917 resultados para Allograft-rejection


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Background. The precise mechanisms underlying the development of chronic allograft nephropathy (CAN) and the associated renal fibrosis remain uncertain. The protein-crosslinking enzyme, tissue transglutaminase (tTg), has recently been implicated in renal fibrosis. Methods. We investigated the involvement of tTg and its crosslink product, [epsilon]-([gamma]-glutamyl) lysine, in 23 human kidney allografts during the early posttransplantation period and related these to changes of CAN that developed in 8 of them. Sequential biopsies were investigated using immunohistochemical, immunofluorescence, and in situ enzyme activity techniques. Results. From implantation, tTg (+266%) and [epsilon]-([gamma]-glutamyl) lysine crosslink (+256.3%) staining increased significantly (P <0.001) in a first renal biopsy performed within 3 months from transplantation. This was paralleled by elevated tTg in situ activity. The eight patients who developed CAN had further increases in immunostainable tTg (+197.2%, P <0.001) and [epsilon]-([gamma]-glutamyl) lysine bonds (+465%, P <0.01) that correlated with interstitial fibrosis (r=0.843, P =0.009 and r=0.622, P =0.05, respectively). The staining for both was predominantly located within the mesangium and the renal interstitium. Both implantation and first biopsies showed tTg and [epsilon]-([gamma]-glutamyl) lysine crosslinking levels in patients who developed CAN to be twice the levels of those with stable renal function. Cox regression analysis suggested the intensity of the early tTg staining was a better predictor of inferior allograft survival that other histologic markers (hazard ratio=4.48, P =0.04). Conclusions. tTg and [epsilon]-([gamma]-glutamyl) lysine crosslink correlated with the initiation and progression of scarring on sequential biopsies from renal-allograft recipients who experienced CAN. Elevated tTg may offer an early predictor of the development of CAN, whereas tTg manipulation may be an attractive therapeutic target

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This paper explores experimentally the impairments in performance that are generated when multiple single-sideband (SSB) subcarrier multiplexing (SCM) signals are closely allocated in frequency to establish a spectrally efficient wavelength division multiplexing (WDM) link. The performance of cost-effective SSB WDM/ SCM implementations, without optical filters in the transmitter, presents a strong dependency on the imperfect sideband suppression ratio that can be directly achieved with the electro-optical modulator. A direct detected broadband multichannel SCM link composed of a state-of-the-art optical IQ modulator and five quadrature phase-shift keyed (QPSK) subcarriers per optical channel is presented, showing that a suppression ratio of 20 dB obtained directly with the modulator produced a penalty of 2 dB in overall performance, due to interference between adjacent optical channels.

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Kidney transplantation is the best treatment for patients who have lost kidney function. Renal transplant patients require accurate immunosuppressive drugs to prevent rejection. In this process T helper cells of the immune system perform key role in the immune response to the graft, and recently the Th17 cells has been investigated by production of IL-17 potent proinflammatory cytokine whose role in the rejection has also been described. Increased of Th17 cell expression has an important association with the development of rejection in renal microenvironment, however the likely mechanism is not well understood. This study aimed to evaluate the Th17 response from the influence of the chemotactic axis CCR6/CCL20 and genetic variants in IL-17 and IL-17RA. We conducted a case-control study involving 148 patients transplanted at the University Hospital Onofre Lopes/UFRN in which assessed by immunohistochemistry protein expression of IL-17 and chemokines CCR6/CCL20 and by PCR-RFLP genetic variants in IL17A and IL17RA. Our results showed no influence of genetic polymorphisms on the outcome of the graft or the protein expression of IL-17. In renal graft microenvironment found several sources producing IL-17: tubular epithelial cells, glomerular cells, neutrophils and cell interstitial infiltration, in turn the expression of chemotactic axis CCR6/CCL20 was restricted to the tubular epithelium cells. There was a slight positive linear correlation between the presence of IL-17 and expression of chemotactic axis CCR6/CCL20 in the microenvironment of renal graft. Therefore, we believe that, combined with our results, further studies with increased "n" sample and greater control over the variables involved in obtaining the renal specimen, can determine more clearly the influence of chemotactic axis CCR6 / CCL20 and polymorphisms in cytokines related to Th17 profile on the control of this cell subtype response in rejection processes to renal allograft.

