Isolated total RNA and protein are preserved after thawing for more than twenty-four hours

OBJECTIVE: The preservation of biological samples at a low temperature is important for later biochemical and/or histological analyses. However, the molecular viability of thawed samples has not been studied sufficiently in depth. The present study was undertaken to evaluate the viability of intact tissues, tissue homogenates, and isolated total RNA after defrosting for more than twenty-four hours. METHODS: The molecular viability of the thawed samples (n = 82) was assessed using the A260/A280 ratio, the RNA concentration, the RNA integrity, the level of intact mRNA determined by reverse transcriptase polymerase chain reaction, the protein level determined by Western blotting, and an examination of the histological structure. RESULTS: The integrity of the total RNA was not preserved in the thawed intact tissue, but the RNA integrity and level of mRNA were perfectly preserved in isolated defrosted samples of total RNA. Additionally, the level of β-actin protein was preserved in both thawed intact tissue and homogenates. CONCLUSION: Isolated total RNA does not undergo degradation due to thawing for at least 24 hours, and it is recommended to isolate the total RNA as soon as possible after tissue collection. Moreover, the protein level is preserved in defrosted tissues

A muitas mãos: contribuição aos estudos surdos

Os textos aqui publicados apresentam discussões sobre a Educação de Surdos, a Língua de Sinais, a Língua Portuguesa Escrita como segunda língua da comunidade surda, as políticas educacionais que tocam o público surdo, a História da Educação de Surdos e a relação surdo-ouvinte. Esta obra representa, também, a materialização de uma narrativa sobre o surdo, a surdez, a Língua de Sinais e a Educação dos Surdos que rompe ou, no mínimo, que se distancia da narrativa clínica até então hegemônica

Isolated total RNA and protein are preserved after thawing for more than twenty-four hours

OBJECTIVE: The preservation of biological samples at a low temperature is important for later biochemical and/or histological analyses. However, the molecular viability of thawed samples has not been studied sufficiently in depth. The present study was undertaken to evaluate the viability of intact tissues, tissue homogenates, and isolated total RNA after defrosting for more than twenty-four hours. METHODS: The molecular viability of the thawed samples (n = 82) was assessed using the A260/A280 ratio, the RNA concentration, the RNA integrity, the level of intact mRNA determined by reverse transcriptase polymerase chain reaction, the protein level determined by Western blotting, and an examination of the histological structure. RESULTS: The integrity of the total RNA was not preserved in the thawed intact tissue, but the RNA integrity and level of mRNA were perfectly preserved in isolated defrosted samples of total RNA. Additionally, the level of beta-actin protein was preserved in both thawed intact tissue and homogenates. CONCLUSION: Isolated total RNA does not undergo degradation due to thawing for at least 24 hours, and it is recommended to isolate the total RNA as soon as possible after tissue collection. Moreover, the protein level is preserved in defrosted tissues

Usefulness of a quick decalcification of bone sections embedded in methyl metacrylate: an improved method for immunohistochemistry

Immunohistochemistry of undecalcified bone sections embedded in methyl methacrylate (MMA) is not commonly employed because of potential destruction of tissue antigenicity by highly exothermic polymerization. The aim of the present study was to describe a new technique in which a quick decalcification of bone sections embedded in MMA improves the results for immunohistochemistry. The quality of interleukin 1 alpha (IL-1 alpha) immunostaining according to the present method was better than the conventional one. Immunostaining for osteoprotegerin (OPG) and the receptor activator of NF-kappa B ligand (RANKL) in bone sections of chronic kidney disease patients with mineral bone disorders (CKD-MBD) was stronger than in controls (postmortem healthy subjects). The present study suggested that this method is easy, fast, and effective to perform both histomorphometry and immunohistochemistry in the same bone fragment, yielding new insights into pathophysiological aspects and therapeutic approaches in bone disease

Isolated total RNA and protein are preserved after thawing for more than twenty-four hours

