906 resultados para Cornea, corneal transplant, keratoplasty, limbal transplant


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PURPOSE: To evaluate the association between corneal hysteresis and axial length/refractive error among rural Chinese secondary school children. DESIGN: Cross-sectional cohort study. METHODS: Refractive error (cycloplegic auto-refraction with subjective refinement), central corneal thickness (CCT) and axial length (ultrasonic measurement), intraocular pressure (IOP), and corneal hysteresis (Reichert Ocular Response Analyzer) were measured on a rural school-based cohort of children. RESULTS: Among 1,233 examined children, the mean age was 14.7 +/- 0.8 years and 699 (56.7%) were girls. The mean spherical equivalent (n = 1,232) was -2.2 +/- 1.6 diopters (D), axial length (n = 643) was 23.7 +/- 1.1 mm, corneal hysteresis (n = 1,153) was 10.7 +/- 1.6 mm Hg, IOP (n = 1,153) was 17.0 +/- 3.4 mm Hg, and CCT (n = 1,226) was 553 +/- 33 microns. In linear regression models, longer axial length was significantly (P < .001 for both) associated with lower corneal hysteresis and higher IOP. Hysteresis in this population was significantly (P < .001) lower than has previously been reported for normal White children (n = 42, 12.3 +/- 1.3 mm Hg), when adjusting for age and gender. This difference did not appear to depend on differences in axial length between the populations, as it persists when only Chinese children with normal uncorrected vision are included. CONCLUSIONS: Prospective studies will be needed to determine if low hysteresis places eyes at risk for axial elongation secondary or if primary elongation results in lower hysteresis.

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PURPOSE:

The purpose of this study was to report on Tsukamurella as a mimic of atypical mycobacterial infection.

METHODS:

We report a patient who had received repeated corneal grafts with culture-proven Tsukamurella keratitis.

RESULTS:

A slow-progressing corneal abscess that initially developed adjacent to a corneal stitch responded poorly to empiric antibiotic treatment. A preliminary culture report revealed fast-growing mycobacterial species. Treatment adjustments successfully controlled the disease. A final diagnosis of Tsukamurella was subsequently made on the basis of cultures.

CONCLUSIONS:

Tsukamurella exhibits laboratory similarities to mycobacteria and should be considered in the differential of atypical infection of the ocular surface.

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PURPOSE: Low corneal hysteresis is associated with longer axial length in Chinese secondary school children. The authors sought to explore this association in primary school children. METHODS: LogMAR presenting visual acuity, cycloplegic refractive error, ocular biometry, central corneal thickness (CCT), and corneal hysteresis (CH) was assessed for children in grades 1 to 3 at an academically competitive urban school in Shantou, China. RESULTS: Among 872 eligible children (mean age, 8.6 ± 2.1 years), 651 (74.7%) completed the examination. Among 1299 examined eyes, 111 (8.5%) had uncorrected vision ≤6/12. Mean spherical equivalent refractive error for all eyes was +0.26 ± 1.41 D, and axial length (AL) was 22.7 ± 0.90 mm. CH for the lowest (mean AL, 21.7 ± 0.39 mm), two middle (mean AL, 22.4 ± 0.15 and 22.9 ± 0.15 mm), and highest quartiles (mean AL, 23.7 ± 0.74 mm) of AL were 10.6 ± 2.1 mm Hg, 10.4 ± 2.1 mm Hg, 10.3 ± 2.3 mm Hg, and 10.2 ± 2.3 mm Hg respectively (age- and gender-adjusted Pearson's correlation coefficient r = -0.052; P = 0.001). In generalized estimating equation models adjusting for age, gender, and CCT, lower CH was significantly associated with longer AL (P < 0.001) and more myopic refractive error (P = 0.001). CONCLUSIONS: CH measurement is practical in young children because this is when myopia undergoes its most rapid progression. Prospective follow-up of this cohort at high risk for myopia is under way to determine whether low CH is predictive, or a consequence, of long AL.