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We intended to evaluate the influence of sex mismatch between donor and recipient, which is still under much debate, on survival and comorbidities after cardiac transplantation. From November 2003 to December 2013, a total of 258 patients were transplanted in our center. From these, 200 receptors were male (77.5%) and constituted our study population, further divided into those who received the heart from a female donor (Group A) - 44 patients (22%) and those who received it from a male donor (Group B) - 156 (78%). Median follow-up was 4.2 ± 3.0 years (1-10 years). The two groups were quite comparable with each other, except for body mass index, systolic pulmonary artery pressure, and transpulmonary gradient, which were significantly lower in Group A. A low donor/recipient weigh ratio (<0.8) was avoided whenever possible. Hospital mortality was not different in the two groups. During follow-up, global survival was similar, as was survival free from acute cellular rejection and cardiac allograft vasculopathy. However, patients in Group A had decreased survival free from serious infections and malignant tumors. Allocation of female donors to male receptors can be done safely, at least in receptors without pulmonary hypertension and when an adequate donor/recipient weigh ratio is ensured.

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BACKGROUND: Patients older than 65 years have traditionally not been considered candidates for heart transplantation. However, recent studies have shown similar survival. We evaluated immediate and medium-term results in patients older than 65 years compared with younger patients. METHODS: From November 2003 to December 2013, 258 patients underwent transplantation. Children and patients with other organ transplantations were excluded from this study. Recipients were divided into two groups: 45 patients (18%) aged 65 years and older (Group A) and 203 patients (81%) younger than 65 years (Group B). RESULTS: Patients differed in age (67.0 ± 2.2 vs. 51.5 ± 9.7 years), but gender (male 77.8 vs. 77.3%; p = 0.949) was similar. Patients in Group A had more cardiovascular risk factors and ischemic cardiomyopathy (60 vs. 33.5%; p < 0.001). Donors to Group A were older (38.5 ± 11.3 vs. 34.0 ± 11.0 years; p = 0.014). Hospital mortality was 0 vs. 5.9% (p = 0.095) and 1- and 5-year survival were 88.8 ± 4.7 versus 86.8 ± 2.4% and 81.5 ± 5.9 versus 77.2 ± 3.2%, respectively. Mean follow-up was 3.8 ± 2.7 versus 4.5 ± 3.1 years. Incidence of cellular/humoral rejection was similar, but incidence of cardiac allograft vasculopathy was higher (15.6 vs. 7.4%; p = 0.081). Incidence of diabetes de novo was similar (p = 0.632), but older patients had more serious infections in the 1st year (p = 0.018). CONCLUSION: Heart transplantation in selected older patients can be performed with survival similar to younger patients, hence should not be restricted arbitrarily. Incidence of infections, graft vascular disease, and malignancies can be reduced with a more personalized approach to immunosuppression. Allocation of donors to these patients does not appear to reduce the possibility of transplanting younger patients.

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We intended to evaluate the influence of sex mismatch between donor and recipient, which is still under much debate, on survival and comorbidities after cardiac transplantation. From November 2003 to December 2013, a total of 258 patients were transplanted in our center. From these, 200 receptors were male (77.5%) and constituted our study population, further divided into those who received the heart from a female donor (Group A) - 44 patients (22%) and those who received it from a male donor (Group B) - 156 (78%). Median follow-up was 4.2 ± 3.0 years (1-10 years). The two groups were quite comparable with each other, except for body mass index, systolic pulmonary artery pressure, and transpulmonary gradient, which were significantly lower in Group A. A low donor/recipient weigh ratio (<0.8) was avoided whenever possible. Hospital mortality was not different in the two groups. During follow-up, global survival was similar, as was survival free from acute cellular rejection and cardiac allograft vasculopathy. However, patients in Group A had decreased survival free from serious infections and malignant tumors. Allocation of female donors to male receptors can be done safely, at least in receptors without pulmonary hypertension and when an adequate donor/recipient weigh ratio is ensured.

