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The aging lacrimal gland: Changes in structure and function

ROCHA, Eduardo M.; ALVES, Monica; RIOS, J. David; DARTT, Darlene A.
Fonte: ETHIS COMMUNICATINS, INC Publicador: ETHIS COMMUNICATINS, INC
Tipo: Artigo de Revista Científica
Português
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36.6%
The afferent nerves of the cornea and conjunctiva, efferent nerves of the lacrimal gland, and the lacrimal gland are a functional unit that works cooperatively to produce the aqueous component of tears. A decrease in the lacrimal gland secretory function can lead to dry eye disease. Because aging is a risk factor for dry eye disease, study of the changes in the function of the lacrimal gland functional unit with age is important for developing treatments to prevent dry eye disease. No one mechanism is known to induce the changes that occur with aging, although multiple different mechanisms have been associated with aging. These fall into two theoretical categories: programmed theories of aging (immunological, genetic, apoptotic, and neuroendocrine) and error theories of aging (protein alteration, somatic mutation, etc). Lacrimal glands undergo structural and functional alteration with increasing age. In mouse models of aging, it has been shown that neural stimulation of protein secretion is an early target of aging, accompanied by an increase in mast cells and lipofuscin accumulation. Hyperglycemia and increased lymphocytic infiltration can contribute to this loss of function at older ages. These findings suggest that an increase in oxidative stress may play a role in the loss of lacrimal gland function with age. For the afferent and efferent neural components of the lacrimal gland functional unit...

Influence of Artificial Accelerated Aging on Dimensional Stability of Acrylic Resins Submitted to Different Storage Protocols

GARCIA, Lucas da Fonseca Roberti; ROSELINO, Lourenco de Moraes Rego; MUNDIM, Fabricio Mariano; PIRES-DE-SOUZA, Fernanda de Carvalho Panzeri; CONSANI, Simonides
Fonte: WILEY-BLACKWELL Publicador: WILEY-BLACKWELL
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
36.66%
Purpose: The aim of this study was to evaluate the influence of artificial accelerated aging on dimensional stability of two types of acrylic resins (thermally and chemically activated) submitted to different protocols of storage. Materials and Methods: One hundred specimens were made using a Teflon matrix (1.5cmx0.5mm) with four imprint marks, following the lost-wax casting method. The specimens were divided into ten groups, according to the type of acrylic resin, aging procedure, and storage protocol (30 days). GI: acrylic resins thermally activated, aging, storage in artificial saliva for 16 hours, distilled water for 8 hours; GII: thermal, aging, artificial saliva for 16 hours, dry for 8 hours; GIII: thermal, no aging, artificial saliva for 16 hours, distilled water for 8 hours, GIV: thermal, no aging, artificial saliva for 16 hours, dry for 8 hours; GV: acrylic resins chemically activated, aging, artificial saliva for 16 hours, distilled water for 8 hours; GVI: chemical, aging, artificial saliva for 16 hours, dry for 8 hours; GVII: chemical, no aging, artificial saliva for 16 hours, distilled water for 8 hours; GVIII: chemical, no aging, artificial saliva for 16 hours, dry for 8 hours GIX: thermal, dry for 24 hours; and GX: chemical...

Long-term leucine supplementation reduces fat mass gain without changing body protein status of aging rats

Vianna, Daiana; Resende, Gabriela Fulin Teodoro; Torres-Leal, Francisco Leonardo; Pantaleao, Lucas Carminatti; DonatoJr. , Jose; Tirapegui, Julio
Fonte: ELSEVIER SCIENCE INC; NEW YORK Publicador: ELSEVIER SCIENCE INC; NEW YORK
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
36.58%
Objective: Aging is characterized by alterations in body composition such as an increase in body fat and decreases in muscle mass (sarcopenia) and bone density (osteopenia). Leucine supplementation has been shown to acutely stimulate protein synthesis and to decrease body fat. However, the long-term effect of consistent leucine supplementation is not well defined. This study investigated the effect of leucine supplementation during aging. Methods: Six-month-old rats were divided into three groups: an adult group (n = 10) euthanized at 6 mo of age, a leucine group (n = 16) that received a diet supplemented with 4% leucine for 40 wk, and a control group (n = 19) that received the control diet for 40 wk. The following parameters were evaluated: body weight, food intake, chemical carcass composition, indicators of acquired chronic diseases, and indicators of protein nutritional status. Results: Body weight and fat were lower in the leucine group after 40 wk of supplementation compared with the control group but still higher than in the adult group. The lipid and glycemic profiles were equally altered in the control and leucine groups because of aging. In addition, leucine supplementation did not affect the changes in protein status parameters associated with aging...

