Publications by authors named "Patience C"

Background: While mallet finger remains a relatively common injury of the hand, mallet thumb is much rarer in occurrence. Mallet thumb management has been noted infrequently within the literature and reliable evidence regarding the most effective method of management remains absent. The aim of this review is to assess the quality of literature that exists pertaining to mallet thumb to determine whether conservative or surgical management is superior.

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Databases catalogue the corpus of research literature into scientific categories and report classes of bibliometric data such as the number of citations to articles, the number of authors, journals, funding agencies, institutes, references, etc. The number of articles and citations in a category are gauges of productivity and scientific impact but a quantitative basis to compare researchers between categories is limited. Here, we compile a list of bibliometric indicators for 236 science categories and citation rates of the 500 most cited articles of each category.

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In this work, internal and external flows over superhydrophobic (SH) polytetrafluoroethylene (PTFE) were studied. The SH surface was fabricated by a one-step femtosecond laser micromachining process. The drag reduction ability of the textured surface was studied experimentally both in microscale and macroscale internal flows.

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Purpose: The main objective of this study was to evaluate the feasibility of a newly developed questionnaire to assess the influence of study design on participation in gait rehabilitation research in a pilot test with individuals with stroke. A secondary objective was to investigate the relationship between participation in gait rehabilitation research and social and clinical factors of interest after stroke.

Methods: A questionnaire was developed with expert opinion and guidance from related previous research.

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Xenotransplantation using porcine cells, tissues, or organs may offer a potential solution for the shortage of allogeneic human organs. Prior to the clinical use of porcine xenotransplants, three main hurdles must be overcome: immunologic rejection, physiologic incompatibility, and risk of transmission of porcine pathogens. Designated pathogen-free breeding of pigs can prevent transmission of most porcine microbes.

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Unlabelled: Porcine endogenous retroviruses (PERVs) released from pig tissue can infect selected human cells in vitro and therefore represent a safety risk for xenotransplantation using pig cells, tissues, or organs. Although PERVs infect cells of numerous species in vitro, attempts to establish reliable animal models failed until now. Absence of PERV transmission has been shown in first experimental and clinical xenotransplantations; however, these trials suffered from the absence of long-term exposure (transplant survival) and profound immunosuppression.

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Porcine endogenous retrovirus (PERV) is considered one of the major risks in xenotransplantation. No valid animal model has been established to evaluate the risks associated with PERV transmission to human patients by pig tissue xenotransplantation or to study the potential pathogenesis associated with PERV infection. In previous work we isolated two genes encoding functional human PERV receptors and proved that introduction of these into mouse fibroblasts allowed the normally nonpermissive mouse cells to become productively infected (T.

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Xenotransplantation, in particular the transplantation of pig cells, tissues and organs into human recipients, may alleviate the current shortage of suitable allografts available for human transplantation. This overview addresses the physiological, immunological and microbial factors involved in xenotransplantation. The issues reviewed include the merits of using pigs as xenograft source species, the compatibility of pig and human organ physiology, and the rejection mechanism and attempts to overcome this immunological challenge.

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Clinical pig-to-human xenotransplantation might be associated with the risk of transmission of xenozoonoses, especially porcine endogenous retroviruses (PERVs). We have established a pig-to-humanised-cynomolgus monkey xenotransplantation model allowing the analysis of potential PERV-transmission from normal or transgenic porcine organs to human vascular tissue. Pig-to-human kidney xenotransplantation was performed in cynomolgus monkeys.

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Hearts from alpha1,3-Galactosyltransferase gene-knockout (GaIT-KO) pigs were transplanted heterotopically into 8 baboons that received an anti-CD154 monoclonal antibody (mAb)-based immunosuppressive regimen and heparin. Three baboons died or were euthanized with beating grafts on 16, 23, and 56 days, respectively, and the remaining 5 grafts functioned for 59-179 days. Hyperacute rejection did not occur, and classical features of acute humoral xenograft or acute cellular rejection were rare.

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Hearts from alpha1,3-galactosyltransferase knockout pigs (GalT-KO, n = 8) were transplanted heterotopically into baboons using an anti-CD154 monoclonal antibody-based regimen. The elimination of the galactose-alpha1,3-galactose epitope prevented hyperacute rejection and extended survival of pig hearts in baboons for 2-6 months (median, 78 d); the predominant lesion associated with graft failure was a thrombotic microangiopathy, with resulting ischemic injury. There were no infectious complications directly related to the immunosuppressive regimen.

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The use of animal organs could potentially alleviate the critical worldwide shortage of donor organs for clinical transplantation. Because of the strong immune response to xenografts, success will probably depend upon new strategies of immune suppression and induction of tolerance. Here we report our initial results using alpha-1,3-galactosyltransferase knockout (GalT-KO) donors and a tolerance induction approach.

