Avaliação do endotélio corneano suíno por microscopia eletrônica de varredura após aplicação de azul brilhante a 0,05% na câmara anterior : estudo in vitro

The aim was to investigate the ultrastructural changes in the corneal endothelium of pigs induced by intracameral 0.05% brilliant blue. Twenty swine corneas were separated into two groups, the right eye bulbs (control group) and the left eye bulbs (experimental group) of the same animal. All the eye bulbs were evaluated with specular microscopy. The cornea of the right eye bulbs was excised and in the left eye bulbs 0.2ml of 0.05% brilliant blue vital dye (OPTH-blue®) was injected into the anterior chamber, where it remained for one minute. Then the anterior chamber was cleaned with a balanced salt solution injection and the cornea was excised too. All the corneas were evaluated by scanning electron microscopy to evaluate the changes on the endothelium caused by the brilliant blue dye. There were no significant differences between the right corneal endothelium cells and the left corneal endothelium cells with scanning electron microscopy after intracameral use of 0.05% brilliant blue dye. The 0.05% brilliant blue dye concentration did not cause deleterious effects for the swine corneal endothelium after intracameral use and can be a choice for safe staining of the anterior capsule of the lens in cataract surgery.[Avaliação do endotélio corneano suíno por microscopia eletrônica de varredura após aplicação de azul brilhante a 0,05% na câmara anterior: estudo in vitro.] Com o objetivo de avaliar as alterações ultraestruturais no endotélio corneano suíno induzidas pela aplicação intracameral do corante azul brilhante 0,05%, vinte córneas suínas foram separadas em dois grupos: olhos direitos (grupo controle) e olhos esquerdos (grupo experimental). Inicialmente todos os bulbos oculares foram avaliados por microscopia especular. As córneas dos bulbos oculares do grupo controle foram excisadas, enquanto nos bulbos oculares do grupo experimental foram injetados 0,2ml do corante vital azul brilhante 0,05% na câmara anterior e mantido por um minuto. Após esse período a câmara anterior foi lavada com solução salina balanceada e as córneas foram excisadas. Todas as córneas excisadas foram avaliadas por microscopia eletrônica de varredura para verificar a ocorrência possíveis alterações no endotélio corneano causadas pelo corante. Não foram observadas diferenças ultraestruturais durante a avaliação endotelial por microscopia eletrônica de varredura das córneas do grupo controle e experimental após a aplicação do azul brilhante 0,05% na câmara anterior. O corante azul brilhante na concentração 0,05% não causou danos endoteliais após seu uso intracameral em suínos e pode ser uma alternativa segura para a coloração da cápsula anterior da lente na cirurgia de catarata

Liver Directed Drugs for Transthyretin-Mediated Amyloidosis

AIM: Transthyretin-mediated amyloidosis (ATTR) is a rare, under-recognized, progressively debilitating, fatal disease caused by the aggregation and extracellular deposition of amyloid transthyretin (TTR) fibrils in multiple organs and tissues throughout the body. TTR is predominantly synthesized by the liver, and normally circulates as a homotetramer, while misfolded monomers aggregate to form amyloid fibrils. One strategy to treat ATTR amyloidosis is to reduce the amount of TTR produced by the liver using drugs that directly target the TTR mRNA or gene. METHODS: This narrative review focuses on how TTR gene silencing tools act to reduce TTR production, describing strategies for improved targeted delivery of these agents to hepatocytes where TTR is preferentially expressed. RESULTS: Antisense oligonucleotides (ASOs) and small interfering RNAs (siRNAs), termed RNA silencers, cause selective degradation of TTR mRNA, while a TTR gene editing tool reduces TTR expression by introducing nonsense mutations into the TTR gene. Two strategies to facilitate tissue-specific delivery of these nucleic acid-based drugs employ endogenous receptors expressed by hepatocytes. Lipid nanoparticles (LNPs) that recruit apolipoprotein E support low density lipoprotein receptor-mediated uptake of unconjugated siRNA and is now used for CRISPR gene editing tools. Additionally, conjugating N-acetylgalactosamine (GalNAc) moieties to ASOs or siRNAs facilitates receptor-mediated uptake by the asialoglycoprotein receptor. CONCLUSION: ATTR is a progressive disease with various clinical manifestations due to TTR aggregation, deposition, and amyloid formation. Receptor-targeted ligands (e.g., GalNAc) and nanoparticle encapsulation (e.g., LNPs) are technologies to deliver ASOs, siRNAs, and gene editing tools to hepatocytes, the primary location of TTR synthesis