Effect of caloric restriction on myenteric neuroplasticity in the rat duodenum during aging

Porto, Gisele da Silva; Bertaglia Pereira, Joice Naiara; Tiburcio, Vanessa Graciele; Stabille, Sandra Regina; de Faria, Haroldo Garcia; Germano, Ricardo de Melo; Mari, Renata de Britto
Fonte: ELSEVIER SCIENCE BV; AMSTERDAM Publicador: ELSEVIER SCIENCE BV; AMSTERDAM
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
36.58%
The objective of this study was to evaluate the effects of caloric restriction (CR) on myenteric neurons in the duodenum of Wistar rats during aging. Thirty rats were divided into three groups: the C group (six-month-old animals that were fed a normal diet from weaning until six months of age), the SR group (18-month-old animals that were fed a normal diet from weaning until 18 months of age) and the CR group (18-month-old animals that were fed a 30% CR diet after six months of age). After 12 months, the animals were euthanized. Whole-mount preparations of the duodenums were either stained with Giemsa or underwent NADPH-diaphorase histochemistry to determine the general myenteric neuron population and the nitrergic neuron subpopulation (NADPH-d +), respectively. The NADPH-d-negative (NADPH-d -) neuron population was estimated based on the difference between the Giemsa-stained and NADPH-d + neurons. The neurons were counted, and the cell body areas were measured. Aging was associated with neuronal loss in the SR group, which was minimized by caloric restriction in the CR group. The density (mm(2)) of the Giemsa-stained neurons was higher in the SR group (79.09 +/- 6.25) than in the CR (92.37 +/- 11.6) and C (111.68 +/- 15.26) groups. The density of the NADPH-d + neurons was higher in the SR group (44.90 +/- 5.88) than in the C (35.75 +/- 1.6) and RC (39.14 +/- 7.02) groups. The density of NADPH-d - neurons was higher in the CR (49.73 +/- 12.08) and C (75.64 +/- 17.05) groups than in the SR group (33.82 +/- 4.5). In the C group...

Número total de neurônios no gânglio mesentérico caudal de cães domésticos nas diferentes fases do desenvolvimento. Qual o papel da idade na população total e no tamanho dos neurônios?; Total number of neurons in the dog´s caudal mesenteric ganglion in different phases of aging. What is the role of aging in the total number and size of neurons?

Gagliardo, Karina Martinez
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: dissertação de mestrado Formato: application/pdf
Publicado em 23/12/2003 Português
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O envelhecimento é caracterizado por um progressivo declínio na função neuronal envolvendo tanto o sistema nervoso central como o periférico. O aumento da idade é verificado por alterações no número e no tamanho dos neurônios. Contudo, estes dados são controversos e pouco conhecidos nos gânglios periféricos. Desta forma, o presente estudo teve como objetivo estudar o gânglio mesentérico caudal (GMC) de cães em dois períodos distintos do desenvolvimento (maturação e envelhecimento) a procura de alterações microestruturais no gânglio e alterações quantitativas e morfométricas nos neurônios presentes neste. A importância do GMC está ligada à inervação simpática do intestino grosso, esfíncter anal interno e parcialmente do aparelho urogenital. Para o estudo foram utilizados nove cães domésticos, sem raça definida e machos, provenientes do Hospital Veterinário da Faculdade de Medicina Veterinária e Zootecnia da Universidade de São Paulo. Estes animais foram divididos em três grupos etários com idades bem definidas (1-2 meses, 1-3 anos e 5-10 anos). Os gânglios foram processados para o estudo da microscopia de luz e as análises morfométrica e estereológica foram, respectivamente, realizadas utilizando o software de análise morfométrica KS 400 ZEISS® e o método estereológico do disector físico. O aumento da idade foi caracterizado por uma maior quantidade de tecido não neuronal entre os neurônios e um aumento no volume do gânglio. O tamanho dos neurônios...

