECTIVE: To investigate the characteristics of porcine esophageal tissues fixed with ethylene glycol diglycidyl ether (EX-810).METHODS: The porcine esophageal tissues were treated with 4% EX-810 for 1 hour to 120 hours, and then they were examinedmorphologically with the electron microscope. The fixation index determination and the biomechanics test were also performed tostudy the degree of cross-linking and the effect of cross-linking on the mechanical properties.RESULTS AND CONCLUSION: The antigenicity of esophageal tissues could be diminished by EX-810 through getting rid of cellsin the esophageal tissues or reducing the level of free amino groups in the esophageal tissues. The structural integrity of collagenin esophageal tissues could be preserved after treating with EX-810. In this study, it was also found that the EX-810-fixed porcineesophageal tissues showed better mechanical properties than the native esophageal tissues, and had a changed stress-straincharacteristics. It could meet the standard used as the prosthetic materials for bridging esophageal defects. The EX-810-fixedporcine esophageal tissues showed low antigenicity and proper mechanical properties, and the structural integrity of collagen inthem could also be preserved.%背景:天然生物组织来源材料能逐渐被吸收,同时能够诱导组织特异性结构重塑,是理想的食管修补材料.目的:观察环氧类交联剂EX-810处理的猪食管组织的性能特点.方法:用4%EX-810处理猪食管组织1~120 h,通过对交联指数的测定观察交联情况;扫描电镜观察组织交联前后的形态学变化;将新鲜的,交联3,7 d的样品进行力学性能测定,观察交联对材料力学性能的影响.结果与结论:EX-810能有效地交联组织,并能通过去除细胞、组织中的自由氨基等抗原性

  12. Aortic aneurysm repair - endovascular

    Science.gov (United States)

    EVAR; Endovascular aneurysm repair - aorta; AAA repair - endovascular; Repair - aortic aneurysm - endovascular ... Endovascular aortic repair is done because your aneurysm is very large, growing quickly, or is leaking or bleeding. You may have ...

  13. Intestinal obstruction repair

    Science.gov (United States)

    Repair of volvulus; Intestinal volvulus - repair; Bowel obstruction - repair ... Intestinal obstruction repair is done while you are under general anesthesia . This means you are asleep and DO NOT feel pain. ...

  14. Motorcycle Repair.

    Science.gov (United States)

    Hein, Jim; Bundy, Mike

    This motorcycle repair curriculum guide contains the following ten areas of study: brake systems, clutches, constant mesh transmissions, final drives, suspension, mechanical starting mechanisms, electrical systems, fuel systems, lubrication systems, and overhead camshafts. Each area consists of one or more units of instruction. Each instructional…

  15. Titanium dioxide nanoparticles provide protection against polycyclic aromatic hydrocarbon BaP and chrysene-induced perturbation of DNA repair machinery: A computational biology approach.

    Science.gov (United States)

    Dhasmana, Anupam; Jamal, Qazi Mohd Sajid; Gupta, Richa; Siddiqui, Mohd Haris; Kesari, Kavindra Kumar; Wadhwa, Gulshan; Khan, Saif; Haque, Shafiul; Lohani, Mohtashim

    2016-07-01

    We examined the interaction of polycyclic hydrocarbons (PAHs) like benzo-α-pyrene (BaP), chrysene, and their metabolites 7,8-dihydro-7,8-dihydroxybenzo(a)pyrene,9,10-oxide (BPDE) and chrysene 1,2-diol-3,4-epoxide-2 (CDE), with the enzymes involved in DNA repair. We investigated interaction of 120 enzymes with PAHs and screened out 40 probable targets among DNA repair enzymes, on the basis of higher binding energy than positive control. Out of which, 20 enzymes lose their function in the presence of BaP, chrysene, and their metabolites, which may fetter DNA repair pathways resulting in damage accumulation and finally leading to cancer formation. We propose the use of nanoparticles as a guardian against the PAH's induced toxicity. PAHs enter the cell via aryl hydrocarbon receptor (AHR). TiO2 NP showed a much higher docking score with AHR (12,074) as compared with BaP and chrysene with AHR (4,600 and 4,186, respectively), indicating a preferential binding of TiO2 NP with the AHR. Further, docking of BaP and chrysene with the TiO2 NP bound AHR complex revealed their strong adsorption on TiO2 NP itself, and not on their original binding site (at AHR). TiO2 NPs thereby prevent the entry of PAHs into the cell via AHR and hence protect cells against the deleterious effects induced by PAHs.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  17. DNA Repair and Genome Maintenance in Bacillus subtilis

    OpenAIRE

    2012-01-01

    Summary: From microbes to multicellular eukaryotic organisms, all cells contain pathways responsible for genome maintenance. DNA replication allows for the faithful duplication of the genome, whereas DNA repair pathways preserve DNA integrity in response to damage originating from endogenous and exogenous sources. The basic pathways important for DNA replication and repair are often conserved throughout biology. In bacteria, high-fidelity repair is balanced with low-fidelity repair and mutage...

  18. Brain aneurysm repair

    Science.gov (United States)

    ... aneurysm repair; Dissecting aneurysm repair; Endovascular aneurysm repair - brain; Subarachnoid hemorrhage - aneurysm ... Your scalp, skull, and the coverings of the brain are opened. A metal clip is placed at ...

  19. Eye muscle repair - discharge

    Science.gov (United States)

    ... Lazy eye repair - discharge; Strabismus repair - discharge; Extraocular muscle surgery - discharge ... You or your child had eye muscle repair surgery to correct eye muscle ... term for crossed eyes is strabismus. Children most often ...

  20. Envisioning the molecular choreography of DNA base excision repair.

    Science.gov (United States)

    Parikh, S S; Mol, C D; Hosfield, D J; Tainer, J A

    1999-02-01

    Recent breakthroughs integrate individual DNA repair enzyme structures, biochemistry and biology to outline the structural cell biology of the DNA base excision repair pathways that are essential to genome integrity. Thus, we are starting to envision how the actions, movements, steps, partners and timing of DNA repair enzymes, which together define their molecular choreography, are elegantly controlled by both the nature of the DNA damage and the structural chemistry of the participating enzymes and the DNA double helix.

  1. Effect of biological mesh on hiatal hernia repair: One-year follow-up%生物补片修补食管裂孔疝的效果:1年随访

    Institute of Scientific and Technical Information of China (English)

    姚国良; 姚琪远; 花荣; 俞建平

    2011-01-01

    BACKGROUND: Although laparoscopic hiatal hernia repair had achieved good therapeutic effect, there is a debate add ressing whether the biological mesh was used for surgery.OBJECTIVE: To analyze the effect of laparoscopic hiatal hernia repair with biological mesh.METHODS: To retrospectively analyze clinical data of 57 patients with esophageal hiatal hernia, all of whom were accepted su rgical treatment at Huashan Hospital Affiliated to Fudan University from November 2006 to June 2009, including 24 cases with simple diaphragm feet suture and Nissen fu ndoplication (control group), 33 cases with simple diaphragm feet suture and Nissen fundoplication were undergoing mesh reforcement simultaneously (experimental group). The therapeutic results of laparoscopic hiatal hernia repair were compared and analyzed with or without mesh.RESULTS AND CONCLUSION: During 1 year follow-up, there was no significant difference between the control and experimental groups, including recurrence rate, patient satisfactory and symptom control (P > 0.05). Compared with the control group, the intraoperative and postoperative com plications were not increased in experimental group; meanwhile, operation interval and hospital stay were not significantly longer either (P > 0.05). The short-term follow-up results showed that laparoscopic hiatal hernia repair with mesh was safe and effective, but indications should be strictly controlled.%背景:尽管腹腔镜食管裂孔疝修补已取得良好的治疗效果,但对术中是否应该使用生物补片仍存在争议.目的:分析生物补片修补腹腔镜食管裂孔疝的效果.方法:回顾性分析2006-11/2009-06在复旦大学附属华山医院实施手术的57例食管裂孔疝患者临床资料,其中单纯膈肌脚缝合+Nissen胃底折叠24例(对照组),单纯膈肌脚缝合+Nissen胃底折叠同时行补片加强33例(实验组).对比分析使用补片和未使用补片的治疗结果.结果与结论:术后随访1年,实验组与

  2. DNA repair. [UV radiation

    Energy Technology Data Exchange (ETDEWEB)

    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. (HLW)

  3. Preparation and performance of biologic antimicrobial materials for pelvic tissue repair%生物型抗菌盆底修复材料的制备与性能

    Institute of Scientific and Technical Information of China (English)

    凌友; 徐斌; 陈晓峰

    2014-01-01

    BACKGROUND:The biological extracellular matrix materials become the focus of pelvic floor repair materials research because of its excellent biocompatibility and mechanical compatibility. However, bacterial infection can damage the function of biological repair materials. OBJECTIVE:To prepare the biologic antimicrobial materials for pelvic tissue function repair. METHODS:Chitosan and tigecycline-loaded chitosan nanoparticles suspension was prepared by the electrostatic adsorption and self-aggregation of nanoparticles preparation techniques. Then the suspension was coated onto the surface of extracellular matrix materials. The morphological examination was performed by scanning electron microscope. The antibacterial property was detected by solid plate microbial culture method. RESULTS AND CONCLUSION:Infrared spectra displayed that aromatic ring skeleton vibration peak of chitosan occurred on the biologic antimicrobial materials, and it was significantly widened at about 3 359 cm-1, indicating the composite coating was successful to modify the surface of extracellular matrix materials. As a very smal dose of tigecycline, there was no characteristic absorption peak on the infrared spectra. Scanning electron microscopy showed the porous structure of the material surface with some nanoparticles adhesion. The prepared materials had good antibacterial properties on Staphylococcus aureus and Escherichia coli, and the inhibition zone diameter was significantly increased with the increasing concentration of antibacterial agent. The biologic antimicrobial materials for pelvic tissue function repair were prepared successful y.%背景:哺乳动物细胞外基质组成的生物型修复材料,在盆底组织修复及功能重建方面表现出较大潜力,但细菌感染对生物型修复材料的功能破坏是其中的一个较大问题。  目的:制备具备抗菌功能的生物型盆底修复材料。  方法:以壳聚糖为基质材料,通过静电

  4. Biology of the repair of central nervous system demyelinated lesions: an appraisal Biologia da reparação de lesões desmielinizantes do sistema nervoso central: uma avaliação

    Directory of Open Access Journals (Sweden)

    L. A. V Peireira

    1996-06-01

    Full Text Available The integrity of myelin sheaths is maintained by oligodendrocytes and Schwann cells respectively in the central nervous system (CNS and in the peripheral nervous system. The process of demyelination consisting of the withdrawal of myelin sheaths from their axons is a characteristic feature of multiple sclerosis, the most common human demyelinating disease. Many experimental models have been designed to study the biology of demyelination and remyelination (repair of the lost myelin in the CNS, due to the difficulties in studying human material. In the ethidium bromide (an intercalating gliotoxic drug model of demyelination, CNS remyelination may be carried out by surviving oligodendrocytes and/or by cells differentiated from the primitive cell lines or either by Schwann cells that invade the CNS. However, some factors such as the age of the experimental animals, intensity and time of exposure to the intercalating chemical and the topography of the lesions have marked influence on the repair of the tissue.A integridade da bainha de mielina é fornecida pelos oligodendrócitos e pelas células de Schwann, no sistema nervoso central (SNC e no sistema nervoso periférico, respectivamente. O fenômeno de desmielinização refere-se à remoção das bainhas de mielina de axônios e este fato é característico na esclerose múltipla, a doença desmielinizante do SNC mais comum no homem. Muitos modelos experimentais têm sido utilizados para o estudo da biologia da desmielinização e remielinização no SNC, face à dificuldade de estudo de material humano. No modelo experimental da droga intercalate, gliotóxica, brometo de etídio, a remielinização do SNC pode ser efetuada por oligodendrócitos sobreviventes à lesão e/ou oriundos de diferenciação de linhagens celulares mais primitivas e por células de Schwann que invadem o SNC. No entanto, fatores como a idade dos animais, a intensidade, e o tempo de exposição ao agente intercalante e a

  5. Pectus excavatum repair

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/002949.htm Pectus excavatum repair To use the sharing features on this page, please enable JavaScript. Pectus excavatum repair is surgery to correct pectus excavatum . This ...

  6. When "Other" Initiate Repair.

    Science.gov (United States)

    Schegloff, Emanuel A.

    2000-01-01

    Elaborates on the locus of other-initiated repair, and reports on a number of environments in which others initiate repair turns later than the one directly following the trouble-source turn. Describes several ways that other initiation of repair, which occurs in next-turn position, may be delayed within that position. (Author/VWL)

  7. A brief history of the DNA repair field

    Institute of Scientific and Technical Information of China (English)

    Errol C Friedberg

    2008-01-01

    The history of the repair of damaged DNA can be traced to the mid-1930s. Since then multiple DNA repair mecha-nisms, as well as other biological responses to DNA damage, have been discovered and their regulation has been studied. This article briefly recounts the early history of this field.

  8. A brief history of the DNA repair field.

    Science.gov (United States)

    Friedberg, Errol C

    2008-01-01

    The history of the repair of damaged DNA can be traced to the mid-1930s. Since then multiple DNA repair mechanisms, as well as other biological responses to DNA damage, have been discovered and their regulation has been studied. This article briefly recounts the early history of this field.

  9. Haemophilus influenzae does not fit theories of postreplication repair

    Energy Technology Data Exchange (ETDEWEB)

    Setlow, J K; Notani, N K

    1980-01-01

    Studies with Escherichia coli have provided all the initial insights into the molecular bases of repair processes. It is the thesis of this article that especially if we believe that there are some general mechanisms in nature, it is important to consider more than one microorganism in arriving at an understanding of the biology of repair of DNA.

  10. Regulatory Challenges for Cartilage Repair Technologies.

    Science.gov (United States)

    McGowan, Kevin B; Stiegman, Glenn

    2013-01-01

    In the United States, few Food and Drug Administration (FDA)-approved options exist for the treatment of focal cartilage and osteochondral lesions. Developers of products for cartilage repair face many challenges to obtain marketing approval from the FDA. The objective of this review is to discuss the necessary steps for FDA application and approval for a new cartilage repair product. FDA Guidance Documents, FDA Panel Meetings, scientific organization recommendations, and clinicaltrials.gov were reviewed to demonstrate the current thinking of FDA and the scientific community on the regulatory process for cartilage repair therapies. Cartilage repair therapies can receive market approval from FDA as medical devices, drugs, or biologics, and the specific classification of product can affect the nonclinical, clinical, and regulatory strategy to bring the product to market. Recent FDA guidance gives an outline of the required elements to bring a cartilage repair product to market, although these standards are often very general. As a result, companies have to carefully craft their study patient population, comparator group, and clinical endpoint to best showcase their product's attributes. In addition, regulatory strategy and manufacturing process validation need to be considered early in the clinical study process to allow for timely product approval following the completion of clinical study. Although the path to regulatory approval for a cartilage repair therapy is challenging and time-consuming, proper clinical trial planning and attention to the details can eventually save companies time and money by bringing a product to the market in the most expeditious process possible.

  11. Biological membrane for repair of different sizes of bone defects surrounding BLB implants%生物膜对不同范围BLB种植体周骨缺损修复的影像学观察

    Institute of Scientific and Technical Information of China (English)

    孟维艳; 周延民; 储顺礼; 杨立明; 蔡青

    2008-01-01

    was 3 mm or less.no significant difference in bone density and bone trabecular morphology and orientating was found between newly formed bone and host bone no matter whether biological membrane was used or not;in the 4-mm-length bone defect areas.implants contacted with newly formed bone directly,but the calcified degree ofnewly formed bone was poor,bone trabecula was thin,and bone trabecular course was irregular,nevertheless,the calcified degree of newly formed bone was better under the condition of being with biological membrane than without biological membrane.CONCLUSION:Biological membrane exhibits strong capacity to promote the regeneration and repair of bone defect tissue with a horizontal length of 3 mm or less,and plays an important role in repatr of large sizes of bone detect%背景:即刻种植体周与骨之间常存在着间隙,究竟是否需要应用生物膜进行引导骨再生目前仍无定论.目的:通过在犬的股骨植入种植体创造不同的骨缺损间隙,观察生物膜对不同范围骨缺损骨组织再生修复的影响.设计、时间及地点:同体对照动物实验,于2005-03/12在吉林大学白求恩医学院实验动物中心及吉林大学口腔医院完成.材料:BLB羟基磷灰石涂层种植体由北京莱顿公司提供,BME-10X医用胶原膜由福建省博特生物科技有限公司提供.方法:在犬两侧股骨近心端植入种植体,并形成水平宽度3mm,垂直深度约5mm、水平长度分别为0,1,2,3,4 mm的标准梯度骨缺损.左侧直接分层严密缝合,右侧于骨缺损区覆盖生物膜后分层缝合.术后3个月处死动物,取含种植体的骨段,制成组织块进行影像学观察.主要观察指标:表面及剖面观察种植体周围骨缺损区新骨形成的量、色泽、质地等情况.应用软X射线观察种植体与骨组织界面的骨结合情况以及骨缺损区新骨形成情况.结果:大体观察:3 mm以下骨缺损区与原皮质骨无界限,有膜组与无膜组基本相同:4

  12. Suppressed expression of non-DSB repair genes inhibits gamma-radiation-induced cytogenetic repair and cell cycle arrest.

    Science.gov (United States)

    Zhang, Ye; Rohde, Larry H; Emami, Kamal; Hammond, Dianne; Casey, Rachael; Mehta, Satish K; Jeevarajan, Antony S; Pierson, Duane L; Wu, Honglu

    2008-11-01

    Changes of gene expression profile are one of the most important biological responses in living cells after ionizing radiation (IR) exposure. Although some studies have shown that genes up-regulated by IR may play important roles in DNA damage repair, the relationship between the regulation of gene expression by IR, particularly genes not known for their roles in double-strand break (DSB) repair, and its impact on cytogenetic responses has not been well studied. The purpose of this study is to identify new roles of IR inducible genes in regulating DSB repair and cell cycle progression. In this study, the expression of 25 genes selected on the basis of their transcriptional changes in response to IR was individually knocked down by small interfering RNA in human fibroblast cells. Frequency of micronuclei (MN) formation and chromosome aberrations were measured to determine efficiency of cytogenetic repair, especially DSB repair. In response to IR, the formation of MN was significantly increased by suppressed expression of five genes: Ku70 (DSB repair pathway), XPA (nucleotide excision repair pathway), RPA1 (mismatch repair pathway), RAD17 and RBBP8 (cell cycle control). Knocked-down expression of four genes (MRE11A, RAD51 in the DSB pathway, SESN1, and SUMO1) significantly inhibited cell cycle progression, possibly because of severe impairment of DNA damage repair. Moreover, decreased XPA, p21, or MLH1 expression resulted in both significantly enhanced cell cycle progression and increased yields of chromosome aberrations, indicating that these gene products modulate both cell cycle control and DNA damage repair. Nine of these eleven genes, whose knock-down expression affected cytogenetic repair, were up-regulated in cells exposed to gamma radiation, suggesting that genes transcriptionally modulated by IR were critical to regulate IR-induced biological consequences. Furthermore, eight non-DBS repair genes showed involvement in regulating DSB repair, indicating that

  13. The Application of Polysaccharide Biocomposites to Repair Cartilage Defects

    Directory of Open Access Journals (Sweden)

    Feng Zhao

    2014-01-01

    Full Text Available Owing to own nature of articular cartilage, it almost has no self-healing ability once damaged. Despite lots of restore technologies having been raised in the past decades, no repair technology has smoothly substituted for damaged cartilage using regenerated cartilage tissue. The approach of tissue engineering opens a door to successfully repairing articular cartilage defects. For instance, grafting of isolated chondrocytes has huge clinical potential for restoration of cartilage tissue and cure of chondral injury. In this paper, SD rats are used as subjects in the experiments, and they are classified into three groups: natural repair (group A, hyaluronic acid repair (group B, and polysaccharide biocomposites repair (hyaluronic acid hydrogel containing chondrocytes, group C. Through the observation of effects of repairing articular cartilage defects, we concluded that cartilage repair effect of polysaccharide biocomposites was the best at every time point, and then the second best was hyaluronic acid repair; both of them were better than natural repair. Polysaccharide biocomposites have good biodegradability and high histocompatibility and promote chondrocytes survival, reproduction, and spliting. Moreover, polysaccharide biocomposites could not only provide the porous network structure but also carry chondrocytes. Consequently hyaluronic acid-based polysaccharide biocomposites are considered to be an ideal biological material for repairing articular cartilage.

  14. Repairs of composite structures

    Science.gov (United States)

    Roh, Hee Seok

    Repair on damaged composite panels was conducted. To better understand adhesively bonded repair, the study investigates the effect of design parameters on the joint strength. The design parameters include bondline length, thickness of adherend and type of adhesive. Adhesives considered in this study were tested to measure their tensile material properties. Three types of adhesively bonded joints, single strap, double strap, and single lap joint were considered under changing bondline lengths, thickness of adherend and type of adhesive. Based on lessons learned from bonded joints, a one-sided patch repair method for composite structures was conducted. The composite patch was bonded to the damaged panel by either film adhesive FM-73M or paste adhesive EA-9394 and the residual strengths of the repaired specimens were compared under varying patch sizes. A new repair method using attachments has been suggested to enhance the residual strength. Results obtained through experiments were analyzed using finite element analysis to provide a better repair design and explain the experimental results. It was observed that the residual strength of the repaired specimen was affected by patch length. Method for rapid repairs of damaged composite structures was investigated. The damage was represented by a circular hole in a composite laminated plate. Pre-cured composite patches were bonded with a quick-curing commercial adhesive near (rather than over) the hole. Tensile tests were conducted on specimens repaired with various patch geometries. The test results showed that, among the methods investigated, the best repair method restored over 90% of the original strength of an undamaged panel. The interfacial stresses in the adhesive zone for different patches were calculated in order to understand the efficiencies of the designs of these patch repairs. It was found that the composite patch that yielded the best strength had the lowest interfacial peel stress between the patch and

  15. Biological materials repair exercise-induced muscle tendon injury: Evaluation of relevant literatures in 2007/2009 CNKI Database%生物材料修复运动性肌肉肌腱损伤:2007/2009CNKI数据库相关文献的评价

    Institute of Scientific and Technical Information of China (English)

    及化娟; 王丽霞

    2011-01-01

    目的:文献分析当前生物材料在修复运动性肌肉肌腱损伤方面研究现状.方法:以"生物材料、运动损伤、修复、肌腱"为中文关键词,采用计算机检索中国期刊论文数据库2007-01/2009-12相关文章.纳入关于生物材料在修复肌肉、肌腱方面研究的文章,排除重复研究或Meta分析类文章.以19篇文献为主,重点对生物材料在修复肌肉肌腱方面研究文献进行了整理分析.结果:组织工程研究的不断深入为运动性肌肉肌腱损伤的修复提供了可靠的生物材料和技术保障,生物材料修复运动性肌腱损伤具有与人体组织相容性好、易被组织吸收、不易感染、无粘连及断裂、无排斥等现象,表现了其优势.同时人工生物材料的妥善运用,为肌腱损伤后的快速良好康复提供了可能及保障.结论:肌腱愈合由内、外源愈合共同作用,以内源性愈合方式为主,同时又与腱鞘、腱纽及滑液等条件有密切联系;肌腱粘连多是由于外源性愈合参与过多及腱周损坏所致.%OBJECTIVE: To analyze the research progress of biological materials to repair exercise-induced muscular tendon damage.METHODS: Using “biological material, sports injury, repair, tendon” in Chinese as the key words, a computer-based online search of Chinese Journal Full-text Database from January 2007 to December 2009 was performed. Articles about the biological materials in repair of muscle and tendon were included, repeated studies or Meta analysis was excluded. Totally 19 articles chiefly focus on the biological materials in repair of muscular tendon damage.RESULTS : The developing tissue engineering research provides a reliable biological materials and technological ensure for the repair of exercise-induced muscle tendon injury, biological materials have many advantages in repair of tendon injury, such as good compatibility with human tissue, susceptible to absorb by tissues and difficult to infection

  16. Regenerative endodontics: regeneration or repair?

    Science.gov (United States)

    Simon, Stéphane R J; Tomson, Phillip L; Berdal, Ariane

    2014-04-01

    Recent advances in biotechnology and translational research have made it possible to provide treatment modalities that protect the vital pulp, allow manipulation of reactionary and reparative dentinogenesis, and, more recently, permit revascularization of an infected root canal space. These approaches are referred to as regenerative procedures. The method currently used to determine the origin of the tissue secreted during the repair/regeneration process is largely based on the identification of cellular markers (usually proteins) left by cells that were responsible for this tissue production. The presence of these proteins in conjunction with other indicators of cellular behavior (especially biomineralization) and analysis of the structure of the newly generated tissue allow conclusions to be made of how it was formed. Thus far, it has not been possible to truly establish the biological mechanism controlling tertiary dentinogenesis. This article considers current therapeutic techniques to treat the dentin-pulp complex and contextualize them in terms of reparative and regenerative processes. Although it may be considered a semantic argument rather than a biological one, the definitions of regeneration and repair are explored to clarify our position in this era of regenerative endodontics.

  17. Laparoscopic lumbar hernia repair.

    Science.gov (United States)

    Madan, Atul K; Ternovits, Craig A; Speck, Karen E; Pritchard, F Elizabeth; Tichansky, David S

    2006-04-01

    Lumbar hernias are rare clinical entities that often pose a challenge for repair. Because of the surrounding anatomy, adequate surgical herniorraphy is often difficult. Minimally invasive surgery has become an option for these hernias. Herein, we describe two patients with lumbar hernias (one with a recurrent traumatic hernia and one with an incisional hernia). Both of these hernias were successfully repaired laparoscopically.

  18. Workshop on DNA repair.

    NARCIS (Netherlands)

    A.R. Lehmann (Alan); J.H.J. Hoeijmakers (Jan); A.A. van Zeeland (Albert); C.M.P. Backendorf (Claude); B.A. Bridges; A. Collins; R.P.D. Fuchs; G.P. Margison; R. Montesano; E. Moustacchi; A.T. Natarajan; M. Radman; A. Sarasin; E. Seeberg; C.A. Smith; M. Stefanini (Miria); L.H. Thompson; G.P. van der Schans; C.A. Weber (Christine); M.Z. Zdzienika

    1992-01-01

    textabstractA workshop on DNA repair with emphasis on eukaryotic systems was held, under the auspices of the EC Concerted Action on DNA Repair and Cancer, at Noordwijkerhout (The Netherlands) 14-19 April 1991. The local organization of the meeting was done under the auspices of the Medical Genetic C

  19. INTERNAL REPAIR OF PIPELINES

    Energy Technology Data Exchange (ETDEWEB)

    Bill Bruce; Nancy Porter; George Ritter; Matt Boring; Mark Lozev; Ian Harris; Bill Mohr; Dennis Harwig; Robin Gordon; Chris Neary; Mike Sullivan

    2005-07-20

    The two broad categories of fiber-reinforced composite liner repair and deposited weld metal repair technologies were reviewed and evaluated for potential application for internal repair of gas transmission pipelines. Both are used to some extent for other applications and could be further developed for internal, local, structural repair of gas transmission pipelines. Principal conclusions from a survey of natural gas transmission industry pipeline operators can be summarized in terms of the following performance requirements for internal repair: (1) Use of internal repair is most attractive for river crossings, under other bodies of water, in difficult soil conditions, under highways, under congested intersections, and under railway crossings. (2) Internal pipe repair offers a strong potential advantage to the high cost of horizontal direct drilling when a new bore must be created to solve a leak or other problem. (3) Typical travel distances can be divided into three distinct groups: up to 305 m (1,000 ft.); between 305 m and 610 m (1,000 ft. and 2,000 ft.); and beyond 914 m (3,000 ft.). All three groups require pig-based systems. A despooled umbilical system would suffice for the first two groups which represents 81% of survey respondents. The third group would require an onboard self-contained power unit for propulsion and welding/liner repair energy needs. (4) The most common size range for 80% to 90% of operators surveyed is 508 mm (20 in.) to 762 mm (30 in.), with 95% using 558.8 mm (22 in.) pipe. Evaluation trials were conducted on pipe sections with simulated corrosion damage repaired with glass fiber-reinforced composite liners, carbon fiber-reinforced composite liners, and weld deposition. Additional un-repaired pipe sections were evaluated in the virgin condition and with simulated damage. Hydrostatic failure pressures for pipe sections repaired with glass fiber-reinforced composite liner were only marginally greater than that of pipe sections without

  20. 生物敷料A对比银离子水胶体油纱修复面部Ⅱ度烧伤%Biological dressing Aversus Physiotulle Ag in the repair of degree ll facial burns

    Institute of Scientific and Technical Information of China (English)

    王强; 刘筱雯; 吕仁荣; 霍然

    2015-01-01

    treated with biological dressing A. The other was selected as the control side and treated with Physiotule Ag. We compared wound healing time, infection, times of changing dressings, skin after healing, drug change comfort and dressing comfort between the two sides. RESULTS AND CONCLUSION:In patients with superficial grade Ⅱ facial burn, times of changing dressings and drug change comfort were better in the experimental side than in the control side (P < 0.05), but the dressing comfort was better in the control side than the experimental side (P< 0.05). No significant difference in wound healing time, infection and skin after healing was detected between the two sides. In patients with deep degree Ⅱ facial burns, wound healing time, times of changing dressings, skin after healing and drug change comfort were better in the experimental side than in the control side (P < 0.05), but the dressing comfort was better in the control side than the experimental side (P< 0.05). No significant difference in infection was detectable between the two sides. Above findings suggested that the therapeutic effects of biological dressing A and Physiotule Ag were similar in treatment of degree Ⅱ facial burns. Biological dressing A in repair of deep degree Ⅱ facial burns promotes the wound healing andelevates the quality of healing.

  1. INTERNAL REPAIR OF PIPELINES

    Energy Technology Data Exchange (ETDEWEB)

    Robin Gordon; Bill Bruce; Ian Harris; Dennis Harwig; George Ritter; Bill Mohr; Matt Boring; Nancy Porter; Mike Sullivan; Chris Neary

    2004-12-31

    The two broad categories of fiber-reinforced composite liner repair and deposited weld metal repair technologies were reviewed and evaluated for potential application for internal repair of gas transmission pipelines. Both are used to some extent for other applications and could be further developed for internal, local, structural repair of gas transmission pipelines. Principal conclusions from a survey of natural gas transmission industry pipeline operators can be summarized in terms of the following performance requirements for internal repair: (1) Use of internal repair is most attractive for river crossings, under other bodies of water, in difficult soil conditions, under highways, under congested intersections, and under railway crossings. (2) Internal pipe repair offers a strong potential advantage to the high cost of horizontal direct drilling when a new bore must be created to solve a leak or other problem. (3) Typical travel distances can be divided into three distinct groups: up to 305 m (1,000 ft.); between 305 m and 610 m (1,000 ft. and 2,000 ft.); and beyond 914 m (3,000 ft.). All three groups require pig-based systems. A despooled umbilical system would suffice for the first two groups which represents 81% of survey respondents. The third group would require an onboard self-contained power unit for propulsion and welding/liner repair energy needs. (4) The most common size range for 80% to 90% of operators surveyed is 508 mm (20 in.) to 762 mm (30 in.), with 95% using 558.8 mm (22 in.) pipe. Evaluation trials were conducted on pipe sections with simulated corrosion damage repaired with glass fiber-reinforced composite liners, carbon fiber-reinforced composite liners, and weld deposition. Additional un-repaired pipe sections were evaluated in the virgin condition and with simulated damage. Hydrostatic failure pressures for pipe sections repaired with glass fiber-reinforced composite liner were only marginally greater than that of pipe sections without

  2. INTERNAL REPAIR OF PIPELINES

    Energy Technology Data Exchange (ETDEWEB)

    Robin Gordon; Bill Bruce; Ian Harris; Dennis Harwig; George Ritter; Bill Mohr; Matt Boring; Nancy Porter; Mike Sullivan; Chris Neary

    2004-08-17

    The two broad categories of fiber-reinforced composite liner repair and deposited weld metal repair technologies were reviewed and evaluated for potential application for internal repair of gas transmission pipelines. Both are used to some extent for other applications and could be further developed for internal, local, structural repair of gas transmission pipelines. Principal conclusions from a survey of natural gas transmission industry pipeline operators can be summarized in terms of the following performance requirements for internal repair: (1) Use of internal repair is most attractive for river crossings, under other bodies of water, in difficult soil conditions, under highways, under congested intersections, and under railway. (2) Internal pipe repair offers a strong potential advantage to the high cost of horizontal direct drilling when a new bore must be created to solve a leak or other problem. (3) Typical travel distances can be divided into three distinct groups: up to 305 m (1,000 ft.); between 305 m and 610 m (1,000 ft. and 2,000 ft.); and beyond 914 m (3,000 ft.). All three groups require pig-based systems. A despooled umbilical system would suffice for the first two groups which represents 81% of survey respondents. The third group would require an onboard self-contained power unit for propulsion and welding/liner repair energy needs. (4) The most common size range for 80% to 90% of operators surveyed is 508 mm (20 in.) to 762 mm (30 in.), with 95% using 558.8 mm (22 in.) pipe. Evaluation trials were conducted on pipe sections with simulated corrosion damage repaired with glass fiber-reinforced composite liners, carbon fiber-reinforced composite liners, and weld deposition. Additional un-repaired pipe sections were evaluated in the virgin condition and with simulated damage. Hydrostatic failure pressures for pipe sections repaired with glass fiber-reinforced composite liner were only marginally greater than that of pipe sections without liners

  3. Salvage hypospadias repairs

    Directory of Open Access Journals (Sweden)

    Sripathi V

    2008-01-01

    Full Text Available Aim: Review of our experience and to develop an algorithm for salvage procedures in the management of hypospadias cripples and treatment of urethral strictures following hypospadias repair. Methods: This is a retrospective review of hypospadias surgeries over a 41-month period. Out of a total 168 surgeries, 20 were salvage/re-operative repairs. In three children a Duplay repair was feasible, while in four others a variety of single-stage repairs could be done. The repair was staged in seven children - buccal mucosal grafts (BMGs in five, buccal mucosal tube in one, and skin graft in one. Five children with dense strictures were managed by dorsal BMG inlay grafting in one, vascularized tunical onlay grafting on the ventrum in one, and a free tunical patch in one. Three children were treated by internal urethrotomy and stenting for four weeks with a poor outcome. Results: The age of children ranged from 1.5-15 years (mean 4.5. Follow-up ranged from 3 months to 3.5 years. Excellent results were obtained in 10 children (50% with a well-surfaced erect penis and a slit-like meatus. Glans closure could not be achieved and meatus was coronal in three. Two children developed fistulae following a Duplay repair and following a staged BMG. Three repairs failed completely - a composite repair broke down, a BMG tube stenosed with a proximal leak, and a stricture recurred with loss of a ventral free tunical graft. Conclusions: In salvage procedures performed on hypospadias cripples, a staged repair with buccal mucosa as an inlay in the first stage followed by tubularization 4-6 months later provides good results. A simple algorithm to plan corrective surgery in failed hypospadias cases and obtain satisfactory results is devised.

  4. Progress of peripheral nerve repair

    Institute of Scientific and Technical Information of China (English)

    陈峥嵘

    2002-01-01

    Study on repair of peripheral nerve injury has been proceeding over a long period of time. With the use of microsurgery technique since 1960s,the quality of nerve repair has been greatly improved. In the past 40 years, with the continuous increase of surgical repair methods, more progress has been made on the basic research of peripheral nerve repair.

  5. Pectus excavatum repair - slideshow

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/presentations/100035.htm Pectus excavatum repair - series—Normal anatomy To use the sharing ... Go to slide 4 out of 4 Overview Pectus excavatum is a deformity of the front of the ...

  6. Diaphragmatic hernia repair - slideshow

    Science.gov (United States)

    ... presentations/100014.htm Diaphragmatic hernia repair - series—Normal anatomy To use the sharing ... Overview The chest cavity includes the heart and lungs. The abdominal cavity includes the liver, the stomach, ...

  7. INTERNAL REPAIR OF PIPELINES

    Energy Technology Data Exchange (ETDEWEB)

    Robin Gordon; Bill Bruce; Ian Harris; Dennis Harwig; Nancy Porter; Mike Sullivan; Chris Neary

    2004-04-12

    The two broad categories of deposited weld metal repair and fiber-reinforced composite liner repair technologies were reviewed for potential application for internal repair of gas transmission pipelines. Both are used to some extent for other applications and could be further developed for internal, local, structural repair of gas transmission pipelines. Preliminary test programs were developed for both deposited weld metal repair and for fiber-reinforced composite liner repair. Evaluation trials have been conducted using a modified fiber-reinforced composite liner provided by RolaTube and pipe sections without liners. All pipe section specimens failed in areas of simulated damage. Pipe sections containing fiber-reinforced composite liners failed at pressures marginally greater than the pipe sections without liners. The next step is to evaluate a liner material with a modulus of elasticity approximately 95% of the modulus of elasticity for steel. Preliminary welding parameters were developed for deposited weld metal repair in preparation of the receipt of Pacific Gas & Electric's internal pipeline welding repair system (that was designed specifically for 559 mm (22 in.) diameter pipe) and the receipt of 559 mm (22 in.) pipe sections from Panhandle Eastern. The next steps are to transfer welding parameters to the PG&E system and to pressure test repaired pipe sections to failure. A survey of pipeline operators was conducted to better understand the needs and performance requirements of the natural gas transmission industry regarding internal repair. Completed surveys contained the following principal conclusions: (1) Use of internal weld repair is most attractive for river crossings, under other bodies of water, in difficult soil conditions, under highways, under congested intersections, and under railway crossings. (2) Internal pipe repair offers a strong potential advantage to the high cost of horizontal direct drilling (HDD) when a new bore must be created

  8. Repairing ceramic insulating tiles

    Science.gov (United States)

    Dunn, B. R.; Laymance, E. L.

    1980-01-01

    Fused-silica tiles containing large voids or gauges are repaired without adhesives by plug insertion method. Tiles are useful in conduits for high-temperature gases, in furnaces, and in other applications involving heat insulation.

  9. Achilles tendon repair

    Science.gov (United States)

    Achilles tendon rupture-surgery; Percutaneous Achilles tendon rupture repair ... To fix your torn Achilles tendon, the surgeon will: Make a cut down the back of your heel Make several small cuts rather than one large cut ...

  10. Cleft lip repair - slideshow

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/presentations/100010.htm Cleft lip repair - series—Normal anatomy To use the sharing ... abnormal opening in the middle of the upper lip. A cleft palate is an opening in the roof of ...

  11. DNA repair mechanisms in eukaryotes: Special focus in Entamoeba histolytica and related protozoan parasites.

    Science.gov (United States)

    López-Camarillo, César; Lopez-Casamichana, Mavil; Weber, Christian; Guillen, Nancy; Orozco, Esther; Marchat, Laurence A

    2009-12-01

    Eukaryotic cell viability highly relies on genome stability and DNA integrity maintenance. The cellular response to DNA damage mainly consists of six biological conserved pathways known as homologous recombination repair (HRR), non-homologous end-joining (NHEJ), base excision repair (BER), mismatch repair (MMR), nucleotide excision repair (NER), and methyltransferase repair that operate in a concerted way to minimize genetic information loss due to a DNA lesion. Particularly, protozoan parasites survival depends on DNA repair mechanisms that constantly supervise chromosomes to correct damaged nucleotides generated by cytotoxic agents, host immune pressure or cellular processes. Here we reviewed the current knowledge about DNA repair mechanisms in the most relevant human protozoan pathogens. Additionally, we described the recent advances to understand DNA repair mechanisms in Entamoeba histolytica with special emphasis in the use of genomic approaches based on bioinformatic analysis of parasite genome sequence and microarrays technology.

  12. Grey Repairable System Analysis

    Institute of Scientific and Technical Information of China (English)

    Renkuan Guo; Charles Ernie Love

    2006-01-01

    In this paper, we systematically discuss the basic concepts of grey theory, particularly the grey differential equation and its mathematical foundation, which is essentially unknown in the reliability engineering community. Accordingly,we propose a small-sample based approach to estimate repair improvement effects by partitioning system stopping times into intrinsic functioning times and repair improvement times. An industrial data set is used for illustrative purposes in a stepwise manner.

  13. Modulation of DNA base excision repair during neuronal differentiation

    DEFF Research Database (Denmark)

    Sykora, Peter; Yang, Jenq-Lin; Ferrarelli, Leslie K

    2013-01-01

    Neurons are terminally differentiated cells with a high rate of metabolism and multiple biological properties distinct from their undifferentiated precursors. Previous studies showed that nucleotide excision DNA repair is downregulated in postmitotic muscle cells and neurons. Here, we characterize...... DNA damage susceptibility and base excision DNA repair (BER) capacity in undifferentiated and differentiated human neural cells. The results show that undifferentiated human SH-SY5Y neuroblastoma cells are less sensitive to oxidative damage than their differentiated counterparts, in part because...

  14. 骨形态发生蛋白、碱性成纤维细胞生长因子生物材料在关节软骨缺损修复中的生物性能%Biological properties of bone morphogenetic proteins and basic fibroblast growth factor in biological materials for repair of articular cartilage defect

    Institute of Scientific and Technical Information of China (English)

    董君博

    2016-01-01

    BACKGROUND:Articular cartilage regeneration can be regulatedbyautocrineorparacrinesecretionof various cytokines. OBJECTIVE:To analyze biological properties of bone morphogenetic proteins and basic fibroblast growth factor in biological materials for repair of articular cartilage defect. METHODS:Forty New Zealand white rabbits were used and equaly randomized intofourgroups: fibrin, basic fibroblast growth factor, bone morphogenetic protein, and combined treatment (basic fibroblast growth factor combined with bone morphogenetic protein) groups, respectively.Bioactivescaffolds with fibrin, basic fibroblast growth factor,bone morphogenetic protein, and basic fibroblast growth factor combined with bone morphogenetic protein were injected to repair the articular cartilage defect. Therapeutic effect andbiological properties of biological materials were compared. RESULTS AND CONCLUSION:(1) Inthefibrin group,tworabbits appearedto havelimps. Inthebasic fibroblast growth factor group hand functionwaslimited inonerabbit. Inthebone morphogenetic protein group, one had a limpandonewasin a limitation of activity. Inthecombined treatment group,rabbitsrecovered wel andshowedno differencesintheknee joint before and aftersurgery (P  目的:分析骨形态发生蛋白、碱性成纤维细胞生长因子生物材料在关节软骨缺损修复中的生物性能。  方法:选取40只新西兰家兔,随机分为4组,纤维蛋白组、碱性成纤维细胞生长因子组、骨形态发生蛋白组、复合组(骨形态发生蛋白+碱性成纤维细胞生长因子),每组10只。建立兔关节软骨缺损模型,止血彻底后将纤维蛋白、碱性成纤维细胞生长因子、骨形态发生蛋白以及骨形态发生蛋白、碱性成纤维细胞生长因子复合等材料组成的支架分别植入缺损部位。比较不同注射材料在家兔关节软骨缺损中的效果及复合材料的生物性能。  结果与结论:①关节软骨缺损修复情

  15. Repairing split ends: SIRT6, mono-ADP ribosylation and DNA repair

    Science.gov (United States)

    Van Meter, Michael; Mao, Zhiyong; Gorbunova, Vera; Seluanov, Andrei

    2011-01-01

    The sirtuin gene family comprises an evolutionarily ancient set of NAD+ dependent protein deacetylase and mono-ADP ribosyltransferase enzymes. Found in all domains of life, sirtuins regulate a diverse array of biological processes, including DNA repair, gene silencing, apoptosis and metabolism. Studies in multiple model organisms have indicated that sirtuins may also function to extend lifespan and attenuate age-related pathologies. To date, most of these studies have focused on the deacetylase activity of sirtuins, and relatively little is known about the other biochemical activity of sirtuins, mono-ADP ribosylation. We recently reported that the mammalian sirtuin, SIRT6, mono-ADP ribosylates PARP1 to promote DNA repair in response to oxidative stress. In this research perspective we review the role of SIRT6 in DNA repair and discuss the emerging implications for sirtuin directed mono-ADP ribosylation in aging and age-related diseases. PMID:21946623

  16. Groin hernia repair in young males: mesh or sutured repair?

    DEFF Research Database (Denmark)

    Bisgaard, T; Bay-Nielsen, M; Kehlet, H

    2010-01-01

    Large-scale data for the optimal inguinal hernia repair in younger men with an indirect hernia is not available. We analysed nationwide data for risk of reoperation in younger men after a primary repair using a Lichtenstein operation or a conventional non-mesh hernia repair....

  17. Abdominal aortic aneurysm repair - open

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/007392.htm Abdominal aortic aneurysm repair - open To use the sharing features on this page, please enable JavaScript. Open abdominal aortic aneurysm repair is surgery to fix a widened part ...

  18. Cleft lip and palate repair

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/002979.htm Cleft lip and palate repair To use the sharing features on this page, please enable JavaScript. Cleft lip and cleft palate repair is surgery to fix birth defects ...

  19. Laparoscopic repair of femoral hernia

    OpenAIRE

    Yang, Xue-Fei; Liu, Jia-Lin

    2016-01-01

    Laparoscopic repair of inguinal hernia is mini-invasive and has confirmed effects. Femoral hernia could be repaired through the laparoscopic procedures for inguinal hernia. These procedures have clear anatomic view in the operation and preoperatively undiagnosed femoral hernia could be confirmed and treated. Lower recurrence ratio was reported in laparoscopic procedures compared with open procedures for repair of femoral hernia. The technical details of laparoscopic repair of femoral hernia, ...

  20. Nanomaterials promise better bone repair

    OpenAIRE

    Qifei Wang; Jianhua Yan; Junlin Yang; Bingyun Li

    2016-01-01

    Nanomaterials mimicking the nano-features of bones and offering unique smart functions are promising for better bone fracture repair. This review provides an overview of the current state-of-the-art research in developing and using nanomaterials for better bone fracture repair. This review begins with a brief introduction of bone fracture repair processes, then discusses the importance of vascularization, the role of growth factors in bone fracture repair, and the failure of bone fracture rep...

  1. Aircraft Propeller Hub Repair

    Energy Technology Data Exchange (ETDEWEB)

    Muth, Thomas R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Peter, William H. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-02-13

    The team performed a literature review, conducted residual stress measurements, performed failure analysis, and demonstrated a solid state additive manufacturing repair technique on samples removed from a scrapped propeller hub. The team evaluated multiple options for hub repair that included existing metal buildup technologies that the Federal Aviation Administration (FAA) has already embraced, such as cold spray, high velocity oxy-fuel deposition (HVOF), and plasma spray. In addition the team helped Piedmont Propulsion Systems, LLC (PPS) evaluate three potential solutions that could be deployed at different stages in the life cycle of aluminum alloy hubs, in addition to the conventional spray coating method for repair. For new hubs, a machining practice to prevent fretting with the steel drive shaft was recommended. For hubs that were refurbished with some material remaining above the minimal material condition (MMC), a silver interface applied by an electromagnetic pulse additive manufacturing method was recommended. For hubs that were at or below the MMC, a solid state additive manufacturing technique using ultrasonic welding (UW) of thin layers of 7075 aluminum to the hub interface was recommended. A cladding demonstration using the UW technique achieved mechanical bonding of the layers showing promise as a viable repair method.

  2. Platinum drugs and DNA repair mechanisms in lung cancer.

    Science.gov (United States)

    Bonanno, Laura; Favaretto, Adolfo; Rosell, Rafael

    2014-01-01

    The standard first-line treatment for around 80% of newly-diagnosed advanced non-small cell lung cancer (NSCLC) is chemotherapy. Currently, patients are allocated to chemotherapy on the basis of clinical conditions, comorbidities and histology. If feasible, platinum-based chemotherapy is considered as the most efficacious option. Due to the heterogeneity in terms of platinum-sensitivity among patients with NSCLC, great efforts have been made in order to identify molecular predictive markers of platinum resistance. Based on the mechanism of action of platinum, several components of DNA repair pathways have been investigated as potential predictive markers. The main DNA repair pathways involved in the repair of platinum-induced DNA damage are nucleotide excision repair and homologous recombination. The most studied potential predictive markers of platinum-sensitivity are Excision Repair Cross Complementing-1 (ERCC1) and Brest Cancer Type-I Susceptibility protein (BRCA1); however, increasing biological knowledge about DNA repair pathways suggests the potential clinical usefulness of integrated analysis of multiple DNA repair components.

  3. Putative Enzymes of UV Photoproduct Repair

    Directory of Open Access Journals (Sweden)

    Cynthia J. Sakofsky

    2011-01-01

    Full Text Available In order to determine the biological relevance of two S. acidocaldarius proteins to the repair of UV photoproducts, the corresponding genes (Saci_1227 and Saci_1096 were disrupted, and the phenotypes of the resulting mutants were examined by various genetic assays. The disruption used integration by homologous recombination of a functional but heterologous pyrE gene, promoted by short sequences attached to both ends via PCR. The phenotypic analyses of the disruptants confirmed that ORF Saci_1227 encodes a DNA photolyase which functions in vivo, but they could not implicate ORF Saci_1096 in repair of UV- or other externally induced DNA damage despite its similarity to genes encoding UV damage endonucleases. The success of the gene-disruption strategy, which used 5′ extensions of PCR primers to target cassette integration, suggests potential advantages for routine construction of Sulfolobus strains.

  4. [New challenge of tissue repair and regenerative medicine: to achieve a perfect repair and regeneration of multiple tissues in wound sites].

    Science.gov (United States)

    Fu, X B

    2016-01-01

    Great achievements in the study of tissue repair and regeneration have been made, and many of these successes have been shown to be beneficial to the patients in recent years. However, perfect tissue repair and regeneration of damaged tissues and organs remain to be great challenges in the management of trauma and diseases. Based on the progress in developmental biology in animals and advances in stem cell biology, it is possible to attain the aim of perfect repair and regeneration by means of somatic cell reprogramming and different inducing techniques.

