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1.
Oper Dent ; 47(6): 658-669, 2022 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-36251571

RESUMO

STATEMENT OF PROBLEM: Customized glass fiber posts using CAD-CAM technology have been suggested for restoring endodontically treated teeth. However, how weakened or non-weakened roots restored with anatomical CAD-CAM posts behave under cyclic fatigue is not clear. OBJECTIVE: To evaluate the load-bearing capacity under fatigue (fatigue failure load [FFL], the number of cycles for failure [CFF], and survival probabilities) and fracture pattern of weakened and non-weakened roots restored with CAD-CAM fiber post and cores, metal cast-post-core, and prefabricated fiber post and resin core. METHODS AND MATERIALS: A total of 60 crack-free bovine incisor roots (13 mm in length) with standard geometry were obtained and randomly allocated considering the factor "root condition" in two levels (weakened and non-weakened). Thus, half of the roots were weakened to obtain a wall thickness of 0.5 mm. After that, the endodontic treatment was executed, all roots embedded with acrylic resin and the specimens randomly allocated (n=10) considering the factor "post system" in three levels (CAD-CAM: CAD-CAM milled glass-fiber post and core; MBC: metallic-based post and core; and FRC: prefabricated glass-fiber post and composite resin core). The posts were luted with a dual-cure self-adhesive luting agent. Then, all teeth received a metallic crown. An initial load of 100 N at 20 Hz for 5000 cycles was applied for the step-stress fatigue test, followed by incremental steps of 50 N for 20,000 cycles each step, up to failure. A fracture pattern analysis was performed. RESULTS: CAD-CAM fiber post (FFL: 865 N; CFF: 311,000 cycles) presented similar fatigue performance (p>0.05) to FRC (FFL: 925 N; CFF: 335,000 cycles), with 100% of repairable fractures for non-weakened roots; however, both groups presented worse performance than MBC (p<0.05; FFL: 1265 N; CFF: 471,000 cycles) which led to 100% of catastrophic failures. No statistical difference was found in fatigue performance among the three systems for weakened roots (p>0.05; FFL: 1035-1170 N; CFF: 379,000-433,000 cycles), with a high rate of catastrophic failures. CONCLUSIONS: CAD-CAM fiber post presented similar fatigue performance to MBC and FRC approaches when restoring weakened roots. CADCAM was similar to FRC when restoring non-weakened roots, while MBC enhanced fatigue properties in this scenario.


Assuntos
Técnica para Retentor Intrarradicular , Fraturas dos Dentes , Dente não Vital , Animais , Bovinos , Cerâmica , Resinas Compostas/uso terapêutico , Desenho Assistido por Computador , Análise do Estresse Dentário , Vidro , Teste de Materiais , Propriedades de Superfície , Dente não Vital/terapia , Estudos Cross-Over
2.
J Virol Methods ; 300: 114426, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34902461

RESUMO

The laboratory diagnosis of rabies is of fundamental importance to the evaluation of suspected cases of rabies virus (RABV) infection. Confirmation of direct fluorescent antibody test (DFAT) results via viral isolation (VI) is recommended, and the mouse inoculation test (MIT) is being replaced by the rabies tissue culture infection (RTCIT) test for ethical reasons. We evaluated 6.514 results from central nervous system (CNS) samples of different animals analyzed at the Pasteur Institute between 2008 and 2016 using the DFAT, RTCIT and MIT techniques and evaluated their concordance, sensitivity, specificity, and accuracy indices. The DFAT technique presented the best sensitivity (93.58 %), specificity (95.90 %), and accuracy (95.67 %) results. The RTCIT values of sensitivity, specificity and accuracy (70.42 %, 86.16 % and 84.62 % respectively) were lower than those of DFAT. The concordance between RTCIT and DFAT was moderate, with a kappa quotient k = 0.341. The MIT values of sensitivity, specificity, and accuracy were 89.58 %, 100 % and 98.97 % respectively. The concordance between MIT and DFAT was substantial, with a k value of 0.720. DFAT, considered the "gold standard", was effective in all animals except horses. Our analyses evidenced that DFAT presents satisfactory results, although RTCIT did not appear favorable as a confirmatory technique.