Avaliação da influência do envelhecimento artificial acelerado e armazenamento em fluorfosfato acidulado a 1,23% na rugosidade superficial e na alteração de cor de cerâmicas odontológicas de ultra-baixa fusão para titânio comercialmente pur; Evaluation of the influence of the accelerated artificial aging and storage in 1.23% acidulated phosphate fluoride over superficial roughness and color stability of two low-fusing dental ceramics to commercially pure titanium

Oliveira, Janisse Martinelli Borges de
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: dissertação de mestrado Formato: application/pdf
Publicado em 20/12/2007 Português
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36.6%
O objetivo do trabalho foi avaliar a influência do envelhecimento artificial acelerado e do fluorfosfato acidulado a 1,23% sobre a rugosidade superficial e alteração de cor de duas cerâmicas odontológicas de ultra-baixa fusão para titânio (Triceram- Dentaurum, e Noritake Ti22- Noritake), livre de metal ou com subestrutura em titânio comercialmente puro (Tritan- Dentaurum). A partir de uma matriz cilíndrica em teflon foram confeccionados, ao todo, 80 corpos-de-prova, com 15mm de diâmetro e 2,5mm de espessura, sendo 40 para cada cerâmica, 20 amostras livre de metal e 20 metalocerâmicas, que foram divididas em dois grupos de 10 amostras cada, sendo submetidas ao envelhecimento artificial acelerado (Sistema Acelerado de Envelhecimento para não-metálicos C-UV - Comexim Matérias Primas Ltda, São Paulo, Brasil) ou ao armazenamento em fluorfosfato acidulado a 1,23%. A rugosidade superficial foi realizada em rugosímetro SJ - 201P (Mitutoyo, Tokyo, Japão) em dois momentos: inicial (R1) foi aquela mensurada logo após obtidos os corpos-de-prova e a rugosidade superficial final (R2) aquela obtida após o envelhecimento artificial acelerado ou armazenamento em fluorfosfato acidulado a 1,23%. Para verificar as alterações de cor ocorridas nas cerâmicas odontológicas utilizou-se o Espectrofotômetro PCB 6807 BYK GARDNER (Columbia...

Efeitos da alimentação com diferentes níveis calóricos nos neurônios mioentéricos do cólon de ratos Wistar durante o processo de envelhecimento; Effects of food with different caloric levels in myenteric neurons of the colon of rats during the aging process

Mari, Renata de Britto
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 18/12/2009 Português
Relevância na Pesquisa
36.6%
Os últimos anos se caracterizaram pelo aumento significativo da população idosa mundial. Por esta razão, a preocupação com o idoso está se tornando uma constante em nossa sociedade, uma vez que o envelhecimento resulta em comprometimento das funções fisiológicas, acompanhado ou não de alterações estruturais. No trato gastrointestinal (TGI), o processo de envelhecimento pode provocar alterações morfofuncionais significativas. A regulação da motilidade do TGI é controlada principalmente pelos neurônios mioentéricos do sistema nervoso entérico. A diminuição na densidade destes neurônios no cólon pode levar à redução na frequência e na amplitude da contração colônica manifestada como constipação. As ações que visam diminuir os efeitos do envelhecimento no TGI incluem aquelas relacionadas à dieta alimentar, entre as quais se destaca a restrição calórica. A restrição calórica, além de apresentar efeito protetor nos neurônios mioentéricos durante o envelhecimento, também é responsável pela diminuição da morte neuronal por apoptose, processo este acentuado com o envelhecimento. Assim sendo, este trabalho teve por objetivo avaliar os efeitos de diferentes níveis de restrição calórica sobre a plasticidade dos neurônios mioentéricos NADPH e acetilcolinesterase positivos do cólon de ratos Wistar durante o processo de envelhecimento por meio das análises ultraestrutural (microscopia eletrônica de transmissão) e morfoquantitativa. Para tanto foram utilizados 40 ratos machos (Rattus norvegicus)...