  5. Current developments in hernia repair; meshes, adhesives, and tacking.

    Science.gov (United States)

    Powell, Benjamin S; Voeller, Guy R

    2010-10-01

    Open and laparoscopic hernia surgery continues to evolve with new products allowing surgeons multiple choices in treating their patients. The evolution towards tension-free techniques in dealing with hernias requires that today's surgeons know the options available in meshes as well as fixation methods in order to have the best outcomes. In recent years, there has been a rapid expansion in the number of meshes available. Currently, there are numerous uncoated, coated, and biologic meshes in production that can be used in hernia repair. This paper will focus on the latest developments in coated meshes that allow for intra-abdominal placement as well as the different types of biologic meshes and their typical uses. Tacking devices for laparoscopic hernia repair now come in titanium as well as absorbable devices. AbsorbaTack™ (Covidien, Norwalk, CT) and Sorbafix™ (Davol, Warwick, RI) are two of the newest absorbable tacking devices thought to possibly benefit patients with decreased pain and long-term complications as compared with their titanium counterparts. Adhesives continue to be used more and more for hernia repair, especially in inguinal and paraesophageal hernia repairs. Tissucol™/Tisseel™ (Baxter, Deerfield, IL) and Evicel™ (Ethicon, Somerville, NJ) are two types of fibrin glues that are available for use in hernia repair. Practitioners using these biologic adhesives think there is less pain compared with tacking.

  6. Nanomaterials promise better bone repair

    Directory of Open Access Journals (Sweden)

    Qifei Wang

    2016-10-01

    Full Text Available Nanomaterials mimicking the nano-features of bones and offering unique smart functions are promising for better bone fracture repair. This review provides an overview of the current state-of-the-art research in developing and using nanomaterials for better bone fracture repair. This review begins with a brief introduction of bone fracture repair processes, then discusses the importance of vascularization, the role of growth factors in bone fracture repair, and the failure of bone fracture repair. Next, the review discusses the applications of nanomaterials for bone fracture repair, with a focus on the recent breakthroughs such as nanomaterials leading to precise immobilization of growth factors at the molecular level, promoting vascularization without the use of growth factors, and re-loading therapeutic agents after implantation. The review concludes with perspectives on challenges and future directions for developing nanomaterials for improved bone fracture repair.

  7. The use of biological meshes in diaphragmatic defects – An evidence-based review of the literature

    Directory of Open Access Journals (Sweden)

    Stavros Athanasios Antoniou

    2015-10-01

    Full Text Available The widespread use of meshes for hiatal hernia repair has emerged in the era of laparoscopic surgery, although sporadic cases of mesh augmentation of traumatic diaphragmatic rupture have been reported. The indications for biologic meshes in diaphragmatic repair are ill defined. This systematic review aims to investigate the available evidence on the role of biologic meshes in diaphragmatic rupture and hiatal hernia repair. Limited data from sporadic case reports and case series have demonstrated that repair of traumatic diaphragmatic rupture with biologic mesh is safe technique in both the acute or chronic setting. High level evidence demonstrates short-term benefits of biologic mesh augmentation in hiatal hernia repair over primary repair, although adequate long-term data are not currently available. Long-term follow-up data suggest no benefit of hiatal hernia repair using porcine small intestine submucosa over suture repair. The effectiveness of different biologic mesh materials on hernia recurrence requires further investigation.

  8. DNA repair: Dynamic defenders against cancer and aging

    Energy Technology Data Exchange (ETDEWEB)

    Fuss, Jill O.; Cooper, Priscilla K.

    2006-04-01

    You probably weren't thinking about your body's cellular DNA repair systems the last time you sat on the beach in the bright sunshine. Fortunately, however, while you were subjecting your DNA to the harmful effects of ultraviolet light, your cells were busy repairing the damage. The idea that our genetic material could be damaged by the sun was not appreciated in the early days of molecular biology. When Watson and Crick discovered the structure of DNA in 1953 [1], it was assumed that DNA is fundamentally stable since it carries the blueprint of life. However, over 50 years of research have revealed that our DNA is under constant assault by sunlight, oxygen, radiation, various chemicals, and even our own cellular processes. Cleverly, evolution has provided our cells with a diverse set of tools to repair the damage that Mother Nature causes. DNA repair processes restore the normal nucleotide sequence and DNA structure of the genome after damage [2]. These responses are highly varied and exquisitely regulated. DNA repair mechanisms are traditionally characterized by the type of damage repaired. A large variety of chemical modifications can alter normal DNA bases and either lead to mutations or block transcription if not repaired, and three distinct pathways exist to remove base damage. Base excision repair (BER) corrects DNA base alterations that do not distort the overall structure of the DNA helix such as bases damaged by oxidation resulting from normal cellular metabolism. While BER removes single damaged bases, nucleotide excision repair (NER) removes short segments of nucleotides (called oligonucleotides) containing damaged bases. NER responds to any alteration that distorts the DNA helix and is the mechanism responsible for repairing bulky base damage caused by carcinogenic chemicals such as benzo [a]pyrene (found in cigarette smoke and automobile exhaust) as well as covalent linkages between adjacent pyrimidine bases resulting from the ultraviolet

  9. Analysis of DNA double-strand break repair pathways in mice

    Energy Technology Data Exchange (ETDEWEB)

    Brugmans, Linda [Department of Cell Biology and Genetics, Erasmus MC, Dr. Molewaterplein 50, PO Box 1738, Rotterdam 3015GE (Netherlands); Kanaar, Roland [Department of Cell Biology and Genetics, Erasmus MC, Dr. Molewaterplein 50, PO Box 1738, Rotterdam 3015GE (Netherlands); Department of Radiation Oncology, Erasmus MC, PO Box 1738, 3000 DR Rotterdam (Netherlands); Essers, Jeroen [Department of Cell Biology and Genetics, Erasmus MC, Dr. Molewaterplein 50, PO Box 1738, Rotterdam 3015GE (Netherlands) and Department of Radiation Oncology, Erasmus MC, PO Box 1738, 3000 DR Rotterdam (Netherlands)]. E-mail: j.essers@erasmusmc.nl

    2007-01-03

    During the last years significant new insights have been gained into the mechanism and biological relevance of DNA double-strand break (DSB) repair in relation to genome stability. DSBs are a highly toxic DNA lesion, because they can lead to chromosome fragmentation, loss and translocations, eventually resulting in cancer. DSBs can be induced by cellular processes such as V(D)J recombination or DNA replication. They can also be introduced by exogenous agents DNA damaging agents such as ionizing radiation or mitomycin C. During evolution several pathways have evolved for the repair of these DSBs. The most important DSB repair mechanisms in mammalian cells are nonhomologous end-joining and homologous recombination. By using an undamaged repair template, homologous recombination ensures accurate DSB repair, whereas the untemplated nonhomologous end-joining pathway does not. Although both pathways are active in mammals, the relative contribution of the two repair pathways to genome stability differs in the different cell types. Given the potential differences in repair fidelity, it is of interest to determine the relative contribution of homologous recombination and nonhomologous end-joining to DSB repair. In this review, we focus on the biological relevance of DSB repair in mammalian cells and the potential overlap between nonhomologous end-joining and homologous recombination in different tissues.

  10. Low molecular weight heparin impairs tendon repair.

    Science.gov (United States)

    Virchenko, O; Aspenberg, P; Lindahl, T L

    2008-03-01

    Thrombin has many biological properties similar to those of growth factors. In a previous study, we showed that thrombin improves healing of the rat tendo Achillis. Low molecular weight heparin (LMWH) inhibits the activity and the generation of thrombin. We therefore considered that LMWH at a thromboprophylactic dose might inhibit tendon repair. Transection of the tendo Achillis was carried out in 86 rats and the healing tested mechanically. Low molecular weight heparin (dalateparin) was either injected a few minutes before the operation and then given continuously with an osmotic mini pump for seven days, or given as one injection before the operation. In another experiment ,we gave LMWH or a placebo by injection twice daily. The anti-factor Xa activity was analysed. Continuous treatment with LMWH impaired tendon healing. After seven days, this treatment caused a 33% reduction in force at failure, a 20% reduction in stiffness and a 67% reduction in energy uptake. However, if injected twice daily, LMWH had no effect on tendon healing. Anti-factor Xa activity was increased by LMWH treatment, but was normal between intermittent injections. Low molecular weight heparin delays tendon repair if given continuously, but not if injected intermittently, probably because the anti-factor Xa activity between injections returns to normal, allowing sufficient thrombin stimulation for repair. These findings indicate the need for caution in the assessment of long-acting thrombin and factor Xa inhibitors.

  11. Current advances in DNA repair: regulation of enzymes and pathways involved in maintaining genomic stability.

    Science.gov (United States)

    Neher, Tracy M; Turchi, John J

    2011-06-15

    Novel discoveries in the DNA repair field have lead to continuous and rapid advancement of our understanding of not only DNA repair but also DNA replication and recombination. Research in the field transcends numerous areas of biology, biochemistry, physiology, and medicine, making significant connections across these broad areas of study. From early studies conducted in bacterial systems to current analyses in eukaryotic systems and human disease, the innovative research into the mechanisms of repair machines and the consequences of ineffective DNA repair has impacted a wide scientific community. This Forum contains a select mix of primary research articles in addition to a number of timely reviews covering a subset of DNA repair pathways where recent advances and novel discoveries are improving our understanding of DNA repair, its regulation, and implications to human disease.

  12. Purification of mammalian DNA repair protein XRCC1

    Energy Technology Data Exchange (ETDEWEB)

    Chen, I. [Univ. of California, Berkeley, CA (United States)

    1995-11-01

    Malfunctioning DNA repair systems lead to cancer mutations, and cell death. XRCC1 (X-ray Repair Cross Complementing) is a human DNA repair gene that has been found to fully correct the x-ray repair defect in Chinese hamster ovary (CHO) cell mutant EM9. The corresponding protein (XRCC1) encoded by this gene has been linked to a DNA repair pathway known as base excision repair, and affects the activity of DNA ligase III. Previously, an XRCC1 cDNA minigene (consisting of the uninterrupted coding sequence for XRCC1 protein followed by a decahistidine tag) was constructed and cloned into vector pET-16b for the purpose of: (1) overproduction of XRCC1 in both prokaryotic and eukaryotic cells; and (2) to facilitate rapid purification of XRCC1 from these systems. A vector is basically a DNA carrier that allows recombinant protein to be cloned and overexpressed in host cells. In this study, XRCC1 protein was overexpressed in E. coli and purified by immobilized metal affinity chromatography. Currently, the XRCC1 minigene is being inserted into a new vector [pET-26b(+)] in hopes to increase overexpression and improve purification. Once purified XRCC1 can be crystallized for structural studies, or studied in vitro for its biological function.

  13. Laparoscopic Repair of Morgagni Hernia

    Directory of Open Access Journals (Sweden)

    ilker murat arer

    2015-03-01

    Full Text Available Morgagni hernia is a congenital herniation of abdominal contents into the thoracic cavity through a retrosternal diaphragmatic defect and make up about 1 % - 5 % of all types of congenital diaphragmatic hernias. Surgical repair of Morgagni hernias is usually indicated when patients are symptomatic and have a high risk of strangulation or incarceration of the contained viscera. 71-year-old male patient admitted to emergency department with a 2-day history of abdominal pain, vomiting and obstipation. Laparoscopic repair for Morgagni hernia was performed. Laparoscopic repair for Morgagni hernia with mesh repair is secure, satisfactory and easily performed. [Cukurova Med J 2015; 40(Suppl 1: 71-74

  14. Mammalian mismatch repair

    DEFF Research Database (Denmark)

    Pena Diaz, Javier; Jiricny, Josef

    2012-01-01

    A considerable surge of interest in the mismatch repair (MMR) system has been brought about by the discovery of a link between Lynch syndrome, an inherited predisposition to cancer of the colon and other organs, and malfunction of this key DNA metabolic pathway. This review focuses on recent...... advances in our understanding of the molecular mechanisms of canonical MMR, which improves replication fidelity by removing misincorporated nucleotides from the nascent DNA strand. We also discuss the involvement of MMR proteins in two other processes: trinucleotide repeat expansion and antibody maturation...

  15. New tools to study DNA double-strand break repair pathway choice.

    Directory of Open Access Journals (Sweden)

    Daniel Gomez-Cabello

    Full Text Available A broken DNA molecule is difficult to repair, highly mutagenic, and extremely cytotoxic. Such breaks can be repaired by homology-independent or homology-directed mechanisms. Little is known about the network that controls the repair pathway choice except that a licensing step for homology-mediated repair exists, called DNA-end resection. The choice between these two repair pathways is a key event for genomic stability maintenance, and an imbalance of the ratio is directly linked with human diseases, including cancer. Here we present novel reporters to study the balance between both repair options in human cells. In these systems, a double-strand break can be alternatively repaired by homology-independent or -dependent mechanisms, leading to the accumulation of distinct fluorescent proteins. These reporters thus allow the balance between both repair pathways to be analyzed in different experimental setups. We validated the reporters by analyzing the effect of protein downregulation of the DNA end resection and non-homologous end-joining pathways. Finally, we analyzed the role of the DNA damage response on double-strand break (DSB repair mechanism selection. Our reporters could be used in the future to understand the roles of specific factors, whole pathways, or drugs in DSB repair pathway choice, or for genome-wide screening. Moreover, our findings can be applied to increase gene-targeting efficiency, making it a beneficial tool for a broad audience in the biological sciences.

  16. Double-strand break repair-adox: Restoration of suppressed double-strand break repair during mitosis induces genomic instability.

    Science.gov (United States)

    Terasawa, Masahiro; Shinohara, Akira; Shinohara, Miki

    2014-12-01

    Double-strand breaks (DSBs) are one of the severest types of DNA damage. Unrepaired DSBs easily induce cell death and chromosome aberrations. To maintain genomic stability, cells have checkpoint and DSB repair systems to respond to DNA damage throughout most of the cell cycle. The failure of this process often results in apoptosis or genomic instability, such as aneuploidy, deletion, or translocation. Therefore, DSB repair is essential for maintenance of genomic stability. During mitosis, however, cells seem to suppress the DNA damage response and proceed to the next G1 phase, even if there are unrepaired DSBs. The biological significance of this suppression is not known. In this review, we summarize recent studies of mitotic DSB repair and discuss the mechanisms of suppression of DSB repair during mitosis. DSB repair, which maintains genomic integrity in other phases of the cell cycle, is rather toxic to cells during mitosis, often resulting in chromosome missegregation and aberration. Cells have multiple safeguards to prevent genomic instability during mitosis: inhibition of 53BP1 or BRCA1 localization to DSB sites, which is important to promote non-homologous end joining or homologous recombination, respectively, and also modulation of the non-homologous end joining core complex to inhibit DSB repair. We discuss how DSBs during mitosis are toxic and the multiple safeguard systems that suppress genomic instability.

  17. Transcript RNA supports precise repair of its own DNA gene.

    Science.gov (United States)

    Keskin, Havva; Meers, Chance; Storici, Francesca

    2016-01-01

    The transfer of genetic information from RNA to DNA is considered an extraordinary process in molecular biology. Despite the fact that cells transcribe abundant amount of RNA with a wide range of functions, it has been difficult to uncover whether RNA can serve as a template for DNA repair and recombination. An increasing number of experimental evidences suggest a direct role of RNA in DNA modification. Recently, we demonstrated that endogenous transcript RNA can serve as a template to repair a DNA double-strand break (DSB), the most harmful DNA lesion, not only indirectly via formation of a DNA copy (cDNA) intermediate, but also directly in a homology driven mechanism in budding yeast. These results point out that the transfer of genetic information from RNA to DNA is more general than previously thought. We found that transcript RNA is more efficient in repairing a DSB in its own DNA (in cis) than in a homologous but ectopic locus (in trans). Here, we summarize current knowledge about the process of RNA-driven DNA repair and recombination, and provide further data in support of our model of DSB repair by transcript RNA in cis. We show that a DSB is precisely repaired predominately by transcript RNA and not by residual cDNA in conditions in which formation of cDNA by reverse transcription is inhibited. Additionally, we demonstrate that defects in ribonuclease (RNase) H stimulate precise DSB repair by homologous RNA or cDNA sequence, and not by homologous DNA sequence carried on a plasmid. These results highlight an antagonistic role of RNase H in RNA-DNA recombination. Ultimately, we discuss several questions that should be addressed to better understand mechanisms and implications of RNA-templated DNA repair and recombination.

  18. Non-DBS DNA Repair Genes Regulate Radiation-induced Cytogenetic Damage Repair and Cell Cycle Progression

    Science.gov (United States)

    Zhang, Ye; Rohde, Larry H.; Emami, Kamal; Casey, Rachael; Wu, Honglu

    2008-01-01

    Changes of gene expression profile are one of the most important biological responses in living cells after ionizing radiation (IR) exposure. Although some studies have shown that genes up-regulated by IR may play important roles in DNA damage repair, the relationship between the regulation of gene expression by IR, particularly genes not known for their roles in DSB repair, and its impact on cytogenetic responses has not been systematically studied. In the present study, the expression of 25 genes selected on the basis of their transcriptional changes in response to IR was individually knocked down by transfection with small interfering RNA in human fibroblast cells. The purpose of this study is to identify new roles of these selected genes on regulating DSB repair and cell cycle progression , as measured in the micronuclei formation and chromosome aberration. In response to IR, the formation of MN was significantly increased by suppressed expression of 5 genes: Ku70 in the DSB repair pathway, XPA in the NER pathway, RPA1 in the MMR pathway, and RAD17 and RBBP8 in cell cycle control. Knocked-down expression of 4 genes (MRE11A, RAD51 in the DSB pathway, SESN1, and SUMO1) significantly inhibited cell cycle progression, possibly because of severe impairment of DNA damage repair. Furthermore, loss of XPA, P21, or MLH1 expression resulted in both significantly enhanced cell cycle progression and increased yields of chromosome aberrations, indicating that these gene products modulate both cell cycle control and DNA damage repair. Most of the 11 genes that affected cytogenetic responses are not known to have clear roles influencing DBS repair. Nine of these 11 genes were up-regulated in cells exposed to gamma radiation, suggesting that genes transcriptionally modulated by IR were critical to regulate the biological consequences after IR.

  19. Stem cells and repair of lung injuries

    Directory of Open Access Journals (Sweden)

    Randell Scott H

    2004-07-01

    Full Text Available Abstract Fueled by the promise of regenerative medicine, currently there is unprecedented interest in stem cells. Furthermore, there have been revolutionary, but somewhat controversial, advances in our understanding of stem cell biology. Stem cells likely play key roles in the repair of diverse lung injuries. However, due to very low rates of cellular proliferation in vivo in the normal steady state, cellular and architectural complexity of the respiratory tract, and the lack of an intensive research effort, lung stem cells remain poorly understood compared to those in other major organ systems. In the present review, we concisely explore the conceptual framework of stem cell biology and recent advances pertinent to the lungs. We illustrate lung diseases in which manipulation of stem cells may be physiologically significant and highlight the challenges facing stem cell-related therapy in the lung.

  20. Kvitebjoern gas pipeline repair - baptism of remote pipeline repair system

    Energy Technology Data Exchange (ETDEWEB)

    Gjertveit, Erling

    2010-07-01

    On the 1st of November 2007, severe anchor damage was discovered on the 30 inch Kvitebjoern gas export pipeline. The damage constituted a localised dent and a 17deg buckle, but no leakage. Statoil has invested in building an effective repair contingency structure for the large pipeline network on the Norwegian Continental shelf, with particular focus on the large gas export pipelines. The repair method for the Kvitebjoern pipeline was remotely operated using two Morgrip couplings and a spool. The installation used the purpose built Pipeline Repair System stored at Killingoey and couplings produced and tested back in 2005. This presentation will cover the initial damage investigations, the temporary operational phase, the repair preparations, the actual repair and lessons learned. (Author)

  1. Handbook of adhesive bonded structural repair

    CERN Document Server

    Wegman, Raymond F

    1992-01-01

    Provides repair methods for adhesive bonded and composite structures; identifies suitable materials and equipment for repairs; describes damage evaluation criteria and techniques, and methods of inspection before and after repair.

  2. Nucleotide excision repair in yeast

    NARCIS (Netherlands)

    Eijk, Patrick van

    2012-01-01

    Nucleotide Excision Repair (NER) is a conserved DNA repair pathway capable of removing a broad spectrum of DNA damage. In human cells a defect in NER leads to the disorder Xeroderma pigmentosum (XP). The yeast Saccharomyces cerevisiae is an excellent model organism to study the mechanism of NER. The

  3. 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.

  4. 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.

  5. 1999 Gordon Research Conference on Mammalian DNA Repair. Final Progress Report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-02-12

    This Conference will examine DNA repair as the key component in genomic surveillance that is so crucial to the overall integrity and function of mammalian cells. Recent discoveries have catapulted the field of DNA repair into a pivotal position for fundamental investigations into oncology, aging, environmental health, and developmental biology. We hope to highlight the most promising and exciting avenues of research in robust discussions at this conference. This Mammalian DNA Repair Gordon Conference differs from the past conferences in this series, in which the programs were broader in scope, with respect to topics and biological systems covered. A conference sponsored by the Genetics Society in April 1998 emphasized recombinational mechanisms for double-strand break repair and the role of mismatch repair deficiency in colorectal cancer. These topics will therefore receive somewhat less emphasis in the upcoming Conference. In view of the recent mechanistic advances in mammalian DNA repair, an upcoming comprehensive DNA repair meeting next autumn at Hilton Head; and the limited enrollment for Gordon Conferences we have decided to focus session-by-session on particular areas of controversy and/or new developments specifically in mammalian systems. Thus, the principal presentations will draw upon results from other cellular systems only to the extent that they impact our understanding of mammalian DNA repair.

  6. DNA Repair Defects and Chromosomal Aberrations

    Science.gov (United States)

    Hada, Megumi; George, K. A.; Huff, J. L.; Pluth, J. M.; Cucinotta, F. A.

    2009-01-01

    Yields of chromosome aberrations were assessed in cells deficient in DNA doublestrand break (DSB) repair, after exposure to acute or to low-dose-rate (0.018 Gy/hr) gamma rays or acute high LET iron nuclei. We studied several cell lines including fibroblasts deficient in ATM (ataxia telangiectasia mutated; product of the gene that is mutated in ataxia telangiectasia patients) or NBS (nibrin; product of the gene mutated in the Nijmegen breakage syndrome), and gliomablastoma cells that are proficient or lacking in DNA-dependent protein kinase (DNA-PK) activity. Chromosomes were analyzed using the fluorescence in situ hybridization (FISH) chromosome painting method in cells at the first division post irradiation, and chromosome aberrations were identified as either simple exchanges (translocations and dicentrics) or complex exchanges (involving >2 breaks in 2 or more chromosomes). Gamma irradiation induced greater yields of both simple and complex exchanges in the DSB repair-defective cells than in the normal cells. The quadratic dose-response terms for both simple and complex chromosome exchanges were significantly higher for the ATM- and NBS-deficient lines than for normal fibroblasts. However, in the NBS cells the linear dose-response term was significantly higher only for simple exchanges. The large increases in the quadratic dose-response terms in these repair-defective cell lines points the importance of the functions of ATM and NBS in chromatin modifications to facilitate correct DSB repair and minimize the formation of aberrations. The differences found between ATM- and NBS-deficient cells at low doses suggest that important questions should with regard to applying observations of radiation sensitivity at high dose to low-dose exposures. For aberrations induced by iron nuclei, regression models preferred purely linear dose responses for simple exchanges and quadratic dose responses for complex exchanges. Relative biological effectiveness (RBE) factors of all of

  7. Comportamento biológico de matriz scaffold acrescida de células progenitoras na reparação óssea Bone marrow progenitor cells enriched scaffold biological behavior in bone repair

    Directory of Open Access Journals (Sweden)

    Débora Cristina Olsson

    2008-11-01

    Full Text Available A engenharia tecidual desenvolve e manipula células ou tecidos para a reconstrução de novos órgãos e tecidos. A perda ou a falência da função de partes teciduais alteradas ou lesadas torna-se um problema severo à saúde animal e uma indicação para tratamento é o transplante para substituir a função biológica perdida. Vários animais são afetados por estes problemas, razões estas que indicam a necessidade de desenvolvimento de terapias alternativas para tratar perdas ósseas. Estudos experimentais contribuem para avanços da medicina regenerativa, como a engenharia de tecidos, com o objetivo de desenvolver suportes sintéticos ou utilizar arcabouços naturais, conhecidos como scaffold, que substituam as funções fisiológicas do tecido ósseo. Atualmente para, a obtenção destes objetivos utilizam-se também, de forma genérica, combinações específicas com células progenitoras (CP da medula óssea (MO do próprio paciente ou doador que são distribuídas em um material de suporte tridimensional com propriedades adequadas, gerando um material híbrido cujas características podem ainda ser moduladas para então ser reinserido no paciente. O objetivo desta revisão é apresentar informações sobre o comportamento biológico de materiais sintéticos e naturais apropriados para implantes ósseos, acrescidos ou não de CP, para o estímulo do processo reparativo de tecido ósseo.Tissue engineering involves the manipulation and the development of cells aiming to create and/or regenerate organs and tissues. Function failure of injuried tissues is a severe animal health problem, nevertheless, the transplantation has been indicated to treat and replace the biological function. A large amount of animals are affected by those problems, and for this reason it is necessary to find alternative therapies to treat bone losses. Studies such those involving tissue engineering have contributed to regenerative medicine advances, to developed

  8. DNA repair in Chromobacterium violaceum.

    Science.gov (United States)

    Duarte, Fábio Teixeira; Carvalho, Fabíola Marques de; Bezerra e Silva, Uaska; Scortecci, Kátia Castanho; Blaha, Carlos Alfredo Galindo; Agnez-Lima, Lucymara Fassarella; Batistuzzo de Medeiros, Silvia Regina

    2004-03-31

    Chromobacterium violaceum is a Gram-negative beta-proteobacterium that inhabits a variety of ecosystems in tropical and subtropical regions, including the water and banks of the Negro River in the Brazilian Amazon. This bacterium has been the subject of extensive study over the last three decades, due to its biotechnological properties, including the characteristic violacein pigment, which has antimicrobial and anti-tumoral activities. C. violaceum promotes the solubilization of gold in a mercury-free process, and has been used in the synthesis of homopolyesters suitable for the production of biodegradable polymers. The complete genome sequence of this organism has been completed by the Brazilian National Genome Project Consortium. The aim of our group was to study the DNA repair genes in this organism, due to their importance in the maintenance of genomic integrity. We identified DNA repair genes involved in different pathways in C. violaceum through a similarity search against known sequences deposited in databases. The phylogenetic analyses were done using programs of the PHILYP package. This analysis revealed various metabolic pathways, including photoreactivation, base excision repair, nucleotide excision repair, mismatch repair, recombinational repair, and the SOS system. The similarity between the C. violaceum sequences and those of Neisserie miningitidis and Ralstonia solanacearum was greater than that between the C. violaceum and Escherichia coli sequences. The peculiarities found in the C. violaceum genome were the absence of LexA, some horizontal transfer events and a large number of repair genes involved with alkyl and oxidative DNA damage.

  9. How to repair an episiotomy.

    Science.gov (United States)

    Steen, Mary; Cummins, Bernie

    2016-02-17

    Rationale and key points Skilful repair of an episiotomy is an important aspect of maternal health care. It is essential that midwives and doctors have the knowledge and skills to undertake this procedure in a safe and effective manner. ▶ An episiotomy should be repaired promptly to reduce blood loss and prevent infection. ▶ Repair of an episiotomy is undertaken in three stages: repair of the vaginal mucosa, repair of the muscle layer and repair of the skin layer. ▶ Adequate pain relief should be provided before suturing. Reflective activity Clinical skills articles can help update your practice and ensure it remains evidence based. Apply this article to your practice. Reflect on and write a short account of: 1. Why a rectal examination is recommended before and following repair of an episiotomy. 2. What you would do to improve your suturing skills. 3. The factors that may prevent or delay an episiotomy from healing. Subscribers can upload their reflective accounts at rcni.com/portfolio .

  10. 40 CFR 798.5500 - Differential growth inhibition of repair proficient and repair deficient bacteria: “Bacterial DNA...

    Science.gov (United States)

    2010-07-01

    ... repair proficient and repair deficient bacteria: âBacterial DNA damage or repair tests.â 798.5500 Section... inhibition of repair proficient and repair deficient bacteria: “Bacterial DNA damage or repair tests.” (a... killing or growth inhibition of repair deficient bacteria in a set of repair proficient and...

  11. Bone repair and stem cells.

    Science.gov (United States)

    Ono, Noriaki; Kronenberg, Henry M

    2016-10-01

    Bones are an important component of vertebrates; they grow explosively in early life and maintain their strength throughout life. Bones also possess amazing capabilities to repair-the bone is like new without a scar after complete repair. In recent years, a substantial progress has been made in our understanding on mammalian bone stem cells. Mouse genetic models are powerful tools to understand the cell lineage, giving us better insights into stem cells that regulate bone growth, maintenance and repair. Recent findings about these stem cells raise new questions that require further investigations.

  12. [Inguinal and femoral hernia repair].

    Science.gov (United States)

    Geissler, B; Anthuber, M

    2011-05-01

    With an incidence of 200,000 new cases per year in Germany, inguinal hernia has a significant socioeconomic impact. The 2009 guidelines from the European Hernia Society established treatment recommendations. Hernia repair is based on reinforcing the posterior wall of the inguinal canal by suture or mesh repair by an anterior or posterior approach. Lightweight mesh reduces recurrence rates and is the treatment of choice even in primary hernias. Laparoscopic hernia repair is associated with specific risks but is superior in postoperative pain and earlier return to work.

  13. Large myelomeningocele repair

    Directory of Open Access Journals (Sweden)

    Farideh Nejat

    2011-01-01

    Full Text Available Background: Wound closure is accomplished in most cases of myelomeningocele (MMC by undermining of the skin edges surrounding the defect. However, large defects cannot be closed reliably by this simple technique. Due to the technical challenge associated with large MMC, surgeons have devised different methods for repairing large defects. In this paper, we report our experience of managing large defects, which we believe bears a direct relationship to decrease the incidence of wound complications. Materials and Methods: Forty children with large MMCs underwent surgical repair and represent our experience. We recommend using all hairy skin around the defect as a way to decrease the tension on the edges of the wound and the possible subsequent necrosis. It is our experience that vertical incision on one or two flanks parallel to the midline can decrease the tension of the wound. Moreover, ventriculo-peritoneal shunting for children who developed hydrocephalus was performed simultaneously, which constitutes another recommendation for preventing fluid collection and build up of pressure on the wound. Results: Patients in this study were in the age range of 2 days to 8 years. The most common location of MMC was in the thoracolumbar area. All but four patients had severe weakness in lower extremities. We used as much hairy skin around the MMC sac as possible in all cases. Vertical incisions on one or both flanks and simultaneous shunt procedure were performed in 36 patients. We treated children with large MMC defects with acceptable tension-free closure. Nonetheless, three patients developed superficial skin infection and partial wound dehiscence, and they were managed conservatively. Conclusions: We recommend using all hairy skin around the MMC defect for closure of large defects. In cases that were expected to be at a higher risk to develop dehiscence release incisions on one or two flanks towards the fascia were found to be useful. Simultaneous

  14. A Two-Unit Cold Standby Repairable System with One Replaceable Repair Facility and Delay Repair:Some Reliability Problems

    Institute of Scientific and Technical Information of China (English)

    WEI Ying-yuan; TANG Ying-hui

    2004-01-01

    This paper considers a two-unit same cold standby repairable system with a replaceable repair facility and delay repair .The failure time of unit is assumed to follow exponential distribution , and the repair time and delay time of failed unit are assumed to follow arbitrary distributions , whereas the failure and replacement time distributions of the repair facility are exponential and arbitrary . By using the Markov renewal process theory, some primary reliability quantities of the system are obtained.

  15. 40 CFR 63.1024 - Leak repair.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 10 2010-07-01 2010-07-01 false Leak repair. 63.1024 Section 63.1024... Standards for Equipment Leaks-Control Level 2 Standards § 63.1024 Leak repair. (a) Leak repair schedule. The owner or operator shall repair each leak detected as soon as practical, but not later than 15...

  16. 40 CFR 65.105 - Leak repair.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 15 2010-07-01 2010-07-01 false Leak repair. 65.105 Section 65.105... FEDERAL AIR RULE Equipment Leaks § 65.105 Leak repair. (a) Leak repair schedule. The owner or operator shall repair each leak detected as soon as practical but not later than 15 calendar days after it...

  17. 40 CFR 63.1005 - Leak repair.

    Science.gov (United States)

    2010-07-01

    ... successful repair of the leak. (3) Maximum instrument reading measured by Method 21 of 40 CFR part 60... 40 Protection of Environment 10 2010-07-01 2010-07-01 false Leak repair. 63.1005 Section 63.1005... Standards for Equipment Leaks-Control Level 1 § 63.1005 Leak repair. (a) Leak repair schedule. The owner...

  18. 77 FR 30053 - Repair Stations

    Science.gov (United States)

    2012-05-21

    ... concerning this proposed rule contact John Goodwin, FAA, Repair Station Branch (AFS-340), 800 Independence....Goodwin@faa.gov . For legal questions concerning this proposed rule contact Edmund Averman, FAA, Office...

  19. DNA repair deficiency in neurodegeneration

    DEFF Research Database (Denmark)

    Jeppesen, Dennis Kjølhede; Bohr, Vilhelm A; Stevnsner, Tinna V.

    2011-01-01

    : homologous recombination and non-homologous end-joining. Ataxia telangiectasia and related disorders with defects in these pathways illustrate that such defects can lead to early childhood neurodegeneration. Aging is a risk factor for neurodegeneration and accumulation of oxidative mitochondrial DNA damage......Deficiency in repair of nuclear and mitochondrial DNA damage has been linked to several neurodegenerative disorders. Many recent experimental results indicate that the post-mitotic neurons are particularly prone to accumulation of unrepaired DNA lesions potentially leading to progressive...... neurodegeneration. Nucleotide excision repair is the cellular pathway responsible for removing helix-distorting DNA damage and deficiency in such repair is found in a number of diseases with neurodegenerative phenotypes, including Xeroderma Pigmentosum and Cockayne syndrome. The main pathway for repairing oxidative...

  20. Early days of DNA repair: discovery of nucleotide excision repair and homology-dependent recombinational repair.

    Science.gov (United States)

    Rupp, W Dean

    2013-12-13

    The discovery of nucleotide excision repair in 1964 showed that DNA could be repaired by a mechanism that removed the damaged section of a strand and replaced it accurately by using the remaining intact strand as the template. This result showed that DNA could be actively metabolized in a process that had no precedent. In 1968, experiments describing postreplication repair, a process dependent on homologous recombination, were reported. The authors of these papers were either at Yale University or had prior Yale connections. Here we recount some of the events leading to these discoveries and consider the impact on further research at Yale and elsewhere.

  1. Laparoscopic repair of postoperative perineal hernia.

    LENUS (Irish Health Repository)

    Ryan, Stephen

    2010-01-01

    Perineal hernias are infrequent complications following abdominoperineal operations. Various approaches have been described for repair of perineal hernias including open transabdominal, transperineal or combined abdominoperineal repairs. The use of laparoscopic transabdominal repair of perineal hernias is not well-described. We present a case report demonstrating the benefits of laparoscopic repair of perineal hernia following previous laparoscopic abdominoperineal resection (APR) using a nonabsorbable mesh to repair the defect. We have demonstrated that the use of laparoscopy with repair of the pelvic floor defect using a non absorbable synthetic mesh offers an excellent alternative with many potential advantages over open transabdominal and transperineal repairs.

  2. Construction, repair and maintenance

    Energy Technology Data Exchange (ETDEWEB)

    Hinger, R. [Terasen Pipelines, Calgary, AB (Canada); Wong, P. [KC Integrity Corp., Calgary, AB (Canada); Yeomans, M.; Glover, A. [TransCanada PipeLines Ltd., Calgary, AB (Canada)

    2003-07-01

    The presentations by Working Group 4 focused on construction, repair and maintenance of pipelines with particular reference to high-strength steels and their applications for natural gas transmission pipelines. Discussions focused on how technology can be used to provide cost-effective design and construction solutions for long distance pipelines in a manner that does not compromise safety and reliability. The role that carbon plays in increasing the toughness of steel was also discussed. A few fundamental changes in steel production technology and a reduction in carbon content can result in a simultaneous increase in strength and toughness of steels. The cost impact of this technology was summarized. It was concluded that high strength steels offer effective solutions to deliver cost-effective pipelines to transport natural gas from northern basins. This session also presented pipeline routes that transport diluted bitumens from the Athabasca Oil Sands Project and the Muskeg River Mine to upgrader facilities in Alberta. Construction issues included design conservatism, water course crossings, winter construction, winter ditching, and public consultation. Examples of high strength steel pipe applications were also included with reference to experience gained by TransCanada and Corridor Pipeline. tabs., figs.

  3. Aircraft Metal Skin Repair and Honeycomb Structure Repair; Sheet Metal Work 3: 9857.02.

    Science.gov (United States)

    Dade County Public Schools, Miami, FL.

    The course helps students determine types of repairs, compute repair sizes, and complete the repair through surface protection. Course content includes goals, specific objectives, protection of metals, repairs to metal skin, and honeycomb structure repair. A bibliography and post-test are appended. A prerequisite for this course is mastery of the…

  4. Photoprotection by topical DNA repair enzymes: molecular correlates of clinical studies.

    Science.gov (United States)

    Yarosh, D B; O'Connor, A; Alas, L; Potten, C; Wolf, P

    1999-02-01

    A new approach to photoprotection is to repair DNA damage after UV exposure. This can be accomplished by delivery of a DNA repair enzyme with specificity to UV-induced cyclobutane pyrimidine dimers into skin by means of specially engineered liposomes. Treatment of DNA-repair-deficient xeroderma pigmentosum patients or skin cancer patients with T4N5 liposome lotion containing such DNA repair liposomes increases the removal of DNA damage in the first few hours after treatment. In these studies, a DNA repair effect was observed in some patients treated with heat-inactivated enzyme. Unexpectedly, it was discovered that the heat-inactivated T4 endonuclease V enzyme refolds and recovers enzymatic activity. These studies demonstrate that measurements of molecular changes induced by biological drugs are useful adjuvants to clinical studies.

  5. Repair Types, Procedures - Part 1

    Science.gov (United States)

    2010-05-01

    New Jersey, USA. Repair Types, Procedures – Part I RTO-EN-AVT-156 9 - 19 [5] Drieker R, Botello C, MacBeth S, and Grody J, “Aircraft Battle... MacBeth S, and Grody J, “Aircraft Battle Damage Assessment and Repair (ABDAR), Vol. III: Field Test Report,” AFRL-HE-WP-TR-2002-0039, July 2000. [8

  6. Cobbler's technique for Iridodialysis repair

    Directory of Open Access Journals (Sweden)

    Surinder Singh Pandav

    2016-01-01

    Full Text Available We describe a novel “Cobbler's technique” for iridodialysis repair in the right eye of a patient aged 18 years, with a traumatic iridodialysis secondary to open globe injury with an iron rod. Our technique is simple with easy surgical maneuvers, that is, effective for repairing iridodialysis. The “Cobbler's technique” allows a maximally functional and cosmetic result for iridodialysis.

  7. Umbilical and epigastric hernia repair.

    Science.gov (United States)

    Muschaweck, Ulrike

    2003-10-01

    The repair of umbilical and epigastric hernias still represents a challenge to surgeons. Although a common and relatively simple procedure, there is no exact protocol today on how the repair should be done. The Mayo technique and its alterations could not stand the test of time: a recurrence rate of 20% and higher is not acceptable for any surgical procedure. Although there is no consensus opinion, one thing is clear: the importance of an anatomic repair without tension and without an artificial enlargement of the defect. In 1987 Lichtenstein reported on 6321 cases of herniorraphy with a tension free repair, and in 1994 Stuart reemphasized that special importance in his editorial in the Lancet. A newer study from Brancato and coworkers in Italy also states the advantage of a tension-free prosthetic repair in 16 patients with epigastric hernia. We have gone even further and recommend a tailored-to-the-patient repair using a customized polypropylene mesh and a one-layer running suture. The advantages should be obvious: no artificial creation of an even bigger than original defect, a completely tension-free repair, and little to no recurrence of the hernia. Our results clearly prove that assumption. Moreover, the procedure is extremely safe and complications are very rare and minor. We conclude that using a mesh plug in a customized tension-free repair of umbilical and epigastric hernia shows many advantages over the commonly used methods. And we finally conclude with the words of Albert Einstein: "The only source of knowledge is experience."

  8. Repairing Learned Knowledge Using Experience

    Science.gov (United States)

    1990-05-01

    It necessar and Identify by’ 6109h nii be) learning precedent-based learning knowledge repair explanation-based learning near - miss groups 20. ABSTRACT...can a program use explanations to repair a recollection, preventing further misapplication? Near - Miss Groups Isolate Suspicious Relations If a metal...pail differs from a porcelain cup only in the position of handle attachment, then we would say that the pail is a near miss . Unfortunately, there are

  9. Scarf Repair of Composite Laminates

    Directory of Open Access Journals (Sweden)

    Xie Zonghong

    2016-01-01

    Full Text Available The use of composite materials, such as carbon-fiber reinforced plastic (CFRP composites, aero-structures has led to an increased need of advanced assembly joining and repair technologies. Adhesive bonded repairs as an alternative to recover full or part of initial strength were investigated. Tests were conducted with the objective of evaluating the effectiveness of techniques used for repairing damage fiber reinforced laminated composites. Failure loads and failure modes were generated and compared with the following parameters: scarf angles, roughness of grind tool and number of external plies. Results showed that scarf angle was the critical parameter and the largest tensile strength was observed with the smallest scarf angle. Besides, the use of external plies at the outer surface could not increase the repairs efficiency for large scarf angle. Preparing the repair surfaces by sanding them with a sander ranging from 60 to 100 grit number had significant effect on the failure load. These results allowed the proposal of design principles for repairing CFRP structures.

  10. Base excision repair in sugarcane

    Directory of Open Access Journals (Sweden)

    Agnez-Lima Lucymara F.

    2001-01-01

    Full Text Available DNA damage can be induced by a large number of physical and chemical agents from the environment as well as compounds produced by cellular metabolism. This type of damage can interfere with cellular processes such as replication and transcription, resulting in cell death and/or mutations. The low frequency of mutagenesis in cells is due to the presence of enzymatic pathways which repair damaged DNA. Several DNA repair genes (mainly from bacteria, yeasts and mammals have been cloned and their products characterized. The high conservation, especially in eukaryotes, of the majority of genes related to DNA repair argues for their importance in the maintenance of life on earth. In plants, our understanding of DNA repair pathways is still very poor, the first plant repair genes having only been cloned in 1997 and the mechanisms of their products have not yet been characterized. The objective of our data mining work was to identify genes related to the base excision repair (BER pathway, which are present in the database of the Sugarcane Expressed Sequence Tag (SUCEST Project. This search was performed by tblastn program. We identified sugarcane clusters homologous to the majority of BER proteins used in the analysis and a high degree of conservation was observed. The best results were obtained with BER proteins from Arabidopsis thaliana. For some sugarcane BER genes, the presence of more than one form of mRNA is possible, as shown by the occurrence of more than one homologous EST cluster.

  11. Complement activation in the context of stem cells and tissue repair

    Institute of Scientific and Technical Information of China (English)

    Ingrid; U; Schraufstatter; Sophia; K; Khaldoyanidi; Richard; G; DiScipio

    2015-01-01

    The complement pathway is best known for its role in immune surveillance and inflammation. However,its ability of opsonizing and removing not only pathogens,but also necrotic and apoptotic cells,is a phylogenetically ancient means of initiating tissue repair. The means and mechanisms of complement-mediated tissue repair are discussed in this review. There is increasing evidence that complement activation contributes to tissue repair at several levels. These range from the chemo-attraction of stem and progenitor cells to areas of complement activation,to increased survival of various cell types in the presence of split products of complement,and to the production of trophic factors by cells activated by the anaphylatoxins C3 a and C5 a. This repair aspect of complement biology has not found sufficient appreciation until recently. The following will examine this aspect of complement biology with an emphasis on the anaphylatoxins C3 a and C5 a.

  12. Higher-order chromatin structure in DSB induction, repair and misrepair.

    Science.gov (United States)

    Falk, Martin; Lukasova, Emilie; Kozubek, Stanislav

    2010-01-01

    Double-strand breaks (DSBs), continuously introduced into DNA by cell metabolism, ionizing radiation and some chemicals, are the biologically most deleterious type of genome damage, and must be accurately repaired to protect genomic integrity, ensure cell survival, and prevent carcinogenesis. Although a huge amount of information has been published on the molecular basis and biological significance of DSB repair, our understanding of DSB repair and its spatiotemporal arrangement is still incomplete. In particular, the role of higher-order chromatin structure in DSB induction and repair, movement of DSBs and the mechanism giving rise to chromatin exchanges, and many other currently disputed questions are discussed in this review. Finally, a model explaining the formation of chromosome translocations is proposed.

  13. 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)

  14. Strategies for cell engineering in tissue repair.

    Science.gov (United States)

    Brown, R A; Smith, K D; Angus McGrouther, D

    1997-01-01

    Cellular and tissue engineering are new areas of research, currently attracting considerable interest because of the remarkable potential they have for clinical application. Some claims have indeed been dramatic, including the possibility of growing complete, artificial organs, such as the liver. However, amid such long-term aspirations there is the very real possibility that small tissues (artificial grafts) may be fabricated in the near future for use in reconstructive surgery. Logically, we should focus on how it is possible to produce modest, engineered tissues for tissue repair. It is evident that strategies to date either depend on innate information within implanted cells, to reform the target tissue or aim to provide appropriate environmental cues or guidance to direct cell behavior. It is argued here that present knowledge of tissue repair biology points us toward the latter approach, providing external cues which will direct how cells should organize the new tissue. This will be particularly true where we need to reproduce microscopic and ultrastructural features of the original tissue architecture. A number of such cues have been identified, and methods are already available, including substrate chemistry, substrate contact guidance, mechanical loading, and biochemical mediators to provide these cues. Examples of these are already being used with some success to control the formation of tissue structures.

  15. Mechanisms and functions of DNA mismatch repair

    Institute of Scientific and Technical Information of China (English)

    Guo MinLi

    2008-01-01

    DNA mismatch repair (MMR) is a highly conserved biological pathway that plays a key role in maintaining genomic stability. The specificity of MMR is primarily for base-base mismatches and insertion/deletion mispairs generated dur-ing DNA replication and recombination. MMR also suppresses homeologous recombination and was recently shown to play a role in DNA damage signaling in eukaryotic cells. Escherichia coli MutS and MutL and their eukaryotic homo-logs, MutSα and MutLα, respectively, are key players in MMR-associated genome maintenance. Many other protein components that participate in various DNA metabolic pathways, such as PCNA and RPA, are also essential for MMR. Defects in MMR are associated with genome-wide instability, predisposition to certain types of cancer including he-reditary non-polyposis colorectal cancer, resistance to certain chemotherapeutic agents, and abnormalities in meiosis and sterility in mammalian systems.

  16. 49 CFR 1242.42 - Administration, repair and maintenance, machinery repair, equipment damaged, dismantling retired...

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 9 2010-10-01 2010-10-01 false Administration, repair and maintenance, machinery repair, equipment damaged, dismantling retired property, fringe benefits, other casualties and insurance... maintenance, machinery repair, equipment damaged, dismantling retired property, fringe benefits,...

  17. All biology is computational biology

    Science.gov (United States)

    2017-01-01

    Here, I argue that computational thinking and techniques are so central to the quest of understanding life that today all biology is computational biology. Computational biology brings order into our understanding of life, it makes biological concepts rigorous and testable, and it provides a reference map that holds together individual insights. The next modern synthesis in biology will be driven by mathematical, statistical, and computational methods being absorbed into mainstream biological training, turning biology into a quantitative science. PMID:28278152

  18. Xenograft scaffold full-wrap reinforcement of Krackow achilles tendon repair.

    Science.gov (United States)

    Wisbeck, Jacob M; Parks, Brent G; Schon, Lew C

    2012-03-07

    Standard 4-strand repair of Achilles tendon tears is effective, but additional strength may be desirable in patients who are compromised or those with reruptures. Use of a xenograft scaffold has not been investigated biomechanically in Achilles tendon repair. This study compared stiffness, gap formation, and ultimate load to failure with Krackow repair vs Krackow repair augmented with xenograft scaffold in 6 matched pairs of fresh-frozen human lower extremities. The Achilles tendon was transected 4 cm above the calcaneal insertion. Specimens were randomized to receive standard Krackow repair or Krackow repair augmented with a porcine xenograft scaffold. The graft was wrapped around the repaired tendon, sutured to itself with 2-0 FiberWire (Arthrex, Naples, Florida), and attached to the tendon distally and proximally and then medially and laterally. Specimens were loaded for 200 cycles between 5 and 30 N. Load to 5-mm gapping and load to ultimate failure were measured. Xenograft scaffold augmentation of standard Krakow Achilles tendon repair was significantly stronger and stiffer than standard Krackow repair in a biomechanical model immediately after repair (39.0±8.8 vs 24.4±4.6 N/mm; P=.01). The augmented repair group had significantly higher load to ultimate failure than did the Krackow group (862.7±174.0 vs 479.5±65.5 N; P<.01). Biological factors remain to be investigated, but this augmentation method could provide additional strength in patients who are compromised or those with reruptures.

