Atualmente, um dos maiores problemas na triagem sorológica de doadores de sangue para doença de Chagas é a alta freqüência de reações indeterminadas, o que faz com que muitos indivíduos sadios sejam rotulados como portadores de uma doença grave. O presente trabalho tem o objetivo de analisar o comportamento sorológico para doença de Chagas dos doadores do Hemocentro Regional de Uberaba, MG e propor mecanismos para reduzir o índice de inaptidão sorológica para essa doença. Através de estudo retrospectivo, foi analisado o resultado sorológico de 79.729 amostras obtidas de doações de sangue realizadas neste Serviço entre janeiro de 2000 e dezembro de 2004. Os resultados foram analisados quanto às variáveis: tipo de doador (novo e de retorno), gênero e idade (inferior ou igual a 30 anos e superior a 30 anos). Para a análise estatística foram realizados os testes do Qui-Quadrado e de comparação de proporções (Z). A ocorrência de doações com sorologia não negativa para doença de Chagas entre doadores novos foi significativamente superior aos de retorno, com p< 0,0001. Quanto à idade, a proporção de positivos no grupo maior de 30 anos foi significativamente superior à do grupo com idade igual ou inferior a 30 anos (p< 0,0001). O elevado número de reações indeterminadas nesse Serviço está de acordo com estudos recentes, reforçando a necessidade da implementação de testes sorológicos 100% específicos ou de exames confirmatórios práticos e rápidos, passíveis de serem introduzidos nas rotinas dos serviços de hemoterapia, reduzindo o descarte desnecessário de bolsas de sangue. Rev. bras. hematol.

ABSTRACT.Purpose: To compare the effect of a single intravitreal injection of triamcinolone acetonide and bevacizumab in reducing macular thickness, which was measured by optical coherence tomography (OCT) in patients with diabetic macular oedema (DMO). Methods: The patients received a single intravitreal injection of 1.25 mg bevacizumab in one randomly selected eye and 4.0 mg triamcinolone acetonide in the contralateral eye. Central foveal thickness measurement (CFT) with OCT was taken at the initial visit and at the 4-week, 12-week and 24-week visits. Results: Eleven patients (22 eyes) were enrolled and statistically analysed. CFT reduced in the eyes treated with triamcinolone and those treated with bevacizumab in weeks 4 and 12 (p < 0.05). At the 24-week follow-up, no significant difference was noted, relative to the initial visit. Comparing the two groups treated with different drugs, a statistically significant difference in CFT in weeks 4 and 12 was noted, with a more significant reduction in triamcinolone-treated eyes (p < 0.05). Regarding visual acuity (VA), patients treated with triamcinolone had improvement in VA at 4-week (p = 0.02) and 12-week follow-up (p = 0.01), while the group treated with bevacizumab had VA improvement at 4 -week follow-up (p = 0.02). Among the eyes treated with triamcinolone, intraocular pressure (IOP) measurement of more than 21 mmHg was found in three eyes (27.3%). Conclusions: Intravitreal triamcinolone proved to be more efficient in reducing DMO, providing longer lasting visual improvement, relative to bevacizumab. Eyes treated with triamcinolone had the highest percentage increase in IOP. Further studies are needed to corroborate these findings.

Purpose: The development of photoreceptor replacement therapy for retinal degenerative disorders requires the identification of the optimal cell source and immunosuppressive regimen in a large animal model. Allotransplants are not acutely rejected in swine subretinal space, although it is not known if survival can be improved with immunosuppression. Here we investigated the survival and integration of expanded pig retinal progenitor cells (pRPCs) in normal recipients with and without transient anti-inflammatory suppression.Methods: pRPCs were derived from the neural retina of E60 GFP transgenic pigs, expanded for six passages, characterized, and transplanted into the subretinal space of 12 pigs. Six recipients received a single intravitreal injection of rapamycin and dexamethasone.Results: pRPCs expressed the photoreceptor development genes Sox2, Pax6, Lhx2, Crx, Nrl, and Recoverin in vitro. Transplanted cells were identified in 9 out of 12 recipients 4 weeks after the injection. pRPCs integrated primarily into the photoreceptor inner segment layer and outer nuclear layer with single cells present in the inner nuclear layer. Donor cells remained recoverin-positive and acquired rhodopsin. We did not observe any signs of graft proliferation. The immunosuppression did not affect the survival or distribution of grafts. No macrophage infiltration or loss of retinal structure was observed in either group.Conclusions: Local immunosuppression with rapamycin and dexamethasone does not improve the outcome of pRPC allotransplantation into the subretinal space.Translational Relevance: Survival and integration of pRPC together with the lack of graft proliferation suggests that allogeneic RPC transplantation without transient immunosuppression is a favorable approach for photoreceptor cell replacement.