Representações do envelhecimento em agentes comunitários da saúde e profissionais da enfermagem comunitária : aspectos psicológicos do processo saúde-doença; Representations of aging for community health agents and nursing professionals: psychological aspects of the health-disease process

Fonseca, Rochele Paz; Trentini, Clarissa Marceli; Valli, Felícia; Silva, Rosane Azevedo Neves da
Tipo: Artigo de Revista Científica Formato: application/pdf
Português
Relevância na Pesquisa
36.58%
No âmbito do tema saúde pública e envelhecimento, o objetivo desse estudo foi averiguar quais são as representações do processo de envelhecimento para profissionais da saúde pública e como essas se expressam na atenção à saúde, no bem-estar e no cuidado do idoso. Participaram 27 profissionais (dez agentes comunitários de saúde e dezessete profissionais de enfermagem). Utilizaram-se dois instrumentos, um questionário sociocultural e um questionário sobre as representações do envelhecimento. Os dados foram analisados qualitativa e quantitativamente (teste qui-quadrado). As palavras mais representativas para expressar o envelhecimento foram aposentadoria e descanso. O fator que mais influenciou o bem-estar e o cuidado do indivíduo idoso foi uma boa rede familiar. Quanto à definição de cuidado, os aspectos biológicos foram os mais freqüentes. A amostra apresentou noções sobre a doença de Alzheimer. Assim sendo, os dados encontrados trazem implicações para a capacitação de recursos humanos. Os agentes de saúde e os profissionais de enfermagem devem ser auxiliados no processo de construção de uma melhor compreensão do contexto biopsicossocial em que o envelhecimento está inserido.; This paper addresses the aging process in the context of public health...

Aging aware design techniques and CMOS gate degradation estimative; Técnicas de projeto considerando envelhecimento e estimativa da degradação em portas lógicas CMOS

Butzen, Paulo Francisco
Tipo: Tese de Doutorado Formato: application/pdf
Português
Relevância na Pesquisa
36.58%
O advento da utilização de circuitos integrados pela sociedade se deu por dois motivos. O primeiro consiste na miniaturização das dimensões dos dispositivos integrados. Essa miniaturização permitiu a construção de dispositivos menores, mais rápidos e que consomem menos frequência. O outro fator é a utilização da metodologia baseada em biblioteca de células. Esta metodologia permite o projeto de um circuito eficiente em um curto espaço de tempo. Com a redução dos dispositivos, novos fatores que eram desconsiderados no fluxo automático passaram a ter importância. Dentre eles podemos citar o consumo estático, a variabilidade, a manufaturabilidade e o envelhecimento. Alguns desses fatores, como o consumo estático e a variabilidade, já estão integrados à metodologia baseada em biblioteca de células. Os efeitos de envelhecimento tem sua degradação aumentada a cada novo processo tecnológico, assim como tem aumentado também a sua importância em relação à confiabilidade do circuito ao longo da sua vida útil. Este trabalho irá explorar estes efeitos de envelhecimento no projeto de circuitos integrados digitais. Dentre as principais contribuições pode-se destacar a definição de um custo de envelhecimento na definição de portas lógicas...

Effect of surface conditioning methods on the microtensile bond strength of resin composite to composite after aging conditions