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PURPOSE: To describe the distribution of central corneal thickness (CCT), intraocular pressure (IOP), and their determinants and association with glaucoma in Chinese adults.DESIGN: Population-based cross-sectional study.METHODS: Chinese adults aged 50 years and older were identified using cluster random sampling in Liwan District, Guangzhou. CCT (both optical [OCCT] and ultrasound [UCCT]), intraocular pressure (by Tonopen, IOP), refractive error (by autorefractor, RE), radius of corneal curvature (RCC), axial length (AL), and body mass index (BMI) were measured, and history of hypertension and diabetes (DM) was collected by questionnaire. Right eye data were analyzed.RESULTS: The mean values of OCCT, UCCT, and IOP were 512 ± 29.0 μm, 542 ± 31.4 μm, and 15.2 ± 3.1 mm Hg, respectively. In multiple regression models, CCT declined with age (P < .001) and increased with greater RCC (P < .001) and DM (P = .037). IOP was positively associated with greater CCT (P < .001), BMI (P < .001), and hypertension (P < .001). All 25 persons with open-angle glaucoma had IOP <21 mm Hg. CCT did not differ significantly between persons with and without open- or closed-angle glaucoma. Among 65 persons with ocular hypertension (IOP >97.5th percentile), CCT (555 ± 29 μm) was significantly (P = .01) higher than for normal persons.CONCLUSIONS: The distributions of CCT and IOP in this study are similar to that for other Chinese populations, though IOP was lower than for European populations, possibly due to lower BMI and blood pressure. Glaucoma with IOP <21 mm Hg is common in this population. We found no association between glaucoma and CCT, though power (0.3) for this analysis was low.

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BACKGROUND: We sought to determine whether corneal biomechanical parameters are predictive of reduction in axial length after anti-metabolite trabeculectomy. METHODS: Chinese subjects undergoing trabeculectomy with mitomycin C by a single experienced surgeon underwent the following measurements: Corneal hysteresis (CH, Ocular Response Analyzer, Reichert Ophthalmic Instruments), Goldmann intra-ocular pressure (IOP), central corneal thickness (CCT) and axial length (AL, IOLMaster, Carl Zeiss Meditec, Dublin, CA) were measured pre-operatively, and AL, CH and IOP were measured 1 day and 1 week post-operatively. RESULTS: Mean age of 31 subjects was 52.0 ± 15.2 years, and 15 (48.4%) were female. The mean pre-operative IOP of 21.4 ± 9.3 mmHg was reduced to 8.2 ± 4.6 mmHg 1 day and 11.0 ± 4.4 mmHg 1 week post-operatively (p < 0.001). AL declined from 22.99 ± 0.90 to 22.76 ± 0.87 mm at 1 day and 22.74 ± 0.9 mm at 1 week; 30/31 (%) eyes had a decline in AL (p < 0.001, sign test). In multivariate linear regression models including post-operative data from 1 day and 1 week, greater decline in Goldmann IOP (p < 0.0001, greater pre-op axial length (p < 0.001) and lower pre-operative CH (p = 0.03), were all associated with greater decline in post-operative axial length. CONCLUSIONS: Eyes with lesser ability of the ocular coat to absorb energy (lower CH) had significantly greater decrease in axial length after trabeculectomy-induced IOP-lowering.

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Acute liver failure is rarely secondary to lymphoma or leukaemia and it is extremely uncommon as the initial presentation of malignancy. We report a case of a young adult patient with severe acute liver failure referred for liver transplant, in which a Burkitt acute lymphoblastic leukaemia was diagnosed by bone marrow examination. A complete recovery and long remission were obtained with chemotherapy.

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BACKGROUND: Fulminant hepatic failure (FHF) is a rare condition. Several series have been reported either by individual centres or in multicentre studies but, to our knowledge, this is the first report from a Portuguese population and might be a good example of FHF cases in a SouthWestern European population. AIMS: To present the experience in FHF of a Portuguese Hepatogastroenterological Intensive Care Unit. MATERIALS AND METHODS: Retrospective study of 61 cases of FHF consecutively admitted between February 1992 and October 2006. Definition and classification of FHF were those suggested by Trey and Davidson (1970) and O'Grady et al. (1993), respectively. Criteria and contraindications for hepatic transplantation (HT) were those proposed by Bernuau et al. (1991) and Muñoz (1993), respectively. RESULTS: Fifty-seven per cent of patients were women and median age was 37 years (range: 8-73). Most common cause of FHF was indeterminate (26%) followed by viral (23%) and drug-induced (23%), with 51% of cases with a hyperacute evolution. Global HT rate was 54% with criteria for HT present in 87% of the patients resulting in an applicability rate of 62%. Overall survival was 69% and transplant-free survival was 15%; transplanted patients had survival rates of 70 and 68% at 6 and 12 months, respectively. CONCLUSIONS: Drug-induced and viral agents were responsible for almost half of FHF cases with a clear predominance of hyperacute presentation. The HT rate was 54% and the applicability rate was 62%. The overall 1 year survival of 69% might reflect the adequacy of the HT criteria used.

