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Tissue Transplantation (tissue + transplantation)
Selected AbstractsSynthesis of Polymerizable Superoxide Dismutase Mimetics to Reduce Reactive Oxygen Species Damage in Transplanted Biomedical Devices,ADVANCED FUNCTIONAL MATERIALS, Issue 20 2008Charles Y. Cheung Abstract A new polymerizable superoxide dismutase (SOD) mimetic metalloporphyrin macromer was synthesized to minimize inflammatory damage associated with tissue transplantation and biomaterial implantation, such as the use of encapsulated pancreatic islets for the treatment of type I diabetes mellitus (TIDM). This functional SOD mimetic, Mn(III) Tetrakis[1-(3-acryloxy-propyl)-4-pyridyl] porphyrin (MnTPPyP-Acryl), was copolymerized and crosslinked with poly(ethylene glycol) diacrylate (PEGDA) to form hydrogel networks that may actively reduce reactive oxygen species (ROS) damage associated with biomaterial implantation. Solution phase activity assays with MnTPPyP-Acryl macromers showed comparable SOD activity to MnTMPyP, a non-polymerizable commercially available SOD mimetic. This work also describes the development of a new, simple, and inexpensive solid phase assay system that was developed to assess the activity of MnTPPyP-Acryl macromers polymerized within PEGDA hydrogels, which has the potential to fulfill an existing void with the biochemical tools available for testing other immobilized ROS antagonists. With this new assay system, hydrogels containing up to 0.25,mol% MnTPPyP-Acryl showed significantly higher levels of SOD activity, whereas control hydrogels polymerized with inactive TPPyP-Acryl macromers showed only background levels of activity. The potential for repeated use of such hydrogel devices to consistently reduce superoxide anion concentrations was demonstrated upon retention of ,100% SOD activity for at least 72,h post-polymerization. These results demonstrate the potential that polymerizable SOD mimetics may have for integration into medical devices for the minimization of inflammatory damage upon transplantation, such as during the delivery of encapsulated pancreatic islets. [source] Distribution of killer cell immunoglobulin-like receptor genes in PolesINTERNATIONAL JOURNAL OF IMMUNOGENETICS, Issue 4-5 2008E. Majorczyk Summary Killer cell immunoglobulin-like receptors (KIRs) present on natural killer cells and minor subpopulations of T cells recognize class I human leucocyte antigen (HLA) molecules on the surface of target cells. Humans differ by the presence or absence of some KIR genes on their chromosomes. As KIRs are important for the outcome of tissue transplantation (particularly for haematopoietic stem cell transplantation) and possibly for pregnancy and autoimmune diseases, knowledge of the KIR gene distribution in a given human population is of practical value. Therefore, we tested 363 healthy individuals from Western Poland for the presence or absence of KIR genes. Results are compared with those published for other human populations. KIR gene frequencies in Poles are close to these in other Caucasoids but different from those in Asian and African populations, and particularly distant from those in Australian Aborigines. [source] Pigmentation development in hatchery-reared flatfishesJOURNAL OF FISH BIOLOGY, Issue 5 2000J. A. Bolker Malpigmentation is common in hatchery-reared flatfishes, decreasing the market value of whole fish, and increasing the risk of predation for juveniles released to enhance wild stocks. Pigmentation development in flatfishes occurs in two phases. First, during embryonic and larval stages pigment cells differentiate on both sides of the body. Second, at metamorphosis larval melanophores disappear, and adult melanophores differentiate on the ocular but not on the blind side. Malpigmentation seems to result from disruptions of the second phase, and may take the form of albinism on the ocular side or darkening of the blind side. Both types of aberration may be related to aspects of the hatchery environment such as lighting, substratum, and diet. Larval nutrition appears to be a key factor and enrichment of larval diets with fatty acids and Vitamin A can greatly reduce malpigmentation rates; however, levels suffcient to prevent pigmentation defects frequently cause other abnormalities. Two developmental explanations for albinism have been proposed. The first is that differentiation of ocular-side skin follows the normal blind-side pathway and adult melanophores therefore fail to develop on the ocular side. The second hypothesis suggests that dietary deficiencies inhibit retinal development and the resulting visual defects lead to failure of a hormonal signal required for melanophore differentiation. These hypotheses may well be complementary; as yet neither has been thoroughly tested. Definitive tests will require