Ozcan, Mutlu; Barbosa, Silvia Helena; Melo, Renata Marques; Galhano, Graziela Avila Prado; Bottino, Marco Antonio
Fonte: Elsevier B.V. Publicador: Elsevier B.V.
Tipo: Artigo de Revista Científica Formato: 1276-1282
Português
Relevância na Pesquisa
36.6%
Objectives. This study evaluated the effect of two different surface conditioning methods on the repair bond strength of a bis-GMA-adduct/bis-EMA/TEGDMA based resin composite after three aging conditions.Methods. Thirty-six composite resin blocks (Esthet X, Dentsply) were prepared (5 mm x 6 mm x 6 mm) and randomly assigned into three groups for aging process: (a) immersion in citric acid (pH 3.0 at 37 degrees C, 1 week) (CA); (b) boiling in water for 8h (BW) and (c) thermocycling (x5000, 5-55 degrees C, dwell time: 30s) (TC). After aging, the blocks were assigned to one of the following surface conditioning methods: (1) silica coating (30 mu m SiOx) (CoJet, 3M ESPE) + silane (ESPE-Sil) (CJ), (2) phosphoric acid + adhesive resin (Single Bond, 3M ESPE) (PA). Resin composite (Esthet.X (R)) was bonded to the conditioned substrates incrementally and light polymerized. The experimental groups formed were as follows: Gr1:CA + PA; Gr2:CA + CJ Gr3:BW + PA; Gr4: BW + CJ; Gr5:TC + PA; Gr6: TC + CJ. The specimens were sectioned in two axes (x and y) with a diamond disc under coolant irrigation in order to obtain non-trimmed bar specimens (sticks, 10 mm x 1 mm x 1 mm) with 1 mm(2) of bonding area. The microtensile test was accomplished in a universal testing machine (crosshead speed: 0.5 mm min(-1)).Results. The means and standard deviations of bond strength (MPa +/- S.D.) per group were as follows: Gr1: 25.5 +/- 10.3; Gr2: 46.3 +/- 10.1; Gr3: 21.7 +/- 7.1; Gr4: 52.3 +/- 15.1; GrS: 16.1 +/- 5.1; Gr6...

Effect of caloric restriction on myenteric neuroplasticity in the rat duodenum during aging

Porto, Gisele da Silva; Bertaglia Pereira, Joice Naiara; Tiburcio, Vanessa Graciele; Stabille, Sandra Regina; de Faria, Haroldo Garcia; Germano, Ricardo de Melo; Mari, Renata de Britto
Fonte: Elsevier B.V. Publicador: Elsevier B.V.
Tipo: Artigo de Revista Científica Formato: 43-47
Português
Relevância na Pesquisa
36.58%
The objective of this study was to evaluate the effects of caloric restriction (CR) on myenteric neurons in the duodenum of Wistar rats during aging. Thirty rats were divided into three groups: the C group (six-month-old animals that were fed a normal diet from weaning until six months of age), the SR group (18-month-old animals that were fed a normal diet from weaning until 18 months of age) and the CR group (18-month-old animals that were fed a 30% CR diet after six months of age). After 12 months, the animals were euthanized. Whole-mount preparations of the duodenums were either stained with Giemsa or underwent NADPH-diaphorase histochemistry to determine the general myenteric neuron population and the nitrergic neuron subpopulation (NADPH-d +), respectively. The NADPH-d-negative (NADPH-d -) neuron population was estimated based on the difference between the Giemsa-stained and NADPH-d + neurons. The neurons were counted, and the cell body areas were measured. Aging was associated with neuronal loss in the SR group, which was minimized by caloric restriction in the CR group. The density (mm(2)) of the Giemsa-stained neurons was higher in the SR group (79.09 +/- 6.25) than in the CR (92.37 +/- 11.6) and C (111.68 +/- 15.26) groups. The density of the NADPH-d + neurons was higher in the SR group (44.90 +/- 5.88) than in the C (35.75 +/- 1.6) and RC (39.14 +/- 7.02) groups. The density of NADPH-d - neurons was higher in the CR (49.73 +/- 12.08) and C (75.64 +/- 17.05) groups than in the SR group (33.82 +/- 4.5). In the C group...

Aging of red wines made from hybrid grape cv. BRS Violeta: Effects of accelerated aging conditions on phenolic composition, color and antioxidant activity