OBJECTIVE: The preservation of biological samples at a low temperature is important for later biochemical and/or histological analyses. However, the molecular viability of thawed samples has not been studied sufficiently in depth. The present study was undertaken to evaluate the viability of intact tissues, tissue homogenates, and isolated total RNA after defrosting for more than twenty-four hours. METHODS: The molecular viability of the thawed samples (n = 82) was assessed using the A260/A280 ratio, the RNA concentration, the RNA integrity, the level of intact mRNA determined by reverse transcriptase polymerase chain reaction, the protein level determined by Western blotting, and an examination of the histological structure. RESULTS: The integrity of the total RNA was not preserved in the thawed intact tissue, but the RNA integrity and level of mRNA were perfectly preserved in isolated defrosted samples of total RNA. Additionally, the level of β-actin protein was preserved in both thawed intact tissue and homogenates. CONCLUSION: Isolated total RNA does not undergo degradation due to thawing for at least 24 hours, and it is recommended to isolate the total RNA as soon as possible after tissue collection. Moreover, the protein level is preserved in defrosted tissues

High and Low Salt Intake during Pregnancy: Impact on Cardiac and Renal Structure in Newborns.

INTRODUCTION:Previous studies from our laboratory demonstrated that dietary salt overload and salt restriction during pregnancy were associated with cardiac and renal structural and/or functional alterations in adult offspring. The present study evaluated renal and cardiac structure and the local renin-angiotensin system in newborns from dams fed high-, normal- or low-salt diets during pregnancy. METHODS:Female Wistar rats were fed low- (LS, 0.15% NaCl), normal- (NS, 1.3% NaCl) or high- (HS, 8% NaCl) salt diets during pregnancy. Kidneys and hearts were collected from newborns (n = 6-8/group) during the first 24 hours after birth to evaluate possible changes in structure using stereology. Protein expression of renin-angiotensin system components was evaluated using an indirect enzyme-linked immunosorbent assay (ELISA). RESULTS:No differences between groups were observed in total renal volume, volume of renal compartments or number of glomeruli. The transverse diameter of the nuclei of cardiomyocytes was greater in HS than NS males in the left and right ventricles. Protein expression of the AT1 receptor was lower in the kidneys of the LS than in those of the NS and HS males but not females. Protein expression of the AT2 receptor was lower in the kidneys of the LS males and females than in those of the NS males and females. CONCLUSION:High salt intake during pregnancy induced left and right ventricular hypertrophy in male newborns. Salt restriction during pregnancy reduced the expression of renal angiotensin II receptors in newborns

DESEMPENHO ACADÊMICO DE UNIVERSITÁRIOS: ASSOCIAÇÃO ENTRE ESTADO NUTRICIONAL, INGESTÃO DIETÉTICA DE FERRO ALIMENTAR E CONCENTRAÇÕES DE HEMOGLOBINA

A associação entre ingestão de ferro e educação desperta o interesse dos pesquisadores no intuito de suscitar ações efetivas que possam reduzir as dificuldades dos estudantes, em especial em seu desempenho acadêmico. O objetivo deste estudo foi avaliar a relação entre a ingestão alimentar de ferro, níveis séricos de hemoglobina e indicadores antropométricos com o desempenho acadêmico de universitários. Participaram do estudo 69 alunos de ambos os sexos do Curso de Nutrição da Universidade Federal do Piauí. O consumo alimentar foi feito pelo Registro Alimentar de três dias e a análise pelo software Nutwin versão 1.5. A anemia foi classificada pelas concentrações de hemoglobina preconizadas pela WHO (2001). Os indicadores antropométricos utilizados foram IMC, PCT e CMB. O desempenho dos graduandos foi avaliado de acordo com o índice de rendimento acadêmico fornecido pela própria Instituição. O projeto foi aprovado pelo Comitê de Ética e Pesquisa da Universidade Federal do Piauí. A população em estudo foi predominantemente do sexo feminino, solteira, com idade média de 21±2,46 anos, sedentários, não fumantes e não consumidores de bebidas alcoólicas. De acordo com o IMC e PCT a maioria dos estudantes apresentaram- -se eutróficos. O estudo mostrou uma média do Índice de Rendimento Acadêmico dentro dos padrões preconizados, apresentou apenas dois anêmicos, porém apontou um elevado percentual de estudantes com consumo inadequado de ferro. Diante do exposto os dados evidenciaram não existir relação entre os parâmetros antropométricos, a anemia, o consumo de ferro e o desempenho acadêmico