a combination of manipulative techniques such as tissue transplantation and cell culture with nutritional, behavioural and hormonal assays. Such integrative studies will further the understanding both of normal pigmentation development and of the environmental factors that contribute to high rates of albinism in hatchery-reared flatfish. [source] In vitro generation and transplantation of precursor-derived human dopamine neuronsJOURNAL OF NEUROSCIENCE RESEARCH, Issue 4 2001Rosario Sánchez-Pernaute Abstract The use of in vitro expanded human CNS precursors has the potential to overcome some of the ethical, logistic and technical problems of fetal tissue transplantation in Parkinson disease. Cultured rat mesencephalic precursors proliferate in response to bFGF and upon mitogen withdrawal, differentiate into functional dopamine neurons that alleviate motor symptoms in Parkinsonian rats (Studer et al. [1998] Nat. Neurosci. 1:290,295). The successful clinical application of CNS precursor technology in Parkinson disease will depend on the efficient in vitro generation of human dopaminergic neurons. We demonstrate that human dopamine neurons can be generated from both midbrain and cortical precursors. Transplantation of midbrain precursor-derived dopamine neurons into Parkinsonian rats resulted in grafts rich in tyrosine hydroxylase positive neurons 6 weeks after transplantation. No surviving tyrosine hydroxylase positive neurons could be detected when dopamine neurons derived from cortical precursors were grafted. Our data demonstrate in vitro derivation of human dopamine neurons from expanded CNS precursors and encourage further studies that systematically address in vivo function and clinical potential. J. Neurosci. Res. 65:284,288, 2001. © 2001 Wiley-Liss, Inc. [source] Impact of donor infections on outcome of orthotopic liver transplantationLIVER TRANSPLANTATION, Issue 5 2003Michael Angelis Infection occurs when microbial agents enter the host, either through airborne transmission or by direct contact of a substance carrying the infectious agent with the host. Human body fluids, solid organs, or other tissues often are ideal vectors to support microbial agents and can transmit infections efficiently from donor to recipient. In the case of blood transfusion and tissue transplantation, the main consequence of such a transmission is infection of the recipient. However, in the case of solid-organ transplantation, and particularly for liver transplantation, donor infections are not only transmitted to the recipient, the donor infection also may affect the donated liver's preservability and subsequent function in the recipient irrespective of the systemic consequences of the infection. In addition, solid organ recipients of infected organs are less able to respond to the infectious agent because of their immunosuppressive treatment. Thus, transmission of infections from organ donor to liver recipient represents serious potential risks that must be weighed against a candidate's mortality risk without the transplant. However, the ever-increasing gap between the number of donors and those waiting for liver grafts makes consideration of every potential donor, regardless of the infection status, essential to minimize waiting list mortality. In this review, we will focus on assessing the risk of transmission of bacterial, fungal, viral, and parasitic infectious agents from cadaveric liver donors to recipients and the effect such a transmission has on liver function, morbidity, and mortality. We will also discuss risk-benefit deliberations for using organs from infected donors for certain types of recipients. These issues are critically important to maximize the use of donated organs but also minimize recipient morbidity and graft dysfunction. [source] Monitoring free flaps using laser-induced fluorescence of indocyanine green: A preliminary experienceMICROSURGERY, Issue 7 2002C. Holm M.D. In a prospective, clinical study, the clinical utility of indocyanine green for intraoperative monitoring of free tissue transfer was evaluated. The study comprised 20 surgical patients undergoing elective microsurgical procedures. Indocyanine green angiography was performed intraoperatively, immediately after flap inset, and the operating team was blind to the fluoremetric findings. Thereafter, postoperative monitoring was done exclusively by clinical examination (color, temperature, time for recapillarization, and bleeding after puncture). Final outcome was compared with results of perioperative indocyanine (ICG)-imaging, and classified either as total flap loss, partial flap loss, or successful tissue transplantation. A total of 2 (10%) complications was recorded, and included one partial and one total flap loss. Both complications were detected by intraoperative ICG imaging. Another case of