  19. Additive manufacturing for in situ repair of osteochondral defects

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, Daniel L; Lipton, Jeffrey I; Bonassar, Lawrence J; Lipson, Hod, E-mail: dlc44@cornell.ed, E-mail: jil26@cornell.ed, E-mail: lb244@cornell.ed, E-mail: hod.lipson@cornell.ed [Cornell University, Mechanical and Aerospace Engineering, Ithaca, NY (United States)

    2010-09-15

    Tissue engineering holds great promise for injury repair and replacement of defective body parts. While a number of techniques exist for creating living biological constructs in vitro, none have been demonstrated for in situ repair. Using novel geometric feedback-based approaches and through development of appropriate printing-material combinations, we demonstrate the in situ repair of both chondral and osteochondral defects that mimic naturally occurring pathologies. A calf femur was mounted in a custom jig and held within a robocasting-based additive manufacturing (AM) system. Two defects were induced: one a cartilage-only representation of a grade IV chondral lesion and the other a two-material bone and cartilage fracture of the femoral condyle. Alginate hydrogel was used for the repair of cartilage; a novel formulation of demineralized bone matrix was used for bone repair. Repair prints for both defects had mean surface errors less than 0.1 mm. For the chondral defect, 42.8 {+-} 2.6% of the surface points had errors that were within a clinically acceptable error range; however, with 1 mm path planning shift, an estimated {approx}75% of surface points could likely fall within the benchmark envelope. For the osteochondral defect, 83.6 {+-} 2.7% of surface points had errors that were within clinically acceptable limits. In addition to implications for minimally invasive AM-based clinical treatments, these proof-of-concept prints are some of the only in situ demonstrations to-date, wherein the substrate geometry was unknown a priori. The work presented herein demonstrates in situ AM, suggests potential biomedical applications and also explores in situ-specific issues, including geometric feedback, material selection and novel path planning techniques.

  20. Resorbable biosynthetic mesh for crural reinforcement during hiatal hernia repair.

    Science.gov (United States)

    Alicuben, Evan T; Worrell, Stephanie G; DeMeester, Steven R

    2014-10-01

    The use of mesh to reinforce crural closure during hiatal hernia repair is controversial. Although some studies suggest that using synthetic mesh can reduce recurrence, synthetic mesh can erode into the esophagus and in our opinion should be avoided. Studies with absorbable or biologic mesh have not proven to be of benefit for recurrence. The aim of this study was to evaluate the outcome of hiatal hernia repair with modern resorbable biosynthetic mesh in combination with adjunct tension reduction techniques. We retrospectively analyzed all patients who had crural reinforcement during repair of a sliding or paraesophageal hiatal hernia with Gore BioA resorbable mesh. Objective follow-up was by videoesophagram and/or esophagogastroduodenoscopy. There were 114 patients. The majority of operations (72%) were laparoscopic primary repairs with all patients receiving a fundoplication. The crura were closed primarily in all patients and reinforced with a BioA mesh patch. Excessive tension prompted a crural relaxing incision in four per cent and a Collis gastroplasty in 39 per cent of patients. Perioperative morbidity was minor and unrelated to the mesh. Median objective follow-up was one year, but 18 patients have objective follow-up at two or more years. A recurrent hernia was found in one patient (0.9%) three years after repair. The use of crural relaxing incisions and Collis gastroplasty in combination with crural reinforcement with resorbable biosynthetic mesh is associated with a low early hernia recurrence rate and no mesh-related complications. Long-term follow-up will define the role of these techniques for hiatal hernia repair.

  1. New composite patches and biologic patches for repair of contaminated abdominal wall defect in dogs: A comparative study%污染环境下新型复合补片和生物补片修补犬腹壁缺损的比较研究

    Institute of Scientific and Technical Information of China (English)

    郑亚杰; 田文; 丁国飞; 姚京; 马冰

    2012-01-01

    Objective To compare the characteristics of two compound patches made of collagen and polypropylene(PP) and the feasibility of their application in repair of contaminated wounds. Methods Twenty-four adult male dogs, weighing 16-20kg, were included in this study. A dog model with 3 contaminated defects at the upper, left and right abdominal wall was established. The 3 abdominal wall defects were repaired by implanting 3 kinds of patches into them. The patches were divided into PP and collagen compound patch group(group A), porcine cross-linked biologic patch group(group B), and cattle cross-linked biologic patch group(group C). A dog abdominal hernia model was established. A segment of small intestine was removed, into which 10ml 0.9% sodium chloride solution was injected and then aspirated to contaminate the abdominal cavity, abdominal wall and patches. The abdominal wall defects were closed with 5cm × 5cm patches. The dogs were killed on day 90 after operation to observe the adhesion of organs in abdominal cavity. The patches and their adjacent tissue were cut into sections for histological study. Results No death occurred while patch and omentum adhesion was observed in different groups 90 days after operation. Histological study showed that the scores of proliferating fibroblasts, inflammatory reaction and formation of new blood vessels were higher in group A than in groups B and C. Conclusion The effect of PP and collagen compound patch and biological patch is similar in preventing adhesion under contaminated environment. However, it leads to severer proliferation of fibroblasts, inflammatory reaction and formation of new blood vessels than biologic patch.%目的 比较胶原蛋白与聚丙烯(polypropylene,PP) 制作的复合补片和两种生物补片的特点及其应用于污染伤口一期修补的可行性.方法 成年雄性普通犬24 只,体质量16-20kg,在同一只动物上、左、右腹部建立三个污染缺损模型,将3 种补

  2. Mitochondrial base excision repair assays

    DEFF Research Database (Denmark)

    Maynard, Scott; de Souza-Pinto, Nadja C; Scheibye-Knudsen, Morten

    2010-01-01

    The main source of mitochondrial DNA (mtDNA) damage is reactive oxygen species (ROS) generated during normal cellular metabolism. The main mtDNA lesions generated by ROS are base modifications, such as the ubiquitous 8-oxoguanine (8-oxoG) lesion; however, base loss and strand breaks may also occur....... Many human diseases are associated with mtDNA mutations and thus maintaining mtDNA integrity is critical. All of these lesions are repaired primarily by the base excision repair (BER) pathway. It is now known that mammalian mitochondria have BER, which, similarly to nuclear BER, is catalyzed by DNA...

  3. Dynamics and mechanism of UV-damaged DNA repair in indole-thymine dimer adduct: molecular origin of low repair quantum efficiency.

    Science.gov (United States)

    Guo, Xunmin; Liu, Zheyun; Song, Qinhua; Wang, Lijuan; Zhong, Dongping

    2015-02-26

    Many biomimetic chemical systems for repair of UV-damaged DNA showed very low repair efficiency, and the molecular origin is still unknown. Here, we report our systematic characterization of the repair dynamics of a model compound of indole-thymine dimer adduct in three solvents with different polarity. By resolving all elementary steps including three electron-transfer processes and two bond-breaking and bond-formation dynamics with femtosecond resolution, we observed the slow electron injection in 580 ps in water, 4 ns in acetonitrile, and 1.38 ns in dioxane, the fast back electron transfer without repair in 120, 150, and 180 ps, and the slow bond splitting in 550 ps, 1.9 ns, and 4.5 ns, respectively. The dimer bond cleavage is clearly accelerated by the solvent polarity. By comparing with the biological repair machine photolyase with a slow back electron transfer (2.4 ns) and a fast bond cleavage (90 ps), the low repair efficiency in the biomimetic system is mainly determined by the fast back electron transfer and slow bond breakage. We also found that the model system exists in a dynamic heterogeneous C-clamped conformation, leading to a stretched dynamic behavior. In water, we even identified another stacked form with ultrafast cyclic electron transfer, significantly reducing the repair efficiency. Thus, the comparison of the repair efficiency in different solvents is complicated and should be cautious, and only the dynamics by resolving all elementary steps can finally determine the total repair efficiency. Finally, we use the Marcus electron-transfer theory to analyze all electron-transfer reactions and rationalize all observed electron-transfer dynamics.

  4. Evaluating the effects of genetic variants of DNA repair genes using cytogenetic mutagen sensitivity approaches.

    Science.gov (United States)

    Abdel-Rahman, Sherif Z; El-Zein, Randa A

    2011-08-01

    Mutagen sensitivity, measured in short-term cultures of peripheral blood lymphocytes by cytogenetic endpoints, is an indirect measure for DNA repair capacity and has been used for many years as a biomarker for intrinsic susceptibility for cancer. In this article, we briefly give an overview of the different cytogenetic mutagen sensitivity approaches that have been used successfully to evaluate the biological effects of polymorphisms in DNA repair genes based on a current review of the literature and based on the need for biomarkers that would allow the characterization of the biological and functional significance of such polymorphisms. We also address some of the future challenges facing this emerging area of research.

  5. Nucleotide excision repair in the test tube.

    NARCIS (Netherlands)

    N.G.J. Jaspers (Nicolaas); J.H.J. Hoeijmakers (Jan)

    1995-01-01

    textabstractThe eukaryotic nucleotide excision-repair pathway has been reconstituted in vitro, an achievement that should hasten the full enzymological characterization of this highly complex DNA-repair pathway.

  6. Abdominal aortic aneurysm repair - open - discharge

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000240.htm Abdominal aortic aneurysm repair - open - discharge To use the sharing features ... References Orandi BJ, Black JH. Open repair of abdominal aortic aneurysms. In: Cameron JL, Cameron AM, eds. Current Surgical ...

  7. Cleft lip and palate repair - discharge

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000004.htm Cleft lip and palate repair - discharge To use the sharing ... Elsevier Saunders; 2015:chap 8. Read More Cleft lip and palate Cleft lip and palate repair Review Date 5/9/ ...

  8. New frontiers in biomaterials research for tissue repair and regeneration

    Institute of Scientific and Technical Information of China (English)

    Huiling Liu; Haoran Liu; Aaron Clasky; Huilin Yang; Lei Yang

    2016-01-01

    The field of biomaterials has recently emerged to augment or replace lost or damaged tissues and organs due to the human body’s limited ability to self-heal large defects. Historically, metallic components, polymers, ceramics, and composite materials were utilized as synthetic materials along with natural materials to assist in therapy. Various novel biomaterials were developed to respond to a significant amount of new medical challenges in the past decade. Therefore, there is a need to review these newly developed biomaterials and their potential to improve tissue repair and regeneration in a variety of applications. Here, we briefly review the different strategies and attempts to use novel biomaterials, including self-assembled and macromolecular biomaterials, hydrogels, metamaterials, decellularized tissues, and biomaterials obtained via synthetic biology, used either for tissue repair and regeneration or for therapeutic use by exploiting other mechanisms of healing. All these methods aim to create functional materials, devices, systems, and/or organisms with novel and useful functions on the basis of catalogued and standardized biological building blocks. This review details the various methods and introduces the applications of these biomaterials in tissue repair and regeneration, especially for bone, nerve, and skin applications.

  9. Microwave Oven Repair. Teacher Edition.

    Science.gov (United States)

    Smreker, Eugene

    This competency-based curriculum guide for teachers addresses the skills a technician will need to service microwave ovens and to provide customer relations to help retain the customer's confidence in the product and trust in the service company that performs the repair. The guide begins with a task analysis, listing 20 cognitive tasks and 5…

  10. How the Brain Repairs Stuttering

    Science.gov (United States)

    Kell, Christian A.; Neumann, Katrin; von Kriegstein, Katharina; Posenenske, Claudia; von Gudenberg, Alexander W.; Euler, Harald; Giraud, Anne-Lise

    2009-01-01

    Stuttering is a neurodevelopmental disorder associated with left inferior frontal structural anomalies. While children often recover, stuttering may also spontaneously disappear much later after years of dysfluency. These rare cases of unassisted recovery in adulthood provide a model of optimal brain repair outside the classical windows of…

  11. Pure robotic retrocaval ureter repair

    Directory of Open Access Journals (Sweden)

    Ashok k. Hemal

    2008-12-01

    Full Text Available PURPOSE: To demonstrate the feasibility of pure robotic retrocaval ureter repair. MATERIALS AND METHODS: A 33 year old female presented with right loin pain and obstruction on intravenous urography with the classical "fish-hook" appearance. She was counseled on the various methods of repair and elected to have a robot assisted repair. The following steps are performed during a pure robotic retrocaval ureter repair. The patient is placed in a modified flank position, pneumoperitoneum created and ports inserted. The colon is mobilized to expose the retroperitoneal structures: inferior vena cava, right gonadal vein, right ureter, and duodenum. The renal pelvis and ureter are mobilized and the renal pelvis transected. The ureter is transposed anterior to the inferior vena cava and a pyelopyelostomy is performed over a JJ stent. RESULTS: This patient was discharged on postoperative day 3. The catheter and drain tube were removed on day 1. Her JJ stent was removed at 6 weeks postoperatively. The postoperative intravenous urography at 3 months confirmed normal drainage of contrast medium. CONCLUSION: Pure robotic retrocaval ureter is a feasible procedure; however, there does not appear to be any great advantage over pure laparoscopy, apart from the ergonomic ease for the surgeon as well the simpler intracorporeal suturing.

  12. Outcome of quadriceps tendon repair.

    Science.gov (United States)

    Puranik, Gururaj S; Faraj, Adnan

    2006-04-01

    Complete rupture of the quadriceps tendon is a well-described injury. There is a scarcity of literature relating to the outcome of patients with this injury after surgery. We undertook a retrospective analysis of patients who had surgical repair of their quadriceps tendon at our institution over a 13-year period, totalling 21 patients. Males were more commonly affected, with a male/female ratio of 4:1. The peak incidence was in the sixth decade of life. Assessment consisted of the completion of a functional knee questionnaire and a clinical examination. Symptomatic outcome following surgical repair was good with a mean symptom score generated of 19.16 out of a maximum of 25 using the Rougraff et al scoring system. Most of the patients returned to their pre-injury level of activity. Five degrees deficit and extension lag was present in three patients; these patients had the quadriceps repaired using transosseous sutures. Patients who had direct repair of the tendon using the Bunnell technique had lower Rougraff scores than the rest.

  13. [Complications of inguinal hernia repair].

    Science.gov (United States)

    Forte, A; D'Urso, A; Gallinaro, L S; Lo Storto, G; Bosco, M R; Vietri, F; Beltrami, V

    2002-03-01

    It's shown by literature and confirmed by Author's experience that, on account of the excellent results, prosthetic repair of inguinal hernia is more effective than "conventional" (Bassini, Mc Vay, Shouldice). Between January 1993 and December 2000 were observed 875 patients with inguinal hernia (814 monolateral, 61 bilateral); all patients underwent a Lichtenstein repair both in the primary version and in its variations (internal ring plastic, trasversalis plicate, plug repair). The patients were discharged from hospital within 24 hours after surgery in 90% of cases. No important intraoperative complications were observed; the patients restarting work varied from 3 to 15 days after the discharging in relation to patient anxiety, onset of complications and to the type of work. The complications observed were: urine retention (1.6%), superficial haematoma (1.3%), superficial infection (1%), wound suppuration (0.5%), serous effusion (0.7%), postsurgery pain (2.1%), scrotal edema (1.7%), persistent inguinal neuralgia (0.6), local hypoesthesia (4.3%), ischemical orchitis (0.1%), recurrence (0.2%). In conclusion Authors assert that "tension free" repair allows optimal results both for the surgery point (easiness of the technique, repeatability, less invasivity, scanty incident of recurrences, low frequency of postoperative complications) and in economic terms, allowing an early mobilization of the patients. A further improvement would be obtained with more care in surgical and patient management, with more excellent results.

  14. Molecular biology study on the effects of ozone and ozone water in repairing the infective wounds%臭氧、臭氧水对感染性创面修复作用的分子生物学研究

    Institute of Scientific and Technical Information of China (English)

    李云恺; 陈丽艳; 王惠; 邱思强

    2014-01-01

    目的:运用分子生物学的方法探讨臭氧水和臭氧对创面愈合的疗效。方法40只Vista大鼠感染性创面造模成功后按换药方式的不同随机分为四组:洗必泰治疗组、臭氧组、臭氧水组、对照组,每组各10只;换药9 d后评价四组大鼠创面的愈合情况并运用ELISA方法测量感染前、感染后2 d以及治疗后第3、6、9天大鼠皮肤肌肉标本中FGFs的含量。结果χ2检验显示四组的有效率差异有统计学意义(t=50.48,P0.05)。结论臭氧和臭氧水均是高效消毒剂,均能够通过提高皮肤肌肉组织中FGFs的含量促使创面的愈合,但臭氧水要优于臭氧。%Objective To explore the effects of ozone and ozone water in repairing the infective wounds by using molecular biology methods. Methods 40 vista rats with infective wounds were randomly divided into 4 groups according to different ways of changing the dressing:chlorhexidine treatment group (n=10), ozone group (n=10), ozone water group (n=10)and the control group (n=10). The reparations of the infective wounds of rats in each group were ob-served and evaluated 9 days after the dressings changing and the FGFs from skin and muscle specimens of all rats in dif-ferent groups were detected before the treatment, 48h after infection and the 3rd, 6th and 9th day of treatment by ELI-SA. Results χ2 test showed the difference of effective rate between each group was significantly important (χ2=50.48, P0.05). Conclusion Ozone and Ozone water were both effective disinfectant, they could contribute to the wound healing by improving the FGFS level in skin and muscle tissue. However, the recovery effect of ozone water was better than that of ozone.

  15. REPAIR MECHANISM IN FOREIGN LANGUAGE CLASSROOM INTERACTION

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    This paper presents practical research on repair mechanismand its four repair trajectories in FL classroom interaction. Thisshows that it is effective and efficient in assisting FL learners todevelop their communicative competence and understand theprocess of language acquisition. Repair strategies that are ofgreat value to FL teachers in FL classroom teaching are also ex-pounded.

  16. Fix-It Careers: Jobs in Repair

    Science.gov (United States)

    Torpey, Elka Maria

    2010-01-01

    From auto mechanic to HVAC technicians, many occupations require repair skills. For jobseekers with the right skills, there are many advantages to a repair career. Repair work provides millions of jobs throughout the United States. Wages are often higher than average. And in many occupations, the employment outlook is bright. Plus, most repair…

  17. 30 CFR 57.6801 - Vehicle repair.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Vehicle repair. 57.6801 Section 57.6801 Mineral... and Underground § 57.6801 Vehicle repair. Vehicles containing explosive material and oxidizers shall not be taken into a repair garage or shop....

  18. Nationwide prevalence of groin hernia repair

    DEFF Research Database (Denmark)

    Burcharth, Jakob; Pedersen, Michael; Bisgaard, Thue;

    2013-01-01

    Groin hernia repair is a commonly performed surgical procedure in the western world but large-scaled epidemiologic data are sparse. Large-scale data on the occurrence of groin hernia repair may provide further understanding to the pathophysiology of groin hernia development. This study was undert...... was undertaken to investigate the age and gender dependent prevalence of groin hernia repair....

  19. REPAIR TECHNOLOGY IMPROVEMENT OF SPECIALIZED FREIGHT CARS

    Directory of Open Access Journals (Sweden)

    V. M. Bubnov

    2016-02-01

    Full Text Available Purpose. The volume of cargo transportation demands the introduction of a new generation of cars that would be able to provide all the needs of carriers. But this is impossible without the implementation of renovation repair facilities with the introduction of new technologies and modernization of the repair process. Repair of rolling stock is a key factor that must proceed with the establishment of new cars, as not all of the inventions may be repaired in car-repair depots, most of which are obsolete. The purpose is to analyze the possibility of increasing the efficiency of the repair process by introducing new repair technologies or improving the existing ones. It will improve not only the quality of the repair, but also its rate. Methodology. Works on improving the designs of freight cars are held by many design organizations in almost all industrialized countries. It makes repair organizations (depots and car-repair plants to upgrade the repair process. Achievements of-this goal is possible by improving the technology renovation and reorganization through the use of flexible flow technologies, which to date are the most effective in the repair of rolling stock. Findings. When performing the analysis it was determined that there are different designs of cars. More of cars are all-purpose and their repair does not cause difficulties for car-repair business. However, the number of specialized cars is also significant, and the technology of their repair should be improved. One of the reasons is that many models, such as tank wagons for the carriage of sulfur, are intended for the carriage of dangerous goods and their failure at the time of motion is not permitted. Originality. Firstly the authors have defined direction at improving technologies of repair specialized cars. Practical value. Actual improvement in the construction of cars is to improve the existing repair facilities. In addition, the repair technology using nowadays when repairing

  20. Inhibition of poly(ADP-ribose)polymerase-1 and DNA repair by uranium

    Science.gov (United States)

    Cooper, Karen L.; Dashner, Erica J.; Tsosie, Ranalda; Cho, Young Mi; Lewis, Johnnye

    2015-01-01

    Uranium has radiological and non-radiological effects within biological systems and there is increasing evidence for genotoxic and carcinogenic properties attributable to uranium through its heavy metal properties. In this study, we report that low concentrations of uranium (as uranyl acetate; <10 μM) is not cytotoxic to human embryonic kidney cells or normal human keratinocytes; however, uranium exacerbates DNA damage and cytotoxicity induced by hydrogen peroxide, suggesting that uranium may inhibit DNA repair processes. Concentrations of uranyl acetate in the low micromolar range inhibited the zinc finger DNA repair protein poly(ADP-ribose) polymerase (PARP)-1 and caused zinc loss from PARP-1 protein. Uranyl acetate exposure also led to zinc loss from the zinc finger DNA repair proteins Xeroderma Pigmentosum, Complementation Group A (XPA) and aprataxin (APTX). In keeping with the observed inhibition of zinc finger function of DNA repair proteins, exposure to uranyl acetate enhanced retention of induced DNA damage. Co-incubation of uranyl acetate with zinc largely overcame the impact of uranium on PARP-1 activity and DNA damage. These findings present evidence that low concentrations of uranium can inhibit DNA repair through disruption of zinc finger domains of specific target DNA repair proteins. This may provide a mechanistic basis to account for the published observations that uranium exposure is associated with DNA repair deficiency in exposed human populations. PMID:26627003

  1. Inhibition of poly(ADP-ribose)polymerase-1 and DNA repair by uranium.

    Science.gov (United States)

    Cooper, Karen L; Dashner, Erica J; Tsosie, Ranalda; Cho, Young Mi; Lewis, Johnnye; Hudson, Laurie G

    2016-01-15

    Uranium has radiological and non-radiological effects within biological systems and there is increasing evidence for genotoxic and carcinogenic properties attributable to uranium through its heavy metal properties. In this study, we report that low concentrations of uranium (as uranyl acetate; uranium exacerbates DNA damage and cytotoxicity induced by hydrogen peroxide, suggesting that uranium may inhibit DNA repair processes. Concentrations of uranyl acetate in the low micromolar range inhibited the zinc finger DNA repair protein poly(ADP-ribose) polymerase (PARP)-1 and caused zinc loss from PARP-1 protein. Uranyl acetate exposure also led to zinc loss from the zinc finger DNA repair proteins Xeroderma Pigmentosum, Complementation Group A (XPA) and aprataxin (APTX). In keeping with the observed inhibition of zinc finger function of DNA repair proteins, exposure to uranyl acetate enhanced retention of induced DNA damage. Co-incubation of uranyl acetate with zinc largely overcame the impact of uranium on PARP-1 activity and DNA damage. These findings present evidence that low concentrations of uranium can inhibit DNA repair through disruption of zinc finger domains of specific target DNA repair proteins. This may provide a mechanistic basis to account for the published observations that uranium exposure is associated with DNA repair deficiency in exposed human populations.

  2. Biological computation

    CERN Document Server

    Lamm, Ehud

    2011-01-01

    Introduction and Biological BackgroundBiological ComputationThe Influence of Biology on Mathematics-Historical ExamplesBiological IntroductionModels and Simulations Cellular Automata Biological BackgroundThe Game of Life General Definition of Cellular Automata One-Dimensional AutomataExamples of Cellular AutomataComparison with a Continuous Mathematical Model Computational UniversalitySelf-Replication Pseudo Code Evolutionary ComputationEvolutionary Biology and Evolutionary ComputationGenetic AlgorithmsExample ApplicationsAnalysis of the Behavior of Genetic AlgorithmsLamarckian Evolution Genet

  3. Metabolism, Genomics, and DNA Repair in the Mouse Aging Liver

    Directory of Open Access Journals (Sweden)

    Michel Lebel

    2011-01-01

    Full Text Available The liver plays a pivotal role in the metabolism of nutrients, drugs, hormones, and metabolic waste products, thereby maintaining body homeostasis. The liver undergoes substantial changes in structure and function within old age. Such changes are associated with significant impairment of many hepatic metabolic and detoxification activities, with implications for systemic aging and age-related disease. It has become clear, using rodent models as biological tools, that genetic instability in the form of gross DNA rearrangements or point mutations accumulate in the liver with age. DNA lesions, such as oxidized bases or persistent breaks, increase with age and correlate well with the presence of senescent hepatocytes. The level of DNA damage and/or mutation can be affected by changes in carcinogen activation, decreased ability to repair DNA, or a combination of these factors. This paper covers some of the DNA repair pathways affecting liver homeostasis with age using rodents as model systems.

  4. High Mobility Group Box Protein-1 in Wound Repair

    Directory of Open Access Journals (Sweden)

    Mauro Patrone

    2012-09-01

    Full Text Available High-mobility group box 1 protein (HMGB1, a member of highly conserved non-histone DNA binding protein family, has been studied as transcription factor and growth factor. Secreted extracellularly by activated monocytes and macrophages or passively released by necrotic or damaged cells, extracellular HMGB1 is a potent mediator of inflammation. Extracellular HMGB1 has apparently contrasting biological actions: it sustains inflammation (with the possible establishment of autoimmunity or of self-maintaining tissue damage, but it also activates and recruits stem cells, boosting tissue repair. Here, we focus on the role of HMGB1 in physiological and pathological responses, the mechanisms by which it contributes to tissue repair and therapeutic strategies base on targeting HMGB1.

  5. 'Hide-then-hit' to explain the importance of genotypic polymorphism of DNA repair genes in determining susceptibility to cancer

    Institute of Scientific and Technical Information of China (English)

    Pei-Ei Wu; Chen-Yang Shen

    2011-01-01

    Interindividual variations in DNA repair capacity/efficiency linked to the presence of polymorphisms in DNA repair-related genes have been suggested to account for different risk of developing cancers. In this review article, on the basis of breast cancer formation as a model, we propose a 'hide-then-hit' hypothesis indicating the importance of escaping checkpoint surveillance for sub-optimal DNA repair variants to cause cancer. Therefore, only cells with subtle defects in repair capacity arising from low-penetrance variants of DNA repair genes would have the opportunity to grow and accumulate the genetic changes needed for cancer formation, without triggering cell-cycle checkpoint surveillance. Furthermore, distinct from high-penetrance alleles, these polymorphic alleles of DNA repair genes would predispose carriers to a higher risk of developing cancer but would not necessarily cause cancer. To examine this,we simultaneously genotyped multiple SNPs of cell-cycle checkpoint genes and the DNA repair genes. Support for the hypothesis came from observations that breast cancer risk associated with variant genotypes of DNA repair genes became more significant in be confirmed by biological evidence in which a cause-effect relationship has to be established. However, based on this, possible gene-gene interaction is considered to play an important role in modifying the cancer risk associated with genotypic polymorphism of DNA repair gene in different study populations.

  6. Histomorphometric and ultrastructural analysis of the tendon-bone interface after rotator cuff repair in a rat model.

    Science.gov (United States)

    Kanazawa, Tomonoshin; Gotoh, Masafumi; Ohta, Keisuke; Honda, Hirokazu; Ohzono, Hiroki; Shimokobe, Hisao; Shiba, Naoto; Nakamura, Kei-Ichiro

    2016-09-20

    Successful rotator cuff repair requires biological anchoring of the repaired tendon to the bone. However, the histological structure of the repaired tendon-bone interface differs from that of a normal tendon insertion. We analysed differences between the normal tendon insertion and the repaired tendon-bone interface after surgery in the mechanical properties, histomorphometric analysis, and 3-dimensional ultrastructure of the cells using a rat rotator cuff repair model. Twenty-four adult Sprague-Dawley (SD) rats underwent complete cuff tear and subsequent repair of the supraspinatus tendon. The repaired tendon-bone interface was evaluated at 4, 8, and 12 weeks after surgery. At each time point, shoulders underwent micro-computed tomography scanning and biomechanical testing (N = 6), conventional histology and histomorphometric analysis (N = 6), and ultrastructural analysis with focused ion beam/scanning electron microscope (FIB/SEM) tomography (N = 4). We demonstrated that the cellular distribution between the repaired tendon and bone at 12 weeks after surgery bore similarities to the normal tendon insertion. However, the ultrastructure of the cells at any time point had a different morphology than those of the normal tendon insertion. These morphological differences affect the healing process, partly contributing to re-tearing at the repair site. These results may facilitate future studies of the regeneration of a normal tendon insertion.

  7. [Studies of the repair of radiation-induced genetic damage in Drosophila]. Annual progress report, February 1, 1993--November 1, 1994

    Energy Technology Data Exchange (ETDEWEB)

    Hawley, R.S.

    1998-09-01

    This research focuses on two repair deficient mutations in Drosophila melanogaster, namely mei-9, mei-41. In addition, the authors propose to extend this study to include the mus-312 mutation. They expect these studies to provide substantial insights into both the molecular mechanisms of DNA repair in Drosophila and the role these genes play in normal biological processes.

  8. Research trends in radiobiology since 40 years. a new approach: the enzymatic repair function of DNA, internal factor in evolution of biological systems under irradiation; Etude des tendances des recherches en radiologie depuis 40 ans. Une nouvelle voie de recherche: la fonction de reparation enzymatique de l'ADN, facteur interne d'evolution des systemes biologiques sous rayonnement

    Energy Technology Data Exchange (ETDEWEB)

    Mouton, R. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1968-07-01

    In the first part of the report, the author attempts to draw an historical scheme of successive research working hypotheses in radiobiology since 1924. Less than a generation ago the effect of radiation exposure were viewed as being direct, immediate, irreparable and unmodifiable. Now it is generally accepted that radiation lesion can also be indirect, delayed, reparable and often modified with appropriate chemical or biochemical treatment. It was however in 1962-1964 that came the decisive breakthrough in radiobiology with the discovery that the cell possesses a natural active self-defense mechanism against whatever stress would affect the integrity of the genetic message contained in the DNA structure itself. The existence of what could be considered as a fourth DNA function i.e. self-repair by enzymatic action under genetic control-brings at least to radiobiology the missing molecular biology basis it needed to get out of its 'phenomenological night' after abandon of the generalization of Lea's theory through lack of experimental evidence. In the second part, which is a prospective one, the author tries to set an enlarged synthesis considering the possible role of DNA repair system not only in cell survival - in presence or absence of dose modifiers or mutagens - but also in the artificial and natural evolution of biological system exposed to sub-lethal doses of radiation. Most recent data from the literature fit well with what must be still considered as a general working hypothesis. Studies dealing with phenotypic and genotypic characters linked with the acquisition of gamma and UV radiation resistance in 'Escherichia coli K12' has been started by the author, in collaboration with O. Tremeau, in order to bring a new experimental contribution in this respect. (author) [French] Dans la premiere partie, l'auteur tente de retracer l'historique des hypotheses successives qui ont jalonne les avances de la radiobiologie depuis 1924

  9. Mapping biological systems to network systems

    CERN Document Server

    Rathore, Heena

    2016-01-01

    The book presents the challenges inherent in the paradigm shift of network systems from static to highly dynamic distributed systems – it proposes solutions that the symbiotic nature of biological systems can provide into altering networking systems to adapt to these changes. The author discuss how biological systems – which have the inherent capabilities of evolving, self-organizing, self-repairing and flourishing with time – are inspiring researchers to take opportunities from the biology domain and map them with the problems faced in network domain. The book revolves around the central idea of bio-inspired systems -- it begins by exploring why biology and computer network research are such a natural match. This is followed by presenting a broad overview of biologically inspired research in network systems -- it is classified by the biological field that inspired each topic and by the area of networking in which that topic lies. Each case elucidates how biological concepts have been most successfully ...

  10. Minimally disruptive schedule repair for MCM missions

    Science.gov (United States)

    Molineaux, Matthew; Auslander, Bryan; Moore, Philip G.; Gupta, Kalyan M.

    2015-05-01

    Mine countermeasures (MCM) missions entail planning and operations in very dynamic and uncertain operating environments, which pose considerable risk to personnel and equipment. Frequent schedule repairs are needed that consider the latest operating conditions to keep mission on target. Presently no decision support tools are available for the challenging task of MCM mission rescheduling. To address this capability gap, we have developed the CARPE system to assist operation planners. CARPE constantly monitors the operational environment for changes and recommends alternative repaired schedules in response. It includes a novel schedule repair algorithm called Case-Based Local Schedule Repair (CLOSR) that automatically repairs broken schedules while satisfying the requirement of minimal operational disruption. It uses a case-based approach to represent repair strategies and apply them to new situations. Evaluation of CLOSR on simulated MCM operations demonstrates the effectiveness of case-based strategy. Schedule repairs are generated rapidly, ensure the elimination of all mines, and achieve required levels of clearance.

  11. Methods of repairing a substrate

    Science.gov (United States)

    Riedell, James A. (Inventor); Easler, Timothy E. (Inventor)

    2011-01-01

    A precursor of a ceramic adhesive suitable for use in a vacuum, thermal, and microgravity environment. The precursor of the ceramic adhesive includes a silicon-based, preceramic polymer and at least one ceramic powder selected from the group consisting of aluminum oxide, aluminum nitride, boron carbide, boron oxide, boron nitride, hafnium boride, hafnium carbide, hafnium oxide, lithium aluminate, molybdenum silicide, niobium carbide, niobium nitride, silicon boride, silicon carbide, silicon oxide, silicon nitride, tin oxide, tantalum boride, tantalum carbide, tantalum oxide, tantalum nitride, titanium boride, titanium carbide, titanium oxide, titanium nitride, yttrium oxide, zirconium boride, zirconium carbide, zirconium oxide, and zirconium silicate. Methods of forming the ceramic adhesive and of repairing a substrate in a vacuum and microgravity environment are also disclosed, as is a substrate repaired with the ceramic adhesive.

  12. Pain after groin hernia repair

    DEFF Research Database (Denmark)

    Callesen, T; Bech, K; Nielsen, R;

    1998-01-01

    BACKGROUND: The purpose of the study was to provide a detailed description of postoperative pain after elective day-case open inguinal hernia repair under local anaesthesia. METHODS: This was a prospective consecutive case series study. After 500 hernia operations in 466 unselected patients aged 18...... between types of surgery or hernia. CONCLUSION: Pain remained a problem despite the pre-emptive use of opioids, non-steroidal anti-inflammatory drugs and local anaesthesia, irrespective of surgical technique....

  13. Shelf Stable Epoxy Repair Adhesive

    Science.gov (United States)

    2015-02-01

    manufacturing operations are more efficient , discarding less expired film. Commercial and military aircraft repair operations at Boeing experience very similar...successfully encapsulated at concentrations greater than 50 wt% within four N N = CC Infoscitex Corporation Shelf Stable Epoxy Resin Adhesive WP-1763 8...affects the composition of the encapsulant , which in turn affects the ability of the encapsulant to wet the core phase, the barrier properties of the

  14. Mechanistic Modelling and Bayesian Inference Elucidates the Variable Dynamics of Double-Strand Break Repair

    Science.gov (United States)

    2016-01-01

    DNA double-strand breaks are lesions that form during metabolism, DNA replication and exposure to mutagens. When a double-strand break occurs one of a number of repair mechanisms is recruited, all of which have differing propensities for mutational events. Despite DNA repair being of crucial importance, the relative contribution of these mechanisms and their regulatory interactions remain to be fully elucidated. Understanding these mutational processes will have a profound impact on our knowledge of genomic instability, with implications across health, disease and evolution. Here we present a new method to model the combined activation of non-homologous end joining, single strand annealing and alternative end joining, following exposure to ionising radiation. We use Bayesian statistics to integrate eight biological data sets of double-strand break repair curves under varying genetic knockouts and confirm that our model is predictive by re-simulating and comparing to additional data. Analysis of the model suggests that there are at least three disjoint modes of repair, which we assign as fast, slow and intermediate. Our results show that when multiple data sets are combined, the rate for intermediate repair is variable amongst genetic knockouts. Further analysis suggests that the ratio between slow and intermediate repair depends on the presence or absence of DNA-PKcs and Ku70, which implies that non-homologous end joining and alternative end joining are not independent. Finally, we consider the proportion of double-strand breaks within each mechanism as a time series and predict activity as a function of repair rate. We outline how our insights can be directly tested using imaging and sequencing techniques and conclude that there is evidence of variable dynamics in alternative repair pathways. Our approach is an important step towards providing a unifying theoretical framework for the dynamics of DNA repair processes. PMID:27741226

  15. Augmented Reality Repair Guidance System

    Directory of Open Access Journals (Sweden)

    Sidharth Bhatia

    2012-07-01

    Full Text Available The daily life of a common man revolves around various forms of appliances/gadgets he uses throughout the day such as a mobile phone, laptop, printer, microwave oven, washing machine, etc. Although these appliances/gadgets are taken by most of the people for granted, the problem occurs when any of these things do not work as they are expected to. Getting them to the repair shops for every small glitch is expensive as well as time consuming. Although most of the companies which produce these appliances/gadgets do supply them with basic manuals, which deal with how to solve these minor issues, but reading them and at the same time repairing the corresponding appliance/gadget can be a frustrating task at times. These problems can be reduced to a large extent if some kind of live guidance is available. In this paper we propose a method to do so with the help of an augmented reality based system that will guide the user to carry out small scale repair jobs on these gadgets. All that is required is a decent webcam and a computing device, with a processor of 1 GHz or more and a display screen.

  16. Matrix metalloproteinases in lung biology

    Directory of Open Access Journals (Sweden)

    Parks William C

    2000-12-01

    Full Text Available Abstract Despite much information on their catalytic properties and gene regulation, we actually know very little of what matrix metalloproteinases (MMPs do in tissues. The catalytic activity of these enzymes has been implicated to function in normal lung biology by participating in branching morphogenesis, homeostasis, and repair, among other events. Overexpression of MMPs, however, has also been blamed for much of the tissue destruction associated with lung inflammation and disease. Beyond their role in the turnover and degradation of extracellular matrix proteins, MMPs also process, activate, and deactivate a variety of soluble factors, and seldom is it readily apparent by presence alone if a specific proteinase in an inflammatory setting is contributing to a reparative or disease process. An important goal of MMP research will be to identify the actual substrates upon which specific enzymes act. This information, in turn, will lead to a clearer understanding of how these extracellular proteinases function in lung development, repair, and disease.

  17. [Biological weapons].

    Science.gov (United States)

    Kerwat, K; Becker, S; Wulf, H; Densow, D

    2010-08-01

    Biological weapons are weapons of mass destruction that use pathogens (bacteria, viruses) or the toxins produced by them to target living organisms or to contaminate non-living substances. In the past, biological warfare has been repeatedly used. Anthrax, plague and smallpox are regarded as the most dangerous biological weapons by various institutions. Nowadays it seems quite unlikely that biological warfare will be employed in any military campaigns. However, the possibility remains that biological weapons may be used in acts of bioterrorism. In addition all diseases caused by biological weapons may also occur naturally or as a result of a laboratory accident. Risk assessment with regard to biological danger often proves to be difficult. In this context, an early identification of a potentially dangerous situation through experts is essential to limit the degree of damage.

  18. Semiconservative replication, genetic repair, and many-gened genomes: Extending the quasispecies paradigm to living systems

    Science.gov (United States)

    Tannenbaum, Emmanuel; Shakhnovich, Eugene I.

    2005-12-01

    Quasispecies theory has emerged as an important tool for modeling the evolutionary dynamics of biological systems. We review recent advances in the field, with an emphasis on the quasispecies dynamics of semiconservatively replicating genomes. Applications to cancer and adult stem cell growth are discussed. Additional topics, such as genetic repair and many-gene genomes, are covered as well.

  19. Bond strength of repaired amalgam restorations.

    Science.gov (United States)

    Rey, Rosalia; Mondragon, Eduardo; Shen, Chiayi

    2015-01-01

    This in vitro study investigated the interfacial flexural strength (FS) of amalgam repairs and the optimal combination of repair materials and mechanical retention required for a consistent and durable repair bond. Amalgam bricks were created, each with 1 end roughened to expose a fresh surface before repair. Four groups followed separate repair protocols: group 1, bonding agent with amalgam; group 2, bonding agent with composite resin; group 3, mechanical retention (slot) with amalgam; and group 4, slot with bonding agent and amalgam. Repaired specimens were stored in artificial saliva for 1, 10, 30, 120, or 360 days before being loaded to failure in a 3-point bending test. Statistical analysis showed significant changes in median FS over time in groups 2 and 4. The effect of the repair method on the FS values after each storage period was significant for most groups except the 30-day storage groups. Amalgam-amalgam repair with adequate condensation yielded the most consistent and durable bond. An amalgam bonding agent could be beneficial when firm condensation on the repair surface cannot be achieved or when tooth structure is involved. Composite resin can be a viable option for amalgam repair in an esthetically demanding region, but proper mechanical modification of the amalgam surface and selection of the proper bonding system are essential.

  20. Treatment and Controversies in Paraesophageal Hernia Repair

    Directory of Open Access Journals (Sweden)

    P. Marco eFisichella

    2015-04-01

    Full Text Available Background: Historically all paraesophageal hernias were repaired surgically, today intervention is reserved for symptomatic paraesophageal hernias. In this review, we describe the indications for repair and explore the controversies in paraesophageal hernia repair, which include a comparison of open to laparoscopic paraesophageal hernia repair, the necessity of complete sac excision, the routine performance of fundoplication, and the use of mesh for hernia repair.Methods: We searched Pubmed for papers published between 1980 and 2015 using the following keywords: hiatal hernias, paraesophageal hernias, regurgitation, dysphagia, gastroesophageal reflux disease, aspiration, GERD, endoscopy, manometry, pH monitoring, proton pump inhibitors, anemia, iron deficiency anemia, Nissen fundoplication, sac excision, mesh, mesh repair. Results: Indications for paraesophageal hernia repair have changed, and currently symptomatic paraesophageal hernias are recommended for repair. In addition, it is important not to overlook iron-deficiency anemia and pulmonary complaints, which tend to improve with repair. Current practice favors a laparoscopic approach, complete sac excision, primary crural repair with or without use of mesh, and a routine fundoplication.

  1. Experimental articular cartilage repair in the Göttingen minipig

    DEFF Research Database (Denmark)

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

    2015-01-01

    BACKGROUND: A gold standard treatment for articular cartilage injuries is yet to be found, and a cost-effective and predictable large animal model is needed to bridge the gap between in vitro studies and clinical studies. Ideally, the animal model should allow for testing of clinically relevant...... treatments and the biological response should be reproducible and comparable to humans. This allows for a reliable translation of results to clinical studies.This study aimed at verifying the Göttingen minipig as a pre-clinical model for articular cartilage repair by testing existing clinical cartilage...

  2. Quantifying electron transfer reactions in biological systems

    DEFF Research Database (Denmark)

    Sjulstok, Emil Sjulstok; Olsen, Jógvan Magnus Haugaard; Solov'yov, Ilia A

    2015-01-01

    Various biological processes involve the conversion of energy into forms that are usable for chemical transformations and are quantum mechanical in nature. Such processes involve light absorption, excited electronic states formation, excitation energy transfer, electrons and protons tunnelling...... which for example occur in photosynthesis, cellular respiration, DNA repair, and possibly magnetic field sensing. Quantum biology uses computation to model biological interactions in light of quantum mechanical effects and has primarily developed over the past decade as a result of convergence between...... quantum physics and biology. In this paper we consider electron transfer in biological processes, from a theoretical view-point; namely in terms of quantum mechanical and semi-classical models. We systematically characterize the interactions between the moving electron and its biological environment...

  3. Targeting human oligodendrocyte progenitors for myelin repair.

    Science.gov (United States)

    Dietz, Karen C; Polanco, Jessie J; Pol, Suyog U; Sim, Fraser J

    2016-09-01

    Oligodendrocyte development has been studied for several decades, and has served as a model system for both neurodevelopmental and stem/progenitor cell biology. Until recently, the vast majority of studies have been conducted in lower species, especially those focused on rodent development and remyelination. In humans, the process of myelination requires the generation of vastly more myelinating glia, occurring over a period of years rather than weeks. Furthermore, as evidenced by the presence of chronic demyelination in a variety of human neurologic diseases, it appears likely that the mechanisms that regulate development and become dysfunctional in disease may be, in key ways, divergent across species. Improvements in isolation techniques, applied to primary human neural and oligodendrocyte progenitors from both fetal and adult brain, as well as advancements in the derivation of defined progenitors from human pluripotent stem cells, have begun to reveal the extent of both species-conserved signaling pathways and potential key differences at cellular and molecular levels. In this article, we will review the commonalities and differences in myelin development between rodents and man, describing the approaches used to study human oligodendrocyte differentiation and myelination, as well as heterogeneity within targetable progenitor pools, and discuss the advances made in determining which conserved pathways may be both modeled in rodents and translate into viable therapeutic strategies to promote myelin repair.

  4. 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.

  5. Surgical management of the failed SLAP repair.

    Science.gov (United States)

    Weber, Stephen C

    2010-09-01

    Repair of superior labral tears anterior to posterior (SLAP) lesions has become an increasingly common procedure, despite the low incidence rates reported in the literature. As the incidence of these procedures increases, the surgeons will be increasingly confronted with patients with painful shoulders after SLAP repair. Persistent pain after SLAP repair is multifactorial; careful preoperative workup is necessary to elucidate the cause of pain. Simple failure of the prior SLAP repair will rarely be the cause of persistent pain. Use of tacks is especially worrisome, and suture anchor repair is preferable. Articular cartilage injuries because of either bioabsorbable or metal hardware will often create significant residual disability. Recent literature suggests that older patients may be better served by primary biceps tenodesis rather than SLAP repair.

  6. DNA double strand break repair, aging and the chromatin connection.

    Science.gov (United States)

    Gorbunova, Vera; Seluanov, Andrei

    2016-06-01

    Are DNA damage and mutations possible causes or consequences of aging? This question has been hotly debated by biogerontologists for decades. The importance of DNA damage as a possible driver of the aging process went from being widely recognized to then forgotten, and is now slowly making a comeback. DNA double strand breaks (DSBs) are particularly relevant to aging because of their toxicity, increased frequency with age and the association of defects in their repair with premature aging. Recent studies expand the potential impact of DNA damage and mutations on aging by linking DNA DSB repair and age-related chromatin changes. There is overwhelming evidence that increased DNA damage and mutations accelerate aging. However, an ultimate proof of causality would be to show that enhanced genome and epigenome stability delays aging. This is not an easy task, as improving such complex biological processes is infinitely more difficult than disabling it. We will discuss the possibility that animal models with enhanced DNA repair and epigenome maintenance will be generated in the near future.

  7. Cytogenetic Response to Ionizing Radiation Exposure in Human Fibroblasts with Suppressed Expression of Non-DSB Repair Genes

    Science.gov (United States)

    Zhang, Ye; Rohde, Larry H.; Emami, Kamal; Hammond, Dianne; Mehta, Satish K.; Jeevarajan, Antony S.; Pierson, Duane L.; Wu, Honglu

    2009-01-01

    Changes of gene expression profile are one of the most important biological responses in living cells after ionizing radiation (IR) exposure. Although some studies have shown that genes up-regulated by IR may play important roles in DNA damage repair, the relationship between the regulation of gene expression by IR, particularly genes not known for their roles in double-strand break (DSB) repair, and its impact on cytogenetic responses has not been well studied. The purpose of this study is to identify new roles of IR inducible genes in radiation-induced chromosome aberrations and micronuclei formation. In the study, the expression of 25 genes selected on the basis of their transcriptional changes in response to IR was individually knocked down by small interfering RNA in human fibroblast cells. Frequencies of micronuclei (MN) formation and chromosome aberrations were measured to determine the efficiency of cytogenetic repair, and the fraction of bi-nucleated cells in the MN analysis was used as a marker for cell cycle progression. In response to gamma radiation, the formation of MN was significantly increased by suppressed expression of five genes: Ku70 (DSB repair pathway), XPA (nucleotide excision repair pathway), RPA1 (mismatch repair pathway), RAD17 and RBBP8 (cell cycle control). Knocked-down expression of four genes (MRE11A, RAD51 in the DSB pathway, SESN1, and SUMO1) significantly inhibited cell cycle progression, possibly because of severe impairment of DNA damage repair. Moreover, decreased XPA, p21, or MLH1 expression resulted in both significantly enhanced cell cycle progression and increased yields of chromosome aberrations, indicating that these gene products modulate both cell cycle control and DNA damage repair. Nine of these eleven genes, whose knock-down expression affected cytogenetic repair, were up-regulated in cells exposed to gamma radiation, suggesting that genes transcriptionally modulated by IR were critical to regulate IR

  8. Research on Hot Gunning Repairing in Laboratory

    Institute of Scientific and Technical Information of China (English)

    CAO Feng; LONG Shigang; MENG Qingmin; SUN Jialin; HONG Yanruo

    2003-01-01

    The lining of blast furnace may be damaged partly,so that gunning repair is needed. The bonding strength of boundary surface between the repairing layer and remained lining of blast furnace has been studied by thermal simulation.The factors influencing the bonding strength are the ingredient gunning repair temperature,remained lining condition and water content of gunning refractory.The bonding strength decreases with the increases of remained lining temperature.

  9. Role of ubiquitination in meiotic recombination repair

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Programmed and unprogrammed double-strand breaks (DSBs) often arise from such physiological requirements as meiotic recombination, and exogenous insults, such as ionizing radiation (IR). Due to deleterious impacts on genome stability, DSBs must be appropriately processed and repaired in a regulatory manner. Recent investigations have indicated that ubiquitination is a critical factor in DNA damage response and meiotic recombination repair. This review summarizes the effects of proteins and complexes associated with ubiquitination with regard to homologous recombination (HR)-dependent DSB repair.