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The genetic nature and biological effects of recombination between porcine endogenous retroviruses (PERV) were studied. An infectious molecular clone was generated from a high-titer, human-tropic PERV isolate, PERV-A 14/220 (B. A.

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Porcine endogenous retrovirus (PERV) is a potential pathogen in clinical xenotransplantation; transmission of PERV in vivo has been suggested in murine xenotransplantation models. We analyzed the transmission of PERV to human cells in vivo using a model in which immunodeficient NOD/SCID transgenic mice were transplanted with porcine and human lymphohematopoietic tissues. Our results demonstrate, we believe for the first time, that human and pig cells can coexist long-term (up to 25 weeks) without direct PERV infection of human cells.

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Xenotransplantation is a possible solution for the shortage of tissues for human transplantation. Multiple hurdles exist to clinical xenotransplantation, including immunologic barriers, metabolic differences between pigs--the source species most commonly considered--and humans, and ethical concerns. Since clinical trials were first proposed almost 10 years ago, the degree of risk for infection transmitted from the xenograft donor to the recipient has been extensively investigated.

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Porcine endogenous retroviruses (PERV) are of concern when the microbiological safety aspects of xenotransplantation are considered. Four unique isolates of PERV B have been identified previously from a lambda library constructed from genomic DNA from a Large White pig. This study shows that none of these isolates are replication competent when transfected into permissive human or pig cells in vitro, and the removal of flanking genomic sequences does not confer a human tropic replication competent (HTRC) phenotype on these PERV proviruses.

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A high incidence of a post-transplant lymphoproliferative disorder (PTLD) is observed in miniature swine conditioned for allogeneic hematopoietic cell transplantation using a protocol involving T-cell depletion and cyclosporine therapy. This study was designed to assess contributing factors to disease development. Forty-six animals were studied including 12 (26%) that developed PTLD.

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Background: Successful hematopoietic cell allotransplantation results in donor-specific tolerance, but this approach has been unsuccessful in the wild-type pig-to-baboon xenotransplantation model, as pig cells were lost from the circulation within 5 days. However, after cessation of immunosuppressive therapy on day 28, all baboons demonstrated non-specific unresponsiveness on mixed leukocyte reaction (MLR) for at least 30 days. We have now investigated the transplantation of bone marrow (BM) cells from miniature swine homozygous for alpha1,3-galactosyltransferase gene-knockout (GalT-KO).

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Background: The aim of this study was to investigate whether transmission of porcine endogenous retrovirus (PERV) occurs in a model of diabetes reversal by the xenotransplantation of adult porcine islets (APIs) into immunoincompetent diabetic rodents.

Methods: Black-6 nu/nu mice and Lewis rats were immunosuppressed with cyclosporin A (CsA) and FTY 720, and rendered diabetic with streptozotocin. Purified APIs were transplanted into the renal subcapsular space; 5,000 islet equivalents (IEQs) were used in the nude mice (n = 4) and 40,000 IEQs in the rats (n = 4).

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Complement activation mediated by the major xenogeneic epitope in the pig, galactosyl-alpha(1-3) galactosyl sugar structure (alpha-Gal), and human natural antibodies could cause hyperacute rejection (HAR) in pig-to-human xenotransplantation. The same reaction on viruses bearing alpha-Gal may serve as a barrier to zoonotic infection. Expressing human complement regulatory proteins or knocking out alpha-Gal epitopes in pig in order to overcome HAR may therefore pose an increased risk in xenotransplantation with regard to zoonosis.

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Galactose alpha1-3 galactose (Gal) trisaccharides are present on the surface of wild-type pig cells, as well as on viruses particles produced from such cells. The recognition of Gal sugars by natural anti-Gal antibodies (NAb) in human and Old World primate serum can cause the lysis of the particles via complement-dependent mechanisms and has therefore been proposed as an important antiviral mechanism. Recently, pigs have been generated that possess disrupted galactosyl-transferase (GGTA1) genes.

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Objectives: The discovery that pig endogenous retroviruses are infectious for human cells in vitro lead to vehement discussions about the possible risk of infection after clinical xenotransplantation. Since PERV transmission to non-human primate cells in vitro has been observed, similar to human cells, infection studies in non-human primates should represent the best model to analyze a potential PERV transmission after xenotransplantation. However, it is still open to discussion, whether non-human primate cells can be infected productively-similar to human cells- and whether those species are suitable to analyze PERV infection risks in vivo.

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The potential transmission of porcine endogenous retroviruses (PERVs) has raised concern in the development of porcine xenotransplantation products. Our previous studies have resulted in the identification of animals within a research herd of inbred miniature swine that lack the capacity to transmit PERV to human cells in vitro. In contrast, other animals were capable of PERV transmission.

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