intraoperative subclinical arterial spasm at the place of microvascular anastomosis was revealed by dynamic ICG-videography. This flap did not develop postoperative complications. In conclusion, evaluation of perfusion by ICG imaging is feasible in all kinds of microsurgical flaps, irrespective of the type of tissue. Even though not meeting all the criteria of an ideal monitoring device, significant additional information can be obtained. In this study, cases with arterial spasm, venous congestion, and regional hypoperfusion were revealed by intraoperative ICG-videography. There was a strong correlation between intraoperative findings and clinical outcome. © 2002 Wiley-Liss, Inc. MICROSURGERY 22:278,287 2002 [source] Stem cells and regenerative medicine for the treatment of type 1 diabetes: the challenges lying aheadPEDIATRIC DIABETES, Issue 2004Andreas Lechner Abstract:, The differentiation of insulin-producing cells in vitro from embryonic or adult stem cells offers potential new treatment options for type 1 diabetes. Progress toward this goal has been made in the recent years, but substantial obstacles still remain. In order to be advantageous over the current standard regimens with exogenous insulin, any stem cell-based therapy would have to restore normal or near normal metabolic control. To achieve this, many of the complex regulatory mechanisms that control physiologic insulin secretion would have to be recreated with in vitro -generated tissue. An alternative approach would be to use the insights gained through stem cell research to develop pharmacologic agents that can induce regeneration of endogenous pancreatic islets in patients with type 1 diabetes. Such a therapy also requires extensive further research, but it could have principal advantages over tissue transplantation. [source] The AJT Report: News and issues that affect organ and tissue transplantationAMERICAN JOURNAL OF TRANSPLANTATION, Issue 10 2010SUE PONDROM This month, "The AJT Report" explores the high cost of pancreas acquisition, and how it hampers islet transplantation in the U.S. Additionally, we review efforts by Yale University researchers to take a first step toward the goal of generating fully functional lungs. [source] The AJT Report: News and issues that affect organ and tissue transplantationAMERICAN JOURNAL OF TRANSPLANTATION, Issue 9 2010SUE PONDROM The FDA proposes granting vascularized composite allografts the definition of "organs," giving them regulation under the Final Rule. This month, "The AJT Report" explores the implications of this potential change, takes a look at a way to track transplant program profitability, and highlights some hot topics from the American Transplant Congress. [source] The AJT Report: News and issues that affect organ and tissue transplantationAMERICAN JOURNAL OF TRANSPLANTATION, Issue 8 2010SUE PONDROM This month, The AJT Report explores new efforts to assess cancer risk in transplant patients, including a multinational study underway to better understand skin cancer in the post-transplant population. [source] The AJT Report: News and issues that affect organ and tissue transplantationAMERICAN JOURNAL OF TRANSPLANTATION, Issue 7 2010SUE PONDROM This month, transplant professionals weigh in on health-care reform, and what the new law might mean for the field. Also "The AJT Report" takes a close look at what happened to the expanded immunosuppressant coverage provision. [source] The AJT Report: News and issues that affect organ and tissue transplantationAMERICAN JOURNAL OF TRANSPLANTATION, Issue 6 2010SUE PONDROM This month "The AJT Report" takes a look at a new policy in the works for the U.S. organ allocation system, and reviews a lawsuit that challenges the constitutionality of NOTA's ban on compensation for bone marrow donors, which could influence solid organ donation policy. [source] The AJT Report: News and issues that affect organ and tissue transplantationAMERICAN JOURNAL OF TRANSPLANTATION, Issue 5 2010SUE PONDROM This month, "The AJT Report" takes a look at the history of the American Journal of Transplantation,what has made it work, and what's in store for its future? Also, we explore upcoming challenges medical journals may face. [source] The AJT Report: News and issues that affect organ and tissue transplantationAMERICAN JOURNAL OF TRANSPLANTATION, Issue 4 2010SUE PONDROM "The AJT Report" explores possible safety concerns over generic immunosuppressants. We also examine new 2009 UNOS data and revisit Australia's organ donation program. [source] The AJT Report: News and issues that affect organ and tissue transplantationAMERICAN JOURNAL OF TRANSPLANTATION, Issue 3 2010SUE PONDROM This month, in another special expanded edition of "The AJT Report," we examine the improvements in intestinal graft survival, and explore why more of these transplants aren't