Immunohistochemical expression of cell differentiation and growth in neonate cardiomyocytes.

BACKGROUND: The cardiac alterations during the fetal heart transition to extrauterine life have been explored by several animal studies and the cell mechanisms responsible for these modifications are not well documented in humans. OBJECTIVE: To evaluate the mechanism of cell differentiation into cardiomyocytes that occur in the first days of life, through immunohistochemical analysis of proteins involved in proliferation and muscle contraction processes, in samples of human neonate myocardium. METHODS: Cross-sectional study of paraffin-sample sections of myocardium from an autopsy database of human neonates, divided into two sample groups: full-term neonates who died after a maximum of two days of life (NEO1) with 10 cases, and full-term infants who died between 3 and 10 days of life (NEO2) with 14 cases, in order to follow a temporal line that would contemplate the transition from fetal circulation to extrauterine life. The samples were studied in tissue microarray and the antibodies used were Ki67, PCNA, PTEN, Bcl2 (proliferation), HHF35 and sarcomeric actin (contractile proteins). RESULTS: Difference was observed regarding Ki67, p = 0.02; HHF35, p <0.01 and sarcomeric actin, p = 0.02, with Ki67 expression being higher in NEO1 group, whereas HHF35 and sarcomeric actin expression was higher in the NEO2 group. CONCLUSION: The results suggest that cardiomyocytes have a proliferation characteristic (Ki67) in NEO1 which, following a temporal line, will be replaced by a differentiation characteristic (HHF35 and sarcomeric actin) in NEO2.

Evaluation of early abnormalities of the sensory retina in a hypercholesterolemia experimental model: an immunohistochemical study.

PURPOSE: The aim of this study is to demonstrate the early changes of the sensory retina induced by hypercholesterolemia in an experimental model. METHODS: New Zealand rabbits were divided into two groups: CG (Control Group) was fed a normal diet for 6 weeks. G1 was initially fed a 1% cholesterol diet for two weeks and from the 14th day on a 0.5% cholesterol diet until the 42nd day. The eyes underwent an immunohistochemical analysis with monoclonal antibodies anti-calretinin and anti-glial fibrillary acidic protein (GFAP). RESULTS: G1 cells and cell elements presented significant immunoreactivity to anti-calretinin. No immunoreactivity to anti-glial fibrillary acidic protein was observed in both groups. CONCLUSION: This study has shown that a hypercholesterolemic diet may induce early changes in the sensory retina in rabbits. The anti-calretinin monoclonal antibody was able to reveal calcium accumulation inside the nerve cells.

[Modifiable risk factors for age-related macular degeneration]. / Fatores modificáveis da degeneração macular relacionada à idade.

The authors present the main modifiable risk factors that may trigger and/or worsen age-related macular degeneration. Mechanisms of action related to these factors as well as preventive measures and intervention effectiveness are discussed.

Expressão imunoistoquímica de diferenciação e crescimento celular em cardiomiócitos de neonatos / Immunohistochemical expression of cell differentiation and growth in neonate cardiomyocytes

FUNDAMENTO: As alterações cardíacas na fase de transição do coração fetal para a vida extrauterina vêm sendo exploradas por inúmeras pesquisas em animais, e os mecanismos celulares responsáveis por essas modificações ainda não estão bem documentado em seres humanos. OBJETIVO: Avaliar o mecanismo de diferenciação celular em cardiomiócitos ocorridas nos primeiros dias de vida, por meio da análise imunoistoquímica de proteínas envolvidas com processos de proliferação e contração muscular, em amostras de miocárdio de recém-natos humanos. MÉTODO: Estudo transversal de amostras parafinadas de miocárdio provenientes de banco de necropsias de recémnascidos humanos, divididos em dois grupos amostrais: recém-nascidos a termo que foram a óbito com no máximo dois dias de vida (NEO1) com 10 casos, e recém- nascidos a termo que foram a óbito entre três e 10 dias de vida (NEO2) com 14 casos, a fim de seguir uma linha de tempo que contemplasse a fase de transição da circulação fetal a vida extrauterina. As amostras foram estudadas em tissue microarray e os anticorpos utilizados foram o Ki67, PCNA, PTEN, Bcl2 (proliferação) e HHF35 e actina sarcomérica (proteínas contráteis). RESULTADOS: Foi encontrada diferença com o Ki67 p = 0,02, HHF35 p < 0,01 e actina sarcomérica p = 0,02, e a expressão do Ki67 foi mais alta no grupo NEO1 e a expressão do HHF35 e da actina sarcomérica foi mais alta no grupo NEO2. CONCLUSÃO: Os resultados sugerem que os cardiomiócitos apresentam uma característica proliferativa (Ki67) nos NEO1 e que essa vai, seguindo uma linha temporal, sendo substituída por um caráter de diferenciação (HHF35 e actina sarcomérica) nos NEO2.