Design and Rationale of the Global Phase 3 NEURO-TTRansform Study of Antisense Oligonucleotide AKCEA-TTR-LRx (ION-682884-CS3) in Hereditary Transthyretin-Mediated Amyloid Polyneuropathy

Introduction: AKCEA-TTR-LRx is a ligand-conjugated antisense (LICA) drug in development for the treatment of hereditary transthyretin amyloidosis (hATTR), a fatal disease caused by mutations in the transthyretin (TTR) gene. AKCEA-TTR-LRx shares the same nucleotide sequence as inotersen, an antisense medicine approved for use in hATTR polyneuropathy (hATTR-PN). Unlike inotersen, AKCEA-TTR-LRx is conjugated to a triantennary N-acetylgalactosamine moiety that supports receptor-mediated uptake by hepatocytes, the primary source of circulating TTR. This advanced design increases drug potency to allow for lower and less frequent dosing. The NEURO-TTRansform study will investigate whether AKCEA-TTR-LRx is safe and efficacious, with the aim of improving neurologic function and quality of life in hATTR-PN patients. Methods/design: Approximately 140 adults with stage 1 (independent ambulation) or 2 (requires ambulatory support) hATTR-PN are anticipated to enroll in this multicenter, open-label, randomized, phase 3 study. Patients will be assigned 6:1 to AKCEA-TTR-LRx 45 mg subcutaneously every 4 weeks or inotersen 300 mg once weekly until the prespecified week 35 interim efficacy analysis, after which patients receiving inotersen will receive AKCEA-TTR-LRx 45 mg subcutaneously every 4 weeks. All patients will then receive AKCEA-TTR-LRx through the remainder of the study treatment period. The final efficacy analysis at week 66 will compare the AKCEA-TTR-LRx arm with the historical placebo arm from the phase 3 trial of inotersen (NEURO-TTR). The primary outcome measures are between-group differences in the change from baseline in serum TTR, modified Neuropathy Impairment Score + 7, and Norfolk Quality of Life-Diabetic Neuropathy questionnaire. Conclusion: NEURO-TTRansform is designed to determine whether targeted delivery of AKCEA-TTR-LRx to hepatocytes with lower and less frequent doses will translate into clinical and quality-of-life benefits for patients with hATTR-PN

Avaliação do endotélio da córnea de coelhos (oryctolagus cuniculus) em diferentes faixas etárias utilizando a microscopia especular