Assuntos
Vírus da Raiva , Raiva , Animais , Técnica Direta de Fluorescência para Anticorpo/métodos , Cavalos , Testes Imunológicos , Camundongos , Raiva/diagnóstico , Raiva/veterinária , Sensibilidade e Especificidade
3.
Environ Res ; 193: 110585, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33309824

RESUMO

Mercury (Hg) is a widespread pollutant across estuarine and coastal areas, raising concern on its potential impact on aquatic organisms. Hg may origin from natural and anthropogenic sources, being persistent and potentially toxic to biota, ultimately representing a serious risk to human health. Hg accumulation and toxicity may also induce reactive oxygen species (ROS) production in marine organisms, responsible for cell and tissue damage. Additionally, the temperature is undoubtedly an important environmental factor to consider regarding accumulation, due to its marked influence on the physiology and ecology of aquatic organisms. This study aimed to investigate the effect of different temperature scenarios (15, 20 and 25 °C) on the Hg accumulation in Pomatoschistus microps (Krøyer, 1838) liver and muscle, as well as on oxidative stress responses and energy metabolism, after short-term exposure to a naturally contaminated sediment with an environmentally relevant [Hg] (1.2 µg g-1). The results showed that Hg accumulation tends to increase along the temperature gradient with higher values of Hg accumulated in liver than in muscle tissue. The action of antioxidant enzymes and stress proteins seems to be effective in combating oxidative stress in the liver. Despite the action of antioxidant defences in the muscle, oxidative damage was observed at the protein level concomitantly with a decrease in aerobic energy production after exposure to Hg at higher temperatures. These findings are ecologically relevant and highlight the importance of further investigation of combined effects of Hg and other stressors, especially in a scenario of a changing climate where events leading to rapid alterations on water parameters are more frequent.


Assuntos
Mercúrio , Poluentes Químicos da Água , Animais , Humanos , Mercúrio/toxicidade , Estresse Oxidativo , Temperatura , Água , Poluentes Químicos da Água/toxicidade
4.
Braz. j. biol ; 80(2): 345-353, Apr.-June 2020. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1132366

RESUMO

Abstract In the implantation of forests, soil tillage can affect the soil fauna, but over the years, it is possible that forest development can recompose the biological indicators of soil quality. So, the aim of this study was to evaluate the influence of different periods of eucalyptus development on community of edaphic fauna. The experiment was carried out in forest areas in the municipality of Ametista do Sul, RS. The Experimental design was completely randomized with 6 treatments, once 4 of the treatments were with different ages of the Eucalyptus grandis (two, four, six and eight years after trasnplant - YAT); plus 2 control treatments: Native Forest and Soil Naked, with 7 collection points. To sample the edaphic fauna, it was used traps such as PROVID. Also, the edaphic fauna was sampled at the depth of 0-5 cm for the quantification of mites. It was carried out the counting of individuals at the level of order and family for the mites, the means of the groups were submitted to the Tukey test and comparisons by Orthogonal Contrasts and calculated indices of Biodiversity: Margalef Richness, Simpson dominance, Shannon diversity and Pielou uniformity. The results showed lower abundance of individuals in Naked soil, while the Native Forest presented the best Biodiversity indices. With eight years of implantation of eucalyptus there was recovered the biological quality of the soil expressed by the population of springtails. The population of oribatídeos mites increased expressively from the six years of implantation of eucalyptus.


Resumo Na implantação de florestas, o revolvimento do solo pode simplificar a fauna edáfica, porém com o passar dos anos é possível que o desenvolvimento florestal possa recompor os indicadores biológicos de qualidade do solo. O objetivo deste trabalho foi avaliar a influência de diferentes períodos de desenvolvimento de eucalipto sobre a comunidade da fauna edáfica. O experimento foi realizado em área florestal no município de Ametista do Sul, RS. O delineamento experimental foi inteiramente casualizado com 6 tratamentos, sendo 4 tratamentos com diferentes períodos de implantação de Eucalyptus grandis (dois, quatro, seis e oito anos após o transplante - YAT) + 2 tratamentos controle - Mata Nativa e Solo Desnudo, com 7 pontos de coleta. A coleta da fauna edáfica foi por meio de armadilhas do tipo PROVID e amostras centrais de solo na profundidade de 0-5 cm para ácaros. Realizou-se a contagem de indivíduos em nível de classe ou ordem e de família para ácaros, as médias dos grupos foram submetidas ao teste de Tukey e comparações por Contrastes Ortogonais e calculados os índices de biodiversidade: Riqueza de Margalef, dominância de Simpson, Diversidade de Shannon e uniformidade de Pielou. Os resultados demonstram menor abundância de indivíduos no solo Desnudo, enquanto a Mata Nativa apresentou os melhores índices de Biodiversidade. Com oito anos de implantação de eucalipto ha recuperação da qualidade biológica do solo expressa pela população de Colêmbolos. A população de ácaros oribatídeos aumenta expressivamente a partir dos seis anos de implantação de eucalipto.


