133 resultados para sense organ


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Background Lack of donor organs remains a major obstacle in organ transplantation. Our aim was to evaluate (1) the association between engaging in high-risk recreational activities and attitudes toward organ donation and (2) the degree of reciprocity between organ acceptance and donation willingness in young men. Methods A 17-item, close-ended survey was offered to male conscripts ages 18 to 26 years in all Swiss military conscription centers. Predictors of organ donation attitudes were assessed in bivariate analyses and multiple logistic regression. Reciprocity of the intentions to accept and to donate organs was assessed by means of donor card status. Results In 1559 responses analyzed, neither motorcycling nor practicing extreme sports reached significant association with donor card holder status. Family communication about organ donation, student, or academic profession and living in a Latin linguistic region were predictors of positive organ donation attitudes, whereas residence in a German-speaking region and practicing any religion predicted reluctance. Significantly more respondents were willing to accept than to donate organs, especially among those without family communication concerning organ donation. Conclusions For the first time, it was shown that high-risk recreational activities do not influence organ donation attitudes. Second, a considerable discrepancy in organ donation reciprocity was identified. We propose that increasing this reciprocity could eventually increase organ donation rates.

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Waddlia chondrophila is a known bovine abortigenic Chlamydia-related bacterium that has been associated with adverse pregnancy outcomes in human. However, there is a lack of knowledge regarding how W. chondrophila infection spreads, its ability to elicit an immune response and induce pathology. A murine model of genital infection was developed to investigate the pathogenicity and immune response associated with a W. chondrophila infection. Genital inoculation of the bacterial agent resulted in a dose-dependent infection that spread to lumbar lymph nodes and successively to spleen and liver. Bacterial-induced pathology peaked on day 14, characterized by leukocyte infiltration (uterine horn, liver, and spleen), necrosis (liver) and extramedullary hematopoiesis (spleen). Immunohistochemistry demonstrated the presence of a large number of W. chondrophila in the spleen on day 14. Robust IgG titers were detected by day 14 and remained high until day 52. IgG isotypes consisted of high IgG2a, moderate IgG3 and no detectable IgG1, indicating a Th1-associated immune response. This study provides the first evidence that W. chondrophila genital infection is capable of inducing a systemic infection that spreads to major organs, induces uterus, spleen, and liver pathology and elicits a Th1-skewed humoral response. This new animal model will help our understanding of the mechanisms related to intracellular bacteria-induced miscarriages, the most frequent complication of pregnancy that affects one in four women.

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Meniscal injuries can occur secondary to trauma or be instigated by the changes in knee-joint function that are associated with aging, osteo- and rheumatoid arthritis, disturbances in gait and obesity. Sixty per cent of persons over 50 years of age manifest signs of meniscal pathology. The surgical and arthroscopic measures that are currently implemented to treat meniscal deficiencies bring only transient relief from pain and effect but a temporary improvement in joint function. Although tissue-engineering-based approaches to meniscal repair are now being pursued, an appropriate in-vitro model has not been conceived. The aim of this study was to develop an organ-slice culturing system to simulate the repair of human meniscal lesions in vitro. The model consists of a ring of bovine meniscus enclosing a chamber that represents the defect and reproduces its sequestered physiological microenvironment. The defect, which is closed with a porous membrane, is filled with fragments of synovial tissue, as a source of meniscoprogenitor cells, and a fibrin-embedded, calcium-phosphate-entrapped depot of the meniscogenic agents BMP-2 and TGF-ß1. After culturing for 2 to 6 weeks, the constructs were evaluated histochemically and histomorphometrically, as well as immunohistochemically for the apoptotic marker caspase 3 and collagen types I and II. Under the defined conditions, the fragments of synovium underwent differentiation into meniscal tissue, which bonded with the parent meniscal wall. Both the parent and the neoformed meniscal tissue survived the duration of the culturing period without significant cell losses. The concept on which the in-vitro system is based was thus validated. This article is protected by copyright. All rights reserved.

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Aberrant antigens expressed by tumor cells, such as in melanoma, are often associated with humoral immune responses, which may in turn influence tumor progression. Despite recent data showing the central role of adaptive immune responses on cancer spread or control, it remains poorly understood where and how tumor-derived antigen (TDA) induces a humoral immune response in tumor-bearing hosts. Based on our observation of TDA accumulation in B cell areas of lymph nodes (LNs) from melanoma patients, we developed a pre-metastatic B16.F10 melanoma model expressing a fluorescent fusion protein, tandem dimer tomato, as a surrogate TDA. Using intravital two-photon microscopy (2PM) and whole-mount 3D LN imaging of tumor-draining LNs in immunocompetent mice, we report an unexpectedly widespread accumulation of TDA on follicular dendritic cells (FDCs), which were dynamically scanned by circulating B cells. Furthermore, 2PM imaging identified macrophages located in the subcapsular sinus of tumor-draining LNs to capture subcellular TDA-containing particles arriving in afferent lymph. As a consequence, depletion of macrophages or genetic ablation of B cells and FDCs resulted in dramatically reduced TDA capture in tumor-draining LNs. In sum, we identified a major pathway for the induction of humoral responses in a melanoma model, which may be exploitable to manipulate anti-TDA antibody production during cancer immunotherapy.