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A indução da doença do transplante contra o hospedeiro (GVHD) depende da activação das células dadoras T pelas células do hospedeiro que apresentamantigenio (APCs). A teoria prevalecente descreve que estas interacções ocorrem nos órgãos linfáticos secundários (SLO), tais como os nóduloslinfáticos (LN), as placas de Peyer’s (PP) e o baço (SP). Esta hipótese foi testada usando ratinhos homozigóticos aly/aly (alinfoplasia) que não têm LN nem PP, usando como controlo os ratinhos heterozigóticos (aly/+) da mesma ninhada. Os dois grupos foram irradiados com dose letal após a remoção do baço aos ratinhos aly/aly (LN/PP/SP-/-), enquanto nos ratinhos aly/+ o baço foi deslocado e recolocado. Ambos receberam transplante de medula óssea (BMT) de ratinhos dadores singénicos (aly/aly, H-2b) ou de ratinhos alogénicos, com diferente complexo principal de histocompatibilidade (MHC) (BALB/c, H-2dou B10.BR, H-2k). A severidade de GVHD foi medida pela sobrevivência,e pelo sistema de pontuação, bem estabelecido, quer de doença clínica quer de doença dos órgãos alvo. Surpreendentemente, todos os ratinhos LN/PP/SP-/-sobreviveram, desenvolvendo GVHD clinicamente significativo, comparável,em severidade, com o observado nos ratinhos LN/PP/SP+/+. Além disso, asanálises histopatológicas demonstraram que os ratinhos LN/PP/SP-/-receptores de BMTdesenvolveram significativamente mais GVHD no fígado,no intestino, e na pele quando comparados com os animais singénicos decontrolo. Os ratinhos LN/PP/SP-/-desenvolveram também GVHD hepático mais severo quando comparados com os ratinhos de controlo LN/PP/SP+/+. Diferenças semelhantes foram ainda observadas, logo ao 7º dia, para o GVHDhepático entre os grupos alogénicos. Para identificar quais os órgãos extra-linfáticos do receptor que poderão servir como sítios iniciais de exposição a antigenios alogénicos, na ausência de SLO, foi examinada a expansão das células T (CD3+), a sua activação (CD69+), e a sua proliferação (CFSE) na medula óssea, 3 dias depois do BMT. Em cada caso, os ratinhos LN/PP/SP-/-transplantados com medula de dadores alogénicos apresentaram númerosabsolutos significativamente maiores quer de células, quer de divisõescelulares, se comparados com os LN/PP/SP+/+. Para garantir que as diferenças experimentais observadas nos animais aly/aly, no sistema díspar do MHC, não são apenas um fenómeno dependente da estirpe de ratinho, foramtransplantados ratinhos sem baço FucT dko (LN/PP/SP-/-), previamente tratados com o anticorpo monoclonal (mAb) anti-MadCAM-1. Após o BMT estes ratinhos apresentaram elevada pontuação clínica de GVHD, mostrando que os SLO não são necessários para a indução de GVHD. Em estudos de transplante-versus-leucemia usando hospedeiros homozigóticos (LN/PP/SP-/-) estes ratinhos morreram devido a expansão tumoral e não devido a GVHD.Estudos in vitro mostraram que a capacidade das APCs, quer das célulasdendríticas (DCs) esplénicas, quer das DCs derivadas da medula óssea, dosratinhos aly/aly e aly/+ eramcomparável. Colectivamente, estes resultados são consistentes com a noção de que os SLO não são necessários para a activação alogénica das celulas T, sugerindo que a medula óssea pode ser umlocal alternativo, embora menos eficiente, para o reconhecimento alogénico deantígenos e consequente activação das células dadoras T. Estas observações desafiam o paradigma de que os tecidos linfáticos secundários sãonecessários para a indução de GVHD.