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BACKGROUND: Patients older than 65 years have traditionally not been considered candidates for heart transplantation. However, recent studies have shown similar survival. We evaluated immediate and medium-term results in patients older than 65 years compared with younger patients. METHODS: From November 2003 to December 2013, 258 patients underwent transplantation. Children and patients with other organ transplantations were excluded from this study. Recipients were divided into two groups: 45 patients (18%) aged 65 years and older (Group A) and 203 patients (81%) younger than 65 years (Group B). RESULTS: Patients differed in age (67.0 ± 2.2 vs. 51.5 ± 9.7 years), but gender (male 77.8 vs. 77.3%; p = 0.949) was similar. Patients in Group A had more cardiovascular risk factors and ischemic cardiomyopathy (60 vs. 33.5%; p < 0.001). Donors to Group A were older (38.5 ± 11.3 vs. 34.0 ± 11.0 years; p = 0.014). Hospital mortality was 0 vs. 5.9% (p = 0.095) and 1- and 5-year survival were 88.8 ± 4.7 versus 86.8 ± 2.4% and 81.5 ± 5.9 versus 77.2 ± 3.2%, respectively. Mean follow-up was 3.8 ± 2.7 versus 4.5 ± 3.1 years. Incidence of cellular/humoral rejection was similar, but incidence of cardiac allograft vasculopathy was higher (15.6 vs. 7.4%; p = 0.081). Incidence of diabetes de novo was similar (p = 0.632), but older patients had more serious infections in the 1st year (p = 0.018). CONCLUSION: Heart transplantation in selected older patients can be performed with survival similar to younger patients, hence should not be restricted arbitrarily. Incidence of infections, graft vascular disease, and malignancies can be reduced with a more personalized approach to immunosuppression. Allocation of donors to these patients does not appear to reduce the possibility of transplanting younger patients.

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Tese (doutorado)—Universidade de Brasília, Faculdade de Medicina, Pós-Graduação em Patologia Molecular, 2016.

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La enfermedad renal crónica ha aumentado a nivel mundial y nacional, mientras que el número de donantes viene en descenso, y los pacientes en lista de espera aumentan. Los donantes cadavéricos son una opción para estos pacientes, y han sido utilizados en últimos años para aumentar los órganos disponibles. La evaluación de la calidad de estos es importante para optimizar su uso. Estudio analítico tipo cohorte retrospectiva, cálculo de KDPI en donantes cadavéricos, seguimiento función renal creatinina sérica 1 mes, 3 meses, 6 meses y un año. Correlación supervivencia del injerto, función renal, KDPI y EPTS. Análisis de supervivencia y regresión logística con variables del donante, receptor y acto quirúrgico.

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This study tested a prediction model of suicidality in a sample of young adults. Predictor variables included perceived parental rejection, self-criticism, neediness, and depression. Participants (N 5 165) responded to the Depressive Experiences Questionnaire,theInventoryforAssessingMemoriesofParentalRearingBehavior, theCenterforEpidemiologicalStudiesDepressionScale,andtheSuicideBehaviors Questionnaire—Revised. Perceived parental rejection, personality, and depression wereassessedinitiallyatTime1,anddepressionagainandsuicidalitywereassessed 5 months later at Time 2. The proposed structural equation model fit the observed data well in a sample of young adults. Parental rejection demonstrated direct and indirect relationships with suicidality, and self-criticism and neediness each had indirect associations with suicidality. Depression was directly related to suicidality. Implications for clinical practice are discussed.