O endotélio é uma monocamada de células achatadas, poligonais e interligadas que recobrem a superfície posterior da córnea, sendo fundamental na manutenção da transparência desta estrutura. Apesar dos coelhos (Orictolagus cuniculus) serem amplamente utilizados em pesquisas oftálmicas, não existem avaliações detalhadas referentes ao endotélio da córnea desta espécie em diferentes idades. Objetivou-se estudar os parâmetros morfológicos e morfométricos do endotélio da córnea de coelhos de diferentes idades, utilizando-se a microscopia especular. Foram estudados 36 bulbos oculares de 18 coelhos, machos ou fêmeas, de diferentes faixas etárias divididos em três grupos com seis animais cada, designados por: G I (animais com idade de seis meses); G II (animais com 1 ano de idade) e G III (animais com quatro anos de idade). A densidade celular endotelial média nos animais dos grupos G I, G II e G III foi de respectivamente 2307,16± 319,04, 1894,75 ± 170,81 e 1818,66 ± 245,11 células/mm2. A área celular média foi de respectivamente 364,43 ± 39,36, 374,79 ± 48,46 e de 378.50 ± 02,97 μm2 para G I, G II e G III. O pleomorfismo médio ou porcentagem de células hexagonais no endotélio central do olho direito e esquerdo de coelhos foi respectivamente de 65,40 ± 23,39% e de 75,15 ± 10,44%, com variação de 42,01 a 88,80% e de 60,71 a 81,60%. Os resultados apontam decréscimo da densidade, do pleomorfismo, e aumento da área celular média com o aumento da idade. O endotélio da córnea de coelhos sofre alterações decorrentes do avanço da idade.The corneal endothelium is a monolayer of interconnected flattened polygonal cells that cover the back surface of the cornea, it is essential for the maintenance of its transparency. Due to the complete lack of data on the endothelial cells of rabbits (Orictolagus cuniculus) it`s ophthalmic widely used in research, no data relating to corneal endothelium in this species correlating their age. Therefore aimed to assess cell density, the average cell area and morphology of the corneal endothelium of rabbits at different ages. It was studied 36 eyes of 18 rabbits, male or female, of different ages. Rabbits were divided into three groups with 6 animals each, designated by: G I (animals aged six months), G II (animals with 1 year) and G III (animals with four years of age). The mean endothelial cell density in the animals of G I, G II and G III were respectively 2307,16± 319,04, 1894,75 ± 170,81 e 1818,66 ± 245,11 células/mm2. The average cell area was respectively 364,43 ± 39,36, 374,79 ± 48,46 e de 378.50 ± 02,97 μm2 for GI, G II and G III. The pleomorphism medium or percentage of hexagonal cells in the endothelium of the central right and left eyes of rabbits was respectively 65.40 ± 23.39% and 75.15 ± 10.44%, ranging from 42.01 to 88.80 %, and 60.71 to 81.60%. The results indicate a decrease in density, pleomorphism, and increased in average cell area with increasing age. The corneal endothelium of rabbits changes with advancing age

Avaliação do endotélio da córnea de coelhos (oryctolagus cuniculus) em diferentes faixas etárias utilizando a microscopia especular

O endotélio é uma monocamada de células achatadas, poligonais e interligadas que recobrem a superfície posterior da córnea, sendo fundamental na manutenção da transparência desta estrutura. Apesar dos coelhos (Orictolagus cuniculus) serem amplamente utilizados em pesquisas oftálmicas, não existem avaliações detalhadas referentes ao endotélio da córnea desta espécie em diferentes idades. Objetivou-se estudar os parâmetros morfológicos e morfométricos do endotélio da córnea de coelhos de diferentes idades, utilizando-se a microscopia especular. Foram estudados 36 bulbos oculares de 18 coelhos, machos ou fêmeas, de diferentes faixas etárias divididos em três grupos com seis animais cada, designados por: G I (animais com idade de seis meses); G II (animais com 1 ano de idade) e G III (animais com quatro anos de idade). A densidade celular endotelial média nos animais dos grupos G I, G II e G III foi de respectivamente 2307,16± 319,04, 1894,75 ± 170,81 e 1818,66 ± 245,11 células/mm2. A área celular média foi de respectivamente 364,43 ± 39,36, 374,79 ± 48,46 e de 378.50 ± 02,97 μm2 para G I, G II e G III. O pleomorfismo médio ou porcentagem de células hexagonais no endotélio central do olho direito e esquerdo de coelhos foi respectivamente de 65,40 ± 23,39% e de 75,15 ± 10,44%, com variação de 42,01 a 88,80% e de 60,71 a 81,60%. Os resultados apontam decréscimo da densidade, do pleomorfismo, e aumento da área celular média com o aumento da idade. O endotélio da córnea de coelhos sofre alterações decorrentes do avanço da idade.The corneal endothelium is a monolayer of interconnected flattened polygonal cells that cover the back surface of the cornea, it is essential for the maintenance of its transparency. Due to the complete lack of data on the endothelial cells of rabbits (Orictolagus cuniculus) it`s ophthalmic widely used in research, no data relating to corneal endothelium in this species correlating their age. Therefore aimed to assess cell density, the average cell area and morphology of the corneal endothelium of rabbits at different ages. It was studied 36 eyes of 18 rabbits, male or female, of different ages. Rabbits were divided into three groups with 6 animals each, designated by: G I (animals aged six months), G II (animals with 1 year) and G III (animals with four years of age). The mean endothelial cell density in the animals of G I, G II and G III were respectively 2307,16± 319,04, 1894,75 ± 170,81 e 1818,66 ± 245,11 células/mm2. The average cell area was respectively 364,43 ± 39,36, 374,79 ± 48,46 e de 378.50 ± 02,97 μm2 for GI, G II and G III. The pleomorphism medium or percentage of hexagonal cells in the endothelium of the central right and left eyes of rabbits was respectively 65.40 ± 23.39% and 75.15 ± 10.44%, ranging from 42.01 to 88.80 %, and 60.71 to 81.60%. The results indicate a decrease in density, pleomorphism, and increased in average cell area with increasing age. The corneal endothelium of rabbits changes with advancing age