done. We also take a look at the outcomes of the Banff Conference on Allograft Pathology, and at a new organ allocation law in Israel. [source] The AJT Report: News and issues that affect organ and tissue transplantationAMERICAN JOURNAL OF TRANSPLANTATION, Issue 2 2010SUE PONDROM This month, "The AJT Report" examines a new generation of drugs to treat hepatitis C that could change the landscape of liver transplantation. We also take a look at the National Living Donor Assistance Center, and review the CDC's quest for a national transplant safety network. [source] The AJT Report: News and issues that affect organ and tissue transplantationAMERICAN JOURNAL OF TRANSPLANTATION, Issue 1 2010SUE PONDROM This month, in a special expanded section, "The AJT Report" examines some of the newer,and in some cases, controversial,desensitization therapies available. We also explore whether transplant centers and procurement organizations are prepared to care for patients with H1N1 influenza. [source] The AJT Report: News and issues that affect organ and tissue transplantationAMERICAN JOURNAL OF TRANSPLANTATION, Issue 12 2009SUE PONDROM This month, "The AJT Report" takes a look at ways to improve quality of life for pediatric transplant patients, and also reviews China's new organ donation policy. [source] The AJT Report: News and issues that affect organ and tissue transplantationAMERICAN JOURNAL OF TRANSPLANTATION, Issue 11 2009SUE PONDROM The AJT Report takes a closer look at this potentially transformative drug. Also this month, we examine the rising interest in Th17, and explore what it means to search for a kidney on Craigslist. [source] The AJT Report: News and issues that affect organ and tissue transplantationAMERICAN JOURNAL OF TRANSPLANTATION, Issue 10 2009SUE PONDROM This month, The AJT Report explores a new OPTN/UNOS policy designed to broaden geographic access to donated livers, as well as the FDA's approval of the use of tacrolimus in conjunction with MMF. [source] The AJT Report: News and issues that affect organ and tissue transplantationAMERICAN JOURNAL OF TRANSPLANTATION, Issue 9 2009SUE PONDROM This month, The AJT Report reviews programs designed to transition adolescent transplant patients to adult care, as well as the heart allocation system and a new approach to double-lung transplant. [source] The AJT Report: News and issues that affect organ and tissue transplantationAMERICAN JOURNAL OF TRANSPLANTATION, Issue 8 2009SUE PONDROM This month, "The AJT Report" examines challenges the proposed national paired kidney donation program may face. We also look at controversial data from a study on double-lung transplants. [source] The AJT Report: News and issues that affect organ and tissue transplantationAMERICAN JOURNAL OF TRANSPLANTATION, Issue 7 2009SUE PONDROM This month The AJT Report looks at the LYFT kidney-allocation concept, and where it may have gone wrong, as well as research that shows how television news stories about transplants often leave out important information for donors. [source] The AJT Report: News and issues that affect organ and tissue transplantationAMERICAN JOURNAL OF TRANSPLANTATION, Issue 6 2009SUE PONDROM Have historical practices for autopsy influenced modern attitudes toward organ donation? The AJT Report investigates. Plus, we look at a new program for recovering DCD organs "in the field." [source] The AJT Report: News and issues that affect organ and tissue transplantationAMERICAN JOURNAL OF TRANSPLANTATION, Issue 5 2009SUE PONDROM This month, The AJT Report investigates the risks associated with using donation after cardiac death livers and explores whether the benefits outweigh the drawbacks. Also this month, we look at two novel methods for donor kidney removal. [source] News and issues that affect organ and tissue transplantationAMERICAN JOURNAL OF TRANSPLANTATION, Issue 4 2009SUE PONDROM How close are we to developing an alternative to human islet cell transplantation? [source] News and issues that affect organ and tissue transplantationAMERICAN JOURNAL OF TRANSPLANTATION, Issue 3 2009SUE PONDROM In Part Two of our look at unused organs, we examine reasons abdominal organsare left behind [source] News and issues that affect organ and tissue transplantationAMERICAN JOURNAL OF TRANSPLANTATION, Issue 2 2009SUE PONDROM In this first of a two-part examination of non-recovered organs, we take a look at the high rate of discarded hearts and lungs [source] News and issues that affect organ and tissue transplantationAMERICAN JOURNAL OF TRANSPLANTATION, Issue 1 2009SUE PONDROM Australia, Canada and the United Kingdom launch national programs [source] News and issues that affect organ and tissue transplantationAMERICAN JOURNAL OF TRANSPLANTATION, Issue 12 2008SUE PONDROM Some concerned over "cherry-picking" of patients. [source] | |||||||||||||