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Background and Aim: Acute cardiac rejection is currently diagnosed by endomyocardial biopsy (EMB), but multiparametric cardiac magnetic resonance (CMR) may be a non-invasive alternative by its capacity for myocardial structure and function characterization. Our primary aim was to determine the utility of multiparametric CMR in identifying acute graft rejection in paediatric heart transplant recipients. The second aim was to compare textural features of parametric maps in cases of rejection versus those without rejection. Methods: Fifteen patients were prospectively enrolled for contrast-enhanced CMR followed by EMB and right heart catheterization. Images were acquired on a 1,5 Tesla scanner including T1 mapping (modified Look-Locker inversion recovery sequence – MOLLI) and T2 mapping (modified GraSE sequence). The extracellular volume (ECV) was calculated using pre- and post-gadolinium T1 times of blood and myocardium and the patient’s hematocrit. Markers of graft dysfunction including hemodynamic measurements from echocardiography, catheterization and CMR were collated. Patients were divided into two groups based on degree of rejection at EMB: no rejection with no change in treatment (Group A) and acute rejection requiring new therapy (Group B). Statistical analysis included student’t t test and Pearson correlation. Results: Acute rejection was diagnosed in five patients. Mean T1 values were significantly associated with acute rejection. A monotonic, increasing trend was noted in both mean and peak T1 values, with increasing degree of rejection. ECV was significantly higher in Group B. There was no difference in T2 signal between two groups. Conclusion: Multiparametric CMR serves as a noninvasive screening tool during surveillance encounters and may be used to identify those patients that may be at higher risk of rejection and therefore require further evaluation. Future and multicenter studies are necessary to confirm these results and explore whether multiparametric CMR can decrease the number of surveillance EMBs in paediatric heart transplant recipients.

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Urinary tract infection (UTI) is the most common infection posttransplant. However, the risk factors for and the impact of UTIs remain controversial. The aim of this study was to identify the incidence of posttransplant UTIs in a series of renal transplant recipients from deceased donors. Secondary objectives were to identify: (1) the most frequent infectious agents; (2) risk factors related to donor; (3) risk factors related to recipients; and (4) impact of UTI on graft function. This was a retrospective analysis of medical records from renal transplant patients from January to December 2010. Local ethics committee approved the protocol. The incidence of UTI in this series was 34.2%. Risk factors for UTI were older age, (independent of gender), biopsy-proven acute rejection episodes, and kidneys from deceased donors (United Network for Organ Sharing criteria). For female patients, the number of pretransplant pregnancies was an additional risk factor. Recurrent UTI was observed in 44% of patients from the UTI group. The most common infectious agents were Escherichia coli and Klebsiella pneumoniae, for both isolated and recurrent UTI. No difference in renal graft function or immunosuppressive therapy was observed between groups after the 1-year follow-up. In this series, older age, previous pregnancy, kidneys from expanded criteria donors, and biopsy-proven acute rejection episodes were risk factors for posttransplant UTI. Recurrence of UTI was observed in 44%, with no negative impact on graft function or survival.

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The relationship between aggressiveness and peer acceptance-rejection were analyzed in 1281 elementary school children. Sociometric measure was based on three positive and three negative classmates choices. The aggressiveness scales gathered information about familiar, scholar and general situations. There were no statistically insignificant differences among the schools related to the sociometric and aggressiveness in familiar situation measures. The scales of the scholar and general aggressiveness formed two sub-groups, in which two schools showed less aggressiveness and the two other more aggressiveness. Scholar aggressiveness showed significant correlations with the sociometric status in all schools and the general aggressiveness in one of them, suggesting that the most social acceptance, the lesser the student's aggressiveness. As the correlations were low, extreme groups in acceptance-rejection conditions had been studied and the scales of scholar and general aggressiveness had differentiated these groups in only one school.

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Purpose: An experimental study to evaluate the behavior of polytetrafluoroethylene (Gore-Tex®) compared with human sclera, in scleral perforations induced in rabbits eyes was performed. Methods: Twenty-two eyes of rabbits were submitted to scleral perforation followed by Gore-Tex® graft in the left eye and human sclera graft in the right eye respectively. During one month the postoperative evolution was analyzed every day: intensity of hyperemia, presence of infection, secretion, rejection and tonicity of the eyes. Results: No cases of secretion, infection or rejection were observed. The histological sections showed fibrosis in the eyes with Gore-Tex®, good adhesion and epithelization. Conclusion: The Gore-Tex® showed to be a plausible material to be used as graft in scleral defects with some advantages such as easy obtention, good handling and durability.