BACKGROUND: The cardiac alterations during the fetal heart transition to extrauterine life have been explored by several animal studies and the cell mechanisms responsible for these modifications are not well documented in humans. OBJECTIVE: To evaluate the mechanism of cell differentiation into cardiomyocytes that occur in the first days of life, through immunohistochemical analysis of proteins involved in proliferation and muscle contraction processes, in samples of human neonate myocardium. METHODS: Cross-sectional study of paraffin-sample sections of myocardium from an autopsy database of human neonates, divided into two sample groups: full-term neonates who died after a maximum of two days of life (NEO1) with 10 cases, and full-term infants who died between 3 and 10 days of life (NEO2) with 14 cases, in order to follow a temporal line that would contemplate the transition from fetal circulation to extrauterine life. The samples were studied in tissue microarray and the antibodies used were Ki67, PCNA, PTEN, Bcl2 (proliferation), HHF35 and sarcomeric actin (contractile proteins). RESULTS: Difference was observed regarding Ki67, p = 0.02; HHF35, p <0.01 and sarcomeric actin, p = 0.02, with Ki67 expression being higher in NEO1 group, whereas HHF35 and sarcomeric actin expression was higher in the NEO2 group. CONCLUSION: The results suggest that cardiomyocytes have a proliferation characteristic (Ki67) in NEO1 which, following a temporal line, will be replaced by a differentiation characteristic (HHF35 and sarcomeric actin) in NEO2.

Evaluation of early abnormalities of the sensory retina in a hypercholesterolemia experimental model: an immunohistochemical study / Avaliação das anormalidades precoces da retina sensorial em modelo experimental de hipercolesterolemia: estudo imunohistoquímico

PURPOSE: The aim of this study is to demonstrate the early changes of the sensory retina induced by hypercholesterolemia in an experimental model. METHODS: New Zealand rabbits were divided into two groups: CG (Control Group) was fed a normal diet for 6 weeks. G1 was initially fed a 1 percent cholesterol diet for two weeks and from the 14th day on a 0.5 percent cholesterol diet until the 42nd day. The eyes underwent an immunohistochemical analysis with monoclonal antibodies anti-calretinin and anti-glial fibrillary acidic protein (GFAP). RESULTS: G1 cells and cell elements presented significant immunoreactivity to anti-calretinin. No immunoreactivity to anti-glial fibrillary acidic protein was observed in both groups. CONCLUSION: This study has shown that a hypercholesterolemic diet may induce early changes in the sensory retina in rabbits. The anti-calretinin monoclonal antibody was able to reveal calcium accumulation inside the nerve cells.

OBJETIVO: O objetivo deste estudo é demonstrar experimentalmente as alterações precoces da retina sensorial induzidas pela hipercolesterolemia. MÉTODOS: Coelhos New Zealand foram organizados em dois grupos: GC (grupo controle), composto por 6 coelhos (6 olhos), recebeu dieta normal por 6 semanas; G1, composto por 12 coelhos (12 olhos), tratado previamente com ração colesterol a 1 por cento (Sigma-Aldrich) por 2 semanas e a partir do 14º dia com ração colesterol a 0,5 por cento (Sigma-Aldrich). Os olhos foram submetidos à análise imunohistoquímica com os anticorpos monoclonais anticalretinina e anti-glial fibrillary acidic protein (GFAP). RESULTADOS: G1 apresentou maior número de células e elementos celulares imunoreativos a anticalretinina que o GC, com relevância estatística. GFAP foi negativo em ambos os grupos. CONCLUSÃO: Este estudo demonstrou que a dieta hipercolesterolêmica pode induzir alterações precoces na retina sensorial em coelhos. O anticorpo monoclonal anticalretinina foi capaz de revelar o acúmulo de cálcio dentro das células neuronais retiniana.

Fatores modificáveis da degeneração macular relacionada à idade / Modifiable risk factors for age-related macular degeneration

Os autores apresentam os principais fatores modificáveis considerados de risco para o desencadeamento e/ou agravamento da degeneração macular relacionada com a idade. São abordados os mecanismos de ação destes fatores, assim como medidas preventivas e eficácia de eventuais intervenções.

The authors present the main modifiable risk factors that may trigger and/or worsen age-related macular degeneration. Mechanisms of action related to these factors as well as preventive measures and intervention effectiveness are discussed.