  10. Adipose, Bone Marrow and Synovial Joint-Derived Mesenchymal Stem Cells for Cartilage Repair

    Science.gov (United States)

    Fellows, Christopher R.; Matta, Csaba; Zakany, Roza; Khan, Ilyas M.; Mobasheri, Ali

    2016-01-01

    Current cell-based repair strategies have proven unsuccessful for treating cartilage defects and osteoarthritic lesions, consequently advances in innovative therapeutics are required and mesenchymal stem cell-based (MSC) therapies are an expanding area of investigation. MSCs are capable of differentiating into multiple cell lineages and exerting paracrine effects. Due to their easy isolation, expansion, and low immunogenicity, MSCs are an attractive option for regenerative medicine for joint repair. Recent studies have identified several MSC tissue reservoirs including in adipose tissue, bone marrow, cartilage, periosteum, and muscle. MSCs isolated from these discrete tissue niches exhibit distinct biological activities, and have enhanced regenerative potentials for different tissue types. Each MSC type has advantages and disadvantages for cartilage repair and their use in a clinical setting is a balance between expediency and effectiveness. In this review we explore the challenges associated with cartilage repair and regeneration using MSC-based cell therapies and provide an overview of phenotype, biological activities, and functional properties for each MSC population. This paper also specifically explores the therapeutic potential of each type of MSC, particularly focusing on which cells are capable of producing stratified hyaline-like articular cartilage regeneration. Finally we highlight areas for future investigation. Given that patients present with a variety of problems it is unlikely that cartilage regeneration will be a simple “one size fits all,” but more likely an array of solutions that need to be applied systematically to achieve regeneration of a biomechanically competent repair tissue. PMID:28066501

  11. Laparoscopic repair for vesicouterine fistulae

    Directory of Open Access Journals (Sweden)

    Rafael A. Maioli

    2015-10-01

    Full Text Available ABSTRACT Objective: The purpose of this video is to present the laparoscopic repair of a VUF in a 42-year-old woman, with gross hematuria, in the immediate postoperative phase following a cesarean delivery. The obstetric team implemented conservative management, including Foley catheter insertion, for 2 weeks. She subsequently developed intermittent hematuria and cystitis. The urology team was consulted 15 days after cesarean delivery. Cystoscopy indicated an ulcerated lesion in the bladder dome of approximately 1.0cm in size. Hysterosalpingography and a pelvic computed tomography scan indicated a fistula. Materials and Methods: Laparoscopic repair was performed 30 days after the cesarean delivery. The patient was placed in the lithotomy position while also in an extreme Trendelenburg position. Pneumoperitoneum was established using a Veress needle in the midline infra-umbilical region, and a primary 11-mm port was inserted. Another 11-mm port was inserted exactly between the left superior iliac spine and the umbilicus. Two other 5-mm ports were established under laparoscopic guidance in the iliac fossa on both sides. The omental adhesions in the pelvis were carefully released and the peritoneum between the bladder and uterus was incised via cautery. Limited cystotomy was performed, and the specific sites of the fistula and the ureteral meatus were identified; thereafter, the posterior bladder wall was adequately mobilized away from the uterus. The uterine rent was then closed using single 3/0Vicryl sutures and two-layer watertight closure of the urinary bladder was achieved by using 3/0Vicryl sutures. An omental flap was mobilized and inserted between the uterus and the urinary bladder, and was fixed using two 3/0Vicryl sutures, followed by tube drain insertion. Results: The operative time was 140 min, whereas the blood loss was 100ml. The patient was discharged 3 days after surgery, and the catheter was removed 12 days after surgery

  12. Changes in DNA repair during aging

    Science.gov (United States)

    Gorbunova, Vera; Seluanov, Andrei; Mao, Zhiyong; Hine, Christpher

    2007-01-01

    DNA is a precious molecule. It encodes vital information about cellular content and function. There are only two copies of each chromosome in the cell, and once the sequence is lost no replacement is possible. The irreplaceable nature of the DNA sets it apart from other cellular molecules, and makes it a critical target for age-related deterioration. To prevent DNA damage cells have evolved elaborate DNA repair machinery. Paradoxically, DNA repair can itself be subject to age-related changes and deterioration. In this review we will discuss the changes in efficiency of mismatch repair (MMR), base excision repair (BER), nucleotide excision repair (NER) and double-strand break (DSB) repair systems during aging, and potential changes in DSB repair pathway usage that occur with age. Mutations in DNA repair genes and premature aging phenotypes they cause have been reviewed extensively elsewhere, therefore the focus of this review is on the comparison of DNA repair mechanisms in young versus old. PMID:17913742

  13. ONSTEP versus laparoscopy for inguinal hernia repair

    DEFF Research Database (Denmark)

    Andresen, Kristoffer; Burcharth, Jakob; Rosenberg, Jacob

    2015-01-01

    INTRODUCTION: The optimal repair of inguinal hernias remains controversial. It is recommended that an inguinal hernia be repaired using a mesh, either with a laparoscopic or an open approach. In Denmark, the laparoscopic approach is used in an increasing number of cases. The laparoscopic repair has...... clinical trial described in this protocol is to evaluate chronic pain after inguinal hernia repair using the ONSTEP method versus the laparoscopic approach. METHODS: This study is designed as a non-inferiority, two-arm, multicentre, randomised clinical trial, with a 1:1 allocation to ONSTEP or laparoscopic...

  14. 33 CFR 127.405 - Repairs.

    Science.gov (United States)

    2010-07-01

    ... FACILITIES WATERFRONT FACILITIES HANDLING LIQUEFIED NATURAL GAS AND LIQUEFIED HAZARDOUS GAS Waterfront Facilities Handling Liquefied Natural Gas Maintenance § 127.405 Repairs. The operator shall ensure that—...

  15. Concrete structures protection, repair and rehabilitation

    CERN Document Server

    Woodson, R Dodge

    2009-01-01

    The success of a repair or rehabilitation project depends on the specific plans designed for it. Concrete Structures: Protection, Repair and Rehabilitation provides guidance on evaluating the condition of the concrete in a structure, relating the condition of the concrete to the underlying cause or causes of that condition, selecting an appropriate repair material and method for any deficiency found, and using the selected materials and methods to repair or rehabilitate the structure. Guidance is also provided for engineers focused on maintaining concrete and preparing concrete investigation r

  16. Integrated Electrical Wire Insulation Repair System

    Science.gov (United States)

    Williams, Martha; Jolley, Scott; Gibson, Tracy; Parks, Steven

    2013-01-01

    An integrated system tool will allow a technician to easily and quickly repair damaged high-performance electrical wire insulation in the field. Low-melt polyimides have been developed that can be processed into thin films that work well in the repair of damaged polyimide or fluoropolymer insulated electrical wiring. Such thin films can be used in wire insulation repairs by affixing a film of this low-melt polyimide to the damaged wire, and heating the film to effect melting, flow, and cure of the film. The resulting repair is robust, lightweight, and small in volume. The heating of this repair film is accomplished with the use of a common electrical soldering tool that has been modified with a special head or tip that can accommodate the size of wire being repaired. This repair method can furthermore be simplified for the repair technician by providing replaceable or disposable soldering tool heads that have repair film already "loaded" and ready for use. The soldering tool heating device can also be equipped with a battery power supply that will allow its use in areas where plug-in current is not available

  17. Extensor tendon repair an overview

    Directory of Open Access Journals (Sweden)

    Mansoor Bin Fayed

    2015-04-01

    Full Text Available The incidence of extensor injuries is more than that of flexor tendon injuries. This is to a great extent because of the extensors being superficially placed and covered by skin and subcutaneous tissue over the distal part of the upper extremity. Thus they are more vulnerable to blunt and sharp trauma, the proximal and distal forearm present with laceration and cut with sharp weapon. Extensor tendon injuries are often taken lightly by many, repairs being taken-up at the ER. Repair is done in or if the retrieval of tendon ends is difficult or the wound is complicated with associated injuries such as fractures or in cases of tendon retraction. Delayed primary repair can be undertaken from 7-10 days. Assessment of the injured finger has to be very meticulous. Extension of finger is brought about by the interossei and lumbricals which are the short muscles of the hand. They extend the proximal interphalangeal joints and distal interphalangeal joints and flex metacarpophalangeal joint, these intrinsic muscles are innervated by the ulnar and median nerves. The long extensors are innervated by the radial nerve, they primarily extend the metacarpophalangeal joints and also interphalangeal joints. In cases of injury the intrinsic system may compensate for an extensor deficit. Closed injuries of zone I may be managed by splinting of the distal interphalangeal joints and open injuries in the zone I and II can be treated with tenodermodesis. Proximal interphalangeal joints and distal interphalangeal joints are immobilized in zone 3 and 4. Metacarpophalangeal joint is immobilized in full extension and the wrist in 10o extension.

  18. 21 CFR 870.1350 - Catheter balloon repair kit.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Catheter balloon repair kit. 870.1350 Section 870... repair kit. (a) Identification. A catheter balloon repair kit is a device used to repair or replace the... effect the repair or replacement. (b) Classification. Class III (premarket approval). (c) Date PMA...

  19. 40 CFR 60.482-9 - Standards: Delay of repair.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standards: Delay of repair. 60.482-9... Standards: Delay of repair. (a) Delay of repair of equipment for which leaks have been detected will be allowed if repair within 15 days is technically infeasible without a process unit shutdown. Repair of...

  20. 14 CFR 145.207 - Repair station manual.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Repair station manual. 145.207 Section 145...) SCHOOLS AND OTHER CERTIFICATED AGENCIES REPAIR STATIONS Operating Rules § 145.207 Repair station manual. (a) A certificated repair station must prepare and follow a repair station manual acceptable to...

  1. Estimating the effect of human base excision repair protein variants on the repair of oxidative DNA base damage.

    Science.gov (United States)

    Sokhansanj, Bahrad A; Wilson, David M

    2006-05-01

    Epidemiologic studies have revealed a complex association between human genetic variance and cancer risk. Quantitative biological modeling based on experimental data can play a critical role in interpreting the effect of genetic variation on biochemical pathways relevant to cancer development and progression. Defects in human DNA base excision repair (BER) proteins can reduce cellular tolerance to oxidative DNA base damage caused by endogenous and exogenous sources, such as exposure to toxins and ionizing radiation. If not repaired, DNA base damage leads to cell dysfunction and mutagenesis, consequently leading to cancer, disease, and aging. Population screens have identified numerous single-nucleotide polymorphism variants in many BER proteins and some have been purified and found to exhibit mild kinetic defects. Epidemiologic studies have led to conflicting conclusions on the association between single-nucleotide polymorphism variants in BER proteins and cancer risk. Using experimental data for cellular concentration and the kinetics of normal and variant BER proteins, we apply a previously developed and tested human BER pathway model to (i) estimate the effect of mild variants on BER of abasic sites and 8-oxoguanine, a prominent oxidative DNA base modification, (ii) identify ranges of variation associated with substantial BER capacity loss, and (iii) reveal nonintuitive consequences of multiple simultaneous variants. Our findings support previous work suggesting that mild BER variants have a minimal effect on pathway capacity whereas more severe defects and simultaneous variation in several BER proteins can lead to inefficient repair and potentially deleterious consequences of cellular damage.

  2. Is synthetic biology mechanical biology?

    Science.gov (United States)

    Holm, Sune

    2015-12-01

    A widespread and influential characterization of synthetic biology emphasizes that synthetic biology is the application of engineering principles to living systems. Furthermore, there is a strong tendency to express the engineering approach to organisms in terms of what seems to be an ontological claim: organisms are machines. In the paper I investigate the ontological and heuristic significance of the machine analogy in synthetic biology. I argue that the use of the machine analogy and the aim of producing rationally designed organisms does not necessarily imply a commitment to mechanical biology. The ideal of applying engineering principles to biology is best understood as expressing recognition of the machine-unlikeness of natural organisms and the limits of human cognition. The paper suggests an interpretation of the identification of organisms with machines in synthetic biology according to which it expresses a strategy for representing, understanding, and constructing living systems that are more machine-like than natural organisms.

  3. CrowdAidRepair: A Crowd-Aided Interactive Data Repairing Method

    KAUST Repository

    Zhou, Jian

    2016-03-25

    Data repairing aims at discovering and correcting erroneous data in databases. Traditional methods relying on predefined quality rules to detect the conflict between data may fail to choose the right way to fix the detected conflict. Recent efforts turn to use the power of crowd in data repairing, but the crowd power has its own drawbacks such as high human intervention cost and inevitable low efficiency. In this paper, we propose a crowd-aided interactive data repairing method which takes the advantages of both rule-based method and crowd-based method. Particularly, we investigate the interaction between crowd-based repairing and rule-based repairing, and show that by doing crowd-based repairing to a small portion of values, we can greatly improve the repairing quality of the rule-based repairing method. Although we prove that the optimal interaction scheme using the least number of values for crowd-based repairing to maximize the imputation recall is not feasible to be achieved, still, our proposed solution identifies an efficient scheme through investigating the inconsistencies and the dependencies between values in the repairing process. Our empirical study on three data collections demonstrates the high repairing quality of CrowdAidRepair, as well as the efficiency of the generated interaction scheme over baselines.

  4. Initiating Repair and Beyond: The Use of Two Repeat-Formatted Repair Initiations in Mandarin Conversation

    Science.gov (United States)

    Wu, Ruey-Jiuan Regina

    2006-01-01

    As part of a growing effort to understand the organization of repair across languages, this study examines 2 repeat-formatted other-initiated repair practices in Mandarin conversation. Using the methodology of conversation analysis as a central framework, this study shows that the 2 Mandarin repair initiations under examination, like…

  5. X-ray repair cross complementing protein 1 in base excision repair

    DEFF Research Database (Denmark)

    Hanssen-Bauer, Audun; Solvang-Garten, Karin; Akbari, Mansour;

    2012-01-01

    X-ray Repair Cross Complementing protein 1 (XRCC1) acts as a scaffolding protein in the converging base excision repair (BER) and single strand break repair (SSBR) pathways. XRCC1 also interacts with itself and rapidly accumulates at sites of DNA damage. XRCC1 can thus mediate the assembly of large...

  6. Simulated microgravity influenced the expression of DNA damage repair genes

    Science.gov (United States)

    Zhang, Meng; Sun, Yeqing; Jiawei, Liu; Wang, Ting

    2016-07-01

    Ionizing radiation and microgravity were considered to be the most important stress factors of space environmental the respective study of the biological effects of the radiation and microgravity carried out earlier, but the interaction of the effects of radiation with microgravity started later, and due to difference of the materials and methods the result of this experiment were not consistent. To further investigate the influence of microgravity on the expression of the radiation damage repair genes, the seed of Arabidopsis (Col) and its gravity-insensitive mutant (PIN2) were exposed to 0.1Gy of the dose of energetic carbon-ion beam radiation (LET = 30KeV / μm), and the germinated seed were than fixed in the 3D random positioning apparatus immediately for a 10-day simulated microgravity. By measuring the deflection angle of root tip and the changes of the expression of Ku70 and RAD51 protein, we investigated the impact of microgravity effect on radiation damage repair systems. The results shown that radiation, microgravity and microgravity with radiation could increase the angle of the root of the Col significantly, but no obvious effect on PIN2 type. The radiation could increase the expression of Ku70 significantly in both Col and PIN2, microgravity does not affect the expression, but the microgravity with radiation could decrease the expression of Ku70. This result shown that the microgravity could influence the radiation damage repair systems in molecular level. Moreover, our findings were important to understand the molecular mechanism of the impact of microgravity effect on radiation damage repair systems in vivo.

  7. Computational biology

    DEFF Research Database (Denmark)

    Hartmann, Lars Røeboe; Jones, Neil; Simonsen, Jakob Grue

    2011-01-01

    Computation via biological devices has been the subject of close scrutiny since von Neumann’s early work some 60 years ago. In spite of the many relevant works in this field, the notion of programming biological devices seems to be, at best, ill-defined. While many devices are claimed or proved t...

  8. Nationwide prevalence of groin hernia repair.

    Directory of Open Access Journals (Sweden)

    Jakob Burcharth

    Full Text Available INTRODUCTION: Groin hernia repair is a commonly performed surgical procedure in the western world but large-scaled epidemiologic data are sparse. Large-scale data on the occurrence of groin hernia repair may provide further understanding to the pathophysiology of groin hernia development. This study was undertaken to investigate the age and gender dependent prevalence of groin hernia repair. METHODS: In a nationwide register-based study, using data from the Civil Registration System covering all Danish citizens, we established a population-based cohort of all people living in Denmark on December 31(st, 2010. Within this population all groin hernia repairs during the past 5 years were identified using data from the ICD 10(th edition in the Danish National Hospital Register. RESULTS: The study population covered n = 5,639,885 persons. During the five years study period 46,717 groin hernia repairs were performed (88.6% males, 11.4% females. Inguinal hernias comprised 97% of groin hernia repairs (90.2% males, 9.8% females and femoral hernias 3% of groin hernia repairs (29.8% males, 70.2% females. Patients between 0-5 years and 75-80 years constituted the two dominant groups for inguinal hernia repair. In contrast, the age-specific prevalence of femoral hernia repair increased steadily throughout life peaking at age 80-90 years in both men and women. CONCLUSION: The age distribution of inguinal hernia repair is bimodal peaking at early childhood and old age, whereas the prevalence of femoral hernia repair increased steadily throughout life. This information can be used to formulate new hypotheses regarding disease etiology with regard to age and gender specifications.

  9. Repair of overheating linear accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Barkley, Walter; Baldwin, William; Bennett, Gloria; Bitteker, Leo; Borden, Michael; Casados, Jeff; Fitzgerald, Daniel; Gorman, Fred; Johnson, Kenneth; Kurennoy, Sergey; Martinez, Alberto; O’Hara, James; Perez, Edward; Roller, Brandon; Rybarcyk, Lawrence; Stark, Peter; Stockton, Jerry

    2004-01-01

    Los Alamos Neutron Science Center (LANSCE) is a proton accelerator that produces high energy particle beams for experiments. These beams include neutrons and protons for diverse uses including radiography, isotope production, small feature study, lattice vibrations and material science. The Drift Tube Linear Accelerator (DTL) is the first portion of a half mile long linear section of accelerator that raises the beam energy from 750 keV to 100 MeV. In its 31st year of operation (2003), the DTL experienced serious issues. The first problem was the inability to maintain resonant frequency at full power. The second problem was increased occurrences of over-temperature failure of cooling hoses. These shortcomings led to an investigation during the 2003 yearly preventative maintenance shutdown that showed evidence of excessive heating: discolored interior tank walls and coper oxide deposition in the cooling circuits. Since overheating was suspected to be caused by compromised heat transfer, improving that was the focus of the repair effort. Investigations revealed copper oxide flow inhibition and iron oxide scale build up. Acid cleaning was implemented with careful attention to protection of the base metal, selection of components to clean and minimization of exposure times. The effort has been very successful in bringing the accelerator through a complete eight month run cycle allowing an incredible array of scientific experiments to be completed this year (2003-2004). This paper will describe the systems, investigation analysis, repair, return to production and conclusion.

  10. DNA Ligase III is critical for mtDNA integrity but not Xrcc1-mediated nuclear DNA repair

    Science.gov (United States)

    Gao, Yankun; Katyal, Sachin; Lee, Youngsoo; Zhao, Jingfeng; Rehg, Jerold E.; Russell, Helen R.; McKinnon, Peter J.

    2011-01-01

    DNA replication and repair in mammalian cells involves three distinct DNA ligases; ligase I (Lig1), ligase III (Lig3) and ligase IV (Lig4)1. Lig3 is considered a key ligase during base excision repair because its stability depends upon its nuclear binding partner Xrcc1, a critical factor for this DNA repair pathway2,3. Lig3 is also present in the mitochondria where its role in mitochondrial DNA (mtDNA) maintenance is independent of Xrcc14. However, the biological role of Lig3 is unclear as inactivation of murine Lig3 results in early embryonic lethality5. Here we report that Lig3 is essential for mtDNA integrity but dispensable for nuclear DNA repair. Inactivation of Lig3 in the mouse nervous system resulted in mtDNA loss leading to profound mitochondrial dysfunction, disruption of cellular homeostasis and incapacitating ataxia. Similarly, inactivation of Lig3 in cardiac muscle resulted in mitochondrial dysfunction and defective heart pump function leading to heart failure. However, Lig3 inactivation did not result in nuclear DNA repair deficiency, indicating essential DNA repair functions of Xrcc1 can occur in the absence of Lig3. Instead, we found that Lig1 was critical for DNA repair, but in a cooperative manner with Lig3. Additionally, Lig3 deficiency did not recapitulate the hallmark features of neural Xrcc1 inactivation such as DNA damage-induced cerebellar interneuron loss6, further underscoring functional separation of these DNA repair factors. Therefore, our data reveal that the critical biological role of Lig3 is to maintain mtDNA integrity and not Xrcc1-dependent DNA repair. PMID:21390131

  11. International congress on DNA damage and repair: Book of abstracts

    Energy Technology Data Exchange (ETDEWEB)

    1987-01-01

    This document contains the abstracts of 105 papers presented at the Congress. Topics covered include the Escherichia coli nucleotide excision repair system, DNA repair in malignant transformations, defective DNA repair, and gene regulation. (TEM)

  12. Improvement of adhesion performance of mortar-repair interface with inducing crack path into repair

    Directory of Open Access Journals (Sweden)

    A. Satoh

    2015-10-01

    Full Text Available The most important performance for repair materials is adhesion to the substrate. The authors experimentally find out that high modulus fine aggregates in repair material enhance strength of it as well as the strength of the interface repaired with it, compared to the ordinary repair without fine aggregates. This paper elaborates the mechanisms for that with fractographic observation and FEM analysis based on the results of experiment. Also the authors discuss the ways for enhancing the strength and ductility of the repaired mortar

  13. Biological Oceanography

    Science.gov (United States)

    Dyhrman, Sonya

    2004-10-01

    The ocean is arguably the largest habitat on the planet, and it houses an astounding array of life, from microbes to whales. As a testament to this diversity and its importance, the discipline of biological oceanography spans studies of all levels of biological organization, from that of single genes, to organisms, to their population dynamics. Biological oceanography also includes studies on how organisms interact with, and contribute to, essential global processes. Students of biological oceanography are often as comfortable looking at satellite images as they are electron micrographs. This diversity of perspective begins the textbook Biological Oceanography, with cover graphics including a Coastal Zone Color Scanner image representing chlorophyll concentration, an electron micrograph of a dinoflagellate, and a photograph of a copepod. These images instantly capture the reader's attention and illustrate some of the different scales on which budding oceanographers are required to think. Having taught a core graduate course in biological oceanography for many years, Charlie Miller has used his lecture notes as the genesis for this book. The text covers the subject of biological oceanography in a manner that is targeted to introductory graduate students, but it would also be appropriate for advanced undergraduates.

  14. Quantum Biology

    Directory of Open Access Journals (Sweden)

    Alessandro Sergi

    2009-06-01

    Full Text Available A critical assessment of the recent developmentsof molecular biology is presented.The thesis that they do not lead to a conceptualunderstanding of life and biological systems is defended.Maturana and Varela's concept of autopoiesis is briefly sketchedand its logical circularity avoided by postulatingthe existence of underlying living processes,entailing amplification from the microscopic to the macroscopic scale,with increasing complexity in the passage from one scale to the other.Following such a line of thought, the currently accepted model of condensed matter, which is based on electrostatics and short-ranged forces,is criticized. It is suggested that the correct interpretationof quantum dispersion forces (van der Waals, hydrogen bonding, and so onas quantum coherence effects hints at the necessity of includinglong-ranged forces (or mechanisms for them incondensed matter theories of biological processes.Some quantum effects in biology are reviewedand quantum mechanics is acknowledged as conceptually important to biology since withoutit most (if not all of the biological structuresand signalling processes would not even exist. Moreover, it is suggested that long-rangequantum coherent dynamics, including electron polarization,may be invoked to explain signal amplificationprocess in biological systems in general.

  15. Some aspects of RNA repair and editing

    Directory of Open Access Journals (Sweden)

    Kovalchuk M. V.

    2010-11-01

    Full Text Available All cellular RNA molecules are damaged at the scale of DNA molecules, or even more. In the present review the RNA damaging agents, some mechanisms of RNA repair and editing, their difference from DNA repair mechanisms have been discussed.

  16. Plan Repair using a Plan Library

    NARCIS (Netherlands)

    Van der Krogt, R.P.J.; De Weerdt, M.M.

    2005-01-01

    Plan library's have proven their added value to the efficiency of planning. In this paper, we present results on the use of a plan library to plan repair. We show that using a relatively simple library, we can already obtain significant improvements in efficiency compared to plan repair without a li

  17. Targeted gene repair – in the arena

    OpenAIRE

    2003-01-01

    The development of targeted gene repair is under way and, despite some setbacks, shows promise as an alternative form of gene therapy. This approach uses synthetic DNA molecules to activate and direct the cell’s inherent DNA repair systems to correct inborn errors. The progress of this technique and its therapeutic potential are discussed in relation to the treatment of genetic diseases.

  18. Laparoscopic Ventral and Incisional Hernia Repair

    NARCIS (Netherlands)

    Wassenaar, E.B.

    2009-01-01

    Ventral and incisional hernia repair is one of the most frequently performed operations in daily surgical practice. Laparoscopic ventral and incisional hernia repair (LVIHR) is gaining increasing adoption in surgical practice. It has theoretical advantages but improvements in technique can still be

  19. 30 CFR 56.6801 - Vehicle repair.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Vehicle repair. 56.6801 Section 56.6801 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND... Vehicle repair. Vehicles containing explosive material and oxidizers shall not be taken into a...

  20. Damage diagnosis and compatible repair mortars

    NARCIS (Netherlands)

    Hees, R.P.J. van

    1999-01-01

    Mortars for repair and maintenance of historic masonry have to meet specific requirements. Several authors have made contributions, however many cases of failure show that there still is quite a lack of knowledge on the compatibility of repair mortars for historic masonry. The diagnosis of the cause

  1. Modelling in Optimal Inspection and Repair

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard; Rackwitz, R.; Faber, M.H.;

    1991-01-01

    A model for reliability based optimal inspection and repair strategies is described. The total expected costs in the lifetime is minimized with the number of inspections, the inspection times and efforts, the repair crack size limit and a design parameter as optimization variables. The equivalenc...

  2. Other-initiated repair in Siwu

    Directory of Open Access Journals (Sweden)

    Dingemanse Mark

    2015-02-01

    Full Text Available This article describes the interactional patterns and linguistic structures associated with other-initiated repair in Siwu, a Kwa language spoken in eastern Ghana. Other-initiated repair is the set of techniques used by people to deal with problems in speaking, hearing and understanding. Formats for repair initiation in Siwu exploit language-specific resources like question words and noun class morphology. At the same time, the basic structure of the system bears a strong similarity to other-initiated repair in other languages. Practices described for Siwu thus are potentially of broader relevance to the study of other-initiated repair. This article documents how different prosodic realisations of repair initiators may index social actions and features of the speech event; how two distinct roles of repetition in repair initiators are kept apart by features of turn design; and what kinds of items can be treated as ‘dispensable’ in resayings. By charting how other-initiated repair uses local linguistic resources and yet is shaped by interactional needs that transcend particular languages, this study contributes to the growing field of pragmatic typology: the study of systems of language use and the principles that shape them.

  3. The Organization of Second Language Classroom Repair.

    Science.gov (United States)

    Jung, Euen Hyuk (Sarah)

    1999-01-01

    Explores classroom pedagogy through a focus on classroom interaction. Takes ideas from conversation analysis as a foundation and starts to unravel some of the structures used for classroom pedagogy. Uses the notion of repair, but takes it one step further by understanding repair to be a pedagogical tool used in the English-as-a-Second-Language…

  4. Mitral valve repair in acquired dextrocardia.

    Science.gov (United States)

    Elmistekawy, Elsayed; Chan, Vincent; Hynes, Mark; Mesana, Thierry

    2015-10-01

    Surgical correction of valvular heart disease in patients with dextrocardia is extremely rare. We report a surgical case of mitral valve repair in a patient with acquired dextrocardia. Successful mitral valve repair was performed through a right lateral thoracotomy. We describe our surgical strategy and summarize the literature.

  5. Pain characteristics after laparoscopic inguinal hernia repair

    DEFF Research Database (Denmark)

    Tolver, Mette A; Strandfelt, Pernille; Rosenberg, Jacob;

    2011-01-01

    Previous studies have shown different pain characteristics in different types of laparoscopic operations, but pain pattern has not been studied in detail after laparoscopic inguinal hernia repair. To optimise preoperative patient information and postoperative analgesic treatment the present study...... investigated postoperative pain in terms of time course, pain intensity and individual pain components during the first 4 days after transabdominal preperitoneal hernia repair (TAPP)....

  6. Thoraco-abdominal aortic aneurysm branched repair

    NARCIS (Netherlands)

    Verhoeven, E. L. G.; Tielliu, I. F. J.; Ferreira, M.; Zipfel, B.; Adam, D. J.

    2010-01-01

    Open thoraco-abdominal aortic aneurysm repair is a demanding procedure with high impact on the patient and the operating team. Results from expert centres show mortality rates between 3-21%, with extensive morbidity including renal failure and paraplegia. Endovascular repair of abdominal aortic aneu

  7. Repairs the added value of being wrong

    CERN Document Server

    Brandt, Patrick

    2013-01-01

    Grammatical structures connect systems of thought and articulation, the conditions of which hardly seem to fit each other. Repairs are productive mechanisms that solve translation problems between modules or levels by adapting derivations or representations to requirements that have to be met unconditionally. Compensating for derivational and interpretive defects, repairs

  8. Foldit Biology

    Science.gov (United States)

    2015-07-31

    Report 8/1/2013-7/31/2015 4. TITLE AND SUBTITLE Sa. CONTRACT NUMBER Foldit Biology NOOO 14-13-C-0221 Sb. GRANT NUMBER N/A Sc. PROGRAM ELEMENT...Include area code) Unclassified Unclassified Unclassified (206) 616-2660 Zoran Popović Foldit Biology (Task 1, 2, 3, 4) Final Report...Period Covered by the Report August 1, 2013 – July 31, 2015 Date of Report: July 31, 2015 Project Title: Foldit Biology Contract Number: N00014-13

  9. Convalescence after laparoscopic inguinal hernia repair

    DEFF Research Database (Denmark)

    Tolver, Mette Astrup; Rosenberg, Jacob; Bisgaard, Thue

    2016-01-01

    BACKGROUND: Duration of convalescence after inguinal hernia repair is of major socio-economic interest and an often reported outcome measure. The primary aim was to perform a critical analysis of duration of convalescence from work and activity and secondary to identify risk factors for unexpected...... prolonged convalescence after laparoscopic inguinal hernia repair. METHODS: A qualitative systematic review was conducted. PubMed, Embase and the Cochrane database were searched for trials reporting convalescence after laparoscopic inguinal hernia repair in the period from January 1990 to January 2016...... factors for prolonged convalescence extending more than a few days after laparoscopic inguinal hernia repair. CONCLUSIONS: Patients should be recommended a duration of 1-2 days of convalescence after laparoscopic inguinal hernia repair. Short and non-restrictive recommendations may reduce duration...

  10. Imperfect repair and lifesaving in heterogeneous populations

    Energy Technology Data Exchange (ETDEWEB)

    Finkelstein, Maxim [Department of Mathematical Statistics, University of the Free State, PO Box 339, 9300 Bloemfontein (South Africa) and Max Planck Institute for Demographic Research, Rostock (Germany)]. E-mail: FinkelM.SCl@mail.uovs.ac.za

    2007-12-15

    In this theoretical paper we generalize the notion of minimal repair to the heterogeneous case, when the lifetime distribution function can be modeled by continuous or a discrete mixture of distributions. The statistical (black box) minimal repair and the minimal repair based on information just before the failure of an object are considered. The corresponding failure (intensity) rate processes are defined and analyzed. Demographic lifesaving model is also considered: each life is saved (cured) with some probability (or equivalently a proportion of individuals who would have died are now resuscitated and given another chance). Those who are saved experience the statistical minimal repair. Both of these models are based on the Poisson or non-homogeneous Poisson processes of underlying events, which allow for considering heterogeneity. We also consider the new model of imperfect repair in the homogeneous case and present generalizations to the heterogeneous setting.

  11. Chromatin structure and DNA damage repair

    Directory of Open Access Journals (Sweden)

    Dinant Christoffel

    2008-11-01

    Full Text Available Abstract The integrity of the genome is continuously challenged by both endogenous and exogenous DNA damaging agents. These damaging agents can induce a wide variety of lesions in the DNA, such as double strand breaks, single strand breaks, oxidative lesions and pyrimidine dimers. The cell has evolved intricate DNA damage response mechanisms to counteract the genotoxic effects of these lesions. The two main features of the DNA damage response mechanisms are cell-cycle checkpoint activation and, at the heart of the response, DNA repair. For both damage signalling and repair, chromatin remodelling is most likely a prerequisite. Here, we discuss current knowledge on chromatin remodelling with respect to the cellular response to DNA damage, with emphasis on the response to lesions resolved by nucleotide excision repair. We will discuss the role of histone modifications as well as their displacement or exchange in nucleotide excision repair and make a comparison with their requirement in transcription and double strand break repair.

  12. ONSTEP versus laparoscopy for inguinal hernia repair

    DEFF Research Database (Denmark)

    Andresen, Kristoffer; Burcharth, Jakob; Rosenberg, Jacob

    2015-01-01

    a learning curve of about 50-100 cases and decreases chronic pain, but slightly increases the risk of serious complications compared with open mesh repairs. Therefore, a simpler kind of operation is needed. The ONSTEP technique is a possible solution to this problem. The objective of the present randomised......INTRODUCTION: The optimal repair of inguinal hernias remains controversial. It is recommended that an inguinal hernia be repaired using a mesh, either with a laparoscopic or an open approach. In Denmark, the laparoscopic approach is used in an increasing number of cases. The laparoscopic repair has...... clinical trial described in this protocol is to evaluate chronic pain after inguinal hernia repair using the ONSTEP method versus the laparoscopic approach. METHODS: This study is designed as a non-inferiority, two-arm, multicentre, randomised clinical trial, with a 1:1 allocation to ONSTEP or laparoscopic...

  13. Repair Development for a Composite Cryotank

    Science.gov (United States)

    Cox, Sarah B.; Danley, Susan E.; Caraccio, Anne J.; Cheshire, Brian C.; Sampson, Jeffrey W.; Taylor, Brian J.

    2014-01-01

    The Composite Cryotank Technologies and Demonstration Project is working to advance the technologies for composite cryogenic propellant tanks at diameters suitable for future heavy lift vehicles and other in-space applications. The main goals of the project are to reduce weight and cost. One aspect of this project has focused on damage evaluation and repair development. Test panels have been impacted, repaired, and tested. Several repair methods were used to compare their effectiveness at restoring the integrity of the composite. Panels were evaluated by nondestructive evaluations at several points during the process to assess the damage and repair. The testing performed and the results and conclusions from the nondestructive evaluations and the destructive testing will be discussed. These results will lead to further development of inspection techniques and repair methods.

  14. ONSTEP versus laparoscopy for inguinal hernia repair

    DEFF Research Database (Denmark)

    Andresen, Kristoffer; Burcharth, Jakob; Rosenberg, Jacob

    2015-01-01

    INTRODUCTION: The optimal repair of inguinal hernias remains controversial. It is recommended that an inguinal hernia be repaired using a mesh, either with a laparoscopic or an open approach. In Denmark, the laparoscopic approach is used in an increasing number of cases. The laparoscopic repair has...... a learning curve of about 50-100 cases and decreases chronic pain, but slightly increases the risk of serious complications compared with open mesh repairs. Therefore, a simpler kind of operation is needed. The ONSTEP technique is a possible solution to this problem. The objective of the present randomised...... clinical trial described in this protocol is to evaluate chronic pain after inguinal hernia repair using the ONSTEP method versus the laparoscopic approach. METHODS: This study is designed as a non-inferiority, two-arm, multicentre, randomised clinical trial, with a 1:1 allocation to ONSTEP or laparoscopic...

  15. Stochastic Modelling Of The Repairable System

    Directory of Open Access Journals (Sweden)

    Andrzejczak Karol

    2015-11-01

    Full Text Available All reliability models consisting of random time factors form stochastic processes. In this paper we recall the definitions of the most common point processes which are used for modelling of repairable systems. Particularly this paper presents stochastic processes as examples of reliability systems for the support of the maintenance related decisions. We consider the simplest one-unit system with a negligible repair or replacement time, i.e., the unit is operating and is repaired or replaced at failure, where the time required for repair and replacement is negligible. When the repair or replacement is completed, the unit becomes as good as new and resumes operation. The stochastic modelling of recoverable systems constitutes an excellent method of supporting maintenance related decision-making processes and enables their more rational use.

  16. Instrument repair for remote eye units

    Directory of Open Access Journals (Sweden)

    Sam Powdrill

    2004-10-01

    Full Text Available Many skilled eye surgeons in remote hospitals face the frustration that a simple instrument, once in good working order, is now bent or broken. Many eye units have a box containing instruments needing repair, hidden away in a stock room cupboard, in the hope that someone, someday, will be able to redeem them. This article gives guidelines on: 1 How to assess instruments and identify those that can be repaired locally, those that should be sent to a professional repair service and those that cannot be repaired at all. 2 How to make adjustments and carry out basic maintenance and repairs of surgical instruments. The article will refer primarily to instruments in an extracapsular cataract extraction set.

  17. Systems Maintenance Automated Repair Tasks (SMART)

    Science.gov (United States)

    Schuh, Joseph; Mitchell, Brent; Locklear, Louis; Belson, Martin A.; Al-Shihabi, Mary Jo Y.; King, Nadean; Norena, Elkin; Hardin, Derek

    2010-01-01

    SMART is a uniform automated discrepancy analysis and repair-authoring platform that improves technical accuracy and timely delivery of repair procedures for a given discrepancy (see figure a). SMART will minimize data errors, create uniform repair processes, and enhance the existing knowledge base of engineering repair processes. This innovation is the first tool developed that links the hardware specification requirements with the actual repair methods, sequences, and required equipment. SMART is flexibly designed to be useable by multiple engineering groups requiring decision analysis, and by any work authorization and disposition platform (see figure b). The organizational logic creates the link between specification requirements of the hardware, and specific procedures required to repair discrepancies. The first segment in the SMART process uses a decision analysis tree to define all the permutations between component/ subcomponent/discrepancy/repair on the hardware. The second segment uses a repair matrix to define what the steps and sequences are for any repair defined in the decision tree. This segment also allows for the selection of specific steps from multivariable steps. SMART will also be able to interface with outside databases and to store information from them to be inserted into the repair-procedure document. Some of the steps will be identified as optional, and would only be used based on the location and the current configuration of the hardware. The output from this analysis would be sent to a work authoring system in the form of a predefined sequence of steps containing required actions, tools, parts, materials, certifications, and specific requirements controlling quality, functional requirements, and limitations.

  18. INTERNAL REPAIR OF PIPELINES REVIEW & EVALUATION OF INTERNAL PIPELINE REPAIR TRIALS REPORT

    Energy Technology Data Exchange (ETDEWEB)

    Robin Gordon; Bill Bruce; Ian Harris; Dennis Harwig; George Ritter; Bill Mohr; Matt Boring; Nancy Porter; Mike Sullivan; Chris Neary

    2004-09-01

    The two broad categories of fiber-reinforced composite liner repair and deposited weld metal repair technologies were reviewed and evaluated for potential application for internal repair of gas transmission pipelines. Both are used to some extent for other applications and could be further developed for internal, local, structural repair of gas transmission pipelines. Evaluation trials were conducted on pipe sections with simulated corrosion damage repaired with glass fiber-reinforced composite liners, carbon fiber-reinforced composite liners, and weld deposition. Additional un-repaired pipe sections were evaluated in the virgin condition and with simulated damage. Hydrostatic failure pressures for pipe sections repaired with glass fiber-reinforced composite liner were only marginally greater than that of pipe sections without liners, indicating that this type of liner is generally ineffective at restoring the pressure containing capabilities of pipelines. Failure pressure for pipe repaired with carbon fiber-reinforced composite liner was greater than that of the un-repaired pipe section with damage, indicating that this type of liner is effective at restoring the pressure containing capability of pipe. Pipe repaired with weld deposition failed at pressures lower than that of un-repaired pipe in both the virgin and damaged conditions, indicating that this repair technology is less effective at restoring the pressure containing capability of pipe than a carbon fiber-reinforced liner repair. Physical testing indicates that carbon fiber-reinforced liner repair is the most promising technology evaluated to-date. Development of a comprehensive test plan for this process is recommended for use in the next phase of this project.

  19. New challenge of tissue repair and regenerative medicine: to achieve a perfect repair and regeneration of multiple tissues in wound sites%组织修复与再生的新挑战:实现多种组织在损伤部位的同步修复与再生

    Institute of Scientific and Technical Information of China (English)

    付小兵

    2016-01-01

    Great achievements in the study of tissue repair and regeneration have been made, and many of these successes have been shown to be beneficial to the patients in recent years.However, perfect tissue repair and regeneration of damaged tissues and organs remain to be great challenges in the management of trauma and diseases.Based on the progress in developmental biology in animals and advances in stem cell biology, it is possible to attain the aim of perfect repair and regeneration by means of somatic cell reprogramming and different inducing techniques.

  20. [SOS-repair--60 years].

    Science.gov (United States)

    Zavil'gel'skiĭ, G B

    2013-01-01

    This review integrates 60 years of research on SOS-repair and SOS-mutagenesis in procaryotes and eucaryotes, from Jean Weigle experiment in 1953 year (mutagenesis of lambda bacteriophage in UV-irradiated bacteria) to the latest achievements in studying SOS-mutagenesis on all living organisms--Eukarya, Archaea and Bacteria. A key role in establishing of a biochemical basis for SOS-mutagenesis belonges to the finding in 1998-1999 years that specific error-prone DNA polymerases (PolV and others) catalysed translesion synthesis on damaged DNA. This review focuses on recent studies addressing the new models for SOS-induced mutagenesis in Escherichia coli and Home sapiens cells.

  1. Laparoscopic repair of vesicovaginal fistula

    Directory of Open Access Journals (Sweden)

    Miłosz Wilczyński

    2011-06-01

    Full Text Available A vesicovaginal fistula is one of the complications that a gynaecologist is bound to face after oncological operations, especially in postmenopausal women. Over the years there have been introduced many techniques of surgical treatment of this entity, including transabdominal and transvaginal approaches.We present a case of a 46-year-old patient who suffered from urinary leakage via the vagina due to the presence of a vesicovaginal fistula that developed after radical abdominal hysterectomy and subsequent radiotherapy. The decision was made to repair it laparoscopically due to retracted, fibrous and scarred tissue in the vaginal apex that precluded a transvaginal approach. A small cystotomy followed by an excision of fistula borders was performed. After six-month follow-up no recurrence of the disease has been noted.We conclude that laparoscopy is an interesting alternative to traditional approaches that provides comparable results.

  2. Shuttle Repair Tools Automate Vehicle Maintenance

    Science.gov (United States)

    2013-01-01

    Successfully building, flying, and maintaining the space shuttles was an immensely complex job that required a high level of detailed, precise engineering. After each shuttle landed, it entered a maintenance, repair, and overhaul (MRO) phase. Each system was thoroughly checked and tested, and worn or damaged parts replaced, before the shuttle was rolled out for its next mission. During the MRO period, workers needed to record exactly what needed replacing and why, as well as follow precise guidelines and procedures in making their repairs. That meant traceability, and with it lots of paperwork. In 2007, the number of reports generated during electrical system repairs was getting out of hand-placing among the top three systems in terms of paperwork volume. Repair specialists at Kennedy Space Center were unhappy spending so much time at a desk and so little time actually working on the shuttle. "Engineers weren't spending their time doing technical work," says Joseph Schuh, an electrical engineer at Kennedy. "Instead, they were busy with repetitive, time-consuming processes that, while important in their own right, provided a low return on time invested." The strain of such inefficiency was bad enough that slow electrical repairs jeopardized rollout on several occasions. Knowing there had to be a way to streamline operations, Kennedy asked Martin Belson, a project manager with 30 years experience as an aerospace contractor, to co-lead a team in developing software that would reduce the effort required to document shuttle repairs. The result was System Maintenance Automated Repair Tasks (SMART) software. SMART is a tool for aggregating and applying information on every aspect of repairs, from procedures and instructions to a vehicle s troubleshooting history. Drawing on that data, SMART largely automates the processes of generating repair instructions and post-repair paperwork. In the case of the space shuttle, this meant that SMART had 30 years worth of operations

  3. Dissecting DNA repair in adult high grade gliomas for patient stratification in the post-genomic era

    Science.gov (United States)

    Perry, Christina; Agarwal, Devika; Abdel-Fatah, Tarek M.A.; Lourdusamy, Anbarasu; Grundy, Richard; Auer, Dorothee T.; Walker, David; Lakhani, Ravi; Scott, Ian S.; Chan, Stephen; Ball, Graham; Madhusudan, Srinivasan

    2014-01-01

    Deregulation of multiple DNA repair pathways may contribute to aggressive biology and therapy resistance in gliomas. We evaluated transcript levels of 157 genes involved in DNA repair in an adult glioblastoma Test set (n=191) and validated in ‘The Cancer Genome Atlas’ (TCGA) cohort (n=508). A DNA repair prognostic index model was generated. Artificial neural network analysis (ANN) was conducted to investigate global gene interactions. Protein expression by immunohistochemistry was conducted in 61 tumours. A fourteen DNA repair gene expression panel was associated with poor survival in Test and TCGA cohorts. A Cox multivariate model revealed APE1, NBN, PMS2, MGMT and PTEN as independently associated with poor prognosis. A DNA repair prognostic index incorporating APE1, NBN, PMS2, MGMT and PTEN stratified patients in to three prognostic sub-groups with worsening survival. APE1, NBN, PMS2, MGMT and PTEN also have predictive significance in patients who received chemotherapy and/or radiotherapy. ANN analysis of APE1, NBN, PMS2, MGMT and PTEN revealed interactions with genes involved in transcription, hypoxia and metabolic regulation. At the protein level, low APE1 and low PTEN remain associated with poor prognosis. In conclusion, multiple DNA repair pathways operate to influence biology and clinical outcomes in adult high grade gliomas. PMID:25026297

  4. Heterologous replicase driven 3' end repair of Cucumber mosaic virus satellite RNA.

    Science.gov (United States)

    Sivanandam, Venkatesh; Varady, Erika; Rao, A L N

    2015-04-01

    To investigate the extent of the 3' end repair in a satellite RNA of Cucumber mosaic virus (CMV) strain Q (Q(sat)) by a heterologous Tomato aspermy virus (TAV), a set of biologically active agrotransformants corresponding to the three genomic RNAs of TAV was developed. Analysis of Nicotiana benthamiana plants agroinfiltrated with TAV and either wild type or each of the six 3' deletion mutants of Q(sat) revealed that (i) heterologous replicase failed to generate Q(sat) multimers, a hallmark feature of homologous replicase dependent replication of Qsat; (ii) manifestation of severe symptom phenotypes and progeny analysis suggested that heterologous replicase was competent to repair Q(sat) deletion mutants lacking up to 3'13 nucleotides (nt) but not beyond and (iii) comparative in silico analysis indicated that the 3' secondary structural features of the repaired Q(sat) progeny from heterologous vs homologous driven replicases are remarkably very similar. The significance of these observations is discussed.

  5. DNA double-strand break repair: a tale of pathway choices

    Institute of Scientific and Technical Information of China (English)

    Jing Li; Xingzhi Xu

    2016-01-01

    Deoxyribonucleic acid double-strand breaks (DSBs) are cytotoxic lesions that must be repaired either through homologous recombination (HR) or non-homologous end-joining (NHEJ) pathways.DSB repair is critical for genome integrity,cellular homeostasis and also constitutes the biological foundation for radiotherapy and the majority of chemotherapy.The choice between HR and NHEJ is a complex yet not completely understood process that will entail more future efforts.Herein we review our current understandings about how the choice is made over an antagonizing balance between p53-binding protein 1 and breast cancer 1 in the context of cell cycle stages,downstream effects,and distinct chromosomal histone marks.These exciting areas of research will surely bring more mechanistic insights about DSB repair and be utilized in the clinical settings.

  6. Dental materials for cleft palate repair.

    Science.gov (United States)

    Sharif, Faiza; Ur Rehman, Ihtesham; Muhammad, Nawshad; MacNeil, Sheila

    2016-04-01

    Numerous bone and soft tissue grafting techniques are followed to repair cleft of lip and palate (CLP) defects. In addition to the gold standard surgical interventions involving the use of autogenous grafts, various allogenic and xenogenic graft materials are available for bone regeneration. In an attempt to discover minimally invasive and cost effective treatments for cleft repair, an exceptional growth in synthetic biomedical graft materials have occurred. This study gives an overview of the use of dental materials to repair cleft of lip and palate (CLP). The eligibility criteria for this review were case studies, clinical trials and retrospective studies on the use of various types of dental materials in surgical repair of cleft palate defects. Any data available on the surgical interventions to repair alveolar or palatal cleft, with natural or synthetic graft materials was included in this review. Those datasets with long term clinical follow-up results were referred to as particularly relevant. The results provide encouraging evidence in favor of dental and other related biomedical materials to fill the gaps in clefts of lip and palate. The review presents the various bones and soft tissue replacement strategies currently used, tested or explored for the repair of cleft defects. There was little available data on the use of synthetic materials in cleft repair which was a limitation of this study. In conclusion although clinical trials on the use of synthetic materials are currently underway the uses of autologous implants are the preferred treatment methods to date.

  7. Magnetic Resonance Imaging of Cartilage Repair

    Science.gov (United States)

    Trattnig, Siegfried; Winalski, Carl S.; Marlovits, Stephan; Jurvelin, Jukka S.; Welsch, Goetz H.; Potter, Hollis G.

    2011-01-01

    Articular cartilage lesions are a common pathology of the knee joint, and many patients may benefit from cartilage repair surgeries that offer the chance to avoid the development of osteoarthritis or delay its progression. Cartilage repair surgery, no matter the technique, requires a noninvasive, standardized, and high-quality longitudinal method to assess the structure of the repair tissue. This goal is best fulfilled by magnetic resonance imaging (MRI). The present article provides an overview of the current state of the art of MRI of cartilage repair. In the first 2 sections, preclinical and clinical MRI of cartilage repair tissue are described with a focus on morphological depiction of cartilage and the use of functional (biochemical) MR methodologies for the visualization of the ultrastructure of cartilage repair. In the third section, a short overview is provided on the regulatory issues of the United States Food and Drug Administration (FDA) and the European Medicines Agency (EMEA) regarding MR follow-up studies of patients after cartilage repair surgeries. PMID:26069565

  8. Management and outcomes of colovesical fistula repair.

    Science.gov (United States)

    Lynn, Elizabeth T; Ranasinghe, Nalin E; Dallas, Kai B; Divino, Celia M

    2012-05-01

    This large retrospective study presents the largest colovesical fistula (CVF) series to date. We report on recurrence risk factors and patient satisfaction based on quality of life after CVF repair. Approval was obtained from The Mount Sinai School of Medicine Institutional Review Board, and a retrospective review was performed from 2003 to 2010 involving 72 consecutive patients who underwent a colovesical fistula repair. The CVF recurrence rate was 11 per cent. Ten percent of our patients who had a history of radiation therapy were at a significantly higher risk of developing a recurrence. Noted recurrence rates were significantly higher in advanced bladder repairs compared with simple repair (P = 0.022). The modified (Gastrointestinal Quality of Life Index) surveys showed overall patient satisfaction score was 3.6, out of a maximum score of 4, regardless of the type of repair or any postoperative complications. Our study found the CVF recurrence rate to be 11 per cent. Patients at higher risk of recurrence include those needing advanced bladder repair, those with "complex" CVF, and those whose fistulas involve the urethra. Patient satisfaction was found to be more closely linked to the resolution of CVF symptoms, irrespective of the type of repair performed or development of postoperative complications.