Lago-Vanzela, Ellen Silva; Procopio, Dielle Pierotti; Filomeno Fontes, Edimar Aparecida; Ramos, Afonso Mota; Stringheta, Paulo Cesar; Da-Silva, Roberto; Castillo-Munoz, Noelia; Hermosin-Gutierrez, Isidro
Fonte: Elsevier B.V. Publicador: Elsevier B.V.
Tipo: Artigo de Revista Científica Formato: 182-189
Português
Relevância na Pesquisa
36.6%
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); Aging is an enological technique usually employed with Vitis vinifera wines for improving and stabilizing wine sensory attributes like red wine color. However, red wines made from non-vinifera grape cultivars are considered not suitable for classic wine aging because they are prone to color loss during processing and storage, mainly due to the major occurrence of non-acylated anthocyanidin 3,5-diglucosides. The recently developed hybrid grape cv. BRS Violeta gives rise to deep red-purplish colored wines characterized by an important contribution of p-coumaroylated anthocyanidin 3,5-diglucosides. In this work, Violeta red wines were subjected to control (storage at 15 degrees C) and accelerated (storage at 25,35 and 50 degrees C) aging for 120 days. Total phenolic content was only significantly decreased by 23% in accelerated aged wines at 50 degrees C, whereas antioxidant capacity was mainly reduced in the first 20 days of aging (around 35% for all the wines, except for 45% for wine aged at 50 degrees C) and then remained almost stable. In contrast, total anthocyanin content decreased following expected first-order kinetics and the variation of rate constants with regard to temperature fitted well with an Arrhenius-type equation. The calculated activation energy for disappearance of anthocyanins (47 kJ/mol) was close to the lower limit of the range of values reported for thermal degradation of anthocyanidin 3-glucosides. In addition...

Avaliação dos produtos finais de glicosilação e o fator nuclear K-B em glandulas lacrimais e superficie ocular de modelos animais de diabetes e envelhecimento; Advanced glycation end-products and Nuclear Factor K-B in lacrimal glands and ocular surface of diabetes and aging animal models

Monica de Cassia Alves
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 21/07/2006 Português
Relevância na Pesquisa
36.64%
Este estudo avaliou as possíveis vias comuns na fisiopatogênese da síndrome do olho seco no Diabetes Mellitus (DM) e no envelhecimento, envolvendo o acúmulo dos produtos de glicosilação ("Advanced Glycation End-products" - AGEs), seu receptor RAGE e a ativação do Fator Nuclear-?B (NF-?B) na glândula lacrimal (GL) e alterações do filme lacrimal nessas condições. Modelos animais de DM induzido com estreptozotocina e animais senis (24 meses de vida) foram comparados a animais controle tratados com tampão citrato e adultos jovens (2 meses de vida). Foram avaliadas vias de sinalização, envolvendo AGEs, RAGE e a ativação do NF-?B na GL e alterações no filme lacrimal em ratos Wistar de todos os grupos. A análise do filme lacrimal foi realizada através de medidas de volume de secreção basal e dosagem de citocinas como a Interleucina-1 ß (IL-1 ß) e Fator de Necrose Tumoral - a (TNF- a). A capacidade secretória da GL foi avaliada através de medidas da atividade de peroxidase. Técnicas de "western blot" foram utilizadas para avaliar a expressão e ativação do NF-?B na GL. A expressão de AGE, RAGE e NF-?B na GL e córnea nos grupos estudados, foi avaliada através de microscopia confocal com imunofluorescência. O volume lacrimal foi significativamente menor nos animais diabéticos e senis (P=0...

Avaliação global de transcritos associados ao envelhecimento da epiderme humana utilizando microarranjos de DNA = : Global evaluation of transcripts associated to human epidermal aging with DNA microarrays; Global evaluation of transcripts associated to human epidermal aging with DNA microarrays

Márcio Lorencini
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 31/01/2014 Português
Relevância na Pesquisa
36.65%
Com o aumento do tempo de vida da população humana muitas modalidades médicas, incluindo a dermatologia, deparam-se com uma revolução na forma de garantir saúde e qualidade de vida aos pacientes. Em contato com o ambiente externo, a pele representa um órgão no qual as mudanças com o envelhecimento causam danos funcionais, além de potencial impacto estético e psicossocial. A epiderme, camada mais externa da pele, constitui uma barreira seletiva com destacada capacidade de renovação e manutenção da homeostasia corporal. Entretanto, o entendimento de diversos mecanismos associados à fisiologia e envelhecimento da epiderme permanece como desafio para a comunidade científica. Com base nesse cenário, o objetivo do presente trabalho foi compreender o atual estado da arte no tema de envelhecimento da epiderme e realizar experimentos voltados para lacunas existentes, com foco na integração de aspectos clínicos, fisiológicos, morfológicos, celulares e moleculares. O capítulo de abertura descreve uma avaliação global de transcritos associados ao envelhecimento da epiderme humana, com a técnica de microarranjos de DNA e coleta não invasiva com fitas adesivas. O estudo indica características moleculares específicas do fotoenvelhecimento epidermal...