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Bien qu’ils soient exposés tous deux aux rayons ultraviolets (UVR) solaires, cette exposition génotoxique n’entraîne pas les mêmes conséquences dans l’oeil et la peau. Le rôle des rayons UV dans l’induction et la progression des cancers cutanés est bien démontré. Ces rayons génotoxiques sont absorbés par l’ADN. Ils y induisent ainsi des changements conformationnels pouvant mener à la formation de différents dommages. On retrouve de façon prédominante la liaison de pyrimidines adjacentes en dimères cyclobutyliques de pyrimidines (CPD). Ceux-ci causent les mutations signatures responsables des cancers de la peau induits par les UVR. Cependant, aucune évidence ne démontre l’existence de cancer induit par les UVR dans la cornée. Nous avons donc tenté de découvrir les mécanismes permettant à la cornée d’éviter la transformation tumorale induite par les UVR. L’irradiation d’yeux de lapins aux rayons UVB a permis de prouver la capacité de ces rayons à induire la formation de CPD, et ce, de la cornée jusqu’au cristallin. Par la suite, l’irradiation d’yeux humains aux trois types de rayons UV (UVA, B et C) a permis d’y établir leur patron d’induction de CPD. Nous avons ainsi démontré que l’épithélium cornéen est particulièrement sensible à l’induction de CPD, tous types de rayons UV confondus. Enfin, la comparaison de la quantité de dommages présents dans des échantillons de peaux et de cornées irradiées à la même dose d’UVB a permis de démontrer que l’épithélium cornéen est 3.4 fois plus sensible à l’induction de CPD que l’épiderme. Nous avons par la suite étudié les mécanismes de réponse à ce stress. L’analyse de la viabilité cellulaire à la suite d’irradiations à différentes doses d’UVB a révélé que les cellules de la cornée et de la peau ont la même sensibilité à la mort cellulaire induite par les UVR. Nous avons alors analysé la vitesse de réparation des dommages induits par les UVR. Nos résultats démontrent que les CPD sont réparés 4 fois plus rapidement dans les cellules de la cornée que de la peau. L’analyse des protéines de reconnaissance des dommages a révélé que les cellules de la cornée possèdent plus de protéines DDB2 que les cellules de la peau, et ce, surtout liées à la chromatine. Nous avons alors tenté d’identifier la cause de cette accumulation. Nos analyses révèlent que la cornée possède une moins grande quantité d’ARNm DDB2, mais que la demi-vie de la protéine y est plus longue. Enfin, nos résultats suggèrent que l’accumulation de DDB2 dans les cellules de la cornée est entre autres due à une demi-vie plus longue de la protéine. Cette forte présence de DDB2 dans les cellules de la cornée permettrait un meilleur balayage de l’ADN, faciliterait de ce fait la détection de CPD ainsi que leur réparation et contribuerait donc à la capacité de la cornée à éviter la transformation tumorale induite par les UVR.

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Relatório de estágio de mestrado, Nutrição Clínica, Universidade de Lisboa, Faculdade de Medicina, 2015

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Portugal é o país que mais transplantes hepáticos efectuou a nível mundial e o segundo com maior número de dadores por milhão de habitantes, com a região centro do país a liderar a doação de órgãos. Esta liderança na área da transplantação hepática contribui também para as elevadas taxas de sobrevivência destes doentes, suportada pela excelência técnica de uma equipa multidisciplinar diferenciada, complementada por recentes avanços terapêuticos. Portugal é, também a nível mundial, o país com maior número de casos de polineuropatia amiloidótica familiar (PAF), variante TTRmet30 (proteína transtirretina mutada) tipo português, diagnosticados, sendo em algumas regiões considerada como uma doença endémica. Apesar de novas terapêuticas em estudo (exemplo: Tafamidis), até à data o transplante hepático parece ser a única terapêutica com eficácia ao retardar ou mesmo na estabilização da evolução desta doença hereditária e degenerativa, progressiva e fatal no prazo de 10-15 anos após o início da sintomatologia.

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INTRODUCTION AND AIMS: Adult orthotopic liver transplantation (OLT) is associated with considerable blood product requirements. The aim of this study was to assess the ability of preoperative information to predict intraoperative red blood cell (RBC) transfusion requirements among adult liver recipients. METHODS: Preoperative variables with previously demonstrated relationships to intraoperative RBC transfusion were identified from the literature: sex, age, pathology, prothrombin time (PT), factor V, hemoglobin (Hb), and platelet count (plt). These variables were then retrospectively collected from 758 consecutive adult patients undergoing OLT from 1997 to 2007. Relationships between these variables and intraoperative blood transfusion requirements were examined by both univariate analysis and multiple linear regression analysis. RESULTS: Univariate analysis confirmed significant associations between RBC transfusion and PT, factor V, Hb, Plt, pathology, and age (P values all < .001). However, stepwise backward multivariate analysis excluded variables Plt and factor V from the multiple regression linear model. The variables included in the final predictive model were PT, Hb, age, and pathology. Patients suffering from liver carcinoma required more blood products than those suffering from other pathologies. Yet, the overall predictive power of the final model was limited (R(2) = .308; adjusted R(2) = .30). CONCLUSION: Preoperative variables have limited predictive power for intraoperative RBC transfusion requirements even when significant statistical associations exist, identifying only a small portion of the observed total transfusion variability. Preoperative PT, Hb, age, and liver pathology seem to be the most significant predictive factors but other factors like severity of liver disease, surgical technique, medical experience in liver transplantation, and other noncontrollable human variables may play important roles to determine the final transfusion requirements.