  9. Arthroscopic Quadriceps Tendon Repair: Two Case Reports

    Directory of Open Access Journals (Sweden)

    Hidetomo Saito

    2015-01-01

    Full Text Available Recently, although some studies of open repair of the tendon of the quadriceps femoris have been published, there have been no reports in the literature on primary arthroscopic repair. In our present study, we present two cases of quadriceps tendon injury arthroscopically repaired with excellent results. Case 1 involved a 68-year-old man who was injured while shifting his weight to prevent a fall. MRI showed complete rupture at the insertion of the patella of the quadriceps tendon. The rupture was arthroscopically repaired using both suture anchor and pull-out suture fixation methods via bone tunnels (hereafter, pull-out fixation. Two years after surgery, retearing was not observed on MRI and both Japan Orthopedic Association (JOA Knee and Lysholm scores had recovered to 100. Case 2 involved a 50-year-old man who was also injured when shifting his weight to prevent a fall. MRI showed incomplete superficial rupture at the insertion of the patella of the quadriceps tendon. The rupture was arthroscopically repaired using pull-out fixation of six strand sutures. One year after surgery, MRI revealed a healed tendon and his JOA and Lysholm scores were 95 and 100, respectively. Thus, arthroscopic repair may be a useful surgical method for repairing quadriceps tendon injury.

  10. Arthroscopic quadriceps tendon repair: two case reports.

    Science.gov (United States)

    Saito, Hidetomo; Shimada, Yoichi; Yamamura, Toshiaki; Yamada, Shin; Sato, Takahiro; Nozaka, Koji; Kijima, Hiroaki; Saito, Kimio

    2015-01-01

    Recently, although some studies of open repair of the tendon of the quadriceps femoris have been published, there have been no reports in the literature on primary arthroscopic repair. In our present study, we present two cases of quadriceps tendon injury arthroscopically repaired with excellent results. Case 1 involved a 68-year-old man who was injured while shifting his weight to prevent a fall. MRI showed complete rupture at the insertion of the patella of the quadriceps tendon. The rupture was arthroscopically repaired using both suture anchor and pull-out suture fixation methods via bone tunnels (hereafter, pull-out fixation). Two years after surgery, retearing was not observed on MRI and both Japan Orthopedic Association (JOA) Knee and Lysholm scores had recovered to 100. Case 2 involved a 50-year-old man who was also injured when shifting his weight to prevent a fall. MRI showed incomplete superficial rupture at the insertion of the patella of the quadriceps tendon. The rupture was arthroscopically repaired using pull-out fixation of six strand sutures. One year after surgery, MRI revealed a healed tendon and his JOA and Lysholm scores were 95 and 100, respectively. Thus, arthroscopic repair may be a useful surgical method for repairing quadriceps tendon injury.

  11. Diverless pipeline repair system for deep water

    Energy Technology Data Exchange (ETDEWEB)

    Spinelli, Carlo M. [Eni Gas and Power, Milan (Italy); Fabbri, Sergio; Bachetta, Giuseppe [Saipem/SES, Venice (Italy)

    2009-07-01

    SiRCoS (Sistema Riparazione Condotte Sottomarine) is a diverless pipeline repair system composed of a suite of tools to perform a reliable subsea pipeline repair intervention in deep and ultra deep water which has been on the ground of the long lasting experience of Eni and Saipem in designing, laying and operating deep water pipelines. The key element of SiRCoS is a Connection System comprising two end connectors and a repair spool piece to replace a damaged pipeline section. A Repair Clamp with elastomeric seals is also available for pipe local damages. The Connection System is based on pipe cold forging process, consisting in swaging the pipe inside connectors with suitable profile, by using high pressure seawater. Three swaging operations have to be performed to replace the damaged pipe length. This technology has been developed through extensive theoretical work and laboratory testing, ending in a Type Approval by DNV over pipe sizes ranging from 20 inches to 48 inches OD. A complete SiRCoS system has been realised for the Green Stream pipeline, thoroughly tested in workshop as well as in shallow water and is now ready, in the event of an emergency situation.The key functional requirements for the system are: diverless repair intervention and fully piggability after repair. Eni owns this technology and is now available to other operators under Repair Club arrangement providing stand-by repair services carried out by Saipem Energy Services. The paper gives a description of the main features of the Repair System as well as an insight into the technological developments on pipe cold forging reliability and long term duration evaluation. (author)

  12. 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

    2014-09-01

    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.

  13. Cartilage regeneration and repair testing in a surrogate large animal model.

    Science.gov (United States)

    Simon, Timothy M; Aberman, Harold M

    2010-02-01

    The aging human population is experiencing increasing numbers of symptoms related to its degenerative articular cartilage (AC), which has stimulated the investigation of methods to regenerate or repair AC. However, the seemingly inherent limited capacity for AC to regenerate persists to confound the various repair treatment strategies proposed or studied. Animal models for testing AC implant devices and reparative materials are an important and required part of the Food and Drug Administration approval process. Although final testing is ultimately performed in humans, animal testing allows for a wider range of parameters and combinations of test materials subjected to all the biological interactions of a living system. We review here considerations, evaluations, and experiences with selection and use of animal models and describe two untreated lesion models useful for testing AC repair strategies. These created lesion models, one deep (6 mm and through the subchondral plate) the other shallow (to the level of the subchondral bone plate) were placed in the middle one-third of the medial femoral condyle of the knee joints of goats. At 1-year neither the deep nor the shallow full-thickness chondral defects generated a repair that duplicated natural AC. Moreover, progressive deleterious changes occurred in the AC surrounding the defects. There are challenges in translation from animals to humans as anatomy and structures are different and immobilization to protect delicate repairs can be difficult. The tissues potentially generated by proposed cartilage repair strategies must be compared with the spontaneous changes that occur in similarly created untreated lesions. The prevention of the secondary changes in the surrounding cartilage and subchondral bone described in this article should be addressed with the introduction of treatments for repairs of the articulating surface.

  14. DNA repair phenotype and dietary antioxidant supplementation

    DEFF Research Database (Denmark)

    Guarnieri, Serena; Loft, Steffen; Riso, Patrizia

    2008-01-01

    of DNA repair incisions were 65.2 (95 % CI 60.4, 70.0) and 86.1 (95 % CI 76.2, 99.9) among the male smokers and well-nourished subjects, respectively. The male smokers also had high baseline levels of oxidised guanines in MNBC. After supplementation, only the male smokers supplemented with slow......-release vitamin C tablets had increased DNA repair activity (27 (95 % CI 12, 41) % higher incision activity). These subjects also benefited from the supplementation by reduced levels of oxidised guanines in MNBC. In conclusion, nutritional status, DNA repair activity and DNA damage are linked, and beneficial...

  15. Repair of umbilical and epigastric hernias.

    Science.gov (United States)

    Earle, David B; McLellan, Jennifer A

    2013-10-01

    Umbilical and epigastric hernias are primary midline defects that are present in up to 50% of the population. In the United States, only about 1% of the population carries this specific diagnosis, and only about 11% of these are repaired. Repair is aimed at symptoms relief or prevention, and the patient's goals and expectations should be explicitly identified and aligned with the health care team. This article details some relevant and interesting anatomic issues, reviews existing data, and highlights some common and important surgical techniques. Emphasis is placed on a patient-centered approach to the repair of umbilical and epigastric hernias.

  16. Method of repairing discontinuity in fiberglass structures

    Science.gov (United States)

    Gelb, L. L.; Helbert, W. B., Jr.; Enie, R. B.; Mulliken, R. F. (Inventor)

    1974-01-01

    Damaged fiberglass structures are repaired by substantially filling the irregular surfaced damaged area with a liquid, self-curing resin, preferably an epoxy resin mixed with chopped fiberglass, and then applying to the resin surface the first of several woven fiberglass swatches which has stitching in a zig-zag pattern parallel to each of its edges and a fringe of warp and fill glass fibers about the edges outward of the stitching. The method is especially applicable to repair of fiberglass rocket engine casings and is particularly advantageous since it restores the repaired fiberglass structure to substantially its original strength without any significant changes in the geometry or mass of the structure.

  17. Repair of Electronics for Long Duration Spaceflight

    Science.gov (United States)

    Pettegrew, Richard D.; Easton, John; Struk, Peter

    2007-01-01

    To reduce mission risk, long duration spaceflight and exploration activities will require greater degrees of self-sufficiency with regards to repair capability than have ever been employed before in space exploration. The current repair paradigm of replacing Orbital Replacement Units (ORUs) of malfunctioning avionics and electronic hardware will be impractical, since carrying all of the spares that could possibly be needed for a long duration mission would require upmass and volume at unprecedented and unacceptable levels. A strategy of component-level repair for electronics, however, could significantly reduce the mass and volume necessary for spares and enhance mission safety via a generic contingency capability. This approach is already used to varying degrees by the U.S. Navy, where vessels at sea experience some similar constraints such as the need for self sufficiency for moderately long time periods, and restrictions on volume of repair spares and infrastructure. The concept of conducting component-level repairs of electronics in spacecraft requires the development of design guidelines for future avionics (to enable repair), development of diagnostic techniques to allow an astronaut to pinpoint the faulty component aboard a vastly complex vehicle, and development of tools and methodologies for dealing with the physical processes of replacing the component. This physical process includes tasks such as conformal coating removal and replacement, component removal, replacement, and alignment--all in the difficulty of a reduced gravity environment. Further, the gravitational effects on the soldering process must be characterized and accounted for to ensure reliability of the newly repaired components. The Component-Level Electronics-Assembly Repair (CLEAR) project under the NASA Supportability program was established to develop and demonstrate the practicality of this repair approach. CLEAR involves collaborative efforts between NASA s Glenn Research Center

  18. Biological preconcentrator

    Science.gov (United States)

    Manginell, Ronald P.; Bunker, Bruce C.; Huber, Dale L.

    2008-09-09

    A biological preconcentrator comprises a stimulus-responsive active film on a stimulus-producing microfabricated platform. The active film can comprise a thermally switchable polymer film that can be used to selectively absorb and desorb proteins from a protein mixture. The biological microfabricated platform can comprise a thin membrane suspended on a substrate with an integral resistive heater and/or thermoelectric cooler for thermal switching of the active polymer film disposed on the membrane. The active polymer film can comprise hydrogel-like polymers, such as poly(ethylene oxide) or poly(n-isopropylacrylamide), that are tethered to the membrane. The biological preconcentrator can be fabricated with semiconductor materials and technologies.

  19. The myofibroblast, multiple origins for major roles in normal and pathological tissue repair

    Directory of Open Access Journals (Sweden)

    Micallef Ludovic

    2012-06-01

    Full Text Available Abstract Myofibroblasts differentiate, invade and repair injured tissues by secreting and organizing the extracellular matrix and by developing contractile forces. When tissues are damaged, tissue homeostasis must be re-established, and repair mechanisms have to rapidly provide harmonious mechanical tissue organization, a process essentially supported by (myofibroblasts. Under physiological conditions, the secretory and contractile activities of myofibroblasts are terminated when the repair is complete (scar formation but the functionality of the tissue is only rarely perfectly restored. At the end of the normal repair process, myofibroblasts disappear by apoptosis but in pathological situations, myofibroblasts likely remain leading to excessive scarring. Myofibroblasts originate from different precursor cells, the major contribution being from local recruitment of connective tissue fibroblasts. However, local mesenchymal stem cells, bone marrow-derived mesenchymal stem cells and cells derived from an epithelial-mesenchymal transition process, may represent alternative sources of myofibroblasts when local fibroblasts are not able to satisfy the requirement for these cells during repair. These diverse cell types probably contribute to the appearance of myofibroblast subpopulations which show specific biological properties and which are important to understand in order to develop new therapeutic strategies for treatment of fibrotic and scarring diseases.

  20. A scaffold-enhanced light-activated surgical adhesive technique: surface selection for enhanced tensile strength in wound repair

    Science.gov (United States)

    Soller, Eric C.; Hoffman, Grant T.; Heintzelman, Douglas L.; Duffy, Mark T.; Bloom, Jeffrey N.; McNally-Heintzelman, Karen M.

    2004-07-01

    An ex vivo study was conducted to determine the effect of the irregularity of the scaffold surface on the tensile strength of repairs formed using our Scaffold-Enhanced Biological Adhesive (SEBA). Two different scaffold materials were investigated: (i) a synthetic biodegradable material fabricated from poly(L-lactic-co-glycolic acid); and (ii) a biological material, small intestinal submucosa, manufactured by Cook BioTech. The scaffolds were doped with protein solder composed of 50%(w/v) bovine serum albumin solder and 0.5mg/ml indocyanine green dye mixed in deionized water, and activated with an 808-nm diode laser. The tensile strength of repairs performed on bovine thoracic aorta, liver, spleen, small intestine and lung, using the smooth and irregular surfaces of the above scaffold-enhanced materials were measured and the time-to-failure was recorded. The tensile strength of repairs formed using the irregular surfaces of the scaffolds were consistently higher than those formed using the smooth surfaces of the scaffolds. The largest difference was observed on repairs formed on the aorta and small intestine, where the repairs were, on average, 50% stronger using the irregular versus the smooth scaffold surfaces. In addition, the time-to-failure of repairs formed using the irregular surfaces of the scaffolds were between 50% and 100% longer than that achieved using the smooth surfaces of the scaffolds. It has previously been shown that distributing or dispersing the adhesive forces over the increased surface area of the scaffold, either smooth or irregular, produces stronger repairs than albumin solder alone. The increase in the absolute strength and longevity of repairs seen in this new study when the irregular surfaces of the scaffolds are used is thought to be due to the distribution of forces between the many independent micro-adhesions provided by the irregular surfaces.

  1. Injectable, high-density collagen gels for annulus fibrosus repair: An in vitro rat tail model.

    Science.gov (United States)

    Borde, Brandon; Grunert, Peter; Härtl, Roger; Bonassar, Lawrence J

    2015-08-01

    A herniated intervertebral disc often causes back pain when disc tissue is displaced through a damaged annulus fibrosus. Currently, the only methods available for annulus fibrosus repair involve mechanical closure of defect, which does little to address biological healing in the damaged tissue. Collagen hydrogels are injectable and have been used to repair annulus defects in vivo. In this study, high-density collagen hydrogels at 5, 10, and 15 mg/mL were used to repair defects made to intact rat caudal intervertebral discs in vitro. A group of gels at 15 mg/mL were also cross-linked with riboflavin at 0.03 mM, 0.07 mM, or 0.10 mM. These cross-linked, high-density collagen gels maintained their presence in the defect under loading and contributed positively to the mechanical response of damaged discs. Discs exhibited increases to 95% of undamaged effective equilibrium and instantaneous moduli as well as up to fourfold decreases in effective hydraulic permeability from the damaged discs. These data suggest that high-density collagen gels may be effective at restoring mechanical function of injured discs as well as potential vehicles for the delivery of biological agents such as cells or growth factors that may aid in the repair of the annulus fibrosus.

  2. The modified Koyanagi hypospadias repair for the one-stage repair of proximal hypospadias

    Directory of Open Access Journals (Sweden)

    Venkata R Jayanthi

    2008-01-01

    Full Text Available Perineal and penoscrotal hypospadias were often managed by two-stage urethroplasty with variable results and significant number of these may need third surgery. Though modified Koyanagi one-stage repair has a learning curve, it has all the advantages of two-stage repair. The aim was to review the results of modified Koyonagi repair from the literature and our own centre experience.

  3. Recent trends in repair and refurbishing of steam turbine components

    Indian Academy of Sciences (India)

    A K Bhaduri; S K Albert; S K Ray; P Rodriguez

    2003-06-01

    The repair and refurbishing of steam generator components is discussed from the perspective of repair welding philosophy including applicable codes and regulations. Some case histories of repair welding of steam generator components are discussed with special emphasis on details of repair welding of cracked steam turbine blades and shrouds in some of the commercial nuclear power plants using procedures developed.

  4. 48 CFR 252.247-7025 - Reflagging or repair work.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Reflagging or repair work... of Provisions And Clauses 252.247-7025 Reflagging or repair work. As prescribed in 247.574(d), use the following clause: Reflagging or Repair Work (JUN 2005) (a) Definition. Reflagging or repair...

  5. 49 CFR 192.309 - Repair of steel pipe.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Repair of steel pipe. 192.309 Section 192.309... Lines and Mains § 192.309 Repair of steel pipe. (a) Each imperfection or damage that impairs the serviceability of a length of steel pipe must be repaired or removed. If a repair is made by grinding,...

  6. Targeting base excision repair as a sensitization strategy in radiotherapy.

    NARCIS (Netherlands)

    Vens, C.; Begg, A.C.

    2010-01-01

    Cellular DNA repair determines survival after ionizing radiation. Human tumors commonly exhibit aberrant DNA repair since they drive mutagenesis and chromosomal instability. Recent reports have shown alterations in the base excision repair (BER) and single strand break repair (SSBR) pathways in huma

  7. 49 CFR 396.3 - Inspection, repair, and maintenance.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 5 2010-10-01 2010-10-01 false Inspection, repair, and maintenance. 396.3 Section..., REPAIR, AND MAINTENANCE § 396.3 Inspection, repair, and maintenance. (a) General. Every motor carrier and... and maintenance operations to be performed; (3) A record of inspection, repairs, and...

  8. 46 CFR 196.30-10 - Notice required before repair.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Notice required before repair. 196.30-10 Section 196.30... OPERATIONS Reports of Accidents, Repairs, and Unsafe Equipment § 196.30-10 Notice required before repair. (a) No repairs or alterations, except in an emergency, shall be made to any lifesaving or fire...

  9. 40 CFR 63.171 - Standards: Delay of repair.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 9 2010-07-01 2010-07-01 false Standards: Delay of repair. 63.171... Standards for Organic Hazardous Air Pollutants for Equipment Leaks § 63.171 Standards: Delay of repair. (a) Delay of repair of equipment for which leaks have been detected is allowed if repair within 15 days...

  10. 40 CFR 61.242-10 - Standards: Delay of repair.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 8 2010-07-01 2010-07-01 false Standards: Delay of repair. 61.242-10... Leaks (Fugitive Emission Sources) § 61.242-10 Standards: Delay of repair. (a) Delay of repair of equipment for which leaks have been detected will be allowed if repair within 15 days is...

  11. 40 CFR 60.692-6 - Standards: Delay of repair.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standards: Delay of repair. 60.692-6... From Petroleum Refinery Wastewater Systems § 60.692-6 Standards: Delay of repair. (a) Delay of repair of facilities that are subject to the provisions of this subpart will be allowed if the repair...

  12. 48 CFR 1371.118 - Changes-ship repair.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Changes-ship repair. 1371... SUPPLEMENTAL REGULATIONS ACQUISITIONS INVOLVING SHIP CONSTRUCTION AND SHIP REPAIR Provisions and Clauses 1371.118 Changes—ship repair. Insert clause 1352.271-87, Changes—Ship Repair, in all solicitations...

  13. 46 CFR 97.30-10 - Notice required before repair.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Notice required before repair. 97.30-10 Section 97.30-10... OPERATIONS Reports of Accidents, Repairs, and Unsafe Equipment § 97.30-10 Notice required before repair. (a) No repairs or alterations, except in an emergency, shall be made to any lifesaving or fire...

  14. 40 CFR 61.350 - Standards: Delay of repair.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 8 2010-07-01 2010-07-01 false Standards: Delay of repair. 61.350... Waste Operations § 61.350 Standards: Delay of repair. (a) Delay of repair of facilities or units that are subject to the provisions of this subpart will be allowed if the repair is technically...

  15. 40 CFR 265.1059 - Standards: Delay of repair.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 25 2010-07-01 2010-07-01 false Standards: Delay of repair. 265.1059... DISPOSAL FACILITIES Air Emission Standards for Equipment Leaks § 265.1059 Standards: Delay of repair. (a) Delay of repair of equipment for which leaks have been detected will be allowed if the repair...

  16. 40 CFR 264.1059 - Standards: Delay of repair.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 25 2010-07-01 2010-07-01 false Standards: Delay of repair. 264.1059... Air Emission Standards for Equipment Leaks § 264.1059 Standards: Delay of repair. (a) Delay of repair of equipment for which leaks have been detected will be allowed if the repair is...

  17. Erosion Resistant Compressor Blade Repair Technologies Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This Phase I SBIR program will demonstrate the use of wear resistant high strength nanocomposites in the turbine engine repair and refurbishment process. The...

  18. Lichtenstein versus Onstep for inguinal hernia repair

    DEFF Research Database (Denmark)

    Andresen, Kristoffer; Burcharth, Jakob; Rosenberg, Jacob

    2013-01-01

    Inguinal hernia is a common condition that affects millions of people world-wide every year. In Denmark (population of 5.5 million), more than 10,000 repairs of inguinal hernias are performed annually. The optimal surgical procedure for mesh placement and fixation is still being debated because...... of which is to evaluate chronic pain and sexual dysfunction after inguinal hernia repair using the Lichtenstein repair compared with the Onstep approach....... of long-term complications such as persisting pain and impairment of sexual function. The Onstep approach is a newer type of groin hernia repair with promising preliminary results in terms of very few cases of chronic pain and recurrences. This protocol describes a randomised clinical trial the objective...

  19. Laparoscopic transabdominal extraperitoneal repair of lumbar hernia

    Directory of Open Access Journals (Sweden)

    Sharma A

    2005-01-01

    Full Text Available Lumbar hernias need to be repaired due to the risk of incarceration and strangulation. A laparoscopic intraperitoneal approach in the modified flank position causes the intraperitoneal viscera to be displaced medially away from the hernia. The creation of a wide peritoneal flap around the hernial defect helps in mobilization of the colon, increased length of margin is available for coverage of mesh and more importantly for secure fixation of the mesh under vision to the underlying fascia. Laparoscopic lumbar hernia repair by this technique is a tensionless repair that diffuses total intra-abdominal pressure on each square inch of implanted mesh. The technique follows current principles of hernia repair and appears to confer all benefits of a minimal access approach.

  20. DNA repair genes in the Megavirales pangenome.

    Science.gov (United States)

    Blanc-Mathieu, Romain; Ogata, Hiroyuki

    2016-06-01

    The order 'Megavirales' represents a group of eukaryotic viruses with a large genome encoding a few hundred up to two thousand five hundred genes. Several members of Megavirales possess genes involved in major DNA repair pathways. Some of these genes were likely inherited from an ancient virus world and some others were derived from the genomes of their hosts. Here we examine molecular phylogenies of key DNA repair enzymes in light of recent hypotheses on the origin of Megavirales, and propose that the last common ancestors of the individual families of the order Megavirales already possessed DNA repair functions to achieve and maintain a moderately large genome and that this repair capacity gradually increased, in a family-dependent manner, during their recent evolution.

  1. Pain characteristics after laparoscopic inguinal hernia repair

    DEFF Research Database (Denmark)

    Tolver, Mette A; Strandfelt, Pernille; Rosenberg, Jacob;

    2011-01-01

    Previous studies have shown different pain characteristics in different types of laparoscopic operations, but pain pattern has not been studied in detail after laparoscopic inguinal hernia repair. To optimise preoperative patient information and postoperative analgesic treatment the present study...

  2. Final Design Analysis : Lake Ladora Dam Repair

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report is intended to present Rocky Mountain Arsenal with details concerning the remedial repair for Ladora Dam to meet the geotechnical concerns and hydrologic...

  3. NIU's Kinder, Gentler, Housing Repair System.

    Science.gov (United States)

    Tillis, Linda; Montgomery, Rogene

    1999-01-01

    Explains the effective use of a centralized housing-repair request system at Northern Illinois University that has improved customer service and increased fiscal accountability. Describes the system and assesses of its effectiveness. (GR)

  4. Fast Cure Repair Kit for Composites Project

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA has a need for technologies that will enable them to repair damage to composite structures. Fiber-reinforced polymer composite materials are fast gaining ground...

  5. Light-Curing Adhesive Repair Tapes

    Science.gov (United States)

    Allred, Ronald; Haight, Andrea Hoyt

    2009-01-01

    Adhesive tapes, the adhesive resins of which can be cured (and thereby rigidized) by exposure to ultraviolet and/or visible light, are being developed as repair patch materials. The tapes, including their resin components, consist entirely of solid, low-outgassing, nonhazardous or minimally hazardous materials. They can be used in air or in vacuum and can be cured rapidly, even at temperatures as low as -20 C. Although these tapes were originally intended for use in repairing structures in outer space, they can also be used on Earth for quickly repairing a wide variety of structures. They can be expected to be especially useful in situations in which it is necessary to rigidize tapes after wrapping them around or pressing them onto the parts to be repaired.

  6. Surgical repair of pulmonary artery branches.

    Science.gov (United States)

    Ghez, Olivier; Saeed, Imran; Serrato, Maria; Quintero, Diana Bernal; Kreitmann, Bernard; Fraisse, Alain; Uemura, Hideki; Seale, Anna; Daubeney, Piers; McCarthy, Karen; Ho, S Yen

    2013-01-01

    Surgical repair of pulmonary artery (PA) branches encompasses many different clinical scenarios and technical challenges. The most common, such as bifurcation and central PA reconstruction, are described, as well as the challenges of complex and peripheral reconstruction.

  7. Biology Notes.

    Science.gov (United States)

    School Science Review, 1981

    1981-01-01

    Outlines a variety of laboratory procedures, techniques, and materials including construction of a survey frame for field biology, a simple tidal system, isolation and applications of plant protoplasts, tropisms, teaching lung structure, and a key to statistical methods for biologists. (DS)

  8. (Biological dosimetry)

    Energy Technology Data Exchange (ETDEWEB)

    Preston, R.J.

    1990-12-17

    The traveler attended the 1st International Conference on Biological Dosimetry in Madrid, Spain. This conference was organized to provide information to a general audience of biologists, physicists, radiotherapists, industrial hygiene personnel and individuals from related fields on the current ability of cytogenetic analysis to provide estimates of radiation dose in cases of occupational or environmental exposure. There is a growing interest in Spain in biological dosimetry because of the increased use of radiation sources for medical and occupational uses, and with this the anticipated and actual increase in numbers of overexposure. The traveler delivered the introductory lecture on Biological Dosimetry: Mechanistic Concepts'' that was intended to provide a framework by which the more applied lectures could be interpreted in a mechanistic way. A second component of the trip was to provide advice with regard to several recent cases of overexposure that had been or were being assessed by the Radiopathology and Radiotherapy Department of the Hospital General Gregorio Maranon'' in Madrid. The traveler had provided information on several of these, and had analyzed cells from some exposed or purportedly exposed individuals. The members of the biological dosimetry group were referred to individuals at REACTS at Oak Ridge Associated Universities for advice on follow-up treatment.

  9. Marine Biology

    Science.gov (United States)

    Dewees, Christopher M.; Hooper, Jon K.

    1976-01-01

    A variety of informational material for a course in marine biology or oceanology at the secondary level is presented. Among the topics discussed are: food webs and pyramids, planktonic blooms, marine life, plankton nets, food chains, phytoplankton, zooplankton, larval plankton and filter feeders. (BT)

  10. Scaffolded biology.

    Science.gov (United States)

    Minelli, Alessandro

    2016-09-01

    Descriptions and interpretations of the natural world are dominated by dichotomies such as organism vs. environment, nature vs. nurture, genetic vs. epigenetic, but in the last couple of decades strong dissatisfaction with those partitions has been repeatedly voiced and a number of alternative perspectives have been suggested, from perspectives such as Dawkins' extended phenotype, Turner's extended organism, Oyama's Developmental Systems Theory and Odling-Smee's niche construction theory. Last in time is the description of biological phenomena in terms of hybrids between an organism (scaffolded system) and a living or non-living scaffold, forming unit systems to study processes such as reproduction and development. As scaffold, eventually, we can define any resource used by the biological system, especially in development and reproduction, without incorporating it as happens in the case of resources fueling metabolism. Addressing biological systems as functionally scaffolded systems may help pointing to functional relationships that can impart temporal marking to the developmental process and thus explain its irreversibility; revisiting the boundary between development and metabolism and also regeneration phenomena, by suggesting a conceptual framework within which to investigate phenomena of regular hypermorphic regeneration such as characteristic of deer antlers; fixing a periodization of development in terms of the times at which a scaffolding relationship begins or is terminated; and promoting plant galls to legitimate study objects of developmental biology.

  11. Biology Notes.

    Science.gov (United States)

    School Science Review, 1984

    1984-01-01

    Presents information on the teaching of nutrition (including new information relating to many current O-level syllabi) and part 16 of a reading list for A- and S-level biology. Also includes a note on using earthworms as a source of material for teaching meiosis. (JN)

  12. Double strand break (DSB) repair in heterochromatin and heterochromatin proteins in DSB repair.

    Science.gov (United States)

    Lemaître, Charlène; Soutoglou, Evi

    2014-07-01

    Chromosomal translocations are a hallmark of cancer cells and they represent a major cause of tumorigenesis. To avoid chromosomal translocations, faithful repair of DNA double strand breaks (DSBs) has to be ensured in the context of high ordered chromatin structure. However, chromatin compaction is proposed to represent a barrier for DSB repair. Here we review the different mechanisms cells use to alleviate the heterochromatic barrier for DNA repair. At the same time, we discuss the activating role of heterochromatin-associated proteins in this process, therefore proposing that chromatin structure, more than being a simple barrier, is a key modulator of DNA repair.

  13. Nucleotide excision repair in differentiated cells

    Energy Technology Data Exchange (ETDEWEB)

    Wees, Caroline van der [Department of Toxicogenetics, Leiden University Medical Center, Leiden (Netherlands); Department of Cardiology, Leiden University Medical Center, Leiden (Netherlands); Jansen, Jacob [Department of Toxicogenetics, Leiden University Medical Center, Leiden (Netherlands); Vrieling, Harry [Department of Toxicogenetics, Leiden University Medical Center, Leiden (Netherlands); Laarse, Arnoud van der [Department of Cardiology, Leiden University Medical Center, Leiden (Netherlands); Zeeland, Albert van [Department of Toxicogenetics, Leiden University Medical Center, Leiden (Netherlands); Mullenders, Leon [Department of Toxicogenetics, Leiden University Medical Center, Leiden (Netherlands)]. E-mail: l.mullenders@lumc.nl

    2007-01-03

    Nucleotide excision repair (NER) is the principal pathway for the removal of a wide range of DNA helix-distorting lesions and operates via two NER subpathways, i.e. global genome repair (GGR) and transcription-coupled repair (TCR). Although detailed information is available on expression and efficiency of NER in established mammalian cell lines, little is known about the expression of NER pathways in (terminally) differentiated cells. The majority of studies in differentiated cells have focused on repair of UV-induced cyclobutane pyrimidine dimers (CPD) and 6-4-photoproducts (6-4PP) because of the high frequency of photolesions at low level of toxicity and availability of sensitive technologies to determine photolesions in defined regions of the genome. The picture that emerges from these studies is blurred and rather complex. Fibroblasts and terminally differentiated myocytes of the rat heart display equally efficient GGR of 6-4PP but poor repair of CPD due to the absence of p48 expression. This repair phenotype is clearly different from human terminal differentiated neurons. Furthermore, both cell types were found to carry out TCR of CPD, thus mimicking the repair phenotype of established rodent cell lines. In contrast, in intact rat spermatogenic cells repair was very inefficient at the genome overall level and in transcriptionally active genes indicating that GGR and TCR are non-functional. Also, non-differentiated mouse embryonic stem (ES) cells exhibit low levels of NER after UV irradiation. However, the mechanisms that lead to low NER activity are clearly different: in differentiated spermatogenic cells differences in chromatin compaction and sequestering of NER proteins may underlie the lack of NER activity in pre-meiotic cells, whereas in non-differentiated ES cells NER is impaired by a strong apoptotic response.

  14. Role of Deubiquitinating Enzymes in DNA Repair

    OpenAIRE

    2016-01-01

    Both proteolytic and nonproteolytic functions of ubiquitination are essential regulatory mechanisms for promoting DNA repair and the DNA damage response in mammalian cells. Deubiquitinating enzymes (DUBs) have emerged as key players in the maintenance of genome stability. In this minireview, we discuss the recent findings on human DUBs that participate in genome maintenance, with a focus on the role of DUBs in the modulation of DNA repair and DNA damage signaling.

  15. Rapid Set Materials for Advanced Spall Repair

    Science.gov (United States)

    2010-08-01

    cement -based polymer- cement mortar and concrete • Magnesium -ammonium- phosphate - cement mortar and concrete • Polymer-based mortar and concrete...material or lodged debris from the joint or crack. • Place a small bead of caulk over the joint or crack. • If using a cement -based repair material, soak...placement equipment immediately after use. • When using cement repair materials, either wet cure or apply curing compound. • Remove the compressible spacer

  16. Chronic pain after inguinal hernia repair

    OpenAIRE

    2008-01-01

    : BACKGROUND: Chronic post herniorrhaphy groin pain is defined as pain lasting > 6 months after surgery, which is one of the most important complication occurring after inguinal hernia repair, occurs with greater frequency than previously thought. Chronic groin pain is one of the most significant complications following inguinal hernia repair, and majority of chronic pain has been attributed to ilioinguinal nerve entrapment. Various other factors are involved in development of...

  17. Hormesis: a fundamental concept in biology

    Science.gov (United States)

    Calabrese, Edward J.

    2014-01-01

    This paper assesses the hormesis dose response concept, including its historical foundations, frequency, generality, quantitative features, mechanistic basis and biomedical, pharmaceutical and environmental health implications. The hormetic dose response is highly generalizable, being independent of biology model (i.e. common from plants to humans), level of biological organization (i.e. cell, organ and organism), endpoint, inducing agent and mechanism, providing the first general and quantitative description of plasticity. The hormetic dose response describes the limits to which integrative endpoints (e.g. cell proliferation, cell migration, growth patterns, tissue repair, aging processes, complex behaviors such as anxiety, learning, memory, and stress, preconditioning responses, and numerous adaptive responses) can be modulated (i.e., enhanced or diminished) by pharmaceutical, chemical and physical means. Thus, the hormesis concept is a fundamental concept in biology with a wide range of biological implications and biomedical applications.

  18. Hormesis: a fundamental concept in biology

    Directory of Open Access Journals (Sweden)

    Edward J. Calabrese

    2014-04-01

    Full Text Available This paper assesses the hormesis dose response concept, including its historical foundations, frequency, generality, quantitative features, mechanistic basis and biomedical, pharmaceutical and environmental health implications. The hormetic dose response is highly generalizable, being independent of biology model (i.e. common from plants to humans, level of biological organization (i.e. cell, organ and organism, endpoint, inducing agent and mechanism, providing the first general and quantitative description of plasticity. The hormetic dose response describes the limits to which integrative endpoints (e.g. cell proliferation, cell migration, growth patterns, tissue repair, aging processes, complex behaviors such as anxiety, learning, memory, and stress, preconditioning responses, and numerous adaptive responses can be modulated (i.e., enhanced or diminished by pharmaceutical, chemical and physical means. Thus, the hormesis concept is a fundamental concept in biology with a wide range of biological implications and biomedical applications.

  19. Schwann cells for spinal cord repair

    Directory of Open Access Journals (Sweden)

    Oudega M.

    2005-01-01

    Full Text Available The complex nature of spinal cord injury appears to demand a multifactorial repair strategy. One of the components that will likely be included is an implant that will fill the area of lost nervous tissue and provide a growth substrate for injured axons. Here we will discuss the role of Schwann cells (SCs in cell-based, surgical repair strategies of the injured adult spinal cord. We will review key studies that showed that intraspinal SC grafts limit injury-induced tissue loss and promote axonal regeneration and myelination, and that this response can be improved by adding neurotrophic factors or anti-inflammatory agents. These results will be compared with several other approaches to the repair of the spinal cord. A general concern with repair strategies is the limited functional recovery, which is in large part due to the failure of axons to grow across the scar tissue at the distal graft-spinal cord interface. Consequently, new synaptic connections with spinal neurons involved in motor function are not formed. We will highlight repair approaches that did result in growth across the scar and discuss the necessity for more studies involving larger, clinically relevant types of injuries, addressing this specific issue. Finally, this review will reflect on the prospect of SCs for repair strategies in the clinic.

  20. Immunobiology of Facial Nerve Repair and Regeneration

    Institute of Scientific and Technical Information of China (English)

    QUAN Shi-ming; GAO Zhi-qiang

    2006-01-01

    Immunobiological study is a key to revealing the important basis of facial nerve repair and regeneration for both research and development of clinic treatments. The microenvironmental changes around an injuried facial motoneuron, i.e., the aggregation and expression of various types of immune cells and molecules in a dynamic equilibrium, impenetrate from the start to the end of the repair of an injured facial nerve. The concept of "immune microenvironment for facial nerve repair and regeneration", mainly concerns with the dynamic exchange between expression and regulation networks and a variaty of immune cells and immune molecules in the process of facial nerve repair and regeneration for the maintenance of a immune microenvironment favorable for nerve repair.Investigation on microglial activation and recruitment, T cell behavior, cytokine networks, and immunological cellular and molecular signaling pathways in facial nerve repair and regeneration are the current hot spots in the research on immunobiology of facial nerve injury. The current paper provides a comprehensive review of the above mentioned issues. Research of these issues will eventually make immunological interventions practicable treatments for facial nerve injury in the clinic.

  1. Achilles Tendon Repair, A Modified Technique

    Directory of Open Access Journals (Sweden)

    Sohrab Keyhani

    2013-12-01

    Full Text Available Background: Wound complications following open repair for acute Achilles tendon ruptures (AATR remain the subject of significant debate. The aim of this study is to investigate the effects of covering repaired AATR using well-nourished connective tissues (paratenon and deep fascia to avoid complications after open repair.   Methods: In this case series study, open repair was performed for 32 active young patients with AATR. After the tendon was repaired, the deep fascia and paratenon was used to cover the Achilles tendon. Patients were followed for two years and any wound complication was recorded. During the last visit, the American Orthopedic Foot and Ankle Society (AOFAS ankle-hind foot score was completed for all patients. Calf circumference and ankle range of motion were measured and compared with the contralateral side. Patients were asked about returning to previous sports activities and limitations with footwear. Results: Only, one patient developed deep wound infection (3%. None of the patients had any discomfort around the operation area, limitation with footwear, sural nerve injury, re-rupture, and skin adhesion. The AOFAS score averaged 92.5±6. Two patients (7% were unable to return to previous sports activities because of moderate pain in heavy physical exercises. The calf circumference and ankle ROM were similar between healthy and operated sides. Conclusion: The present study showed that fascial envelope for full covering of the repaired Achilles tendon may help to prevent the occurrence of wound complications.

  2. Achilles Tendon Repair, A Modified Technique

    Directory of Open Access Journals (Sweden)

    Sohrab Keyhani

    2013-12-01

    Full Text Available   Background: Wound complications following open repair for acute Achilles tendon ruptures (AATR remain the subject of significant debate. The aim of this study is to investigate the effects of covering repaired AATR using well-nourished connective tissues (paratenon and deep fascia to avoid complications after open repair.   Methods: In this case series study, open repair was performed for 32 active young patients with AATR. After the tendon was repaired, the deep fascia and paratenon was used to cover the Achilles tendon. Patients were followed for two years and any wound complication was recorded. During the last visit, the American Orthopedic Foot and Ankle Society (AOFAS ankle-hind foot score was completed for all patients. Calf circumference and ankle range of motion were measured and compared with the contralateral side. Patients were asked about returning to previous sports activities and limitations with footwear. Results: Only, one patient developed deep wound infection (3%. None of the patients had any discomfort around the operation area, limitation with footwear, sural nerve injury, re-rupture, and skin adhesion. The AOFAS score averaged 92.5±6. Two patients (7% were unable to return to previous sports activities because of moderate pain in heavy physical exercises. The calf circumference and ankle ROM were similar between healthy and operated sides. Conclusion: The present study showed that fascial envelope for full covering of the repaired Achilles tendon may help to prevent the occurrence of wound complications.

  3. The forked flap repair for hypospadias

    Directory of Open Access Journals (Sweden)

    Anil Chadha

    2012-01-01

    Full Text Available Context: Despite the abundance of techniques for the repair of Hypospadias, its problems still persist and a satisfactory design to correct the penile curvature with the formation of neourethra from the native urethral tissue or genital or extragenital tissues, with minimal postoperative complications has yet to evolve. Aim: Persisting with such an endeavor, a new technique for the repair of distal and midpenile hypospadias is described. Materials and Methods: The study has been done in 70 cases over the past 11 years. The "Forked-Flap" repair is a single stage method for the repair of such Hypospadias with chordee. It takes advantage of the rich vascular communication at the corona and capitalizes on the established reliability of the meatal based flip-flap. The repair achieves straightening of the curvature of the penis by complete excision of chordee tissue from the ventral surface of the penis beneath the urethral plate. The urethra is reconstructed using the native plate with forked flap extensions and genital tissue relying on the concept of meatal based flaps. Water proofing by dartos tissue and reinforcement by Nesbit′s prepucial tissue transfer completes the one stage procedure. Statistical Analysis: An analysis of 70 cases of this single stage technique of repair of penile hypospadias with chordee, operated at 3 to 5 years of age over the past 11 years is presented. Results and Conclusion: The Forked Flap gives comparable and replicable results; except for a urethrocutaneous fistula rate of 4% no other complications were observed.

  4. Hypospadias Repair: A Single Centre Experience

    Directory of Open Access Journals (Sweden)

    Mansoor Khan

    2014-01-01

    Full Text Available Objectives. To determine the demographics and analyze the management and factors influencing the postoperative complications of hypospadias repair. Settings. Hayatabad Medical Complex Peshawar, Pakistan, from January 2007 to December 2011. Material and Methods. All male patients presenting with hypospadias irrespective of their ages were included in the study. The data were acquired from the hospital’s database and analyzed with Statistical Package for Social Sciences (SPSS. Results. A total of 428 patients with mean age of 8.12 ± 5.04 SD presented for hypospadias repair. Midpenile hypospadias were the most common. Chordee, meatal abnormalities, cryptorchidism, and inguinal hernias were observed in 74.3%, 9.6%, 2.8%, and 2.1% cases, respectively. Two-stage (Bracka and TIP (tubularized incised urethral plate repairs were performed in 76.2% and 20.8% of cases, respectively. The most common complications were edema and urethrocutaneous fistula (UCF. The complications were significantly lower in the hands of specialists than residents (P-value = 0.0086. The two-stage hypospadias repair resulted in higher complications frequency than single-stage repair (P value = 0.0001. Conclusion. Hypospadias surgery has a long learning curve because it requires a great deal of temperament, surgical skill and acquaintance with magnifications. Single-stage repair should be encouraged wherever applicable due to its lower postoperative complications.

  5. Investigation of DNA repair in human oocytes and preimplantation embryos

    OpenAIRE

    Jaroudi, S.

    2010-01-01

    DNA repair genes are expressed in mammalian embryos and in human germinal vesicles, however, little is known about DNA repair in human preimplantation embryos. This project had three aims: 1) to produce a DNA repair profile of human MII oocytes and blastocysts using expression arrays and identify repair pathways that may be active before and after embryonic genome activation; 2) to design an in vitro functional assay that targeted mismatch repair and which could be applied to human oocytes...

  6. The human RAD54 recombinational DNA repair protein is a double-stranded DNA-dependent ATPase

    NARCIS (Netherlands)

    J. Essers (Jeroen); J. de Wit (Jan); R. Kanaar (Roland); J.H.J. Hoeijmakers (Jan); S.M.A. Swagemakers (Sigrid)

    1998-01-01

    textabstractDNA double-strand break repair through the RAD52 homologous recombination pathway in the yeast Saccharomyces cerevisiae requires, among others, the RAD51, RAD52, and RAD54 genes. The biological importance of homologous recombination is underscored by the conservation of

  7. Large Extremity Peripheral Nerve Repair

    Science.gov (United States)

    2015-10-01

    MB, Roberts AB, Wakersfield LM, de Crombrugghe B. Some recent advances in the chemistry and biology of trans- forming growth factor-beta. J Cell Biol...with donor age ! þ þ Age and environmental acquired DNA damage ! þ þ Cryogenic storage of cells for future use following birth þ ! ! The clinical...Adobe Systems, Inc., San Jose, Calif.). Two blinded researchers manually measured nerve cross-sectional area from 40× images and counted axons from

  8. Diversity of Endonuclease V: From DNA Repair to RNA Editing

    Directory of Open Access Journals (Sweden)

    Isao Kuraoka

    2015-09-01

    Full Text Available Deamination of adenine occurs in DNA, RNA, and their precursors via a hydrolytic reaction and a nitrosative reaction. The generated deaminated products are potentially mutagenic because of their structural similarity to natural bases, which in turn leads to erroneous nucleotide pairing and subsequent disruption of cellular metabolism. Incorporation of deaminated precursors into the nucleic acid strand occurs during nucleotide synthesis by DNA and RNA polymerases or base modification by DNA- and/or RNA-editing enzymes during cellular functions. In such cases, removal of deaminated products from DNA and RNA by a nuclease might be required depending on the cellular function. One such enzyme, endonuclease V, recognizes deoxyinosine and cleaves 3' end of the damaged base in double-stranded DNA through an alternative excision repair mechanism in Escherichia coli, whereas in Homo sapiens, it recognizes and cleaves inosine in single-stranded RNA. However, to explore the role of endonuclease V in vivo, a detailed analysis of cell biology is required. Based on recent reports and developments on endonuclease V, we discuss the potential functions of endonuclease V in DNA repair and RNA metabolism.

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

    Energy Technology Data Exchange (ETDEWEB)

    Matteini, P; Ratto, F; Rossi, F; Pini, R [Institute of Applied Physics ' Nello Carrara' , National Research Council, via Madonna del Piano 10 50019 Sesto Fiorentino (Italy)

    2014-07-31

    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)

  10. 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.

  11. Energy and Technology Review: Unlocking the mysteries of DNA repair

    Energy Technology Data Exchange (ETDEWEB)

    Quirk, W.A.

    1993-04-01

    DNA, the genetic blueprint, has the remarkable property of encoding its own repair following diverse types of structural damage induced by external agents or normal metabolism. We are studying the interplay of DNA damaging agents, repair genes, and their protein products to decipher the complex biochemical pathways that mediate such repair. Our research focuses on repair processes that correct DNA damage produced by chemical mutagens and radiation, both ionizing and ultraviolet. The most important type of DNA repair in human cells is called excision repair. This multistep process removes damaged or inappropriate pieces of DNA -- often as a string of 29 nucleotides containing the damage -- and replaces them with intact ones. We have isolated, cloned, and mapped several human repair genes associated with the nucleotide excision repair pathway and involved in the repair of DNA damage after exposure to ultraviolet light or mutagens in cooked food. We have shown that a defect in one of these repair genes, ERCC2, is responsible for the repair deficiency in one of the groups of patients with the recessive genetic disorder xeroderma pigmentosum (XP group D). We are exploring ways to purify sufficient quantities (milligrams) of the protein products of these and other repair genes so that we can understand their functions. Our long-term goals are to link defective repair proteins to human DNA repair disorders that predispose to cancer, and to produce DNA-repair-deficient mice that can serve as models for the human disorders.

  12. Mesoscopic biology

    Indian Academy of Sciences (India)

    G V Shivashankar

    2002-02-01

    In this paper we present a qualitative outlook of mesoscopic biology where the typical length scale is of the order of nanometers and the energy scales comparable to thermal energy. Novel biomolecular machines, governed by coded information at the level of DNA and proteins, operate at these length scales in biological systems. In recent years advances in technology have led to the study of some of the design principles of these machines; in particular at the level of an individual molecule. For example, the forces that operate in molecular interactions, the stochasticity involved in these interactions and their spatio-temporal dynamics are beginning to be explored. Understanding such design principles is opening new possibilities in mesoscopic physics with potential applications.