The aging lacrimal gland: Changes in structure and function

ROCHA, Eduardo M.; ALVES, Monica; RIOS, J. David; DARTT, Darlene A.
Fonte: ETHIS COMMUNICATINS, INC Publicador: ETHIS COMMUNICATINS, INC
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
36.6%
The afferent nerves of the cornea and conjunctiva, efferent nerves of the lacrimal gland, and the lacrimal gland are a functional unit that works cooperatively to produce the aqueous component of tears. A decrease in the lacrimal gland secretory function can lead to dry eye disease. Because aging is a risk factor for dry eye disease, study of the changes in the function of the lacrimal gland functional unit with age is important for developing treatments to prevent dry eye disease. No one mechanism is known to induce the changes that occur with aging, although multiple different mechanisms have been associated with aging. These fall into two theoretical categories: programmed theories of aging (immunological, genetic, apoptotic, and neuroendocrine) and error theories of aging (protein alteration, somatic mutation, etc). Lacrimal glands undergo structural and functional alteration with increasing age. In mouse models of aging, it has been shown that neural stimulation of protein secretion is an early target of aging, accompanied by an increase in mast cells and lipofuscin accumulation. Hyperglycemia and increased lymphocytic infiltration can contribute to this loss of function at older ages. These findings suggest that an increase in oxidative stress may play a role in the loss of lacrimal gland function with age. For the afferent and efferent neural components of the lacrimal gland functional unit...

Influence of Artificial Accelerated Aging on Dimensional Stability of Acrylic Resins Submitted to Different Storage Protocols

GARCIA, Lucas da Fonseca Roberti; ROSELINO, Lourenco de Moraes Rego; MUNDIM, Fabricio Mariano; PIRES-DE-SOUZA, Fernanda de Carvalho Panzeri; CONSANI, Simonides
Fonte: WILEY-BLACKWELL Publicador: WILEY-BLACKWELL
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
36.66%
Purpose: The aim of this study was to evaluate the influence of artificial accelerated aging on dimensional stability of two types of acrylic resins (thermally and chemically activated) submitted to different protocols of storage. Materials and Methods: One hundred specimens were made using a Teflon matrix (1.5cmx0.5mm) with four imprint marks, following the lost-wax casting method. The specimens were divided into ten groups, according to the type of acrylic resin, aging procedure, and storage protocol (30 days). GI: acrylic resins thermally activated, aging, storage in artificial saliva for 16 hours, distilled water for 8 hours; GII: thermal, aging, artificial saliva for 16 hours, dry for 8 hours; GIII: thermal, no aging, artificial saliva for 16 hours, distilled water for 8 hours, GIV: thermal, no aging, artificial saliva for 16 hours, dry for 8 hours; GV: acrylic resins chemically activated, aging, artificial saliva for 16 hours, distilled water for 8 hours; GVI: chemical, aging, artificial saliva for 16 hours, dry for 8 hours; GVII: chemical, no aging, artificial saliva for 16 hours, distilled water for 8 hours; GVIII: chemical, no aging, artificial saliva for 16 hours, dry for 8 hours GIX: thermal, dry for 24 hours; and GX: chemical...