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Sepsis is an infection-induced systemic inflammatory syndrome, potentially causing organ failure. We previously showed attenuating effects on inflammation, thrombogenicity and haemodynamics by inhibiting the Toll-like receptor co-factor CD14 and complement factor C5 in a porcine Escherichia coli-induced sepsis model. The present study explored the effect on organ inflammation in these pigs. Tissue samples were examined from the combined treatment group (n = 8), the positive (n = 8) and negative (n = 6) control groups after 4h of sepsis. Inflammatory biomarkers were measured using ELISA, multiplex and qPCR analysis. Combined inhibition of C5 and CD14 markedly attenuated IL-1β by 31-66% (P < 0.05) and IL-6 by 54-96% (P < 0.01) in liver, kidney, lung and spleen; IL-8 by 65-100% in kidney, lung, spleen, and heart (P < 0.05) and MCP-1 by 46-69% in liver, kidney, spleen and heart (P < 0.05). Combined inhibition significantly attenuated tissue factor mRNA upregulation in spleen (P < 0.05) and IP-10 mRNA upregulation in four out of five organs. Finally, C5aR mRNA downregulation was prevented in heart and kidney (P < 0.05). Combined inhibition of C5 and CD14 thus markedly attenuated inflammatory responses in all organs examined. The anti-inflammatory effects observed in lung and heart may explain the delayed haemodynamic disturbances observed in septic pigs receiving combined inhibition of C5 and CD14.

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BACKGROUND The process of neurite outgrowth is the initial step in producing the neuronal processes that wire the brain. Current models about neurite outgrowth have been derived from classic two-dimensional (2D) cell culture systems, which do not recapitulate the topographical cues that are present in the extracellular matrix (ECM) in vivo. Here, we explore how ECM nanotopography influences neurite outgrowth. METHODOLOGY/PRINCIPAL FINDINGS We show that, when the ECM protein laminin is presented on a line pattern with nanometric size features, it leads to orientation of neurite outgrowth along the line pattern. This is also coupled with a robust increase in neurite length. The sensing mechanism that allows neurite orientation occurs through a highly stereotypical growth cone behavior involving two filopodia populations. Non-aligned filopodia on the distal part of the growth cone scan the pattern in a lateral back and forth motion and are highly unstable. Filopodia at the growth cone tip align with the line substrate, are stabilized by an F-actin rich cytoskeleton and enable steady neurite extension. This stabilization event most likely occurs by integration of signals emanating from non-aligned and aligned filopodia which sense different extent of adhesion surface on the line pattern. In contrast, on the 2D substrate only unstable filopodia are observed at the growth cone, leading to frequent neurite collapse events and less efficient outgrowth. CONCLUSIONS/SIGNIFICANCE We propose that a constant crosstalk between both filopodia populations allows stochastic sensing of nanotopographical ECM cues, leading to oriented and steady neurite outgrowth. Our work provides insight in how neuronal growth cones can sense geometric ECM cues. This has not been accessible previously using routine 2D culture systems.

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BACKGROUND Pyogenic tonsillitis may often be observed in the general Western population. In severe cases, it may require antibiotic treatment or even hospitalization and often a prompt clinical response will be noted. Here we present an unusual case of progressive multiple organ failure including fulminant liver failure following acute tonsillitis initially mistaken for "classic" pyogenic (that is bacterial) tonsillitis. CASE PRESENTATION A 68-year-old previously healthy white man was referred with suspicion of pyogenic angina. After tonsillectomy, he developed acute liver failure and consecutive multiple organ failure including acute hemodynamic, pulmonary and dialysis-dependent renal failure. Immunohistopathological analysis of his tonsils and liver as well as serum polymerase chain reaction analyses revealed herpes simplex virus-2 to be the causative pathogen. Treatment included high-dose acyclovir and multiorgan supportive intensive care therapy. His final outcome was favorable. CONCLUSIONS Fulminant herpes simplex virus-2-induced multiple organ failure is rarely observed in the Western hemisphere and should be considered a potential diagnosis in patients with tonsillitis and multiple organ failure including acute liver failure. From a clinical perspective, it seems important to note that fulminant herpes simplex virus-2 infection may masquerade as "routine" bacterial severe sepsis/septic shock. This persevering condition should be diagnosed early and treated goal-oriented in order to gain control of this life-threatening condition.