  13. The impact of heterochromatin on DSB repair.

    Science.gov (United States)

    Goodarzi, Aaron A; Noon, Angela T; Jeggo, Penny A

    2009-06-01

    DNA NHEJ (non-homologous end-joining) is the major DNA DSB (double-strand break) repair pathway in mammalian cells. Although NHEJ-defective cell lines show marked DSB-repair defects, cells defective in ATM (ataxia telangiectasia mutated) repair most DSBs normally. Thus NHEJ functions independently of ATM signalling. However, approximately 15% of radiation-induced DSBs are repaired with slow kinetics and require ATM and the nuclease Artemis. DSBs persisting in the presence of an ATM inhibitor, ATMi, localize to heterochromatin, suggesting that ATM is required for repairing DSBs arising within or close to heterochromatin. Consistent with this, we show that siRNA (small interfering RNA) of key heterochromatic proteins, including KAP-1 [KRAB (Krüppel-associated box) domain-associated protein 1], HP1 (heterochromatin protein 1) and HDAC (histone deacetylase) 1/2, relieves the requirement for ATM for DSB repair. Furthermore, ATMi addition to cell lines with genetic alterations that have an impact on heterochromatin, including Suv39H1/2 (suppressor of variegation 3-9 homologue 1/2)-knockout, ICFa (immunodeficiency, centromeric region instability, facial anomalies syndrome type a) and Hutchinson-Guilford progeria cell lines, fails to have an impact on DSB repair. KAP-1 is a highly dose-dependent, transient and ATM-specific substrate, and mutation of the ATM phosphorylation site on KAP-1 influences DSB repair. Collectively, the findings show that ATM functions to overcome the barrier to DSB repair posed by heterochromatin. However, even in the presence of ATM, gamma-H2AX (phosphorylated histone H2AX) foci form on the periphery rather than within heterochromatic centres. Finally, we show that KAP-1's association with heterochromatin is diminished as cells progress through mitosis. We propose that KAP-1 is a critical heterochromatic factor that undergoes specific modifications to promote DSB repair and mitotic progression in a manner that allows localized and transient

  14. Biological strategies to enhance rotator cuff healing.

    Science.gov (United States)

    Longo, Umile Giuseppe; Rizzello, Giacomo; Berton, Alessandra; Maltese, Ludovica; Fumo, Caterina; Khan, Wasim S; Denaro, Vincenzo

    2013-11-01

    Rotator cuff tear causes a high rate of morbidity. After surgical repair, the presence of a scar tissue reduces tendon biomechanical properties. Emerging strategies for enhancing tendon healing are growth factors, cytokines, gene therapy and tissue engineering. However their efficacy has to be proved. Growth factors help the process of tendon healing by aiding cells chemotaxis, differentiation and proliferation. Numerous growth factors, including the bone morphogenetic proteins and platelet-derived growth factor can be found during the early healing process of a rotator cuff repair. Growth factors are delivered to the repair site using tissue-engineered scaffolding, coated sutures, or dissolved in a fibrin sealant. Platelet-rich plasma is an autologous concentration of platelets and contains an high density of growth factors. There is some evidence that platelet-rich plasma may improve pain and recovery of function in a short time period, but it does not improve healing rates in rotator cuff. Thus the routine use of platelet-rich plasma in rotator cuff repair is not recommended. The addition of mesenchymal stem cells to scaffolds can lead to the production of a better quality healing tissue. Gene therapy is a gene transfer from a cell into another, in order to over-express the gene required. In this way, cultures of stem cells can over-express growth factors. Better understanding of the mechanisms of physiological tendon healing can promote the correct use of these new biological therapies for a better healing tissue.

  15. Marine biology

    Energy Technology Data Exchange (ETDEWEB)

    Thurman, H.V.; Webber, H.H.

    1984-01-01

    This book discusses both taxonomic and ecological topics on marine biology. Full coverage of marine organisms of all five kingdoms is provided, along with interesting and thorough discussion of all major marine habitats. Organization into six major parts allows flexibility. It also provides insight into important topics such as disposal of nuclear waste at sea, the idea that life began on the ocean floor, and how whales, krill, and people interact. A full-color photo chapter reviews questions, and exercises. The contents are: an overview marine biology: fundamental concepts/investigating life in the ocean; the physical ocean, the ocean floor, the nature of water, the nature and motion of ocean water; general ecology, conditions for life in the sea, biological productivity and energy transfer; marine organisms; monera, protista, mycota and metaphyta; the smaller marine animals, the large animals marine habitats, the intertidal zone/benthos of the continental shelf, the photic zone, the deep ocean, the ocean under stress, marine pollution, appendix a: the metric system and conversion factors/ appendix b: prefixes and suffixes/ appendix c: taxonomic classification of common marine organisms, and glossary, and index.

  16. Multiple tipping points and optimal repairing in interacting networks

    Science.gov (United States)

    Majdandzic, Antonio; Braunstein, Lidia A.; Curme, Chester; Vodenska, Irena; Levy-Carciente, Sary; Eugene Stanley, H.; Havlin, Shlomo

    2016-03-01

    Systems composed of many interacting dynamical networks--such as the human body with its biological networks or the global economic network consisting of regional clusters--often exhibit complicated collective dynamics. Three fundamental processes that are typically present are failure, damage spread and recovery. Here we develop a model for such systems and find a very rich phase diagram that becomes increasingly more complex as the number of interacting networks increases. In the simplest example of two interacting networks we find two critical points, four triple points, ten allowed transitions and two `forbidden' transitions, as well as complex hysteresis loops. Remarkably, we find that triple points play the dominant role in constructing the optimal repairing strategy in damaged interacting systems. To test our model, we analyse an example of real interacting financial networks and find evidence of rapid dynamical transitions between well-defined states, in agreement with the predictions of our model.

  17. Metabolism, genomics, and DNA repair in the mouse aging liver

    DEFF Research Database (Denmark)

    Lebel, Michel; de Souza-Pinto, Nadja C; Bohr, Vilhelm A

    2011-01-01

    The liver plays a pivotal role in the metabolism of nutrients, drugs, hormones, and metabolic waste products, thereby maintaining body homeostasis. The liver undergoes substantial changes in structure and function within old age. Such changes are associated with significant impairment of many...... hepatic metabolic and detoxification activities, with implications for systemic aging and age-related disease. It has become clear, using rodent models as biological tools, that genetic instability in the form of gross DNA rearrangements or point mutations accumulate in the liver with age. DNA lesions......, such as oxidized bases or persistent breaks, increase with age and correlate well with the presence of senescent hepatocytes. The level of DNA damage and/or mutation can be affected by changes in carcinogen activation, decreased ability to repair DNA, or a combination of these factors. This paper covers some...

  18. Composite vascular repair grafts via micro-imprinting and electrospinning

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yuanyuan, E-mail: yuanyuan-liu@shu.edu.cn; Hu, Qingxi, E-mail: huqingxi@shu.edu.cn [Rapid Manufacturing Engineering Center, Shanghai University, Shanghai 200444 (China); Shanghai Key Laboratory of Intelligent Manufacturing and Robotics, Shanghai 200072 (China); Xiang, Ke, E-mail: xiangke@shu.edu.cn; Chen, Haiping, E-mail: 519673062@qq.com; Li, Yu, E-mail: liyu@hpu.edu.cn [Rapid Manufacturing Engineering Center, Shanghai University, Shanghai 200444 (China)

    2015-04-15

    Composite vascular grafts formed by micro-imprinting and electrospinning exhibited improved mechanical properties relative to those formed by electrospinning alone. The three-layered composite grafts mimic the three-layered structure of natural blood vessels. The middle layer is made by micro-imprinting poly-p-dioxanone (PPDO), while the inner and outer layers are electrospun mixtures of chitosan and polyvinyl alcohol. The graft morphology is characterized with scanning electron microscopy. For constant graft thicknesses, the PPDO increases the mechanical strength. Cells cultivated on the vascular grafts adhere and proliferate better because of the natural, biological chitosan in the inner and outer layers. Overall, the composite scaffolds could be good candidates for blood vessel repair.

  19. Multiple Tipping Points and Optimal Repairing in Interacting Networks

    CERN Document Server

    Majdandzic, Antonio; Curme, Chester; Vodenska, Irena; Levy-Carciente, Sary; Stanley, H Eugene; Havlin, Shlomo

    2015-01-01

    Systems that comprise many interacting dynamical networks, such as the human body with its biological networks or the global economic network consisting of regional clusters, often exhibit complicated collective dynamics. To understand the collective behavior of these systems, we investigate a model of interacting networks exhibiting the fundamental processes of failure, damage spread, and recovery. We find a very rich phase diagram that becomes exponentially more complex as the number of networks is increased. In the simplest example of $n=2$ interacting networks we find two critical points, 4 triple points, 10 allowed transitions, and two "forbidden" transitions, as well as a manifold of metastable regions represented by complex hysteresis. Knowing and understanding the phase diagram have an immediate practical implication; it enables us to find the optimal strategy for repairing partially or fully damaged interconnected networks. To support our model, we analyze an example of real interacting financial net...

  20. Application of Biomaterials in Cardiac Repair and Regeneration

    Directory of Open Access Journals (Sweden)

    Zhi Cui

    2016-03-01

    Full Text Available Cardiovascular disease is a leading cause of death throughout the world. The demand for new therapeutic interventions is increasing. Although pharmacological and surgical interventions dramatically improve the quality of life of cardiovascular disease patients, cheaper and less invasive approaches are always preferable. Biomaterials, both natural and synthetic, exhibit great potential in cardiac repair and regeneration, either as a carrier for drug delivery or as an extracellular matrix substitute scaffold. In this review, we discuss the current treatment options for several cardiovascular diseases, as well as types of biomaterials that have been investigated as potential therapeutic interventions for said diseases. We especially highlight investigations into the possible use of conductive polymers for correcting ischemic heart disease-induced conduction abnormalities, and the generation of biological pacemakers to improve the conduction pathway in heart block.

  1. Proximal Contact Repair of Complex Amalgam Restorations.

    Science.gov (United States)

    Zguri, M N; Casey, J A; Jessup, J P; Vandewalle, K S

    2017-01-12

    The carving of a complex amalgam restoration may occasionally result in light proximal contact with the adjacent tooth. The purpose of this study was to investigate the strength of complex amalgam restorations repaired with a proximal slot amalgam preparation. Extracted human third molars of similar coronal size were sectioned 1 mm apical to the height of the contour using a saw and were randomly distributed into 9 groups of 10 teeth each. One pin was placed at each line angle of the flattened dentinal tooth surface. A metal matrix band was placed and an admixed alloy was condensed and carved to create a full crown contour but with a flat occlusal surface. A proximal slot was prepared with or without a retention groove and repaired using a single-composition spherical amalgam 15 minutes, 24 hours, one week, or six months after the initial crown condensation. The specimens were stored for 24 hours in 37°C water before fracture at the marginal ridge using a round-ended blade in a universal testing machine. The control group was not repaired. The mean maximum force in newtons and standard deviation were determined per group. Data were analyzed with a 2-way analysis of variance as well as Tukey and Dunnett tests (α=0.05). Significant differences were found between groups based on type of slot preparation (p=0.017) but not on time (p=0.327), with no significant interaction (p=0.152). No significant difference in the strength of the marginal ridge was found between any repair group and the unrepaired control group (p>0.076). The proximal repair strength of a complex amalgam restoration was not significantly different from an unrepaired amalgam crown. Placing a retention groove in the proximal slot preparation resulted in significantly greater fracture strength than a slot with no retention grooves. Time of repair had no significant effect on the strength of the repair.

  2. Inguinal hernia repair: toward Asian guidelines.

    Science.gov (United States)

    Lomanto, Davide; Cheah, Wei-Keat; Faylona, Jose Macario; Huang, Ching Shui; Lohsiriwat, Darin; Maleachi, Andy; Yang, George Pei Cheung; Li, Michael Ka-Wai; Tumtavitikul, Sathien; Sharma, Anil; Hartung, Rolf Ulrich; Choi, Young Bai; Sutedja, Barlian

    2015-02-01

    Groin hernias are very common, and surgical treatment is usually recommended. In fact, hernia repair is the most common surgical procedure performed worldwide. In countries such as the USA, China, and India, there may easily be over 1 million repairs every year. The need for this surgery has become an important socioeconomic problem and may affect health-care providers, especially in aging societies. Surgical repair using mesh is recommended and widely employed in Western countries, but in many developing countries, tissue-to-tissue repair is still the preferred surgical procedure due to economic constraints. For these reason, the development and implementation of guidelines, consensus, or recommendations may aim to clarify issues related to best practices in inguinal hernia repair in Asia. A group of Asian experts in hernia repair gathered together to debate inguinal hernia treatments in Asia in an attempt to reach some consensus or develop recommendations on best practices in the region. The need for recommendations or guidelines was unanimously confirmed to help overcome the discrepancy in clinical practice between countries; the experts decided to focus mainly on the technical aspects of open repair, which is the most common surgery for hernia in our region. After the identification of 12 main topics for discussion (indication, age, and sex; symptomatic and asymptomatic hernia: type of hernia; type of treatment; hospital admission; preoperative care; anesthesia; surgical technique; perioperative care; postoperative care; early complications; and long-term complications), a search of the literature was carried out according to the five levels of the Oxford Classification of Evidence and the four grades of recommendation.

  3. Bone Repair and Military Readiness

    Science.gov (United States)

    2014-08-01

    L929, and HUVEC ). Months 1-24. FY10 Task 3: Determine the biological response to silorane bone cement in animal models, Subtask 3a. Small Animal...cement identified in Specific Aim 1 with relevant cell lines (i.e., MLO-A5, MSCs, L929, and HUVEC ). Months 1-36. FY10 Task 3: Determine the...chemically initiated silorane bone cement identified in Specific Aim 1 with relevant cell lines (i.e., MLO-A5, MSCs, L929, and HUVEC ). Months 1-36

  4. How Trypanosoma cruzi deals with oxidative stress: Antioxidant defence and DNA repair pathways.

    Science.gov (United States)

    Machado-Silva, Alice; Cerqueira, Paula Gonçalves; Grazielle-Silva, Viviane; Gadelha, Fernanda Ramos; Peloso, Eduardo de Figueiredo; Teixeira, Santuza Maria Ribeiro; Machado, Carlos Renato

    2016-01-01

    Trypanosoma cruzi, the causative agent of Chagas disease, is an obligatory intracellular parasite with a digenetic life cycle. Due to the variety of host environments, it faces several sources of oxidative stress. In addition to reactive oxygen species (ROS) produced by its own metabolism, T. cruzi must deal with high ROS levels generated as part of the host's immune responses. Hence, the conclusion that T. cruzi has limited ability to deal with ROS (based on the lack of a few enzymes involved with oxidative stress responses) seems somewhat paradoxical. Actually, to withstand such variable sources of oxidative stress, T. cruzi has developed complex defence mechanisms. This includes ROS detoxification pathways that are distinct from the ones in the mammalian host, DNA repair pathways and specialized polymerases, which not only protect its genome from the resulting oxidative damage but also contribute to the generation of genetic diversity within the parasite population. Recent studies on T. cruzi's DNA repair pathways as mismatch repair (MMR) and GO system suggested that, besides a role associated with DNA repair, some proteins of these pathways may also be involved in signalling oxidative damage. Recent data also suggested that an oxidative environment might be beneficial for parasite survival within the host cell as it contributes to iron mobilization from the host's intracellular storages. Besides contributing to the understanding of basic aspects of T. cruzi biology, these studies are highly relevant since oxidative stress pathways are part of the poorly understood mechanisms behind the mode of action of drugs currently used against this parasite. By unveiling new peculiar aspects of T. cruzi biology, emerging data on DNA repair pathways and other antioxidant defences from this parasite have revealed potential new targets for a much needed boost in drug development efforts towards a better treatment for Chagas disease.

  5. Nuclear translocation contributes to regulation of DNA excision repair activities

    DEFF Research Database (Denmark)

    Knudsen, Nina Østergaard; Andersen, Sofie Dabros; Lützen, Anne;

    2009-01-01

    , it is evident that proteins from the different DNA repair pathways interact [Y. Wang, D. Cortez, P. Yazdi, N. Neff, S.J. Elledge, J. Qin, BASC, a super complex of BRCA1-associated proteins involved in the recognition and repair of aberrant DNA structures, Genes Dev. 14 (2000) 927-939; M. Christmann, M......DNA mutations are circumvented by dedicated specialized excision repair systems, such as the base excision repair (BER), nucleotide excision repair (NER), and mismatch repair (MMR) pathways. Although the individual repair pathways have distinct roles in suppressing changes in the nuclear DNA.......T. Tomicic, W.P. Roos, B. Kaina, Mechanisms of human DNA repair: an update, Toxicology 193 (2003) 3-34; N.B. Larsen, M. Rasmussen, L.J. Rasmussen, Nuclear and mitochondrial DNA repair: similar pathways? Mitochondrion 5 (2005) 89-108]. Protein interactions are not only important for function, but also...

  6. Etiology, Diagnosis, and Management of Failed SLAP Repair.

    Science.gov (United States)

    Werner, Brian C; Brockmeier, Stephen F; Miller, Mark D

    2014-09-01

    In general, favorable outcomes have been achieved with arthroscopic repair of superior labral anterior-posterior (SLAP) tears. However, some patients remain dissatisfied or suffer further injury after SLAP repair and may seek additional treatment to alleviate their symptoms. The cause of persistent pain or recurrent symptoms after repair is likely multifactorial; therefore, careful preoperative workup is required to elucidate the cause of pain. Review of the details of previous surgical procedures is crucial because certain fixation methods are prone to failure or can cause additional injury. Failed SLAP repair can be managed with nonsurgical or surgical options. Nonsurgical modalities include physical therapy and strengthening programs, anti-inflammatory agents, and activity modification. Surgical options include revision SLAP repair and biceps tenotomy or tenodesis with or without revision SLAP repair. Outcomes after surgical management of failed SLAP repair are inferior to those of primary repair. Select patients may be better served by primary biceps tenodesis rather than SLAP repair.

  7. Resection and repair of large abdominal wall lesions in gynecologic patients

    Institute of Scientific and Technical Information of China (English)

    LIU Zhu-feng; WANG Jin-hui; CUI Bing-qian; FAN Qing-bo; WANG Xiao-jun; ZHAO Ru; SONG Ke-xin

    2013-01-01

    Background The techniques of resection and repair of large lesions in the abdominal wall are very challenging in the area of gynecology.We explored the techniques of resection and plastic surgical repair of large abdominal wall lesions in gynecologic patients.Methods Twenty-six patients with large lesions in the abdominal wall underwent resection by the gynecologists and repair through abdominal plasty and V-Y plasty with or without fascia patch grafting by the gynecologists or plastic surgeons from March 2003 to October 2010.Results All patients had a history of cesarean section.One patient had an infected sinus tract after cesarean section,one patient had an inflammatory nodule,and the others had lesions of endometriosis,including one cancer.The average largest lesion diameter was (4.79 ± 4.18) cm according to the ultrasonography results.The lesions of all patients were completely resected with pretty abdominal contour.A polypropylene biological mesh was added to the fascia in 20 patients.One patient underwent groin flap repair,and one underwent V-Y advanced skin flap repair on the left of the incision to relieve the suture tension.Conclusions Multi-department cooperation involving the gynecology and plastic surgery departments,and even the general surgery department,is essential for patients with large lesions in the abdominal wall.This cooperative effort enabled surgeons to completely resect large lesions.Abdominal wall plastic surgical repair can ameliorate large wounds of the abdominal wall.

  8. BIOLOGIC JOINT RECONSTRUCTION: ALTERNATIVES TO ARTHROPLASTY

    Directory of Open Access Journals (Sweden)

    Brian J. Cole

    2009-06-01

    Full Text Available A comprehensive source of information in the management of cartilage lesions of major joints using nonoperative or surgical techniques other than total joint replacement. The text also includes chapters in basic sciences, imaging and rehabilitation.The editors are aiming to provide a reference about the latest concepts and techniques in the treatment of cartilage lesions including future aspects by a comprehensive approach to the alternative joint restoration procedures such as biological, pharmacological and surgical techniques of cartilage repairing and partial resurfacing etc.Orthopedic surgeons in sports medicine, orthopedic surgeons performing joint replacements, orthopedic resident and fellows will be the main audiences.The text is 349 pages, divided into 34 chapters in 7 sections. Section I is "Background-articular cartilage and allograft processing" including chapters about pathology, patient evaluation, imaging and allograft processing. Section II is "Nonoperative treatment" including chapters about neutraceuticals, pharmacological treatment and rehabilitation. Section III is "Operative treatment-knee" including chapters about arthroscopic debridment, microfracture, osteochondral autograft transplantation, mosaicplasty, osteochondral autograft transfer, osteochondral allografts, autologous chondrocyte implantation, existing cell-based technologies, minimally invasive second-generation autologous chondrocyte implantation, future development in cartilage repair, meniscus transplantation, management of OCD, patellafemoral chondral disease, proximal tibial and distal femoral osteotomies, unicompartmental arthritis current techniques, unicompartmental knee replacement. Section IV is "Operative treatment-Hip" including chapters about hip arthroscopy and arthroscopic partial resurfacing, related osteotomies. Section V is "operative treatment-shoulder" including chapters about arthroscopic debridment and release, biologic resurfacing and

  9. Wellbore Seal Repair Using Nanocomposite Materials

    Energy Technology Data Exchange (ETDEWEB)

    Stormont, John [Univ. of New Mexico, Albuquerque, NM (United States)

    2016-08-31

    Nanocomposite wellbore repair materials have been developed, tested, and modeled through an integrated program of laboratory testing and numerical modeling. Numerous polymer-cement nanocomposites were synthesized as candidate wellbore repair materials using various combinations of base polymers and nanoparticles. Based on tests of bond strength to steel and cement, ductility, stability, flowability, and penetrability in opening of 50 microns and less, we identified Novolac epoxy reinforced with multi-walled carbon nanotubes and/or alumina nanoparticles to be a superior wellbore seal material compared to conventional microfine cements. A system was developed for testing damaged and repaired wellbore specimens comprised of a cement sheath cast on a steel casing. The system allows independent application of confining pressures and casing pressures while gas flow is measured through the specimens along the wellbore axis. Repair with the nanocomposite epoxy base material was successful in dramatically reducing the flow through flaws of various sizes and types, and restoring the specimen comparable to an intact condition. In contrast, repair of damaged specimens with microfine cement was less effective, and the repair degraded with application of stress. Post-test observations confirm the complete penetration and sealing of flaws using the nanocomposite epoxy base material. A number of modeling efforts have supported the material development and testing efforts. We have modeled the steel-repair material interface behavior in detail during slant shear tests, which we used to characterize bond strength of candidate repair materials. A numerical model of the laboratory testing of damaged wellbore specimens was developed. This investigation found that microannulus permeability can satisfactorily be described by a joint model. Finally, a wellbore model has been developed that can be used to evaluate the response of the wellbore system (casing, cement, and microannulus

  10. Effectiveness of prophylactic antibiotic administration for inguinal hernia repair with biological patch: A Meta-analysis%生物补片植入腹股沟疝无张力疝修补后预防性应用抗生素的荟萃分析

    Institute of Scientific and Technical Information of China (English)

    梁兆克; 孙林

    2011-01-01

    背景:预防性应用抗生素在腹股沟疝无张力修补后非常普遍,但是,不加选择的应用抗生素会增加患者的费用及抗生素耐药.目的:系统评价预防性应用抗生素对腹股沟疝无张力疝修补术后手术部位感染发生率的影响.方法:计算机检索PubMed、EMBASE、Cochrane Library、CBM、CNKI、VIP 数据库,用RevMan5.0 软件进行统计分析.结果与结论:纳入8 篇随机对照试验进行分析,Meta 分析结果显示:预防性应用抗生素和安慰剂在预防腹股沟疝无张力疝修补术后手术部位感染发生率方面两组间差异有显著性意义[RR=0.68,95%CI(0.49,0.94)];而敏感性分析结果提示:两组差异无显著性意义[RR=0.78,95%CI(0.56,1.10)].亚组分析提示β-内酰胺类抗生素和安慰剂相比在预防腹股沟疝无张力疝修补后手术部位感染发生率方面差异无显著性意义[RR=0.63,95%CI(0.16,2.57)],头孢类抗生素和安慰剂相比差异也无显著性意义[RR=0.66,95%CI(0.41,1.06)].结果提示,没有足够的证据支持腹股沟疝无张力疝修补后常规预防性应用抗生素.%BACKGROUND: Prophylactic antibiotics are very common following tension-free inguinal hernia repair; however, indiscriminate use of antibiotics will increase the cost and antibiotic resistance of patients.OBJECTIVE: To systematic review the effectiveness of prophylactic antibiotic administration in reducing postoperative wound infection rates in inguinal hernia repair.METHODS: We searched PubMed, EMBASE, the Cochrane Library, CBM, CNKI, VIP databases, and the data were analyzed using Review Manager 5.0.RESULTS AND CONCLUSION: Eight randomized controlled tri als were included. The Meta analysis showed that there was significant difference between prophylactic antibiotic group and placebo group in surgical site infection rate [RR=0.68,95%CI(0.49, 0.94)]; The heterogeneity analysis did not reach statistical significance neither for the sensitivity analysis [RR=0

  11. 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.

  12. DNA repair responses in human skin cells

    Energy Technology Data Exchange (ETDEWEB)

    Hanawalt, P.C.; Liu, S.C.; Parsons, C.S.

    1981-07-01

    Sunlight and some environmental chemical agents produce lesions in the DNA of human skin cells that if unrepaired may interfere with normal functioning of these cells. The most serious outcome of such interactions may be malignancy. It is therefore important to develop an understanding of mechanisms by which the lesions may be repaired or tolerated without deleterious consequences. Our models for the molecular processing of damaged DNA have been derived largely from the study of bacterial systems. Some similarities but significant differences are revealed when human cell responses are tested against these models. It is also of importance to learn DNA repair responses of epidermal keratinocytes for comparison with the more extensive studies that have been carried out with dermal fibroblasts. Our experimental results thus far indicate similarities for the excision-repair of ultraviolet-induced pyrimidine dimers in human keratinocytes and fibroblasts. Both the monoadducts and the interstrand crosslinks produced in DNA by photoactivated 8-methoxypsoralen (PUVA) can be repaired in normal human fibroblasts but not in those from xeroderma pigmentosum patients. The monoadducts, like pyrimidine dimers, are probably the more mutagenic/carcinogenic lesions while the crosslinks are less easily repaired and probably result in more effective blocking of DNA function. It is suggested that a split-dose protocol that maximizes the production of crosslinks while minimizing the yield of monoadducts may be more effective and potentially less carcinogenic than the single ultraviolet exposure regimen in PUVA therapy for psoriasis.

  13. Umbilical Hernia Repair: Analysis After 934 Procedures.

    Science.gov (United States)

    Porrero, José L; Cano-Valderrama, Oscar; Marcos, Alberto; Bonachia, Oscar; Ramos, Beatriz; Alcaide, Benito; Villar, Sol; Sánchez-Cabezudo, Carlos; Quirós, Esther; Alonso, María T; Castillo, María J

    2015-09-01

    There is a lack of consensus about the surgical management of umbilical hernias. The aim of this study is to analyze the medium-term results of 934 umbilical hernia repairs. In this study, 934 patients with an umbilical hernia underwent surgery between 2004 and 2010, 599 (64.1%) of which were evaluated at least one year after the surgery. Complications, recurrence, and the reoperation rate were analyzed. Complications were observed in 5.7 per cent of the patients. With a mean follow-up time of 35.5 months, recurrence and reoperation rates were 3.8 per cent and 4.7 per cent, respectively. A higher percentage of female patients (60.9 % vs 29 %, P = 0.001) and a longer follow-up time (47.4 vs 35 months, P = 0.037) were observed in patients who developed a recurrence. No significant differences were observed between complications and the reoperation rate in patients who underwent Ventralex(®) preperitoneal mesh reinforcement and suture repair; however, a trend toward a higher recurrence rate was observed in patients with suture repair (6.5 % vs 3.2 %, P = 0.082). Suture repair had lower recurrence and reoperation rates in patients with umbilical hernias less than 1 cm. Suture repair is an appropriate procedure for small umbilical hernias; however, for larger umbilical hernias, mesh reinforcement should be considered.

  14. Repair of mismatched basepairs in mammalian DNA

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, J.H.; Hare, J.T.

    1991-08-01

    We have concentrated on three specific areas of our research plan. Our greatest emphasis is on the role of single strand nicks in influencing template strand selection in mismatch repair. We have found, that the ability of a nick in one strand to influence which strand is repaired is not a simple function of distance from the mismatched site but rather that an hot spot where a nick is more likely to have an influence can exist. The second line was production of single-genotype heteroduplexes in order to examine independently the repair of T/G and A/C mispairs within the same sequence context as in our mixed mispair preparations. We have shown preparations of supercoiled heteroduplex can be prepared that were exclusively T/G or exclusively A/C at the mispair site. The third effort has been to understand the difference in repair bias of different cell lines or different transfection conditions as it may relate to different repair systems in the cell. We have identified some of the sources of variation, including cell cycle position. We hope to continue this work to more precisely identify the phase of the cell cycle.

  15. Repair of DNA Double-Strand Breaks

    Science.gov (United States)

    Falk, Martin; Lukasova, Emilie; Kozubek, Stanislav

    The genetic information of cells continuously undergoes damage induced by intracellular processes including energy metabolism, DNA replication and transcription, and by environmental factors such as mutagenic chemicals and UV and ionizing radiation. This causes numerous DNA lesions, including double strand breaks (DSBs). Since cells cannot escape this damage or normally function with a damaged genome, several DNA repair mechanisms have evolved. Although most "single-stranded" DNA lesions are rapidly removed from DNA without permanent damage, DSBs completely break the DNA molecule, presenting a real challenge for repair mechanisms, with the highest risk among DNA lesions of incorrect repair. Hence, DSBs can have serious consequences for human health. Therefore, in this chapter, we will refer only to this type of DNA damage. In addition to the biochemical aspects of DSB repair, which have been extensively studied over a long period of time, the spatio-temporal organization of DSB induction and repair, the importance of which was recognized only recently, will be considered in terms of current knowledge and remaining questions.

  16. Repair Optimal Erasure Codes through Hadamard Designs

    CERN Document Server

    Papailiopoulos, Dimitris S; Cadambe, Viveck R

    2011-01-01

    In distributed storage systems that employ erasure coding, the issue of minimizing the total {\\it communication} required to exactly rebuild a storage node after a failure arises. This repair bandwidth depends on the structure of the storage code and the repair strategies used to restore the lost data. Designing high-rate maximum-distance separable (MDS) codes that achieve the optimum repair communication has been a well-known open problem. In this work, we use Hadamard matrices to construct the first explicit 2-parity MDS storage code with optimal repair properties for all single node failures, including the parities. Our construction relies on a novel method of achieving perfect interference alignment over finite fields with a finite file size, or number of extensions. We generalize this construction to design $m$-parity MDS codes that achieve the optimum repair communication for single systematic node failures and show that there is an interesting connection between our $m$-parity codes and the systematic-...

  17. In utero repair of spina bifida.

    Science.gov (United States)

    Moldenhauer, Julie S

    2014-08-01

    Open spina bifida or myelomeningocele (MMC) is the most common congenital malformation of the central nervous system compatible with long-term survival and is associated with significant lifelong disabilities. Postnatal care of MMC involves covering the exposed spinal cord, infection prevention, and ventricular shunting for hydrocephalus. The aim of postnatal MMC surgery is not to reverse or prevent the neurologic injury seen in MMC, but to palliate. The neurologic defects result from primary incomplete neurulation and secondary chronic in utero damage to the exposed neural elements through mechanical and chemical trauma-the two-hit hypothesis. With the ability to accurately diagnose spina bifida prenatally and the concept of the two-hit hypothesis, in utero repair to decrease exposure and alter the antenatal course of neurologic destruction was conceived. Through animal models and human pilot studies, the feasibility of fetal spina bifida repair was demonstrated. Subsequently, the prospective randomized multicenter Management of Myelomeningocele Study (MOMS trial) revealed a decreased need for shunting, reversal of hindbrain herniation, and preservation of neurologic function, making in utero repair an accepted care alternative for select women carrying a fetus with spina bifida. This article will highlight the background and rationale for in utero repair, and the progression to becoming an alternative standard of care. The future directions of fetal spina bifida repair will also be addressed.

  18. Transcription-coupled repair: an update.

    Science.gov (United States)

    Spivak, Graciela

    2016-11-01

    Nucleotide excision repair (NER) is a versatile pathway that removes helix-distorting DNA lesions from the genomes of organisms across the evolutionary scale, from bacteria to humans. The serial steps in NER involve recognition of lesions, adducts or structures that disrupt the DNA double helix, removal of a short oligonucleotide containing the offending lesion, synthesis of a repair patch copying the opposite undamaged strand, and ligation, to restore the DNA to its original form. Transcription-coupled repair (TCR) is a subpathway of NER dedicated to the repair of lesions that, by virtue of their location on the transcribed strands of active genes, encumber elongation by RNA polymerases. In this review, I report on recent findings that contribute to the elucidation of TCR mechanisms in the bacterium Escherichia coli, the yeast Saccharomyces cerevisiae and human cells. I review general models for the biochemical pathways and how and when cells might choose to utilize TCR or other pathways for repair or bypass of transcription-blocking DNA alterations.

  19. DNA repair variants and breast cancer risk.

    Science.gov (United States)

    Grundy, Anne; Richardson, Harriet; Schuetz, Johanna M; Burstyn, Igor; Spinelli, John J; Brooks-Wilson, Angela; Aronson, Kristan J

    2016-05-01

    A functional DNA repair system has been identified as important in the prevention of tumour development. Previous studies have hypothesized that common polymorphisms in DNA repair genes could play a role in breast cancer risk and also identified the potential for interactions between these polymorphisms and established breast cancer risk factors such as physical activity. Associations with breast cancer risk for 99 single nucleotide polymorphisms (SNPs) from genes in ten DNA repair pathways were examined in a case-control study including both Europeans (644 cases, 809 controls) and East Asians (299 cases, 160 controls). Odds ratios in both additive and dominant genetic models were calculated separately for participants of European and East Asian ancestry using multivariate logistic regression. The impact of multiple comparisons was assessed by correcting for the false discovery rate within each DNA repair pathway. Interactions between several breast cancer risk factors and DNA repair SNPs were also evaluated. One SNP (rs3213282) in the gene XRCC1 was associated with an increased risk of breast cancer in the dominant model of inheritance following adjustment for the false discovery rate (P breast cancer risk or their modification by breast cancer risk factors were observed.

  20. Biological Databases

    Directory of Open Access Journals (Sweden)

    Kaviena Baskaran

    2013-12-01

    Full Text Available Biology has entered a new era in distributing information based on database and this collection of database become primary in publishing information. This data publishing is done through Internet Gopher where information resources easy and affordable offered by powerful research tools. The more important thing now is the development of high quality and professionally operated electronic data publishing sites. To enhance the service and appropriate editorial and policies for electronic data publishing has been established and editors of article shoulder the responsibility.

  1. Repairing VLSI/WSI Redundant Memories with Minimum Cost

    Institute of Scientific and Technical Information of China (English)

    黄维康; F.Lombardi

    1990-01-01

    A new approach to repair memory chips with redundancy is proposed.This approach s based on the minimization of the repair cost.Algorithms for cost driven repair are presented.The algorithms can be executed either on -line(concurrently with the testing of the memory),or off-lin(at completion of testing).Analytical expressions for the repair cost under both circumstances are given.The presented algorithms are also perfect in the sense that they can correctly diagnose a repairable/unrepairable memory and find the optimal repair-solution.

  2. Biological biomaterials

    Energy Technology Data Exchange (ETDEWEB)

    Jorge-Herrero, E. [Servicio de Cirugia Experimental. Clinica Puerta de Hierro, Madrid (Spain)

    1997-05-01

    There are a number of situations in which substances of biological origin are employed as biomaterials. Most of them are macromolecules derived from isolated connective tissue or the connective tissue itself in membrane form, in both cases, the tissue can be used in its natural form or be chemically treated. In other cases, certain blood vessels can be chemically pretreated and used as vascular prostheses. Proteins such as albumin, collagen and fibrinogen are employed to coat vascular prostheses. Certain polysaccharides have also been tested for use in controlled drug release systems. Likewise, a number of tissues, such as dura mater, bovine pericardium, procine valves and human valves, are used in the preparation of cardiac prostheses. We also use veins from animals or humans in arterial replacement. In none of these cases are the tissues employed dissimilar to the native tissues as they have been chemically modified, becoming a new bio material with different physical and biochemical properties. In short, we find that natural products are being utilized as biomaterials and must be considered as such; thus, it is necessary to study both their chemicobiological and physicomechanical properties. In the present report, we review the current applications, problems and future prospects of some of these biological biomaterials. (Author) 84 refs.

  3. Cell biology of mitotic recombination

    DEFF Research Database (Denmark)

    Lisby, Michael; Rothstein, Rodney

    2015-01-01

    Homologous recombination provides high-fidelity DNA repair throughout all domains of life. Live cell fluorescence microscopy offers the opportunity to image individual recombination events in real time providing insight into the in vivo biochemistry of the involved proteins and DNA molecules...... of this review include the stoichiometry and dynamics of recombination complexes in vivo, the choreography of assembly and disassembly of recombination proteins at sites of DNA damage, the mobilization of damaged DNA during homology search, and the functional compartmentalization of the nucleus with respect...... as well as the cellular organization of the process of homologous recombination. Herein we review the cell biological aspects of mitotic homologous recombination with a focus on Saccharomyces cerevisiae and mammalian cells, but will also draw on findings from other experimental systems. Key topics...

  4. Chronic pain after childhood groin hernia repair

    DEFF Research Database (Denmark)

    Aasvang, Eske Kvanner; Kehlet, Henrik

    2007-01-01

    BACKGROUND: In contrast to the well-described 10% risk of chronic pain affecting daily activities after adult groin hernia repair, chronic pain after childhood groin hernia repair has never been investigated. Studies of other childhood surgery before the age of 3 months suggest a risk of increased...... pain responsiveness later in life, but its potential relationship to chronic pain in adult life is unknown. METHODS: This was a nationwide detailed questionnaire study of chronic groin pain in adults having surgery for a groin hernia repair before the age of 5 years (n = 1075). RESULTS: The response...... the age of 3 months (n = 122) did not report groin pain more often or with higher intensity than other patients did. CONCLUSIONS: Groin pain in adult patients operated on for a groin hernia in childhood is uncommon and usually mild and occurs in relation to physical activity. Operation before the age of 3...

  5. Amniotic membrane covering for facial nerve repair

    Institute of Scientific and Technical Information of China (English)

    Murat Karaman; Arzu Tuncel; Shahrouz Sheidaei; Mehmet Güney (S)enol; Murat Hakan Karabulut; Ildem Deveci; Nihan Karaman

    2013-01-01

    Amniotic membranes have been widely used in ophthalmology and skin injury repair because of their anti-inflammatory properties. In this study, we measured therapeutic efficacy and determined if amniotic membranes could be used for facial nerve repair. The facial nerves of eight rats were dissected and end-to-end anastomosis was performed. Amniotic membranes were covered on the anastomosis sites in four rats. Electromyography results showed that, at the end of the 3rd and 8th weeks after amniotic membrane covering, the latency values of the facial nerves covered by amniotic membranes were significantly shortened and the amplitude values were significantly increased. Compared with simple facial nerve anastomosis, after histopathological examination, facial nerve anastomosed with amniotic membrane showed better continuity, milder inflammatory reactions, and more satisfactory nerve conduction. These findings suggest that amniotic membrane covering has great potential in facial nerve repair.

  6. Transactivation of repair genes by BRCA1.

    Science.gov (United States)

    El-Deiry, Wafik S

    2002-01-01

    Recent studies have identified a link between the BRCA1 tumor suppressor and transcriptional regulation of a group of genes involved in nucleotide excision repair. There is some controversy regarding the precise mechanism of upregulation of XPE DDB2 or XPC by BRCA1, with some evidence suggesting that p53 is involved in their regulation. Some evidence suggests BRCA1 may stabilize p53 and direct regulation of DNA repair genes, although how BRCA1 stabilizes p53 remains unclear and whether BRCA1 can upregulate DNA repair genes in a p53-independent manner remains a possibility. A transcriptional component to the action of BRCA1 and involvement of XP genes brings up new and interesting questions about breast cancer development and therapy.

  7. [DNA homologous recombination repair in mammalian cells].

    Science.gov (United States)

    Popławski, Tomasz; Błasiak, Janusz

    2006-01-01

    DNA double-strand breaks (DSBs) are the most serious DNA damage. Due to a great variety of factors causing DSBs, the efficacy of their repair is crucial for the cell's functioning and prevents DNA fragmentation, chromosomal translocation and deletion. In mammalian cells DSBs can be repaired by non-homologous end joining (NHEJ), homologous recombination (HRR) and single strand annealing (SSA). HRR can be divided into the first and second phase. The first phase is initiated by sensor proteins belonging to the MRN complex, that activate the ATM protein which target HRR proteins to obtain the second response phase--repair. HRR is precise because it utilizes a non-damaged homologous DNA fragment as a template. The key players of HRR in mammalian cells are MRN, RPA, Rad51 and its paralogs, Rad52 and Rad54.

  8. Exosomes and cardiac repair after myocardial infarction.

    Science.gov (United States)

    Sahoo, Susmita; Losordo, Douglas W

    2014-01-17

    Myocardial infarction is a leading cause of death among all cardiovascular diseases. The analysis of molecular mechanisms by which the ischemic myocardium initiates repair and remodeling indicates that secreted soluble factors are key players in communication to local and distant tissues, such as bone marrow. Recently, actively secreted membrane vesicles, including exosomes, are being recognized as new candidates with important roles in intercellular and tissue-level communication. In this review, we critically examine the emerging role of exosomes in local and distant microcommunication mechanisms after myocardial infarction. A comprehensive understanding of the role of exosomes in cardiac repair after myocardial infarction could bridge a major gap in knowledge of the repair mechanism after myocardial injury.

  9. Enhanced recovery after giant ventral hernia repair

    DEFF Research Database (Denmark)

    Jensen, K K; Brøndum, T L; Harling, H.;

    2016-01-01

    PURPOSE: Giant ventral hernia repair is associated with a high risk of postoperative morbidity and prolonged length of stay (LOS). Enhanced recovery (ERAS) measures have proved to lead to decreased morbidity and LOS after various surgical procedures, but never after giant hernia repair. The current...... study prospectively examined the results of implementation of an ERAS pathway including high-dose preoperative glucocorticoid, and compared the outcome with patients previously treated according to standard care (SC). METHODS: Consecutive patients who underwent giant ventral hernia repair were included...... was 0.92. There were no differences when comparing readmission (5 vs. 2, P = 0.394), postoperative complications (7 vs. 4, P = 0. 458), or reoperation (5 vs. 1, P = 0.172) in ERAS versus controls. CONCLUSIONS: The current study suggests that an ERAS pathway including preoperative high...

  10. Macrophages in Tissue Repair, Regeneration, and Fibrosis.

    Science.gov (United States)

    Wynn, Thomas A; Vannella, Kevin M

    2016-03-15

    Inflammatory monocytes and tissue-resident macrophages are key regulators of tissue repair, regeneration, and fibrosis. After tissue injury, monocytes and macrophages undergo marked phenotypic and functional changes to play critical roles during the initiation, maintenance, and resolution phases of tissue repair. Disturbances in macrophage function can lead to aberrant repair, such that uncontrolled production of inflammatory mediators and growth factors, deficient generation of anti-inflammatory macrophages, or failed communication between macrophages and epithelial cells, endothelial cells, fibroblasts, and stem or tissue progenitor cells all contribute to a state of persistent injury, and this could lead to the development of pathological fibrosis. In this review, we discuss the mechanisms that instruct macrophages to adopt pro-inflammatory, pro-wound-healing, pro-fibrotic, anti-inflammatory, anti-fibrotic, pro-resolving, and tissue-regenerating phenotypes after injury, and we highlight how some of these mechanisms and macrophage activation states could be exploited therapeutically.

  11. Mitral Valve Repair: The Chordae Tendineae

    Directory of Open Access Journals (Sweden)

    Carlos-A Mestres

    2015-10-01

    Full Text Available Repair of the mitral valve is the treatment of choice for mitral valve regurgitation when the anatomy is favorable. It is well known that mitral valve repair enjoys better clinical and functional results than any other type of valve substitute. This fact is beyond doubt regardless of the etiology of the valve lesion and is of particular importance in degenerative diseases.This review analyzes the most important advances in the knowledge of the anatomy, pathophysiology, and chordal function of the mitral valve as well as the different alternatives in the surgical repair and clinical results of the most prevalent diseases of the mitral valve. An attempt has been made to organize the acquired information available in a practical way.

  12. Process-induced extracellular matrix alterations affect the mechanisms of soft tissue repair and regeneration

    Directory of Open Access Journals (Sweden)

    Wendell Q Sun

    2013-09-01

    Full Text Available Extracellular matrices derived from animal tissues for human tissue repairs are processed by various methods of physical, chemical, or enzymatic decellularization, viral inactivation, and terminal sterilization. The mechanisms of action in tissue repair vary among bioscaffolds and are suggested to be associated with process-induced extracellular matrix modifications. We compared three non-cross-linked, commercially available extracellular matrix scaffolds (Strattice, Veritas, and XenMatrix, and correlated extracellular matrix alterations to in vivo biological responses upon implantation in non-human primates. Structural evaluation showed significant differences in retaining native tissue extracellular matrix histology and ultrastructural features among bioscaffolds. Tissue processing may cause both the condensation of collagen fibers and fragmentation or separation of collagen bundles. Calorimetric analysis showed significant differences in the stability of bioscaffolds. The intrinsic denaturation temperature was measured to be 51°C, 38°C, and 44°C for Strattice, Veritas, and XenMatrix, respectively, demonstrating more extracellular matrix modifications in the Veritas and XenMatrix scaffolds. Consequently, the susceptibility to collagenase degradation was increased in Veritas and XenMatrix when compared to their respective source tissues. Using a non-human primate model, three bioscaffolds were found to elicit different biological responses, have distinct mechanisms of action, and yield various outcomes of tissue repair. Strattice permitted cell repopulation and was remodeled over 6 months. Veritas was unstable at body temperature, resulting in rapid absorption with moderate inflammation. XenMatrix caused severe inflammation and sustained immune reactions. This study demonstrates that extracellular matrix alterations significantly affect biological responses in soft tissue repair and regeneration. The data offer useful insights into the

  13. Global genome nucleotide excision repair is organized into domains that promote efficient DNA repair in chromatin

    Science.gov (United States)

    Yu, Shirong; Evans, Katie; Bennett, Mark; Webster, Richard M.; Leadbitter, Matthew; Teng, Yumin; Waters, Raymond

    2016-01-01

    The rates at which lesions are removed by DNA repair can vary widely throughout the genome, with important implications for genomic stability. To study this, we measured the distribution of nucleotide excision repair (NER) rates for UV-induced lesions throughout the budding yeast genome. By plotting these repair rates in relation to genes and their associated flanking sequences, we reveal that, in normal cells, genomic repair rates display a distinctive pattern, suggesting that DNA repair is highly organized within the genome. Furthermore, by comparing genome-wide DNA repair rates in wild-type cells and cells defective in the global genome–NER (GG-NER) subpathway, we establish how this alters the distribution of NER rates throughout the genome. We also examined the genomic locations of GG-NER factor binding to chromatin before and after UV irradiation, revealing that GG-NER is organized and initiated from specific genomic locations. At these sites, chromatin occupancy of the histone acetyl-transferase Gcn5 is controlled by the GG-NER complex, which regulates histone H3 acetylation and chromatin structure, thereby promoting efficient DNA repair of UV-induced lesions. Chromatin remodeling during the GG-NER process is therefore organized into these genomic domains. Importantly, loss of Gcn5 significantly alters the genomic distribution of NER rates; this has implications for the effects of chromatin modifiers on the distribution of mutations that arise throughout the genome. PMID:27470111

  14. Laparoscopic repair of a Morgagni hernia

    Directory of Open Access Journals (Sweden)

    Sherigar J

    2005-01-01

    Full Text Available We report a case of laparoscopic repair of symptomatic Morgagni hernia (MH in an adult. A tension-free closure of the defect was carried out using a polypropylene mesh. The recovery was quick and uneventful. Two years after surgery, the patient is doing well. A search of the English-language surgical literature revealed a total of 55 cases of laparoscopic repair of MH reported: 40 in adults and 15 in children. The various modalities of diagnosis, operative techniques, and disease presentation are discussed.

  15. Generic and Automated Runtime Program Repair

    Science.gov (United States)

    2012-09-01

    out using 15% of the memory and 5% of the disk space of pre-award work, and concrete examples of repairs using Nokia N900 smartphones are described...red. Experiments were run either on a machine with 2.2 GHz AMD Opteron processors and 120 GB of memory or on Nokia N900 smartphones, each of which...the memory usage when performing repairs for each combination of program and representation. Our Nokia smartphones have 256+768 MB of RAM plus swap. In

  16. Valve radio and audio repair handbook

    CERN Document Server

    MILLER, CHAS

    2000-01-01

    This book is not only an essential read for every professional working with antique radio and gramophone equipment, but also dealers, collectors and valve technology enthusiasts the world over. The emphasis is firmly on the practicalities of repairing and restoring, so technical content is kept to a minimum, and always explained in a way that can be followed by readers with no background in electronics. Those who have a good grounding in electronics, but wish to learn more about the practical aspects, will benefit from the emphasis given to hands-on repair work, covering mechanical as

  17. Chromatin challenges during DNA replication and repair

    DEFF Research Database (Denmark)

    Groth, Anja; Rocha, Walter; Verreault, Alain;

    2007-01-01

    Inheritance and maintenance of the DNA sequence and its organization into chromatin are central for eukaryotic life. To orchestrate DNA-replication and -repair processes in the context of chromatin is a challenge, both in terms of accessibility and maintenance of chromatin organization. To meet...... the challenge of maintenance, cells have evolved efficient nucleosome-assembly pathways and chromatin-maturation mechanisms that reproduce chromatin organization in the wake of DNA replication and repair. The aim of this Review is to describe how these pathways operate and to highlight how the epigenetic...

  18. Histone displacement during nucleotide excision repair

    DEFF Research Database (Denmark)

    Dinant, C.; Bartek, J.; Bekker-Jensen, S.

    2012-01-01

    Nucleotide excision repair (NER) is an important DNA repair mechanism required for cellular resistance against UV light and toxic chemicals such as those found in tobacco smoke. In living cells, NER efficiently detects and removes DNA lesions within the large nuclear macromolecular complex called...... of histone variants and histone displacement (including nucleosome sliding). Here we review current knowledge, and speculate about current unknowns, regarding those chromatin remodeling activities that physically displace histones before, during and after NER. © 2012 by the authors; licensee MDPI, Basel...

  19. Repairable chip bonding/interconnect process

    Science.gov (United States)

    Bernhardt, Anthony F.; Contolini, Robert J.; Malba, Vincent; Riddle, Robert A.

    1997-01-01

    A repairable, chip-to-board interconnect process which addresses cost and testability issues in the multi-chip modules. This process can be carried out using a chip-on-sacrificial-substrate technique, involving laser processing. This process avoids the curing/solvent evolution problems encountered in prior approaches, as well is resolving prior plating problems and the requirements for fillets. For repairable high speed chip-to-board connection, transmission lines can be formed on the sides of the chip from chip bond pads, ending in a gull wing at the bottom of the chip for subsequent solder.