Laboratory comparison of aging characteristics of warm mix asphalts involving natural and synthetic water containing additives

Topal,Ali; Dokandari,Peyman Aghazadeh
Fonte: ABM, ABC, ABPol Publicador: ABM, ABC, ABPol
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/10/2014 Português
Relevância na Pesquisa
36.6%
When comparing the aging characteristics of hot and warm mix asphalts from a technical point of view, it can intuitively be expected that a warm mix asphalt would be less subjected to aging-induced failures due to lower application temperatures. Since the side effects of warm asphalt technology should be investigated distinctly. This study addresses the aging investigation of properties of bituminous mixtures containing two (i.e., natural and synthetic zeolite) water based additives available on the market. Within the scope of this study, short- and long-term aging conditions were simulated on mixtures containing various contents of additives as well as on control specimens. The aging indices were determined based on the hardness ratio employing indirect tensile strength values in order to investigate the aging induced failures betide by time. Aging indices showed that the specimens with water containing additives demonstrate relatively better resistance against hardening than conventional hot mix asphalt specimens.

Laboratory comparison of aging characteristics of warm mix asphalts involving natural and synthetic water containing additives

Topal,Ali; Dokandari,Peyman Aghazadeh
Fonte: ABM, ABC, ABPol Publicador: ABM, ABC, ABPol
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/10/2014 Português
Relevância na Pesquisa
36.6%
When comparing the aging characteristics of hot and warm mix asphalts from a technical point of view, it can intuitively be expected that a warm mix asphalt would be less subjected to aging-induced failures due to lower application temperatures. Since the side effects of warm asphalt technology should be investigated distinctly. This study addresses the aging investigation of properties of bituminous mixtures containing two (i.e., natural and synthetic zeolite) water based additives available on the market. Within the scope of this study, short- and long-term aging conditions were simulated on mixtures containing various contents of additives as well as on control specimens. The aging indices were determined based on the hardness ratio employing indirect tensile strength values in order to investigate the aging induced failures betide by time. Aging indices showed that the specimens with water containing additives demonstrate relatively better resistance against hardening than conventional hot mix asphalt specimens.

Cats, “Rats,” and Bats: The Comparative Biology of Aging in the 21st Century

Austad, Steven N.
Fonte: Oxford University Press Publicador: Oxford University Press
Tipo: text
Português
Relevância na Pesquisa
36.64%
Laboratory models have suggested a link between metabolism and life span in vertebrates, and it is well known that the evolution of specific life histories can be driven by metabolic factors. However, little is known regarding how the adoption of specific life-history strategies can shape aging and life span in populations facing different energetic demands from either a theoretical or a mechanistic viewpoint but significant insight can be gained by using a comparative approach. Comparative biology plays several roles in our understanding of the virtually ubiquitous phenomenon of aging in animals. First, it provides a critical evaluation of broad hypotheses concerning the evolutionary forces underlying the modulation of aging rate. Second, it suggests mechanistic hypotheses about processes of aging. Third, it illuminates particularly informative species because of their exceptionally slow or rapid aging rates to be interrogated about potentially novel mechanisms of aging. Although comparative biology has played a significant role in research on aging for more than a century, the new comparative biology of aging is poised to dwarf those earlier contributions, because: (1) new cellular and molecular techniques for investigating novel species are in place and more are being continually generated...

Evidence that mutation accumulation does not cause aging in Saccharomyces cerevisiae

Kaya, Alaattin; Lobanov, Alexei V; Gladyshev, Vadim N
Fonte: BlackWell Publishing Ltd Publicador: BlackWell Publishing Ltd
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
36.64%
The concept that mutations cause aging phenotypes could not be directly tested previously due to inability to identify age-related mutations in somatic cells and determine their impact on organismal aging. Here, we subjected Saccharomyces cerevisiae to multiple rounds of replicative aging and assessed de novo mutations in daughters of mothers of different age. Mutations did increase with age, but their low numbers, < 1 per lifespan, excluded their causal role in aging. Structural genome changes also had no role. A mutant lacking thiol peroxidases had the mutation rate well above that of wild-type cells, but this did not correspond to the aging pattern, as old wild-type cells with few or no mutations were dying, whereas young mutant cells with many more mutations continued dividing. In addition, wild-type cells lost mitochondrial DNA during aging, whereas shorter-lived mutant cells preserved it, excluding a causal role of mitochondrial mutations in aging. Thus, DNA mutations do not cause aging in yeast. These findings may apply to other damage types, suggesting a causal role of cumulative damage, as opposed to individual damage types, in organismal aging.