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Introduction. This study aims to compare the molecular gene expression during ischemia reperfusion injury. Several surgical times were considered: in the beginning of the harvesting (T0), at the end of the cold ischemia period (T1), and after reperfusion (T2) and compared with graft dysfunction after liver transplant (OLT). Methods. We studied 54 patients undergoing OLT. Clinical, laboratory data, and histologic data (Suzuki classification) as well as the Survival Outcomes Following Liver Transplantation (SOFT) score were used and compared with the molecular gene expression of the following genes: Interleukin (IL)-1b, IL-6, tumor necrosis factor-a, perforin, E-selectin (SELE), Fas-ligand, granzyme B, heme oxygenase-1, and nitric oxide synthetase. Results. Fifteen patients presented with graft dysfunction according to SOFT criteria. No relevant data were obtained by comparing the variables graft dysfunction and histologic variables. We observed a statistically significant relation between SELE at T0 (P ¼ .013) and IL-1b at T0 (P ¼ .028) and early graft dysfunction. Conclusions. We conclude that several genetically determined proinflammatory expressions may play a critical role in the development of graft dysfunction after OLT.

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In a liver transplant (LT) center, treatments with Prometheus were evaluated. The main outcome considered was 1 and 6 months survival. Methods. During the study period, 74 patients underwent treatment with Prometheus; 64 were enrolled,with a mean age of 51 13 years; 47men underwent 212 treatments (mean, 3.02 per patient). The parameters evaluated were age, sex, laboratorial (liver enzymes, ammonia) and clinical (model for end-stage liver disease and Child-Turcotte-Pugh score) data. Results. Death was verified in 23 patients (35.9%) during the hospitalization period, 20 patients (31.3%) were submitted to liver transplantation, and 21 were discharged. LT was performed in 4 patients with acute liver failure (ALF, 23.7%), in 7 patients with acute on chronic liver failure (AoCLF, 43.7%), and in 6 patients with liver disease after LT (30%). Seven patients who underwent LT died (35%). In the multivariate analysis, older age (P ¼ .015), higher international normalized ratio (INR) (P ¼ .019), and acute liver failure (P ¼ .039) were independently associated with an adverse 1-month clinical outcome. On the other hand, older age (P ¼ .011) and acute kidney injury (P ¼ .031) at presentation were both related to worse 6-month outcome. For patients with ALF and AoCLF we did not observe the same differences. Conclusions. In this cohort, older age was the most important parameter defining 1- and 6-month survival, although higher INR and presence of ALF were important for 1-month survival and AKI for 6-month survival. No difference was observed between patients who underwent LT or did not have LT.

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Objective. To access the incidence of infectious problems after liver transplantation (LT). Design. A retrospective, single-center study. Materials and Methods. Patients undergoing LT from January 2008 to December 2011 were considered. Exclusion criterion was death occurring in the first 48 hours after LT. We determined the site of infection and the bacterial isolates and collected and compared recipient’s variables, graft variables, surgical data, post-LT clinical data. Results. Of the 492 patients who underwent LT and the 463 considered for this study, 190 (Group 1, 41%) developed at least 1 infection, with 298 infections detected. Of these, 189 microorganisms were isolated, 81 (51%) gram-positive bacteria (most frequently Staphylococcus spp). Biliary infections were more frequent (mean time of 160.4 167.7 days after LT); from 3 months after LT, gram-negative bacteria were observed (57%). Patients with infections after LT presented lower aminotransferase levels, but higher requirements in blood transfusions, intraoperative vasopressors, hemodialysis, and hospital stay. Operative and cold ischemia times were similar. Conclusion. We found a 41% incidence of all infections in a 2-year follow-up after LT. Gram-positive bacteria were more frequent isolated; however, negative bacteria were commonly isolated later. Clinical data after LT were more relevant for the development of infections. Donors’ variables should be considered in future analyses.