  20. Synthetic, biological and composite scaffolds for abdominal wall reconstruction.

    Science.gov (United States)

    Meintjes, Jennifer; Yan, Sheng; Zhou, Lin; Zheng, Shusen; Zheng, Minghao

    2011-03-01

    The reconstruction of abdominal wall defects remains a huge surgical challenge. Tension-free repair is proven to be superior to suture repair in abdominal wall reconstruction. Scaffolds are essential for tension-free repair. They are used to bridge a defect or reinforce the abdominal wall. A huge variety of scaffolds are now commercially available. Most of the synthetic scaffolds are composed of polypropylene. They provide strong tissue reinforcement, but cause a foreign body reaction, which can result in serious complications. Absorbable synthetic scaffolds, such as Dexon™ (polyglycolic acid) and Vicryl™ (polyglactin 910), are not suitable for abdominal wall reconstruction as they usually require subsequent surgeries to repair recurrent hernias. Composite scaffolds combine the strength of nonabsorbable synthetic scaffolds with the antiadhesive properties of the absorbable scaffold, but require long-term follow-up. Biological scaffolds, such as Permacol™, Surgisis(®) and Alloderm(®), are derived from acellular mammalian tissues. Non-cross-linked biological scaffolds show excellent biocompatibility and degrade slowly over time. However, remnant DNA has been found in several products and the degradation leads to recurrence. Randomized controlled trials with long-term follow-up studies are lacking for all of the available scaffolds, particularly those derived from animal tissue. This article provides an overview of the different types of scaffolds available, and presents the key clinical studies of the commercially available synthetic, composite and biological scaffolds for abdominal wall reconstruction.

  1. Effect of chemical surface treatments and repair material on transverse strength of repaired acrylic denture resin

    Directory of Open Access Journals (Sweden)

    Vojdani Mahroo

    2008-01-01

    Full Text Available Purpose: This study was performed to evaluate the transverse strength of a denture base resin (H, repaired with an autopolymerizing acrylic resin (A or a visible light-curing (VLC resin (T following the use of three chemical solvents: methyl methacrylate monomer, aceton or chloroform. Materials and Methods: Eighty specimens (65.0 x 10.0 x 3.3 mm of H were fabricated and stored in distilled water at 37°C for seven days. Specimens were divided into eight equal groups of 10. In each group, specimens were sectioned in the middle to create a 10 mm gap. Two groups served as controls and had no surface treatment. They were repaired with A or T materials. In the remaining six experimental groups, specimen surfaces were treated with ac for 30 sec or mma for 180 sec or ch for 5 sec. Then A or T material was placed on the treated surfaces, using the same preparation molds. After seven days′ storage at 37°C, the transverse bond strength (MPa of the specimens was measured using a three-point bending test. A two-way ANOVA and a Tukey HSD were performed to identify significant differences ( P < 0.05. The nature of the failures was noted as adhesive, cohesive or mixed. Results: Significant differences were found between the controls and experimental groups ( P < 0.05. In the control groups, repair with A showed significantly higher strength (60.3 MPa than those repaired with T (51.3 MPa. Mean transverse strength of experimental specimens repaired with A was (75.06 MPa which was significantly greater than those repaired with T (67.9 MPa. Although surface treatment increased repair strength, no significant differences were detected between the effects of the chemical etchants. Conclusions: The autopolymerizing resin exhibited significantly higher repair strength than VLC resin. The transverse strength of the repaired specimens was increased significantly after chemical treatments.

  2. Lipid Rafts in Mast Cell Biology

    Directory of Open Access Journals (Sweden)

    Adriana Maria Mariano Silveira e Souza

    2011-01-01

    Full Text Available Mast cells have long been recognized to have a direct and critical role in allergic and inflammatory reactions. In allergic diseases, these cells exert both local and systemic responses, including allergic rhinitis and anaphylaxis. Mast cell mediators are also related to many chronic inflammatory conditions. Besides the roles in pathological conditions, the biological functions of mast cells include roles in innate immunity, involvement in host defense mechanisms against parasites, immunomodulation of the immune system, tissue repair, and angiogenesis. Despite their growing significance in physiological and pathological conditions, much still remains to be learned about mast cell biology. This paper presents evidence that lipid rafts or raft components modulate many of the biological processes in mast cells, such as degranulation and endocytosis, play a role in mast cell development and recruitment, and contribute to the overall preservation of mast cell structure and organization.

  3. Sumoylation influences DNA break repair partly by increasing the solubility of a conserved end resection protein.

    Directory of Open Access Journals (Sweden)

    Prabha Sarangi

    2015-01-01

    Full Text Available Protein modifications regulate both DNA repair levels and pathway choice. How each modification achieves regulatory effects and how different modifications collaborate with each other are important questions to be answered. Here, we show that sumoylation regulates double-strand break repair partly by modifying the end resection factor Sae2. This modification is conserved from yeast to humans, and is induced by DNA damage. We mapped the sumoylation site of Sae2 to a single lysine in its self-association domain. Abolishing Sae2 sumoylation by mutating this lysine to arginine impaired Sae2 function in the processing and repair of multiple types of DNA breaks. We found that Sae2 sumoylation occurs independently of its phosphorylation, and the two modifications act in synergy to increase soluble forms of Sae2. We also provide evidence that sumoylation of the Sae2-binding nuclease, the Mre11-Rad50-Xrs2 complex, further increases end resection. These findings reveal a novel role for sumoylation in DNA repair by regulating the solubility of an end resection factor. They also show that collaboration between different modifications and among multiple substrates leads to a stronger biological effect.

  4. Sumoylation Influences DNA Break Repair Partly by Increasing the Solubility of a Conserved End Resection Protein

    Science.gov (United States)

    Sarangi, Prabha; Steinacher, Roland; Altmannova, Veronika; Fu, Qiong; Paull, Tanya T.; Krejci, Lumir; Whitby, Matthew C.; Zhao, Xiaolan

    2015-01-01

    Protein modifications regulate both DNA repair levels and pathway choice. How each modification achieves regulatory effects and how different modifications collaborate with each other are important questions to be answered. Here, we show that sumoylation regulates double-strand break repair partly by modifying the end resection factor Sae2. This modification is conserved from yeast to humans, and is induced by DNA damage. We mapped the sumoylation site of Sae2 to a single lysine in its self-association domain. Abolishing Sae2 sumoylation by mutating this lysine to arginine impaired Sae2 function in the processing and repair of multiple types of DNA breaks. We found that Sae2 sumoylation occurs independently of its phosphorylation, and the two modifications act in synergy to increase soluble forms of Sae2. We also provide evidence that sumoylation of the Sae2-binding nuclease, the Mre11-Rad50-Xrs2 complex, further increases end resection. These findings reveal a novel role for sumoylation in DNA repair by regulating the solubility of an end resection factor. They also show that collaboration between different modifications and among multiple substrates leads to a stronger biological effect. PMID:25569253

  5. A New Absorbable Synthetic Substitute With Biomimetic Design for Dural Tissue Repair.

    Science.gov (United States)

    Shi, Zhidong; Xu, Tao; Yuan, Yuyu; Deng, Kunxue; Liu, Man; Ke, Yiquan; Luo, Chengyi; Yuan, Tun; Ayyad, Ali

    2016-04-01

    Dural repair products are evolving from animal tissue-derived materials to synthetic materials as well as from inert to absorbable features; most of them lack functional and structural characteristics compared with the natural dura mater. In the present study, we evaluated the properties and tissue repair performance of a new dural repair product with biomimetic design. The biomimetic patch exhibits unique three-dimensional nonwoven microfiber structure with good mechanical strength and biocompatibility. The animal study showed that the biomimetic patch and commercially synthetic material group presented new subdural regeneration at 90 days, with low level inflammatory response and minimal to no adhesion formation detected at each stage. In the biological material group, no new subdural regeneration was observed and severe adhesion between the implant and the cortex occurred at each stage. In clinical case study, there was no cerebrospinal fluid leakage, and all the postoperation observations were normal. The biomimetic structure and proper rate of degradation of the new absorbable dura substitute can guide the meaningful reconstruction of the dura mater, which may provide a novel approach for dural defect repair.

  6. Mechanics and mechano-biology of fracture healing in normal and osteoporotic bone.

    Science.gov (United States)

    Augat, Peter; Simon, Ulrich; Liedert, Astrid; Claes, Lutz

    2005-03-01

    Fracture repair, which aims at regaining the functional competence of a bone, is a complex and multifactorial process. For the success of fracture repair biology and mechanics are of immense importance. The biological and mechanical environments must be compatible with the processes of cell and tissue proliferation and differentiation. The biological environment is characterized by the vascular supply and by many biochemical components, the biochemical milieu. A good vascular supply is a prerequisite for the initiation of the fracture repair process. The biochemical milieu involves complex interactions among local and systemic regulatory factors such as growth factors or cytokines. The mechanical environment is determined by the local stress and strain within the fracture. However, the local stress and strain is not accessible, and the mechanical environment, therefore, is described by global mechanical factors, e.g., gap size or interfragmentary movement. The relationship between local stress and strain and the global mechanical factors can be obtained by numerical models (Finite Element Model). Moreover, there is considerable interaction between biological factors and mechanical factors, creating a biomechanical environment for the fracture healing process. The biomechanical environment is characterized by osteoblasts and osteocytes that sense the mechanical signal and express biological markers, which effect the repair process. This review will focus on the effects of biomechanical factors on fracture repair as well as the effects of age and osteoporosis.

  7. Reduced cellular DNA repair capacity after environmentally relevant arsenic exposure. Influence of Ogg1 deficiency

    Energy Technology Data Exchange (ETDEWEB)

    Bach, Jordi; Peremartí, Jana; Annangi, Balasubramnayam [Grup de Mutagènesi, Departament de Genètica i de Microbiologia, Facultat de Biociències, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Barcelona (Spain); Marcos, Ricard, E-mail: ricard.marcos@uab.es [Grup de Mutagènesi, Departament de Genètica i de Microbiologia, Facultat de Biociències, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Barcelona (Spain); CIBER Epidemiología y Salud Pública, ISCIII, Madrid (Spain); Hernández, Alba, E-mail: alba.hernandez@uab.es [Grup de Mutagènesi, Departament de Genètica i de Microbiologia, Facultat de Biociències, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Barcelona (Spain); CIBER Epidemiología y Salud Pública, ISCIII, Madrid (Spain)

    2015-09-15

    Highlights: • Repair ability under long-term exposure to arsenic was tested using the comet assay. • Effects were measured under Ogg1 wild-type and deficient backgrounds. • Exposed cells repair less efficiency the DNA damage induced by SA, KBrO{sub 3}, MMA{sup III} or UVC radiation. • Oxidative damage and Ogg1 deficient background exacerbate repair deficiencies. • Overexpression of the arsenic metabolizing enzyme As3mt acts as adaptive mechanism. - Abstract: Inorganic arsenic (i-As) is a genotoxic and carcinogenic environmental contaminant known to affect millions of people worldwide. Our previous work demonstrated that chronic sub-toxic i-As concentrations were able to induce biologically significant levels of genotoxic and oxidative DNA damage that were strongly influenced by the Ogg1 genotype. In order to study the nature of the observed levels of damage and the observed differences between MEF Ogg1{sup +/+} and Ogg1{sup −/−} genetic backgrounds, the genotoxic and oxidative DNA repair kinetics of 18-weeks exposed MEF cells were evaluated by the comet assay. Results indicate that MEF Ogg1{sup +/+} and Ogg1{sup −/−} cells chronically exposed to i-As repair the DNA damage induced by arsenite, potassium bromide and UVC radiation less efficiently than control cells, being that observation clearly more pronounced in MEF Ogg1{sup −/−} cells. Consequently, exposed cells accumulate a higher percentage of unrepaired DNA damage at the end of the repair period. As an attempt to eliminate i-As associated toxicity, chronically exposed MEF Ogg1{sup −/−} cells overexpress the arsenic metabolizing enzyme As3mt. This adaptive response confers cells a significant resistance to i-As-induced cell death, but at expenses of accumulating high levels of DNA damage due to their repair impairment. Overall, the work presented here evidences that i-As chronic exposure disrupts the normal cellular repair function, and that oxidative DNA damage—and Ogg1 deficiency

  8. Gastroesophageal junction adenocarcinoma displays abnormalities in homologous recombination and nucleotide excision repair

    Directory of Open Access Journals (Sweden)

    Dewalt RI

    2014-02-01

    Full Text Available Robin I Dewalt,1 Kenneth A Kesler,2 Zane T Hammoud,3 LeeAnn Baldridge,4 Eyas M Hattab,4 Shadia I Jalal1,5 1Division of Hematology/Oncology, Department of Medicine, 2Cardiothoracic Division, Department of Surgery, Indiana University School of Medicine, Indianapolis, IN, USA; 3Henry Ford Hospital, Detroit, MI, USA; 4Department of Pathology and Laboratory Medicine, Indiana University School of Medicine, Indianapolis, IN, USA; 5Indiana University Melvin and Bren Simon Cancer Center, Indianapolis, IN, USA Objective: Esophageal adenocarcinoma (EAC continues to be a disease associated with high mortality. Among the factors leading to poor outcomes are innate resistance to currently available therapies, advanced stage at diagnosis, and complex biology. Platinum and ionizing radiation form the backbone of treatment for the majority of patients with EAC. Of the multiple processes involved in response to platinum chemotherapy or ionizing radiation, deoxyribonucleic acid (DNA repair has been a major player in cancer sensitivity to these agents. DNA repair defects have been described in various malignancies. The purpose of this study was to determine whether alterations in DNA repair are present in EAC compared with normal gastroesophageal tissues. Methods: We analyzed the expression of genes involved in homologous recombination (HR, nonhomologous end-joining, and nucleotide excision repair (NER pathways in 12 EAC tumor samples with their matched normal counterparts. These pathways were chosen because they are the main pathways involved in the repair of platinum- or ionizing-radiation-induced damage. In addition, abnormalities in these pathways have not been well characterized in EAC. Results: We identified increased expression of at least one HR gene in eight of the EAC tumor samples. Alterations in the expression of EME1, a structure-specific endonuclease involved in HR, were the most prevalent, with messenger (mRNA overexpression in six of the EAC samples

  9. Neurophysiological characterization of persistent pain after laparoscopic inguinal hernia repair

    DEFF Research Database (Denmark)

    Linderoth, G; Kehlet, H; Aasvang, E K;

    2011-01-01

    About 2-5% of patients undergoing laparoscopic inguinal repair experience persistent pain influencing everyday activities. However, compared with persistent pain after open repair, the combined clinical and neurophysiological characteristics have not been described in detail. Thus, the aim...

  10. Optimization of repair cycles of VOMD-24 blowers

    Energy Technology Data Exchange (ETDEWEB)

    Kosarev, N.P.; Kuznetsov, S.V. (Sverdlovskii Gornyi Institut (USSR))

    1990-04-01

    Evaluates service life, reliability and repair of VOMD-24 blowers used for ventilation in underground coal mines in the USSR. Depending on operational conditions and ventilation systems, the overhaul life ranges from 7.2 to 14.7 months or 17.7 and 22.5 months (if general overhauls are considered). The mean-time-to repair ranges from 23.3 to 24.0 months, mean-time-to general overhaul from 32.6 to 38.0 months. The average labor consumption of blower repair and of general overhauls is analyzed along with labor consumption of service operations and repair. The recommended and actual standard repair cost, labor consumption and repair intervals are comparatively evaluated. Mathematical models for optimization of repair intervals are evaluated. Use of mathematical modeling for reducing repair cost, increasing blower reliability and reducing losses caused by blower failures is analyzed. 4 refs.

  11. Phosphorylation: The Molecular Switch of Double-Strand Break Repair

    Directory of Open Access Journals (Sweden)

    K. C. Summers

    2011-01-01

    Full Text Available Repair of double-stranded breaks (DSBs is vital to maintaining genomic stability. In mammalian cells, DSBs are resolved in one of the following complex repair pathways: nonhomologous end-joining (NHEJ, homologous recombination (HR, or the inclusive DNA damage response (DDR. These repair pathways rely on factors that utilize reversible phosphorylation of proteins as molecular switches to regulate DNA repair. Many of these molecular switches overlap and play key roles in multiple pathways. For example, the NHEJ pathway and the DDR both utilize DNA-PK phosphorylation, whereas the HR pathway mediates repair with phosphorylation of RPA2, BRCA1, and BRCA2. Also, the DDR pathway utilizes the kinases ATM and ATR, as well as the phosphorylation of H2AX and MDC1. Together, these molecular switches regulate repair of DSBs by aiding in DSB recognition, pathway initiation, recruitment of repair factors, and the maintenance of repair mechanisms.

  12. Nucleotide excision repair of DNA: The very early history.

    Science.gov (United States)

    Friedberg, Errol C

    2011-07-15

    This article, taken largely from the book Correcting the Blueprint of Life: An Historical Account of the Discovery of DNA Repair Mechanisms, summarizes the very early history of the discovery of nucleotide excision repair.

  13. Fragile DNA Repair Mechanism Reduces Ageing in Multicellular Model

    DEFF Research Database (Denmark)

    Bendtsen, Kristian Moss; Juul, Jeppe Søgaard; Trusina, Ala

    2012-01-01

    DNA damages, as well as mutations, increase with age. It is believed that these result from increased genotoxic stress and decreased capacity for DNA repair. The two causes are not independent, DNA damage can, for example, through mutations, compromise the capacity for DNA repair, which in turn...... to DNA damage can undergo full repair, go apoptotic, or accumulate mutations thus reducing DNA repair capacity. Our model predicts that at the tissue level repair rate does not continuously decline with age, but instead has a characteristic extended period of high and non-declining DNA repair capacity...... of compromised cells, thus freeing the space for healthy peers. This finding might be a first step toward understanding why a mutation in single DNA repair protein (e.g. Wrn or Blm) is not buffered by other repair proteins and therefore, leads to severe ageing disorders...

  14. Sequelae of Endoscopic Inguinal Hernia Repair : Incidence, evaluation and management

    NARCIS (Netherlands)

    Burgmans, J.P.J.

    2015-01-01

    The endoscopic preperitoneal technique (TEP) is an appealing inguinal hernia repair technique, theoretically superior to other approaches. In practice some problems remain unsolved. Real incidences of chronic postoperative inguinal pain (CPIP) and other important sequelae of endoscopic hernia repair

  15. Structural Biology Fact Sheet

    Science.gov (United States)

    ... Home > Science Education > Structural Biology Fact Sheet Structural Biology Fact Sheet Tagline (Optional) Middle/Main Content Area What is structural biology? Structural biology is a field of science focused ...

  16. Bioactive Nanocomposites for Tissue Repair and Regeneration: A Review

    Science.gov (United States)

    Bramhill, Jane; Ross, Sukunya; Ross, Gareth

    2017-01-01

    This review presents scientific findings concerning the use of bioactive nanocomposites in the field of tissue repair and regeneration. Bioactivity is the ability of a material to incite a specific biological reaction, usually at the boundary of the material. Nanocomposites have been shown to be ideal bioactive materials due the many biological interfaces and structures operating at the nanoscale. This has resulted in many researchers investigating nanocomposites for use in bioapplications. Nanocomposites encompass a number of different structures, incorporating organic-inorganic, inorganic-inorganic and bioinorganic nanomaterials and based upon ceramic, metallic or polymeric materials. This enables a wide range of properties to be incorporated into nanocomposite materials, such as magnetic properties, MR imaging contrast or drug delivery, and even a combination of these properties. Much of the classical research was focused on bone regeneration, however, recent advances have enabled further use in soft tissue body sites too. Despite recent technological advances, more research is needed to further understand the long-term biocompatibility impact of the use of nanoparticles within the human body. PMID:28085054

  17. Bioactive Nanocomposites for Tissue Repair and Regeneration: A Review

    Directory of Open Access Journals (Sweden)

    Jane Bramhill

    2017-01-01

    Full Text Available This review presents scientific findings concerning the use of bioactive nanocomposites in the field of tissue repair and regeneration. Bioactivity is the ability of a material to incite a specific biological reaction, usually at the boundary of the material. Nanocomposites have been shown to be ideal bioactive materials due the many biological interfaces and structures operating at the nanoscale. This has resulted in many researchers investigating nanocomposites for use in bioapplications. Nanocomposites encompass a number of different structures, incorporating organic-inorganic, inorganic-inorganic and bioinorganic nanomaterials and based upon ceramic, metallic or polymeric materials. This enables a wide range of properties to be incorporated into nanocomposite materials, such as magnetic properties, MR imaging contrast or drug delivery, and even a combination of these properties. Much of the classical research was focused on bone regeneration, however, recent advances have enabled further use in soft tissue body sites too. Despite recent technological advances, more research is needed to further understand the long-term biocompatibility impact of the use of nanoparticles within the human body.

  18. Intervertebral disc (IVD): Structure, degeneration, repair and regeneration

    Energy Technology Data Exchange (ETDEWEB)

    Whatley, Benjamin R.; Wen Xuejun, E-mail: xjwen@clemson.edu

    2012-02-01

    Low back pain affects a large portion of the population, resulting in high care costs for therapy and treatment. One primary cause of low back pain is the degeneration of the intervertebral disc (IVD) resulting in the compression of the spinal nerves and adjacent vertebrae. Exact causes of degeneration are unknown, but it is thought that natural aging, and both biological and genetic factors may play a significant role in the degenerative process. Conventional methods to alleviate low back pain include spinal fusion and artificial disc replacement. Traditional treatments through spinal fusion may eliminate pain yet do not restore disc function and lead to further degeneration of adjacent levels by altering disc biomechanics and natural kinematics. Recently, artificial IVD replacements have started to gain interest, with two IVD implants currently approved in the United States. Although these implants facilitate the preservation of motions and disc space height, they are unable to sustain compressive forces due to their lack of elasticity. In addition, the implants may produce wear debris that can cause osteolysis and other deleterious effects. As an alternative to these conventional approaches, tissue engineered IVD constructs offer the advantage of biointegration while preserving the essential attributes of natural motion and disc space restoration. There is a great need for the development of tissue engineered scaffolds that simulate the natural 3D morphology and microenvironment of the targeted tissue. Scaffolds should facilitate biological transport to satisfy nutrition and waste removal requirements within the IVD. The discrete tissue architectures of the nucleus pulposus (NP) and annulus fibrosus (AF) have posed great challenges to IVD tissue engineering. Current attempts have not been able to satisfy the biological functions and/or mechanical properties of native tissue. Therefore, these current scaffolds are far from satisfactory. This review highlights the

  19. Failure strengths of repair devices versus meniscus suturing techniques

    OpenAIRE

    Asik, Mehmet; Sener, Nadir; Dikici, Fatih; Sen, Cengiz

    2004-01-01

    Objectives: The purpose of this study was to compare the load to failure of different common suturing techniques with that of repair devices. Methods: Seventy-one calf medial menisci were cut to simulate peripheral longitudinal tears and repaired using either one of the two suture techniques or one of the seven repair devices. Then the two parts of the meniscus were pulled using an Instron tensometer until failure occurred. The techniques and repair devices tested included vertical (0 PDS,...

  20. Health effects among refrigeration repair workers exposed to fluorocarbons.

    OpenAIRE

    1986-01-01

    Refrigeration repair workers may be intermittently exposed to fluorocarbons and their thermal decomposition products. A case of peripheral neuropathy (distal axonopathy) in a commercial refrigeration repairman prompted an epidemiological investigation of the health of refrigeration repair workers. No additional cases of peripheral neuropathy were identified among the 27 refrigeration repair workers studied. A reference group of 14 non-refrigeration repair workers was also studied. No differen...

  1. Prognostic factors in sensory recovery after digital nerve repair

    OpenAIRE

    Bulut, Tugrul; Akgun, Ulas; Citlak, Atilla; Aslan, Cihan; Sener, Ufuk; Sener, Muhittin

    2017-01-01

    Objective: The prognostic factors that affect sensory nerve recovery after digital nerve repair are variable because of nonhomogeneous data, subjective tests, and different assessment/scoring methods. The aim of this study was to evaluate the success of sensory nerve recovery after digital nerve repair and to investigate the prognostic factors in sensorial healing.Methods: Ninety-six digital nerve repairs of 63 patients were retrospectively evaluated. All nerves were repaired with end-to-end ...

  2. Total Extraperitoneal Preperitoneal Laparoscopic Hernia Repair Using Spinal Anesthesia

    OpenAIRE

    2006-01-01

    Background: Laparoscopic herniorrhaphy is a well-debated approach to inguinal hernia repair. Multiple technical and outcome variables have been compared with those of traditional open inguinal hernia repairs. One of these variables is the choice of anesthesia. To date, no reports describe the use of spinal anesthesia for laparoscopic hernia repairs. We present herein a review of our experience with spinal anesthesia for the total extraperitoneal preperitoneal laparoscopic hernia repair (TEP)....

  3. Finite element analysis to model complex mitral valve repair.

    Science.gov (United States)

    Labrosse, Michel; Mesana, Thierry; Baxter, Ian; Chan, Vincent

    2016-01-01

    Although finite element analysis has been used to model simple mitral repair, it has not been used to model complex repair. A virtual mitral valve model was successful in simulating normal and abnormal valve function. Models were then developed to simulate an edge-to-edge repair and repair employing quadrangular resection. Stress contour plots demonstrated increased stresses along the mitral annulus, corresponding to the annuloplasty. The role of finite element analysis in guiding clinical practice remains undetermined.

  4. Oxidative DNA damage background estimated by a system model of base excision repair.

    Science.gov (United States)

    Sokhansanj, Bahrad A; Wilson, David M

    2004-08-01

    Human DNA can be damaged by natural metabolism through free radical production. It has been suggested that the equilibrium between innate damage and cellular DNA repair results in an oxidative DNA damage background that potentially contributes to disease and aging. Efforts to quantitatively characterize the human oxidative DNA damage background level, based on measuring 8-oxoguanine lesions as a biomarker, have led to estimates that vary over three to four orders of magnitude, depending on the method of measurement. We applied a previously developed and validated quantitative pathway model of human DNA base excision repair, integrating experimentally determined endogenous damage rates and model parameters from multiple sources. Our estimates of at most 100 8-oxoguanine lesions per cell are consistent with the low end of data from biochemical and cell biology experiments, a result robust to model limitations and parameter variation. Our findings show the power of quantitative system modeling to interpret composite experimental data and make biologically and physiologically relevant predictions for complex human DNA repair pathway mechanisms and capacity.

  5. Oxidative DNA damage background estimated by a system model of base excision repair

    Energy Technology Data Exchange (ETDEWEB)

    Sokhansanj, B A; Wilson, III, D M

    2004-05-13

    Human DNA can be damaged by natural metabolism through free radical production. It has been suggested that the equilibrium between innate damage and cellular DNA repair results in an oxidative DNA damage background that potentially contributes to disease and aging. Efforts to quantitatively characterize the human oxidative DNA damage background level based on measuring 8-oxoguanine lesions as a biomarker have led to estimates varying over 3-4 orders of magnitude, depending on the method of measurement. We applied a previously developed and validated quantitative pathway model of human DNA base excision repair, integrating experimentally determined endogenous damage rates and model parameters from multiple sources. Our estimates of at most 100 8-oxoguanine lesions per cell are consistent with the low end of data from biochemical and cell biology experiments, a result robust to model limitations and parameter variation. Our results show the power of quantitative system modeling to interpret composite experimental data and make biologically and physiologically relevant predictions for complex human DNA repair pathway mechanisms and capacity.

  6. Simulating Biological and Non-Biological Motion

    Science.gov (United States)

    Bruzzo, Angela; Gesierich, Benno; Wohlschlager, Andreas

    2008-01-01

    It is widely accepted that the brain processes biological and non-biological movements in distinct neural circuits. Biological motion, in contrast to non-biological motion, refers to active movements of living beings. Aim of our experiment was to investigate the mechanisms underlying mental simulation of these two movement types. Subjects had to…

  7. A Brief Introduction to Chinese Biological Biological

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Chinese Biological Abstracts sponsored by the Library, the Shanghai Institutes for Biological Sciences, the Biological Documentation and Information Network, all of the Chinese Academy of Sciences, commenced publication in 1987 and was initiated to provide access to the Chinese information in the field of biology.

  8. DNA repair, immunosuppression, and skin cancer.

    Science.gov (United States)

    Yarosh, Daniel B

    2004-11-01

    UV radiation (UVR) produces erythema within the first 24 hours of exposure, suppression of the immune system within the first 10 days, and, for many people, over the course of decades, skin cancer. Although UVR damages many skin targets, DNA damage in the form of cyclobutane pyrimidine dimers (CPDs) is an important mediator of these sequelae. The action spectrum for erythema parallels the action spectrum for CPD formation in skin, and in the absence of repair, as in the genetic disease xeroderma pigmentosum (XP), skin cancer rates are dramatically increased. DNA repair in skin can be enhanced by the delivery of DNA repair enzymes encapsulated in liposomes. Used in this way, photoreactivation of CPDs greatly diminishes erythema and the suppression of contact hypersensitivity (CHS). UV endonucleases delivered by liposomes also prevent UV-induced suppression of delayed-type hypersensitivity. In a clinical study of patients with XP, T4 endonuclease V (T4N5) liposome lotion applied for one year reduced the rates of actinic keratosis (AK) and skin cancer compared with placebo. These results showed that strategies to increase sun protection should include measures to reduce DNA damage and increase the rate of DNA repair.

  9. ROAD REPAIR WORKS ON THE MEYRIN SITE

    CERN Multimedia

    ST-TFM Group

    2001-01-01

    ST Division will proceed, as from Monday 23 July, in repairing some parts of roads on the Meyrin site (see drawing). This work will last for one week depending on the weather conditions and will cause some traffic hold ups during this period. Please follow the indications on the temporary road signs. Thanking you in advance for your comprehension.

  10. Repairing Hidden Cracks in Coolant Tubes

    Science.gov (United States)

    Mills, R. C., Sr.; Duesberg, J.

    1984-01-01

    Repair technique closes leaks in tubes or conduits where access limited to wall opposite crack. Technique applicable to any tubular assembly where tubes bundled together or bonded to supporting shell, such as in heat exchangers. Procedure provides structural support to area failed and uninterrupted flow without significantly altering heat-transfer profile.

  11. Systems with randomly failing repairable components

    DEFF Research Database (Denmark)

    Der Kiureghian, Armen; Ditlevsen, Ove Dalager; Song, Junho

    2005-01-01

    Closed-form expressions are derived for the steady-state availability, mean rate of failure, mean duration of downtime and reliability of a general system with randomly and independently failing repairable components. Component failures are assumed to be homogeneous Poisson events in time and rep...

  12. The Onstep Method for Inguinal Hernia Repair

    DEFF Research Database (Denmark)

    Rosenberg, Jacob; Andresen, Kristoffer

    2016-01-01

    Inguinal hernia repair is one of the most common surgical procedures and several different surgical techniques are available. The Onstep method is a new promising technique. The technique is simple with a number of straightforward steps. This paper provides a full description of the technique...

  13. Parabolic resection for mitral valve repair.

    Science.gov (United States)

    Drake, Daniel H; Drake, Charles G; Recchia, Dino

    2010-02-01

    Parabolic resection, named for the shape of the cut edges of the excised tissue, expands on a common 'trick' used by experienced mitral surgeons to preserve tissue and increase the probability of successful repair. Our objective was to describe and clinically analyze this simple modification of conventional resection. Thirty-six patients with mitral regurgitation underwent valve repair using parabolic resection in combination with other techniques. Institution specific mitral data, Society of Thoracic Surgeons data and preoperative, post-cardiopulmonary bypass (PCPB) and postoperative echocardiography data were collected and analyzed. Preoperative echocardiography demonstrated mitral regurgitation ranging from moderate to severe. PCPB transesophageal echocardiography demonstrated no regurgitation or mild regurgitation in all patients. Thirty-day surgical mortality was 2.8%. Serial echocardiograms demonstrated excellent repair stability. One patient (2.9%) with rheumatic disease progressed to moderate regurgitation 33 months following surgery. Echocardiography on all others demonstrated no or mild regurgitation at a mean follow-up of 22.8+/-12.8 months. No patient required mitral reintervention. Longitudinal analysis demonstrated 80% freedom from cardiac death, reintervention and greater than moderate regurgitation at four years following repair. Parabolic resection is a simple technique that can be very useful during complex mitral reconstruction. Early and intermediate echocardiographic studies demonstrate excellent results.

  14. PRP and Metaplasia in repaired tendon

    Institute of Scientific and Technical Information of China (English)

    Kamal Seyed-Forootan; Hamid Karimi; Ahmad-Reza Dayani

    2014-01-01

    Objective:To evaluate effects ofPRP injection in strengthening of repaired tendon.Methods:This study was conducted in animal lab of our hospital on20 rats.The animals were divided into two groups randomly and distal third of leftAchillis tendons were cut and then repaired with Vicryl2/0.The first group was control group and in the second group0.5 cc ofPRP was injected into the repair site.After4 weeks all of the rats were executed and70% of tendons were sent randomly for tensilometry and the force that required to rupture the tendons were measured.In next stage the tendons were sent for pathological exam.Results:The force that was needed to rupture the tendon were not significantly different in the two groups.Neovascularization were more prevalent inPRP group but not statistically significant.There were two cases ofCartilage Metaplasia inPRP group.Conclusion:It seems that usingPRP has no effect on strengthening the tendons repair and may have some adverse effects.It usage needs further studies to evaluate their probable adverse side effects.

  15. Umbilical Hernia Repair with Proceed Ventral Patch

    Directory of Open Access Journals (Sweden)

    Salati Sajad Ahmad

    2014-07-01

    Full Text Available Umbilical hernia is one the commonest surgical lesions and there is a variety of methods available for its repair. Proceed Ventral Patch is a recent and novel innovation in hernia management and we present a successful management of umbilical hernia in a 45 years old obese patient with this technique

  16. Repairing organs : lessons from intestine and liver

    NARCIS (Netherlands)

    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 liv

  17. Ceramic restoration repair: report of two cases

    Directory of Open Access Journals (Sweden)

    Luís Henrique Araújo Raposo

    2009-04-01

    Full Text Available The esthetic and functional rehabilitation of patients with multiple missing teeth can be performed with several techniques and materials. Ceramic restorations provide reliable masticatory function and good esthetics. However, fracture can occur in some cases due to their brittle behavior. In some cases, the replacement of an extensive prosthesis is a problem due to the high treatment cost. In this paper, two cases are presented, in which fractures occurred in extensive metal-ceramic fixed partial dentures, and their replacement was not possible. Ceramic repair was chosen and the sequences of treatment with and without presence of the ceramic fragment are also discussed. The cases illustrate that, in some situations, fractured metal-ceramic partial dentures can be successfully repaired when prosthetic replacement is not a choice. Prosthodontists must use alternatives that allow a reliable repair to extensive metal-ceramic fixed partial dentures. Surface preparation of the ceramic with hydrofluoric acid in conjunction with a silane coupling agent is essential for a predictable bonding of composite resin. The repair performed with composite resin is an esthetic and functional alternative when extensive fixed partial dentures cannot be replaced.

  18. 49 CFR 195.422 - Pipeline repairs.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Pipeline repairs. 195.422 Section 195.422 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) PIPELINE SAFETY TRANSPORTATION OF HAZARDOUS LIQUIDS...

  19. Repair Negotiation by English L2 Learners

    Science.gov (United States)

    Choi, Yujeong

    2012-01-01

    It is widely accepted that L2 learners often face communication problems due to lack of competency in the target language and familiarity with its culture of origin. One way to resolve miscommunication problems is to seek clarification of the utterance; this process is called "repair negotiation" (Nakahama et al. 2001). Repair…

  20. Collaborative Repair in EFL Classroom Talk.

    Science.gov (United States)

    Iles, Zara

    1996-01-01

    Drawing data from audiotaped lessons with 10 native-speaker English-as-a-Foreign-Language (EFL) teachers and 12 EFL learners of varied linguistic backgrounds, a study explored some of the ways in which classroom talk by learners is collaboratively built to repair errors, misunderstandings, and non-communication. Focus is on both explicit and…

  1. Back Channelling, Repair, Pausing, and Private Speech.

    Science.gov (United States)

    White, Ron

    1997-01-01

    Focuses on differences in back channelling, repair, repetition, pausing, and private speech among Japanese and American study participants, based on sales negotiations. Findings indicate that differences in the deployment of such features as back channelling and pausing can result in pragma-linguistic breakdown, which is linked to culturally…

  2. Cockayne syndrome: defective repair of transcription?

    NARCIS (Netherlands)

    A.J. van Gool (Alain); G.T.J. van der Horst (Gijsbertus); E. Citterio (Elisabetta); J.H.J. Hoeijmakers (Jan)

    1997-01-01

    textabstractIn the past years, it has become increasingly evident that basal metabolic processes within the cell are intimately linked and influenced by one another. One such link that recently has attracted much attention is the close interplay between nucleotide excision DNA repair and transcripti

  3. Postpartum perineal repair performed by midwives

    DEFF Research Database (Denmark)

    Kindberg, S; Stehouwer, M; Hvidman, L

    2008-01-01

    OBJECTIVE: To compare a continuous suture technique with interrupted stitches using inverted knots for postpartum perineal repair of second-degree lacerations and episiotomies. DESIGN: A double-blind randomised controlled trial. SETTING: A Danish university hospital with more than 4800 deliveries...

  4. Biomaterial and Cell Based Cartilage Repair

    NARCIS (Netherlands)

    Zhao, X

    2015-01-01

    Injuries to human native cartilage tissue are particularly troublesome because cartilage has little ability to heal or regenerate itself. The reconstruction, repair, and regeneration of cartilage tissue continue to be one of the greatest clinical challenges, especially in orthopaedic and plastic sur

  5. Macrophage diversity in renal injury and repair

    NARCIS (Netherlands)

    Ricardo, Sharon D.; van Goor, Harry; Eddy, Allison A.

    2008-01-01

    Monocyte-derived macrophages can determine the outcome of the immune response and whether this response contributes to tissue repair or mediates tissue destruction. In addition to their important role in immune-mediated renal disease and host defense, macrophages play a fundamental role in tissue re

  6. CLEFT-PALATE REPAIR - FURLOW VERSUS VONLANGENBECK

    NARCIS (Netherlands)

    SPAUWEN, PHM; GOORHUISBROUWER, SM; SCHUTTE, HK

    1992-01-01

    The Furlow cleft palate repair using a double opposing Z-plasty appears to be very promising. In order to detect advantages and disadvantages concerning the technique as well as speech- and hearing results, the Furlow palatoplasty was compared with the classical von Langenbeck technique. Data analys

  7. Repair technology for steam generator tubes

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seung Ho; Jung, Hyun Kyu; Jung, Seung Ho; Kim, Chang Hoi; Jung, Young Moo; Seo, Yong Chil; Kim, Jung Su; Seo, Moo Hong

    2001-02-01

    The most commonly used sleeving materials are thermally treated Alloy 600 and thermally treated Alloy 690 Alloy. Currently, thermally treated Alloy 690 and Alloy 800 are being offered although Alloy 800 has not been licensed in the US. To install sleeve, joint strength, leak tightness, PWSCC resistance, evaluation on process parameter range and the effect of equipments and procedures on repair plan and radiation damage have to be investigated before sleeving. ABB CE provides three type of leak tight Alloy 690 TIG welded and PLUSS sleeve. Currently, Direct Tube Repair technique using Nd:YAG laser has been developed by ABB CE and Westinghouse. FTI has brazed and kinetic sleeve designs for recirculating steam generator and hydraulic and rolled sleeve designs for one-through steam generators. Westinghouse provides HEJ, brazed and laser welded sleeve design. When sleeve is installed in order to repair the damaged S/G tubes, it is certain that defects can be occurred due to the plastic induced stress and thermal stress. Therefore it is important to minimize the residual stress. FTI provides the electrosleeve technique as a future repair candidate using electroplating.

  8. Repairing A Shaft Prone To Fatigue

    Science.gov (United States)

    Sharp, Roger A.; Larsen, David V.; Bates, Garold A.

    1991-01-01

    Shaft of hydraulic motor now outlives its bearings. Procedure for repairing John Deere Series 50 (or equivalent) hydraulic motor solves problem posed by common type of fatigue failure of shaft. Includes forming internally threaded hole in end of shaft, inserting double-threaded end stud, and adding washers and collars.

  9. [Exposure assessment to metals in an armament repair shop of a military organization].

    Science.gov (United States)

    Neves, Eduardo Borba; Mendonça Junior, Nelson; Moreira, Maria de Fátima Ramos

    2009-01-01

    The aim of this study was the occupational exposure assessment to lead and manganese of workers in an armament repair shop of a military organization. The air of the working environment was assessed in the environmental monitoring while the internal dose biological indicators for lead and manganese, in blood and urine, were used in biological monitoring. Metals concentration in filters and biological fluids were determined by electrothermal atomic absorption spectrometry. The results of the environmental monitoring showed lead and manganese levels above the TLV-TWA during the process of painting (313.33 g m-3) and solder (951 microg m-3). The biological indicators revealed that five of the nine employees presented Pb-S levels that suggested an environmental exposure to lead (values between 5 and 10 microg dL-1). It can be concluded that there is a small occupational exposure to lead and manganese in the superficial treatment repair shop. This exposure is influenced by weather conditions and the variable demand of work.

  10. Component Repair Times Obtained from MSPI Data

    Energy Technology Data Exchange (ETDEWEB)

    Eide, Steven A. [Curtiss-Wright/Scietech, Ketchum, ID (United States); Cadwallader, Lee [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-05-01

    Information concerning times to repair or restore equipment to service given a failure is valuable to probabilistic risk assessments (PRAs). Examples of such uses in modern PRAs include estimation of the probability of failing to restore a failed component within a specified time period (typically tied to recovering a mitigating system before core damage occurs at nuclear power plants) and the determination of mission times for support system initiating event (SSIE) fault tree models. Information on equipment repair or restoration times applicable to PRA modeling is limited and dated for U.S. commercial nuclear power plants. However, the Mitigating Systems Performance Index (MSPI) program covering all U.S. commercial nuclear power plants provides up-to-date information on restoration times for a limited set of component types. This paper describes the MSPI program data available and analyzes the data to obtain median and mean component restoration times as well as non-restoration cumulative probability curves. The MSPI program provides guidance for monitoring both planned and unplanned outages of trains of selected mitigating systems deemed important to safety. For systems included within the MSPI program, plants monitor both train UA and component unreliability (UR) against baseline values. If the combined system UA and UR increases sufficiently above established baseline results (converted to an estimated change in core damage frequency or CDF), a “white” (or worse) indicator is generated for that system. That in turn results in increased oversight by the US Nuclear Regulatory Commission (NRC) and can impact a plant’s insurance rating. Therefore, there is pressure to return MSPI program components to service as soon as possible after a failure occurs. Three sets of unplanned outages might be used to determine the component repair durations desired in this article: all unplanned outages for the train type that includes the component of interest, only

  11. Content-Related Repairing of Inconsistencies in Distributed Data

    Institute of Scientific and Technical Information of China (English)

    Yue-Feng Du; De-Rong Shen; Tie-Zheng Nie; Yue Kou; Ge Yu

    2016-01-01

    Conditional functional dependencies (CFDs) are a critical technique for detecting inconsistencies while they may ignore some potential inconsistencies without considering the content relationship of data. Content-related conditional functional dependencies (CCFDs) are a type of special CFDs, which combine content-related CFDs and detect potential inconsistencies by putting content-related data together. In the process of cleaning inconsistencies, detection and repairing are interactive: 1) detection catches inconsistencies, 2) repairing corrects caught inconsistencies while may bring new incon-sistencies. Besides, data are often fragmented and distributed into multiple sites. It consequently costs expensive shipment for inconsistencies cleaning. In this paper, our aim is to repair inconsistencies in distributed content-related data. We propose a framework consisting of an inconsistencies detection method and an inconsistencies repairing method, which work iteratively. The detection method marks the violated CCFDs for computing the inconsistencies which should be repaired preferentially. Based on the repairing-cost model presented in this paper, we prove that the minimum-cost repairing using CCFDs is NP-complete. Therefore, the repairing method heuristically repairs the inconsistencies with minimum cost. To improve the efficiency and accuracy of repairing, we propose distinct values and rules sequences. Distinct values make less data shipments than real data for communication. Rules sequences determine appropriate repairing sequences to avoid some incorrect repairs. Our solution is proved to be more effective than CFDs by empirical evaluation on two real-life datasets.

  12. 46 CFR 176.700 - Permission for repairs and alterations.

    Science.gov (United States)

    2010-10-01

    ... (UNDER 100 GROSS TONS) INSPECTION AND CERTIFICATION Repairs and Alterations § 176.700 Permission for... refastening of deck or hull planking, plating, and structural members; repair of plate or frame cracks; damage repair or replacement, other than replacement in kind, of electrical wiring, fuel lines, tanks,...

  13. 49 CFR 237.133 - Supervision of repairs and modifications.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Supervision of repairs and modifications. 237.133... Supervision of repairs and modifications. Each repair or modification pursuant to this part shall be performed under the immediate supervision of a railroad bridge supervisor as defined in § 237.55 of this part...

  14. Repair welding process of friction stir welding groove defect

    Institute of Scientific and Technical Information of China (English)

    LIU Hui-jie; ZHANG Hui-jie

    2009-01-01

    The groove defect formed in the friction stir welding dramatically deteriorates weld appearances and mechanical properties of the joints owing to its larger size and penetration. Therefore, the friction stir repair welding was utilized to remove such a groove defect, and the focus was placed on the mechanical properties and microstructural characteristics of the repair joints so as to obtain an optimum repair welding process. The experimental results indicate that the groove defect can be removed by friction stir repair welding, and the offset repair welding process is superior to the symmetrical repair welding process. In the symmetrical repair welding process, a large number of fine cavity defects and an obvious aggregation of hard-brittle phase Al2Cu occur, accordingly the mechanical properties of the repair joint are weakened, and the fracture feature of repair joint is partially brittle and partially plastic. A good-quality repair joint can be obtained by the offset repair welding process, and the repair joint is fractured near the interface between the weld nugget zone and thermal-mechanically affected zone.

  15. 21 CFR 872.3570 - OTC denture repair kit.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false OTC denture repair kit. 872.3570 Section 872.3570...) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3570 OTC denture repair kit. (a) Identification. An OTC denture repair kit is a device consisting of a material, such as a resin monomer system...

  16. 10 CFR 35.605 - Installation, maintenance, adjustment, and repair.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Installation, maintenance, adjustment, and repair. 35.605... Installation, maintenance, adjustment, and repair. (a) Only a person specifically licensed by the Commission or an Agreement State shall install, maintain, adjust, or repair a remote afterloader unit,...

  17. 33 CFR 158.240 - Ship repair yards.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Ship repair yards. 158.240... Facilities: Oily Mixtures § 158.240 Ship repair yards. The reception facility that services oceangoing ships using a ship repair yard must have a capacity for receiving— (a) An amount of ballast from bunker...

  18. 27 CFR 555.216 - Repair of magazines.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2010-04-01 2010-04-01 false Repair of magazines. 555... EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES Storage § 555.216 Repair of magazines. Before repairing the interior of magazines, all explosive materials are to be removed and the...

  19. 14 CFR 145.209 - Repair station manual contents.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Repair station manual contents. 145.209... manual contents. A certificated repair station's manual must include the following: (a) An organizational... for revising the repair station's manual and notifying its certificate holding district office...

  20. 30 CFR 57.19109 - Shaft inspection and repair.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Shaft inspection and repair. 57.19109 Section 57.19109 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND... Hoisting Shafts § 57.19109 Shaft inspection and repair. Shaft inspection and repair work in vertical...

  1. 46 CFR 131.575 - Yearly inspections and repair.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Yearly inspections and repair. 131.575 Section 131.575..., Drills, and Inspections § 131.575 Yearly inspections and repair. (a) Each lifeboat, rescue boat, rigid... expiration date must be replaced during the annual inspection and repair if this date has passed. (d)...

  2. 46 CFR 170.005 - Vessel alteration or repair.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Vessel alteration or repair. 170.005 Section 170.005... REQUIREMENTS FOR ALL INSPECTED VESSELS General Provisions § 170.005 Vessel alteration or repair. (a) Alterations and repairs to inspected vessels must be done— (1) Under the direction of the Officer in...

  3. 30 CFR 56.19109 - Shaft inspection and repair.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Shaft inspection and repair. 56.19109 Section 56.19109 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND... Hoisting Shafts § 56.19109 Shaft inspection and repair. Shaft inspection and repair work in vertical...

  4. 40 CFR 1033.815 - Maintenance, operation, and repair.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Maintenance, operation, and repair... Maintenance, operation, and repair. All persons who own, operate, or maintain locomotives are subject to this... components of the diagnostics system itself. For most repairs, this paragraph (b) requires that...

  5. 40 CFR 92.1004 - Maintenance and repair.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Maintenance and repair. 92.1004... Owners and Operators of Locomotives and Locomotive Engines § 92.1004 Maintenance and repair. (a) Unless..., all maintenance and repair of locomotives and locomotive engines subject to the provisions of...

  6. 46 CFR 169.211 - Permit to proceed for repair.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Permit to proceed for repair. 169.211 Section 169.211... Inspection and Certification Certificate of Inspection § 169.211 Permit to proceed for repair. (a) The Officer in Charge, Marine Inspection, may issue a permit to proceed to another port for repair, Form...

  7. 24 CFR 3285.804 - Bottom board repair.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 5 2010-04-01 2010-04-01 false Bottom board repair. 3285.804....804 Bottom board repair. (a) The bottom board covering must be inspected for any loosening or areas... to be replaced prior to closure and repair of the bottom board. (b) Any splits or tears in the...

  8. 32 CFR 174.14 - Maintenance and repair.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 1 2010-07-01 2010-07-01 false Maintenance and repair. 174.14 Section 174.14... REVITALIZING BASE CLOSURE COMMUNITIES AND ADDRESSING IMPACTS OF REALIGNMENT Maintenance and Repair § 174.14 Maintenance and repair. (a) Facilities and equipment located on installations being closed are often...

  9. 48 CFR 1352.271-87 - Changes-ship repair.

    Science.gov (United States)

    2010-10-01

    ...—ship repair. As prescribed in 48 CFR 1371.118, insert the following clause: Changes—Ship Repair (APR... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Changes-ship repair. 1352.271-87 Section 1352.271-87 Federal Acquisition Regulations System DEPARTMENT OF COMMERCE CLAUSES...