Densidade celular e morfologia das células do endotélio da córnea de coelhos obtidas com microscopia especular

The goal of this study was to describe the normal values of corneal endothelial cell density and hexagonality in healthy rabbits’ eyes using contact specular microscopy. Both eyes of 18 rabbits, males and females, of different ages were evaluated. The eyes were divided into three groups of 12 each according to the age range of the animals: G1 (6 months old), G2 (12 months old), and G3 (48 months old). Parameters studied included mean endothelial cell density and hexagonality. For Group I, the mean cell density was 2307 cells per mm2. For GII, the mean cell density was 1895 cells per mm2. For G III, the mean cell density was 1818 cells per mm2. Cell density decreased significantly with aging (P<0.001) among the three groups. Pleomorphism in the rabbits of GI was 74.33±10.08. In the rabbits of GII it was 71.83±11.38. In the rabbits of GIII it was 64.02±28.80. Significant differences (P<0.001) were evident between GI and GIII and GII and GIII but not between Groups I and II. The results showed a decrease in number of cells and hexagonality with aging. Corneal endothelium of rabbits suffers changes due to advancing age both in terms of cell density and morphology.Objetivou-se avaliar a densidade celular e a hexagonalidade do endotélio da córnea de coelhos saudáveis usando um microscópio especular de contato. Os dois olhos de 18 coelhos, machos ou fêmeas, de diferentes idades foram avaliados. Os olhos foram separados em três grupos de 12 olhos cada em função da idade: G1 (6 meses de idade), G2 (12 meses de idade) e G3 (48 meses de idade). Os parâmetros estudados incluíram a densidade celular e a hexagonalidade. Para o Grupo I, a densidade celular média foi de 2307 células por mm2. Para GII, a densidade celular média foi de 1895 células por mm2. Para G III, a densidade celular média foi de 1818 células por mm2. A densidade celular diminuiu significativamente com o envelhecimento (P<0,001) entre os três grupos. O pleomorfismo nos coelhos de GI foi de 74,33±10,08. Nos coelhos do GII foi 71,83±11,38. Nos coelhos de GIII foi de 64,02±28,80. Diferenças significativas (P<0,001) foram evidentes entre GI e GIII e GII e GIII, mas não entre os Grupos I e II. Os resultados revelaram diminuição da densidade celular e da hexagonalidade com o avanço da idade. O endotélio da córnea de coelhos sofre alterações devido ao avanço da idade tanto na densidade celular e quanto na morfologia

Effects of intracameral brilliant blue on the corneal endothelium of swine: in vitro study

Abstract: The aim was to investigate the ultrastructural changes in the corneal endothelium of pigs induced by intracameral 0.05% brilliant blue. Twenty swine corneas were separated into two groups, the right eye bulbs (control group) and the left eye bulbs (experimental group) of the same animal. All the eye bulbs were evaluated with specular microscopy. The cornea of the right eye bulbs was excised and in the left eye bulbs 0.2ml of 0.05% brilliant blue vital dye (OPTH-blue±) was injected into the anterior chamber, where it remained for one minute. Then the anterior chamber was cleaned with a balanced salt solution injection and the cornea was excised too. All the corneas were evaluated by scanning electron microscopy to evaluate the changes on the endothelium caused by the brilliant blue dye. There were no significant differences between the right corneal endothelium cells and the left corneal endothelium cells with scanning electron microscopy after intracameral use of 0.05% brilliant blue dye. The 0.05% brilliant blue dye concentration did not cause deleterious effects for the swine corneal endothelium after intracameral use and can be a choice for safe staining of the anterior capsule of the lens in cataract surgery