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Antigenic variation of the intestinal protozoan parasite Giardia lamblia is caused by an exchange of the parasite's variant surface protein (VSP) coat. Many investigations on antigenic variation were performed with G. lamblia clone GS/M-83-H7 which produces surface antigen VSP H7. To generate novel information on giardial vsp gene transcription, vsp RNA levels were assessed by quantitative reverse transcription-(RT)-PCR in both axenic VSP H7-type trophozoites and subvariants obtained after negative selection of GS/M-83-H7 trophozoites by treatment with a cytotoxic, VSP H7-specific monoclonal antibody. Our investigation was not restricted to the assessment of the sense vsp transcript levels but also included an approach aimed at the detection of complementary antisense vsp transcripts within the two trophozoite populations. We found that sense vsp H7 RNA predominated in VSP H7-type trophozoites while sense RNA from only one (vsp IVg) of 8 subvariant vsp genes totally analysed predominated in subvariant-type trophozoites. Interestingly, the two trophozoite populations exhibited a similar relative distribution regarding the vsp H7 and vsp IVg antisense RNA molecules. An analogous sense versus antisense RNA pattern was also observed when the transcripts of gene cwp 1 (encoding cyst wall protein 1) were investigated. Here, both types of RNA molecules only appeared after cwp 1 had been induced through in vitro encystation of the parasite. These findings for the first time demonstrated that giardial antisense RNA production did not occur in a constitutive manner but was directly linked to complementary sense RNA production after activation of the respective gene systems.

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Introduction: Mechanical stress is often associated to interverterbal disc (IVD) degeneration and the effect of mechanical loading on IVD has been studied and reviewed.1,2 Previously, expression of heat shock proteins, HSP70 and HSP27 has been found in pathological discs.3 However, there is no direct evidence on whether IVD cells respond to the mechanical loading by expression of HSPs. The objective of this study is to investigate the stress response of IVD cells during compressive loading in an organ culture. Materials and Methods: Fresh adult bovine caudal discs were cultured with compressive loading applied at physiological range. Effect of loading type (static and dynamic) and repeated loading (2 hours per day for 2 days) were studied. Nucleus pulposus (NP) and annulus fibrosus (AF) of the IVD were retrieved at different time points: right after loading and right after resting. Positive control discs were heat shocked (43°C). Cell activity was assessed and expression of stress response genes (HSP70 and HSF1) and matrix remodeling genes (ACAN, COL2, COL1, ADAMTS4, MMP3 and MMP13) were studied. Results: Cell activity was maintained in all groups. Both NP and AF expressed high level of HSP70 in heat shock groups, confirming their expression in response to stress. In NP, expression of HSP70 was up-regulated after static loading and dynamic loading with higher fold change was observed after static loading. During repeated loading, HSP70 appeared to be upregulated right after loading and decreased after resting. Such trend was not observed in AF and HSF1 levels. Expressions of matrix remodeling genes did not change significantly with loading except ADAMTS4 decreased in AF during static loading. Conclusion: This study demonstrated that NP cells upregulate expression of HSP70 in response to loading induced stress without changing cell activity and matrix remodeling significantly. Acknowledgments: This project was funded by AO Spine (AOSPN) (grant number: SRN_2011_14) and a fellowship exchange award by AO Spine Scientific Research Network (SRN).

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BACKGROUND  Nocardiosis is a rare, life-threatening opportunistic infection, affecting 0.04% to 3.5% of patients after solid organ transplantation (SOT). The aim of this study was to identify risk factors for Nocardia infection after SOT and to describe the presentation of nocardiosis in these patients. METHODS  We performed a retrospective case-control study of adult patients diagnosed with nocardiosis after SOT between 2000 and 2014 in 36 European (France, Belgium, Switzerland, Netherlands, Spain) centers. Two control subjects per case were matched by institution, transplant date and transplanted organ. A multivariable analysis was performed using conditional logistic regression to identify risk factors for nocardiosis. RESULTS  One hundred and seventeen cases of nocardiosis and 234 control patients were included. Nocardiosis occurred at a median of 17.5 [range 2-244] months after transplantation. In multivariable analysis, high calcineurin inhibitor trough levels in the month before diagnosis (OR=6.11 [2.58-14.51]), use of tacrolimus (OR=2.65 [1.17-6.00]) and corticosteroid dose (OR=1.12 [1.03-1.22]) at the time of diagnosis, patient age (OR=1.04 [1.02-1.07]) and length of stay in intensive care unit after SOT (OR=1.04 [1.00-1.09]) were independently associated with development of nocardiosis; low-dose cotrimoxazole prophylaxis was not found to prevent nocardiosis. Nocardia farcinica was more frequently associated with brain, skin and subcutaneous tissue infections than were other Nocardia species. Among the 30 cases with central nervous system nocardiosis, 13 (43.3%) had no neurological symptoms. CONCLUSIONS  We identified five risk factors for nocardiosis after SOT. Low-dose cotrimoxazole was not found to prevent Nocardia infection. These findings may help improve management of transplant recipients.