  10. 49 CFR 192.311 - Repair of plastic pipe.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Repair of plastic pipe. 192.311 Section 192.311... Lines and Mains § 192.311 Repair of plastic pipe. Each imperfection or damage that would impair the serviceability of plastic pipe must be repaired or removed....

  11. Language Repair Strategies in Bilingual Tutoring of Mathematics Word Problems

    Science.gov (United States)

    Oliveira, Alandeom W.; Meskill, Carla; Judson, Darlene; Gregory, Karen; Rogers, Patterson; Imperial, Christopher J.; Casler-Failing, Shelli

    2015-01-01

    This study explores the "language repair strategies" (aimed at repairing communication problems) of two bilingual speakers during mathematics word problem tutoring sessions. Bilingual repair was shown to gradually shift from a linguistic to an epistemic focus during problem solving (i.e., communication became more conceptually focused…

  12. Bueno y la autorreparacion ("Bueno" and Conversational Self Repairs).

    Science.gov (United States)

    Carranza, Isolda

    The paper discusses the Spanish expression "bueno," which marks the beginning or the end of background and assertion self-repairs in conversation, and often co-occurs with other expressions, such as "viste" and "no?" which mark the other end of the repair. Background repairs provide information the speaker considers necessary for the hearer to…

  13. A heart team's perspective on interventional mitral valve repair

    DEFF Research Database (Denmark)

    Treede, Hendrik; Schirmer, Johannes; Rudolph, Volker

    2012-01-01

    Surgical mitral valve repair carries an elevated perioperative risk in the presence of severely reduced ventricular function and relevant comorbidities. We sought to assess the feasibility of catheter-based mitral valve repair using a clip-based percutaneous edge-to-edge repair system in selected...

  14. Assessment of Human DNA Repair (NER) Capacity With DNA Repair Rate (DRR) by Comet Assay

    Institute of Scientific and Technical Information of China (English)

    WEI ZHENG; JI-LIANG HE; LI-FEN JIN; JIAN-LIN LOU; BAO-HONG WANG

    2005-01-01

    Objective Alkaline comet assay was used to evaluate DNA repair (nucleotide excision repair, NER) capacity of human fresh lymphocytes from 12 young healthy non-smokers (6 males and 6 females). Methods Lymphocytes were exposed to UV-C (254 nm) at the dose rate of 1.5 J/m2/sec. Novobiocin (NOV) and aphidicolin (APC), DNA repair inhibitors, were utilized to imitate the deficiency of DNA repair capacity at the incision and ligation steps of NER. Lymphocytes from each donor were divided into three grougs: UVC group, UVC plus NOV group, and UVC plus APC group. DNA single strand breaks were detected in UVC irradiated cells incubated for 0, 30, 60, 90, 120, 180, and 240 min after UVC irradiation. DNA repair rate (DRR) served as an indicator of DNA repair capacity. Results The results indicated that the maximum DNA damage (i.e. maximum tail length) in the UVC group mainly appeared at 90 min. The ranges of DRRs in the UVC group were 62.84%-98.71%. Average DRR value was 81.84%. The DRR difference between males and females was not significant (P<0.05). However, the average DRR value in the UVC plus NOV group and the UVC plus APC group was 52.98% and 39.57% respectively, which were significantly lower than that in the UVC group (P<0.01). Conclusion The comet assay is a rapid, simple and sensitive screening test to assess individual DNA repair (NER) capacity. It is suggested that the time to detect DNA single strand breaks in comet assay should include 0 (before UV irradiation), 90 and 240 min after exposure to 1.5 J·m-2 UVC at least. The DRR, as an indicator, can represent the individual DNA repair capacity in comet assay.

  15. Controversies in laparoscopic repair of incisional hernia

    Directory of Open Access Journals (Sweden)

    Sarela Abeezar

    2006-01-01

    Full Text Available Background: Incisional hernias can be a significant problem after open abdominal surgery. Laparoscopic incisional hernia repair (LIHR is conceptually appealing: a large, abdominal wall re-incision with potential wound-related ill effects is avoided and an intra-peritoneal onlay mesh is expected to provide security that is equivalent to open, retro-muscular mesh repair. As such, LIHR has gained substantial popularity despite sparse, randomised clinical data to compare with conventional, open repair. Aim: To enumerate and discuss important, controversial issues in patient-selection, technique and early post-operative care for LIHR. Materials and Methods: Pragmatic summary of comprehensive review of English language literature, discussion with experts and personal experience. Outcomes: Six important areas of some dispute were identified: 1. Size of abdominal-wall defect that is suitable for LIHR: Generally, defect-diameter > 10 cm is better served by open retromuscular repair with tension-free re-approximation of the edges of the defect. 2. Extent of adhesiolysis: Complete division of adhesions to the anterior abdominal wall may identify sub-clinical "Swiss-cheese" defects but incurs some risk of additional complications. 3. Intra-operative recognition of enterotomy: Possible options are either laparoscopic suture of bowel injury and simultaneous completion of LIHR, or staged LIHR or conversion to open suture-repair. 4. Choice of mesh: "Composite" meshes are regarded as the current standard of care but there is paucity of data regarding potential dangers of intra-peritoneal polypropylene mesh. 5. Technique of mesh-fixation: Trans-parietal sutures are more secure than tacks, with limited data to correlate with post-operative pain. 6. Alarm over post-operative pain: Unlike other advanced laparoscopic operations, the specificity of pain as a marker of intra-abdominal sepsis after LIHR remains unclear. Conclusion : Recognition of and attention to

  16. Endovascular repair of blunt popliteal arterial injuries

    Energy Technology Data Exchange (ETDEWEB)

    Zhong, Shan; Zhang, Xiquan; Chen, Zhong; Zhu, Wei; Pan, Xiaolin [Dept. of nterventional Vascular, The 148th Hospital of Chinese People' s Liberation Army, Zibo (China); Dong, Peng; Sun, Yequan [Dept. of Medical Imaging, Weifang Medical University, Weifang (China); Qi, Deming [Dept. of Medical Imaging, Qilu Medical University, Zibo (China)

    2016-09-15

    To evaluate the feasibility and effectiveness of endovascular repair for blunt popliteal arterial injuries. A retrospective analysis of seven patients with clinical suspicion of popliteal arterial injuries that were confirmed by arteriography was performed from September 2009 to July 2014. Clinical data included demographics, mechanism of injury, type of injury, location of injury, concomitant injuries, time of endovascular procedures, time interval from trauma to blood flow restoration, instrument utilized, and follow-up. All patients were male (mean age of 35.9 ± 10.3 years). The type of lesion involved intimal injury (n = 1), partial transection (n = 2), complete transection (n = 2), arteriovenous fistula (n = 1), and pseudoaneurysm (n = 1). All patients underwent endovascular repair of blunt popliteal arterial injuries. Technical success rate was 100%. Intimal injury was treated with a bare-metal stent. Pseudoaneurysm and popliteal artery transections were treated with bare-metal stents. Arteriovenous fistula was treated with bare-metal stent and coils. No perioperative death and procedure-related complication occurred. The average follow-up was 20.9 ± 2.3 months (range 18–24 months). One patient underwent intra-arterial thrombolysis due to stent thrombosis at 18 months after the procedure. All limbs were salvaged. Stent migration, deformation, or fracture was not found during the follow-up. Endovascular repair seems to be a viable approach for patients with blunt popliteal arterial injuries, especially on an emergency basis. Endovascular repair may be effective in the short-term. Further studies are required to evaluate the long-term efficacy of endovascular repair.

  17. A COMPARATIVE STUDY BETWEEN LAPAROSCOPIC TRANSABDOMINAL PREPERITONEAL REPAIR AND TOTAL EXTRAPERITONEAL REPAIR OF INGUINAL HERNIA

    Directory of Open Access Journals (Sweden)

    Narendra

    2016-05-01

    Full Text Available BACKGROUND Groin hernia surgeries have come a long way since knowledge of modern surgery. Among them laparoscopic hernia repair is the advanced and better method in terms of less pain and speedy recovery. AIMS AND OBJECTIVES To compare and assess the outcome between laparoscopic transabdominal preperitoneal repair and total extraperitoneal repair of inguinal hernia. 1. To compare the duration of procedure between two techniques. 2. To assess the complications encountered (Intraoperative and postoperative. 3. To evaluate the post-operative pain. MATERIALS AND METHODS 40 cases of groin hernia admitted in Sri Siddhartha Medical College, Tumkur, between 2013 and 2015 randomly picked for TAPP and TEP surgeries, assigning 20 for each, prospective analysis made results compared and evaluated using Fischer’s test and Chisquare test. RESULTS Comparatively TEP repair took more operative time and TAPP repair had more post-operative pain. CONCLUSION No major complications seen in both procedures. Laparoscopy repair has long learning curve, which demands skills. TEP is more technically demanding and takes more time than TAPP, but with postoperative pain in comparison.

  18. A new incision for unilateral cleft lip repair developed using animated simulation of repair on computer

    Directory of Open Access Journals (Sweden)

    Sahay A

    2007-01-01

    Full Text Available Background: Unilateral cleft lip repair continues to leave behind some amount of dissatisfaction, as a scope for further improvement is always felt. Most surgeons do not like to deviate from the standard Millard′s/ triangular techniques, or their minor modifications, as no one likes to experiment on the face for fear of unfavourable outcomes. The computer can be utilized as a useful tool in the analysis and planning of surgery and new methods can be developed and attempted subsequently with greater confidence. Aim: We decided to see if an improved lip repair could be developed with the use of computers. Materials and Methods: Analysis of previous lip repairs was done to determine where an improvement was required. Movement of tissues, by simulating an ideal repair, using image warping software, on digital images of cleft lip was studied in animation sequences. A repair which could reproduce these movements was planned. A new incision emerged, which had combined the principles of Millard′s and Randall / Tennyson repairs, with additional features. The new method was performed on 30 cases. Conclusions: The results were encouraging as the shortcomings of these methods were minimized, and the advantages maximized.

  19. Biological effects of electric fields: an overview

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, L.E.; Phillips, R.D.

    1983-11-01

    An overview of the literature suggests tha electric-field exposure is an environmental agent/influence of relatively low potential toxicity to biological systems. Generally, many of the biological effects which have been reported are quite subtle and differences between exposed and unexposed subjects may be masked by normal biological variations. However, several recent reports indicate possibly more serious consequences from chronic exposure, emphasizing the need for more research in epidemiology and laboratory experiments. This paper presents a cursory overview of investigations on the biological consequences of exposure to ELF electromagnetic fields. Three important topics are discussed, including: 1) the general methodology of exposure experiments, including those elements which are critical for definitive studies in biological systems; 2) a brief discussion of epidemiological and clinical studies conducted to date; and 3) a somewhat more extensive examination of animal experiments representing major areas of investigation (behavior, biological rhythms, nervous and endocrine systems, bone growth and repair, cardiovascular system and blood chemistry, immunology, reproduction, growth and development mortality and pathology, cellular and membrane studies, and mutagenesis). A discussion of current concepts, possible mechanisms and future directions of research is presented. 110 references.

  20. 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

    1996-01-01

    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 perfusio

  1. Neural stem cell transplantation in the repair of spinal cord injury

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Neural stem cells are a pronising candidate for neural transplantation aimed at neural cell replacement and repair of the damaged host central nervous system (CNS). Recent studies using neural stem cells have shown that implanted neural stem cells can effectively incorporate into the damaged CNS and differentiate into neurons, astrocytes, and oligodendrocytes. The recent explosion in the field of neural stem cell research has provided insight into the inductive factors influencing neural stem cell differentiation and may yield potential therapies for several neurological disorders, including spinal cord injury. In this review, we summarize recent studies involving neural stem cell biology in both rodents and humans. We also discuss unique advantages and possible mechanisms of using neural stem cell trans plantation in the repair of spinal cord injury.

  2. Future dentistry: cell therapy meets tooth and periodontal repair and regeneration.

    Science.gov (United States)

    Catón, Javier; Bostanci, Nagihan; Remboutsika, Eumorphia; De Bari, Cosimo; Mitsiadis, Thimios A

    2011-05-01

    Cell-based tissue repair of the tooth and - tooth-supporting - periodontal ligament (PDL) is a new attractive approach that complements traditional restorative or surgical techniques for replacement of injured or pathologically damaged tissues. In such therapeutic approaches, stem cells and/or progenitor cells are manipulated in vitro and administered to patients as living and dynamic biological agents. In this review, we discuss the clonogenic potential of human dental and periodontal tissues such as the dental pulp and the PDL and their potential for tooth and periodontal repair and/or regeneration. We propose novel therapeutic approaches using stem cells or progenitor cells, which are targeted to regenerate the lost dental or periodontal tissue.

  3. The green microalga Tetraselmis suecica reduces oxidative stress and induces repairing mechanisms in human cells

    Science.gov (United States)

    Sansone, Clementina; Galasso, Christian; Orefice, Ida; Nuzzo, Genoveffa; Luongo, Elvira; Cutignano, Adele; Romano, Giovanna; Brunet, Christophe; Fontana, Angelo; Esposito, Francesco; Ianora, Adrianna

    2017-01-01

    Green microalgae contain many active pigments such as carotenoids having antioxidant and protective activity on human cells. Here we investigate the biological activity of an ethanol/water extract of the marine green microalga Tetraselmis suecica containing high levels of carotenoids such as the xanthophylls lutein, violaxanthin, neoxanthin, antheraxanthin and loroxanthin esters. This extract has a strong antioxidant and repairing activity in the human lung cancer cell line (A549) as shown by the increased expression of dehydrocholesterol reductase-24 (DHCR24) and prostaglandin reductase 1 (PTGR1) genes and proteins. The extract also reduces prostaglandin E2 (PGE2) levels in cells damaged by H2O2 and has tissue repairing effects on reconstructed human epidermal tissue cells (EpiDermTM) indicating a potential cosmeceutical activity of this microalgal species. PMID:28117410

  4. Ulnar Collateral Ligament Repair: An Old Idea With a New Wrinkle.

    Science.gov (United States)

    Dugas, Jeffrey R

    2016-01-01

    At our practice, we have successfully treated thousands of overhead athletes with the modified Jobe technique of ulnar collateral ligament (UCL) repair. We used this technique regardless of the amount and location of the pathology encountered at the time of surgery. We asked whether the availability of modern anchor and suture technology, vast clinical experience with these injuries and their outcomes, and even biologic additives could be applied to some of these patients to achieve an equal or superior outcome in less time. This led us to create a construct that could be used to not only repair the torn native UCL tissue to bone, but also span the anatomic native ligament from its origin to its insertion. This construct includes an ultra-strong collagen coated tape attached at the anatomic insertions of the ligament using two 3.5-mm nonabsorbable PEEK corkscrew anchors and a suture through the eyelet of one of the anchors.

  5. Arsenic Biotransformation as a Cancer Promoting Factor by Inducing DNA Damage and Disruption of Repair Mechanisms

    Directory of Open Access Journals (Sweden)

    Victor D. Martinez

    2011-01-01

    Full Text Available Chronic exposure to arsenic in drinking water poses a major global health concern. Populations exposed to high concentrations of arsenic-contaminated drinking water suffer serious health consequences, including alarming cancer incidence and death rates. Arsenic is biotransformed through sequential addition of methyl groups, acquired from s-adenosylmethionine (SAM. Metabolism of arsenic generates a variety of genotoxic and cytotoxic species, damaging DNA directly and indirectly, through the generation of reactive oxidative species and induction of DNA adducts, strand breaks and cross links, and inhibition of the DNA repair process itself. Since SAM is the methyl group donor used by DNA methyltransferases to maintain normal epigenetic patterns in all human cells, arsenic is also postulated to affect maintenance of normal DNA methylation patterns, chromatin structure, and genomic stability. The biological processes underlying the cancer promoting factors of arsenic metabolism, related to DNA damage and repair, will be discussed here.

  6. The green microalga Tetraselmis suecica reduces oxidative stress and induces repairing mechanisms in human cells.

    Science.gov (United States)

    Sansone, Clementina; Galasso, Christian; Orefice, Ida; Nuzzo, Genoveffa; Luongo, Elvira; Cutignano, Adele; Romano, Giovanna; Brunet, Christophe; Fontana, Angelo; Esposito, Francesco; Ianora, Adrianna

    2017-01-24

    Green microalgae contain many active pigments such as carotenoids having antioxidant and protective activity on human cells. Here we investigate the biological activity of an ethanol/water extract of the marine green microalga Tetraselmis suecica containing high levels of carotenoids such as the xanthophylls lutein, violaxanthin, neoxanthin, antheraxanthin and loroxanthin esters. This extract has a strong antioxidant and repairing activity in the human lung cancer cell line (A549) as shown by the increased expression of dehydrocholesterol reductase-24 (DHCR24) and prostaglandin reductase 1 (PTGR1) genes and proteins. The extract also reduces prostaglandin E2 (PGE2) levels in cells damaged by H2O2 and has tissue repairing effects on reconstructed human epidermal tissue cells (EpiDerm(TM)) indicating a potential cosmeceutical activity of this microalgal species.

  7. Reduced cellular DNA repair capacity after environmentally relevant arsenic exposure. Influence of Ogg1 deficiency.

    Science.gov (United States)

    Bach, Jordi; Peremartí, Jana; Annangi, Balasubramnayam; Marcos, Ricard; Hernández, Alba

    2015-09-01

    Inorganic arsenic (i-As) is a genotoxic and carcinogenic environmental contaminant known to affect millions of people worldwide. Our previous work demonstrated that chronic sub-toxic i-As concentrations were able to induce biologically significant levels of genotoxic and oxidative DNA damage that were strongly influenced by the Ogg1 genotype. In order to study the nature of the observed levels of damage and the observed differences between MEF Ogg1(+/+) and Ogg1(-/-) genetic backgrounds, the genotoxic and oxidative DNA repair kinetics of 18-weeks exposed MEF cells were evaluated by the comet assay. Results indicate that MEF Ogg1(+/+) and Ogg1(-/-) cells chronically exposed to i-As repair the DNA damage induced by arsenite, potassium bromide and UVC radiation less efficiently than control cells, being that observation clearly more pronounced in MEF Ogg1(-/-) cells. Consequently, exposed cells accumulate a higher percentage of unrepaired DNA damage at the end of the repair period. As an attempt to eliminate i-As associated toxicity, chronically exposed MEF Ogg1(-/-) cells overexpress the arsenic metabolizing enzyme As3mt. This adaptive response confers cells a significant resistance to i-As-induced cell death, but at expenses of accumulating high levels of DNA damage due to their repair impairment. Overall, the work presented here evidences that i-As chronic exposure disrupts the normal cellular repair function, and that oxidative DNA damage-and Ogg1 deficiency-exacerbates this phenomenon. The observed cell death resistance under a chronic scenario of genotoxic and oxidative stress may in turn contribute to the carcinogenic effects of i-As.

  8. The New Technology of Composite Materials Repairing by Light Wave

    Institute of Scientific and Technical Information of China (English)

    ZHAO Zhi-min; CHEN Yu-ming; YU Xiao-lei; WANG Le-xin

    2004-01-01

    The repairing of damaged composite materials becomes a hot research subject in the late 1990s.In this paper a new technology of repairing composite materials is given on the basis of our previous research.The light wave of 675nm transmitted by optical fiber is used as repairing light source,special repairable adhesive which can be stimulated by the light is adopted.By comparing the stiffness of the composite material before and after being damaged,it can be concluded that the mechanical property will not be changed with the feasible repairing technology.

  9. Biological evaluation on poly lactic-co-glycolic acid/pyrite composite active bone repair scaffold%聚乳酸-乙醇酸复合中药自然铜活性骨修复支架生物学评价

    Institute of Scientific and Technical Information of China (English)

    田嘉军; 郑华; 黄聘和; 王定国; 熊成东

    2015-01-01

    目的:评价新型骨修复材料聚乳酸-乙醇酸复合中药自然铜活性骨修复支架的生物安全性。方法根据医疗器械生物学评价标准的要求,选取了溶血试验、细胞毒性试验、遗传毒性试验、刺激与致敏试验、全身毒性试验、植入试验等,全方位评价该新型材料的生物安全性。结果聚乳酸-乙醇酸复合中药自然铜活性骨修复支架的血液相容性良好,无全身毒性和细胞毒性,未发现短期遗传毒性,无皮肤刺激和致敏作用,材料植入骨后周围组织反应正常,骨修复情况良好。结论聚乳酸-乙醇酸复合中药自然铜活性骨修复支架是一种生物相容性好的骨修复材料,可安全应用于临床。%Objective To evaluate biological safety of poly lactic-co-glycolic acid( PLGA )/pyrite composite active bone repalr scaffold. Methods According to biological evaluation criterion of medical devices, we selected hemolytic test, cytotoxicity test, genotoxicity test, tests for irritation and delayed-type hypersensitivity,general toxicity test and implantation test,to evaluate biological safety of the new materials. Results PLGA /pyrite composite active bone repalr scaffold had good blood compatibility,without general toxicity,cell toxicity,skin irritation and sensitization. The tissue reaction was normal after planting to the bone and the bone repalring was in good condition. Conclusions PLGA/ pyrite composite active bone repalr scaffold was one kind of bone repalr material with good biocompatibility and could be safely applied to clinical use.

  10. Cold Spray Repair of Martensitic Stainless Steel Components

    Science.gov (United States)

    Faccoli, M.; Cornacchia, G.; Maestrini, D.; Marconi, G. P.; Roberti, R.

    2014-12-01

    The possibility of using cold spray as repair technique of martensitic stainless steel components was evaluated through laboratory investigations. An austenitic stainless steel feedstock powder was chosen, instead of soft metals powders like nickel, copper, or aluminum, used for repairing components made in light alloy or cast iron. The present study directly compares the microstructure, the residual stresses, and the micro-hardness of repairs obtained by cold spray and by TIG welding, that is commonly used as repair technique in large steel components. XRD and optical metallographic analysis of the repairs showed that cold spray offers some advantages, inducing compressive residual stresses in the repair and avoiding alterations of the interface between repair and base material. For these reasons, a heat treatment after the cold spray repair is not required to restore the base material properties, whereas a post-weld heat treatment is needed after the welding repair. Cold spray repair also exhibits a higher micro-hardness than the welding repair. In addition, the cavitation erosion resistance of a cold spray coating was investigated through ultrasonic cavitation tests, and the samples worn surfaces were observed by scanning electron microscopy.

  11. The democratization of gene editing: Insights from site-specific cleavage and double-strand break repair.

    Science.gov (United States)

    Jasin, Maria; Haber, James E

    2016-08-01

    DNA double-strand breaks (DSBs) are dangerous lesions that if not properly repaired can lead to genomic change or cell death. Organisms have developed several pathways and have many factors devoted to repairing DSBs, which broadly occurs by homologous recombination, which relies on an identical or homologous sequence to template repair, or nonhomologous end-joining. Much of our understanding of these repair mechanisms has come from the study of induced DNA cleavage by site-specific endonucleases. In addition to their biological role, these cellular pathways can be co-opted for gene editing to study gene function or for gene therapy or other applications. While the first gene editing experiments were done more than 20 years ago, the recent discovery of RNA-guided endonucleases has simplified approaches developed over the years to make gene editing an approach that is available to the entire biomedical research community. Here, we review DSB repair mechanisms and site-specific cleavage systems that have provided insight into these mechanisms and led to the current gene editing revolution.

  12. Muscle repair and regeneration: stem cells, scaffolds, and the contributions of skeletal muscle to amphibian limb regeneration.

    Science.gov (United States)

    Milner, Derek J; Cameron, Jo Ann

    2013-01-01

    Skeletal muscle possesses a robust innate capability for repair of tissue damage. Natural repair of muscle damage is a stepwise process that requires the coordinated activity of a number of cell types, including infiltrating macrophages, resident myogenic and non-myogenic stem cells, and connective tissue fibroblasts. Despite the proficiency of this intrinsic repair capability, severe injuries that result in significant loss of muscle tissue overwhelm the innate repair process and require intervention if muscle function is to be restored. Recent advances in stem cell biology, regenerative medicine, and materials science have led to attempts at developing tissue engineering-based methods for repairing severe muscle defects. Muscle tissue also plays a role in the ability of tailed amphibians to regenerate amputated limbs through epimorphic regeneration. Muscle contributes adult stem cells to the amphibian regeneration blastema, but it can also contribute blastemal cells through the dedifferentiation of multinucleate myofibers into mononuclear precursors. This fascinating plasticity and its contributions to limb regeneration have prompted researchers to investigate the potential for mammalian muscle to undergo dedifferentiation. Several works have shown that mammalian myotubes can be fragmented into mononuclear cells and induced to re-enter the cell cycle, but mature myofibers are resistant to fragmentation. However, recent works suggest that there may be a path to inducing fragmentation of mature myofibers into proliferative multipotent cells with the potential for use in muscle tissue engineering and regenerative therapies.

  13. DESARDA’S NO MESH REPAIR VERSUS LICHTENSTEIN’S OPEN MESH REPAIR OF INGUINAL HERNIA: A COMPARATIVE STUDY

    Directory of Open Access Journals (Sweden)

    Zaheer

    2015-09-01

    Full Text Available BACKGROUND : The tissue - based techniques are still acceptable for primary inguinal hernia repair according to the European Hernia Society guidelines. Desarda’s no mesh technique, introduced in 2001, is a hernia repair method using an undetached strip of external oblique Apo neurosis . This study compared outcomes after hernia repair with Desarda (D and mesh - based Lichtenstein (L techniques. METHODS : A total of 100 patients were randomly assigned to the D or L group (50 each. The primary outcomes measured were post - operative pain ( D ay1 and day 7, mean hospital stay (in days, return to basic activity (in days and recurrence. RESULTS : During the follow - up, no recurrences were observed in each group (p = 1.000. Average duration of the Desarda’s repair was 65.64 minutes, while the Lichtenstein repair lasted for 65.76 minutes. Mean VAS on 1 st post - operative day was significantly less in Desarda’s repair (2.86 than Lichenstein’s repair (3.50, (p=0.0004. Mean hospital stay was less in Desarda’s repair (2.58 days versus Lichtenstein’s repair (3.90 days p=0.0001. Return to basic physical activity was earlier in Desarda’s repair (7.04 days than Lichenstein’s repair (11.30 days, (p=<0.0001. However there was no recurrence in either group in 18 months follow up. CONCLUSIONS : The Desarda’s and Lichtenstein’s methods of primary inguinal hernia repair do not differ in the means of procedure complexity, surgery time and complication profile. However the return to basic physical activity was earlier in Desarda’s repair. Desarda’s no mesh repair is equally safe and more cost effective than Lichtenstein’s repair. The technique may potentially increase the number of tissue - based methods a vailable for treating inguinal hernias.

  14. Cell biology perspectives in phage biology.

    Science.gov (United States)

    Ansaldi, Mireille

    2012-01-01

    Cellular biology has long been restricted to large cellular organisms. However, as the resolution of microscopic methods increased, it became possible to study smaller cells, in particular bacterial cells. Bacteriophage biology is one aspect of bacterial cell biology that has recently gained insight from cell biology. Despite their small size, bacteriophages could be successfully labeled and their cycle studied in the host cells. This review aims to put together, although non-extensively, several cell biology studies that recently pushed the elucidation of key mechanisms in phage biology, such as the lysis-lysogeny decision in temperate phages or genome replication and transcription, one step further.

  15. Progress in patch repair of aerospace composite structures

    Science.gov (United States)

    Hou, Weiguo; Zhang, Weifang; Tang, Qingyun

    2012-04-01

    With the rapid application of the composite structure in the aerospace industry, more load-bearing structures and components are used with composites instead of conventional engineering materials. However, the composite structures are inevitably suffered damages in the complex environment, the composites structures repair become more important in the airplane maintenance. This paper describes the composites patch repair progress. Firstly, the flaws and damages concerned to composite structures are concluded, and also the repair principles are presented. Secondly, the advantages and disadvantages for different repair methods are analyzed, as well as the different bonded repair and their applicability to different structures is discussed. According the recent research in theory and experiment, the scarf repair effects under different parameters are analyzed. Finally, the failure mechanisms of repair structure are discussed, and some prospects are put forward.

  16. Engineering a multimodal nerve conduit for repair of injured peripheral nerve

    Science.gov (United States)

    Quigley, A. F.; Bulluss, K. J.; Kyratzis, I. L. B.; Gilmore, K.; Mysore, T.; Schirmer, K. S. U.; Kennedy, E. L.; O'Shea, M.; Truong, Y. B.; Edwards, S. L.; Peeters, G.; Herwig, P.; Razal, J. M.; Campbell, T. E.; Lowes, K. N.; Higgins, M. J.; Moulton, S. E.; Murphy, M. A.; Cook, M. J.; Clark, G. M.; Wallace, G. G.; Kapsa, R. M. I.

    2013-02-01

    Injury to nerve tissue in the peripheral nervous system (PNS) results in long-term impairment of limb function, dysaesthesia and pain, often with associated psychological effects. Whilst minor injuries can be left to regenerate without intervention and short gaps up to 2 cm can be sutured, larger or more severe injuries commonly require autogenous nerve grafts harvested from elsewhere in the body (usually sensory nerves). Functional recovery is often suboptimal and associated with loss of sensation from the tissue innervated by the harvested nerve. The challenges that persist with nerve repair have resulted in development of nerve guides or conduits from non-neural biological tissues and various polymers to improve the prognosis for the repair of damaged nerves in the PNS. This study describes the design and fabrication of a multimodal controlled pore size nerve regeneration conduit using polylactic acid (PLA) and (PLA):poly(lactic-co-glycolic) acid (PLGA) fibers within a neurotrophin-enriched alginate hydrogel. The nerve repair conduit design consists of two types of PLGA fibers selected specifically for promotion of axonal outgrowth and Schwann cell growth (75:25 for axons; 85:15 for Schwann cells). These aligned fibers are contained within the lumen of a knitted PLA sheath coated with electrospun PLA nanofibers to control pore size. The PLGA guidance fibers within the nerve repair conduit lumen are supported within an alginate hydrogel impregnated with neurotrophic factors (NT-3 or BDNF with LIF, SMDF and MGF-1) to provide neuroprotection, stimulation of axonal growth and Schwann cell migration. The conduit was used to promote repair of transected sciatic nerve in rats over a period of 4 weeks. Over this period, it was observed that over-grooming and self-mutilation (autotomy) of the limb implanted with the conduit was significantly reduced in rats implanted with the full-configuration conduit compared to rats implanted with conduits containing only an alginate

  17. Epigenetic reduction of DNA repair in progression togastrointestinal cancer

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    Deficiencies in DNA repair due to inherited germ-linemutations in DNA repair genes cause increased risk ofgastrointestinal (GI) cancer. In sporadic GI cancers,mutations in DNA repair genes are relatively rare.However, epigenetic alterations that reduce expressionof DNA repair genes are frequent in sporadic GI cancers.These epigenetic reductions are also found in fielddefects that give rise to cancers. Reduced DNA repairlikely allows excessive DNA damages to accumulatein somatic cells. Then either inaccurate translesionsynthesis past the un-repaired DNA damages or errorproneDNA repair can cause mutations. ErroneousDNA repair can also cause epigenetic alterations (i.e. ,epimutations, transmitted through multiple replicationcycles). Some of these mutations and epimutations maycause progression to cancer. Thus, deficient or absentDNA repair is likely an important underlying cause ofcancer. Whole genome sequencing of GI cancers showthat between thousands to hundreds of thousands ofmutations occur in these cancers. Epimutations thatreduce DNA repair gene expression and occur early inprogression to GI cancers are a likely source of this highgenomic instability. Cancer cells deficient in DNA repairare more vulnerable than normal cells to inactivation byDNA damaging agents. Thus, some of the most clinicallyeffective chemotherapeutic agents in cancer treatmentare DNA damaging agents, and their effectivenessoften depends on deficient DNA repair in cancer cells.Recently, at least 18 DNA repair proteins, each activein one of six DNA repair pathways, were found to besubject to epigenetic reduction of expression in GIcancers. Different DNA repair pathways repair differenttypes of DNA damage. Evaluation of which DNA repairpathway(s) are deficient in particular types of GI cancerand/or particular patients may prove useful in guidingchoice of therapeutic agents in cancer therapy.

  18. Emergent cardiopulmonary bypass during pectus excavatum repair

    Directory of Open Access Journals (Sweden)

    Ryan Craner

    2013-01-01

    Full Text Available Pectus excavatum is a chest wall deformity that produces significant cardiopulmonary disability and is typically seen in younger patients. Minimally invasive repair of pectus excavatum or Nuss procedure has become a widely accepted technique for adult and pediatric patients. Although it is carried out through a thoracoscopic approach, the procedure is associated with a number of potential intraoperative and post-operative complications. We present a case of cardiac perforation requiring emergent cardiopulmonary bypass in a 29-year-old male with Marfan syndrome and previous mitral valve repair undergoing a Nuss procedure for pectus excavatum. This case illustrates the importance of vigilance and preparation by the surgeons, anesthesia providers as well as the institution to be prepared with resources to handle the possible complications. This includes available cardiac surgical backup, perfusionist support and adequate blood product availability.

  19. Radiologic investigation after laparoscopic inguinal hernia repair

    Energy Technology Data Exchange (ETDEWEB)

    Larmark, Martin; Ekberg, Olle [Department of Diagnostic Radiology, Malmoe University Hospital, 205 02, Malmoe (Sweden); Montgomery, Agneta [Department of Surgery, Malmoe University Hospital, 205 02, Malmoe (Sweden)

    2003-12-01

    Laparoscopic instead of open surgical repair of inguinal hernias is becoming more frequent. Radiologists may expect different postoperative findings depending on the technique used. We studied how radiology had been used postoperatively and what findings were encountered after laparoscopic herniorraphy. Postoperative radiologic examinations related to hernia repair of all consecutive patients that had had laparoscopic herniorraphy in Malmoe University hospital between 1992 and 1998 were retrospectively evaluated. A total of 538 groins were included, 3.9% (n=21) of these were postoperatively examined with ultrasound (n=10), herniography (n=7), plain abdominal films (n=2), CT (n=1), or fistulography (n=1). Significant findings were found in five groins, namely, one sinus tract, two hematomas, one small bowel obstruction, and one recurrence of hernia. Four insignificant seromas were found. The characteristics of the findings and pitfalls are described. Symptoms resulting in radiologic examination are rare after laparoscopic herniorraphy. The radiologist must be familiar with the spectrum of such findings. (orig.)

  20. Carbon nanotubes in neuroregeneration and repair.

    Science.gov (United States)

    Fabbro, Alessandra; Prato, Maurizio; Ballerini, Laura

    2013-12-01

    In the last decade, we have experienced an increasing interest and an improved understanding of the application of nanotechnology to the nervous system. The aim of such studies is that of developing future strategies for tissue repair to promote functional recovery after brain damage. In this framework, carbon nanotube based technologies are emerging as particularly innovative tools due to the outstanding physical properties of these nanomaterials together with their recently documented ability to interface neuronal circuits, synapses and membranes. This review will discuss the state of the art in carbon nanotube technology applied to the development of devices able to drive nerve tissue repair; we will highlight the most exciting findings addressing the impact of carbon nanotubes in nerve tissue engineering, focusing in particular on neuronal differentiation, growth and network reconstruction.

  1. Biodegradable Materials for Bone Repairs: A Review

    Institute of Scientific and Technical Information of China (English)

    Lili Tan; Xiaoming Yu; Peng Wan; Ke Yang

    2013-01-01

    With attractive research and development of biomaterials,more and more opportunities have been brought to the treatments of human tissue repairs.The implant is usually no need to exist in the body accompanied with the recovery or regeneration of the tissue lesions,and the long-term effect of exotic substance to human body should be reduced as lower as possible.For this purpose,biodegradable materials,including polymers,magnesium alloys and ceramics,have attracted much attention for medical applications due to their biodegradable characters in body environment.This paper in turn introduces these three different types of widely studied biodegradable materials as well as their advantages as implants in applications for bone repairs.Relevant history and research progresses are summarized.

  2. Regulation of nucleotide excision repair through ubiquitination

    Institute of Scientific and Technical Information of China (English)

    Jia Li; Audesh Bhat; Wei Xiao

    2011-01-01

    Nucleotide excision repair (NER) is the most versatile DNA-repair pathway in all organisms.While bacteria require only three proteins to complete the incision step of NER,eukaryotes employ about 30 proteins to complete the same step.Here we summarize recent studies demonstrating that ubiquitination,a post-translational modification,plays critical roles in regulating the NER activity either dependent on or independent of ubiquitin-proteolysis.Several NER components have been shown as targets of ubiquitination while others are actively involved in the ubiquitination process.We argue through this analysis that ubiquitination serves to coordinate various steps of NER and meanwhile connect NER with other related pathways to achieve the efficient global DNA-damage response.

  3. Lessons learned using Snodgrass hypospadias repair.

    LENUS (Irish Health Repository)

    O'Connor, K M

    2012-02-03

    BACKGROUND: This is a review of our experience with the Snodgrass technique for distal hypospadias repair and we point to lessons learned in improving results. METHODS: We reviewed all patients who underwent Snodgrass hypospadias repair for distal hypospadias over a four-year period by a single surgeon. Chart review followed by parental telephone interview was used to determine voiding function, cosmesis and complication rate. RESULTS: Thirty children and three adults were identified. Age at surgery ranged from seven months to 39 years. The urinary stream was straight in 94%, and 97% reported a good or satisfactory final cosmetic outcome. One patient (3.3%) developed a urethral fistula and 21% developed meatal stenosis which required general anaesthetic. CONCLUSION: The Snodgrass urethroplasty provides satisfactory cosmetic and functional results. High rates of meatal stenosis initially encountered have improved with modifications to technique which include modified meatoplasty and routine meatal dilatation by the parents.

  4. DNA Repair Systems: Guardians of the Genome

    Indian Academy of Sciences (India)

    2016-10-01

    The 2015 Nobel Prize in Chemistry was awarded jointly to Tomas Lindahl, Paul Modrich and Aziz Sancar to honour their accomplishments in the field of DNA repair. Ever since the discovery of DNA structure and their importance in the storage of genetic information, questions about their stability became pertinent. A molecule which is crucial for the development and propagation of an organism must be closely monitored so that the genetic information is not corrupted. Thanks to the pioneering research work of Lindahl, Sancar, Modrich and their colleagues, we now have an holistic awareness of how DNA damage occurs and how the damage is rectified in bacteria as well as in higher organisms including human beings. A comprehensive understanding of DNA repair has proven crucial in the fight against cancer and other debilitating diseases.

  5. Balanitis xerotica obliterans complicating hypospadias repair.

    Science.gov (United States)

    Kumar, M V; Harris, D L

    1999-01-01

    We review the literature and report a series of eight cases of balanitis xerotica obliterans (BXO) developing in patients following primary hypospadias repair. The ages of these patients ranged from 8 to 25 years with BXO developing from 1 to 16 years postoperatively. Six patients were treated by excision of the BXO tissue and two-stage urethroplasties with full-thickness grafts. Three of these patients had further recurrence of BXO and had re-do urethroplasty using a combination of bladder and buccal mucosa. The last two patients in this series had re-do urethroplasty using bladder mucosa only and bladder-buccal mucosa technique, respectively, as first choice for BXO complicating their hypospadias repair.

  6. Repair bond strength of resin composite to a novel CAD/CAM hybrid ceramic using different repair systems.

    Science.gov (United States)

    Elsaka, Shaymaa E

    2015-01-01

    This study evaluated the repair bond strength of a nanohybrid resin composite to a novel CAD/CAM hybrid ceramic based on four intraoral ceramic repair systems. Vita Enamic (VE) CAD/CAM hybrid ceramic was used in this study. Specimens were divided into five test groups according to the repair method performed on the ceramic surface: Gr C (No treatment; control); Gr CZ (Cimara Zircon); Gr PR (Porcelain Repair); Gr CR (Clearfil Repair); and Gr CS (CoJet system). Nanohybrid resin composite (GrandioSO) was packed onto treated ceramic surfaces for adhesion testing using microtensile bond strength test. Debonded specimens were examined with a stereomicroscope and SEM to determine the fracture mode. Data were analyzed using ANOVA and Tukey's HSD test. PR and CZ repair systems significantly enhanced the bond strength of nanohybrid resin composite to VE CAD/CAM hybrid ceramic when compared with the other tested repair systems.

  7. Use of buccal mucosa in hypospadias repair.

    Science.gov (United States)

    Cruz-Diaz, Omar; Castellan, Miguel; Gosalbez, Rafael

    2013-08-01

    Hypospadias is an embryological disorder that results in an abnormal ventral positioning of the urethral meatus. Among multiple surgical techniques described to correct this anomaly, the use of buccal mucosa grafts has gained popularity among pediatric urologists, pediatric surgeons and plastic surgeons. Buccal mucosa grafts have shown favorable histological changes that result in an excellent scaffold for urethral reconstructive surgery. This review describes the evolution of the use of buccal mucosa grafts in hypospadias repair.

  8. Road repair works on the Meyrin site

    CERN Multimedia

    2003-01-01

    ST Division will proceed, as from Monday 15th of September, in repairing some parts of roads on the Meyrin site (see drawing). This work will last for three weeks depending on the weather conditions and will cause some traffic hold ups during this period. Please follow the indications on the temporary road signs. Thanking you in advance for your comprehension. ST-CE and ST-FM Groups GSM 160224 - 163976

  9. Civil liability for ecologic damage and repairing

    OpenAIRE

    Basílio, Patrícia Droeber; Faculdades de Vitória, Espírito Santo, Brasil

    2009-01-01

    This article analyses how civil liability takes position regarding situations connected to damages caused to the environment, defined ways in our legislation reprimanding damages caused and existent ways of prevention and repairing. The text contemplates how law disciplines such issue, looking for efficient and effective solutions and also checking evolution and modification from law which are relevant to the environment, the environmental law, whereas we observe it is a serious issue that ha...

  10. Promising results after percutaneous mitral valve repair

    DEFF Research Database (Denmark)

    Ihlemann, Nikolaj; Franzen, Olaf; Jørgensen, Erik;

    2011-01-01

    Mitral valve regurgitation (MR) is the secondmost frequent valve disease in Europe. Untreated MR causes considerable morbidity and mortality. In the elderly, as many as half of these patients are denied surgery because of an estimated high surgical risk. Percutaneous mitral valve repair with the ...... with the MitraClip system resembles the Alfieristitch where a clip is used to connect the tip of the mitral valve leaflets....

  11. Augmented Reality for Maintenance and Repair (ARMAR)

    Science.gov (United States)

    2007-08-01

    The purpose of this research, Augmented Reality for Maintenance and Repair (ARMAR), was to research the design and development of experimental... augmented reality systems for maintenance job aiding. The goal was to explore and evaluate the feasibility of developing prototype adaptive augmented ... reality systems that can be used to investigate how real time computer graphics, overlaid on and registered with the actual equipment being maintained, can

  12. Repair of ultraviolet-light-induced damage

    Energy Technology Data Exchange (ETDEWEB)

    Sutherland, B.M.

    1981-01-01

    Studies are reviewed which present three major new findings in the photobiology of skin. First, detectable numbers of dimers are formed even at sub-erythymal doses. Second, excision of dimers is much more rapid than would be predicted from results obtained in cell culture. Third, comparison of the rates of excision and photoreactivation in skin indicates that in normal sunlight exposure, photoreactivation may well be the predominant repair pathway in skin. (ACR)

  13. Schedule Planning for Repairing Power Supply System

    OpenAIRE

    Kuo-Wei Lin; Chein-Jen Kang

    2012-01-01

    Problem statement: Taiwan is located in the tropical ocean areas. The strong typhoon in summer often causes the collapse of electric transmission towers and results in power outages that seriously affect peoples lives and industrial production. Approach: In light of this situation, this study aims to employ project management techniques of Theory of Constraints (TOC) to develop a practical TOC model to quickly repair the towers and restore power supplied system. Results: The actual applicatio...

  14. Revision of Failed Artroscopic Bankart Repairs

    Science.gov (United States)

    Muiño, José María Silberberg; Gimenez, Martín Alejandro; Salvucci, Mauro Gabriel Maroa; Ferro, Diego; Rullan, Ramón Muiña

    2017-01-01

    Objectives: To present our functional outcomes from patients treated arthroscopically for a failed Bankart repair, using suture anchors and capsulolabral tissue only. Methods: Series of 22 patients presented with a recurrence of instability after a previous stabilization surgery (3 Latarjet, Bankart 19). We treated them by a an all-arthroscopic procedure, avoiding bone grafts, when glenoid track was found to be enough to proceed. The failure was associated with trauma in 11 patients, a non-anatomic repair in 6 patients, capsular laxity in 4 patients and a non-union of the coracoid graft in 1 patient. Revision surgery included: Bankart repair with anchors in 17 cases, a posterior-inferior capsulo-labral plication in one case, and 5 remplissages. In 4 cases subscapularis augmentation was used because of poor capsular quality. Screw removal was necessary when treating the non-union case. Patients were followed-up by a minimum of 23 months (range 23-26), and evaluated by the UCLA Test, SS test and Rowe score. Results: Thirteen patients had an excellent result, 6 good, 2 satisfactory and one bad result, according to UCLA score. The mean Rowe score was 90.4, at final follow up. The Simple Shoulder Test went from an 8 preoperative to an 11 postoperative, mean scores. 19 of 22 patients returned to the same level of activity prior to the injury. Complications: recurrence in 2 cases, subluxation in 2 and one shoulder stiffness that required an arthrolysis. Conclusion: An arthroscopic revision surgery, after a failed Bankart repair, presents satisfactory results in selected patients. Arthroscopic vision allows a correct diagnosis of injuries as possible causes of failure and subsequent treatment.

  15. Aortic coarctation repair in the adult.

    Science.gov (United States)

    Cardoso, Goncalo; Abecasis, Miguel; Anjos, Rui; Marques, Marta; Koukoulis, Giovanna; Aguiar, Carlos; Neves, José Pedro

    2014-07-01

    Aortic coarctation can be repaired surgically or percutaneously. The decision should be made according to the anatomy and location of the coarctation, age of the patient, presence of other cardiac lesions, and other anatomic determinants (extensive collaterals or aortic calcification). This article reviews the different therapeutic options available, explaining the differences between children and adults, describing different approaches to the same disease, exemplified by three cases of nonclassic surgical approach and one percutaneous treatment.

  16. Repairs to Concrete Port and Harbor Structures

    Science.gov (United States)

    1991-11-18

    and the availability of repair equipment. Potential unzipping or unlocking of form seams requires familiarity with banding or strapping procedures...that when it is installed it will be free of the puckers between the nails known as "fish mouths" . The PE (150 mil) wraps are primarily used in the...inter-tidal zone because of their toughness. Foam seals may also be used on the top, bottom and vertical seam , although if installed properly with a 6

  17. Promising results after percutaneous mitral valve repair

    DEFF Research Database (Denmark)

    Ihlemann, Nikolaj; Franzen, Olaf; Jørgensen, Erik;

    2011-01-01

    Mitral valve regurgitation (MR) is the secondmost frequent valve disease in Europe. Untreated MR causes considerable morbidity and mortality. In the elderly, as many as half of these patients are denied surgery because of an estimated high surgical risk. Percutaneous mitral valve repair...... with the MitraClip system resembles the Alfieristitch where a clip is used to connect the tip of the mitral valve leaflets....

  18. A Percutaneous Knotless Technique for SLAP Repair.

    Science.gov (United States)

    Tennent, Duncan; Pearse, Eyiyemi

    2016-02-01

    We describe a percutaneous technique for repair of type II SLAP lesions. Through the Neviaser portal, a spinal needle is used to pass a FiberStick suture (Arthrex, Naples, FL) through the labrum to create 2 mattress sutures that are secured with PushLock anchors (Arthrex). This technique is simple, reproducible, and knotless and requires no cannulas. At the end of the procedure, minimal suture material remains in the joint.

  19. Chronic Pain after Inguinal Hernia Repair

    OpenAIRE

    2014-01-01

    Background. Chronic postherniorrhaphy groin pain is defined as pain lasting >6 months after surgery, which is one of the most important complications occurring after inguinal hernia repair, which occurs with greater frequency than previously thought. Material and Methods. Patients undergoing elective inguinal hernioplasty in Victoria Hospital from November 2011 to May 2013 were included in the study. A total of 227 patients met the inclusion criteria and were available for followup at end of ...

  20. Mononuclear Cells and Vascular Repair in HHT

    Directory of Open Access Journals (Sweden)

    Calinda eDingenouts

    2015-03-01

    Full Text Available Hereditary hemorrhagic telangiectasia (HHT or Rendu-Osler-Weber disease is a rare genetic vascular disorder known for its endothelial dysplasia causing arteriovenous malformations and severe bleedings. HHT-1 and HHT-2 are the most prevalent variants and are caused by heterozygous mutations in endoglin and ALK1, respectively. An undervalued aspect of the disease is that HHT patients experience persistent inflammation. Although endothelial and mural cells have been the main research focus trying to unravel the mechanism behind the disease, wound healing is a process with a delicate balance between inflammatory and vascular cells. Inflammatory cells are part of the mononuclear cells (MNCs fraction, and can, next to eliciting an immune response, also have angiogenic potential. This biphasic effect of MNC can hold a promising mechanism to further elucidate treatment strategies for HHT patients. Before MNC are able to contribute to repair, they need to home to and retain in ischemic and damaged tissue. Directed migration (homing of mononuclear cells following tissue damage is regulated by the stromal cell derived factor 1 (SDF1. MNCs that express the C-X-C chemokine receptor 4 (CXCR4 migrate towards the tightly regulated gradient of SDF1. This directed migration of monocytes and lymphocytes can be inhibited by dipeptidyl peptidase 4 (DPP4. Interestingly, MNC of HHT patients express elevated levels of DPP4 and show impaired homing towards damaged tissue. Impaired homing capacity of the MNCs might therefore contribute to the impaired angiogenesis and tissue repair observed in HHT patients. This review summarizes recent studies regarding the role of MNCs in the etiology of HHT and vascular repair, and evaluates the efficacy of DPP4 inhibition in tissue integrity and repair.