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In this review, we discuss about current knowledge about stem cell (SC) therapy in the treatment of retinal degeneration. Both human embryonic stem cell and induced pluripotent stem cell has been growth in culture for a long time, and started to be explored in the treatment of blinding conditions. The Food and Drug Administration, recently, has granted clinical trials using SC retinal therapy to treat complex disorders, as Stargardt's dystrophy, and patients with geographic atrophy, providing good outcomes. This study's intent is to overview the critical regeneration of the subretinal anatomy through retinal pigment epithelium transplantation, with the goal of reestablish important pathways from the retina to the occipital cortex of the brain, as well as the differentiation from pluripotent quiescent SC to adult retina, and its relationship with a primary retinal injury, different techniques of transplantation, management of immune rejection and tumorigenicity, its potential application in improving patients' vision, and, finally, approaching future directions and challenges for the treatment of several conditions.

Background To evaluate the in vivo and in vitro toxicity of a new formulation of liposome-encapsulated sirolimus (LES). Methods In vitro experiments were done using ARPE-19 and HRP cells. An MTT assay was used to determine cell metabolic activity and a TUNEL assay for detecting DNA fragmentation. In vivo experiments were conducted on New Zealand albino rabbits that received intravitreal injections of empty liposomes (EL) or different concentrations of LES. Histopathological and immunohistochemical analyses were performed on the rabbit’s eyes following injection. Results Eighteen eyes of nine rabbits were used. MTT assay cell viability was 95.04% in group 1 (12.5 µL/mL LES). 92.95% in group 2 (25 µL/mL LES), 91.59% in group 3 (50 µL/mL LES), 98.09% in group 4 (12.5 µL/mL EL), 95.20% on group 5 (50 µL/mL EL), 98.53% in group 6 (50 µL/mL EL), and 2.84% on group 8 (50 µL/mL DMSO). There was no statistically significant difference among groups 1 to 7 in cell viability (p = 1.0), but the comparison of all groups with group 8 was significant (p < 0.0001). The TUNEL assay comparing two groups was not statistically significant from groups 1 to 7 (p = 1.0). The difference between groups 1 to 7 and group 8 (p < 0.0001) was significant. Histopathological changes were not found in any group. No activation of Müller cells was detected. Conclusion A novel formulation of LES delivered intravitreally did not cause in vitro toxicity, as evaluated by MTT and TUNEL assays, nor in vivo toxicity as evaluated by histopathology and immunohistochemistry in rabbit eyes.

RESUMOObjetivo: Determinar os níveis de toxicidade de duas e três aplicações intravítreas de infliximabe na retina de coelhos albinos, por meio de exames clínicos oftalmoló-gicos, eletrorretinográficos e histológicos. Métodos: Foram utilizados doze coelhos albinos divididos em dois grupos. No primeiro grupo de 10 coelhos, cada olho recebeu duas (n=10 olhos) ou três injeções (n=10 olhos) intravítreas de 2 mg de infliximabe dissolvidos em 0,06 ml de solução salina, em intervalos mensais. Um segundo grupo de dois coelhos, que serviu como grupo controle (n=4 olhos), foram submetidos a duas e três aplicações intravítreas de BSS. Noventa dias após, os coelhos foram novamente submetidos a exame oftalmológico (biomicroscopia, oftalmoscopia e tonometria), eletrorretinográfico e, após enucleados, a exame histológico. Resultados: O exame biomicroscópico e oftalmoscópico não revelou anormalidades retinianas nos olhos injetados com infliximabe e no grupo controle. Alteração histológica notada foi a presença de raros linfócitos e eosinófilos no vítreo posterior em quatro e em seis olhos submetidos a duas e três aplicações de infliximabe sem significado clínico. A única alteração clinicamente significante foi uma reação inflamatória severa com presença de exsudatos vítreos na interface vítreo retiniana e discreto edema de células ganglionares nos dois olhos de um único coelho, sem alterações no vítreo posterior. Os exames eletrorretinográficos mostraram amplitudes em média 12-13% menores daquelas obtidas antes do tratamento, contudo não houve nenhuma diferença estatisticamente significante quando comparamos as amplitudes e a latencia entre os achados electrorretinográficos pré e pós-tratamento. Conclusão: Duas e três aplicações intravítreas de infliximabe em olhos de coelhos em intervalos mensais, na dosagem de 2 mg, não provocam alterações significantes após um seguimento de noventa dias, quer no exame histológico, na eletrorretinografia e na avaliação clínica oftalmológica. Conclui-se que doses seriadas de infliximabe por via intravítrea é um procedimento seguro. Estudos clínicos em humanos devem ser realizados para melhor avaliação da segurança do seu uso no tratamento de determinadas doenças que acometem a retina e a coroide. Descritores

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