Assuntos
Animais , Eucalyptus , Ácaros , Solo , Florestas , Biodiversidade
5.
Sci Total Environ ; 713: 136659, 2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-31955109

RESUMO

Microplastics (1 µm-5 mm), a ubiquitous and persistent marine pollutant, pose a severe threat to coral reefs when recently associated with physiological distress and increased diseases on corals. Studies conducted so far have only reported effects on scleractinian species. Knowledge about its effects on other corals (e.g. Order Zoantharia) remains uncovered, and responses at biochemical levels remain poorly documented. This study aimed to assess the potential effects induced by the presence of microplastics (1 and 10 mg L-1 low-density polyethylene, LDPE MP, or polyvinyl chloride, PVC MP) in the tropical and subtropical cosmopolitan species Zoanthus sociatus (order Zoantharia. Anthozoa: Hexacorallia), at organism level (survival and behaviour), endosymbionts (photosynthetic efficiency) and the cellular level (oxidative stress, detoxification capacity and energy metabolism). In a short-term exposure (96 h), this species was more sensitive to PVC MP. The presence of this polymer at a concentration of 10 mg L-1 caused a ten-fold higher adhesion to the coral epidermis, increased photosynthetic efficiency, lipid peroxidation, and antioxidant defences; without, however, inducing energetic costs. Although the observed physiological and biochemical effects did not compromise Z. sociatus survival in the short term, it does not rule out potential long-term (cumulative) effects that could endanger this and other physiologically similar species that underlie coral reefs.


Assuntos
Antozoários , Animais , Recifes de Corais , Microplásticos
6.
Braz J Biol ; 80(2): 345-353, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31508656

RESUMO

In the implantation of forests, soil tillage can affect the soil fauna, but over the years, it is possible that forest development can recompose the biological indicators of soil quality. So, the aim of this study was to evaluate the influence of different periods of eucalyptus development on community of edaphic fauna. The experiment was carried out in forest areas in the municipality of Ametista do Sul, RS. The Experimental design was completely randomized with 6 treatments, once 4 of the treatments were with different ages of the Eucalyptus grandis (two, four, six and eight years after trasnplant - YAT); plus 2 control treatments: Native Forest and Soil Naked, with 7 collection points. To sample the edaphic fauna, it was used traps such as PROVID. Also, the edaphic fauna was sampled at the depth of 0-5 cm for the quantification of mites. It was carried out the counting of individuals at the level of order and family for the mites, the means of the groups were submitted to the Tukey test and comparisons by Orthogonal Contrasts and calculated indices of Biodiversity: Margalef Richness, Simpson dominance, Shannon diversity and Pielou uniformity. The results showed lower abundance of individuals in Naked soil, while the Native Forest presented the best Biodiversity indices. With eight years of implantation of eucalyptus there was recovered the biological quality of the soil expressed by the population of springtails. The population of oribatídeos mites increased expressively from the six years of implantation of eucalyptus.


Assuntos
Eucalyptus , Ácaros , Animais , Biodiversidade , Florestas , Solo
7.
Artigo em Inglês | LILACS-Express | LILACS, VETINDEX | ID: biblio-1467315

RESUMO

Abstract In the implantation of forests, soil tillage can affect the soil fauna, but over the years, it is possible that forest development can recompose the biological indicators of soil quality. So, the aim of this study was to evaluate the influence of different periods of eucalyptus development on community of edaphic fauna. The experiment was carried out in forest areas in the municipality of Ametista do Sul, RS. The Experimental design was completely randomized with 6 treatments, once 4 of the treatments were with different ages of the Eucalyptus grandis (two, four, six and eight years after trasnplant YAT); plus 2 control treatments: Native Forest and Soil Naked, with 7 collection points. To sample the edaphic fauna, it was used traps such as PROVID. Also, the edaphic fauna was sampled at the depth of 0-5 cm for the quantification of mites. It was carried out the counting of individuals at the level of order and family for the mites, the means of the groups were submitted to the Tukey test and comparisons by Orthogonal Contrasts and calculated indices of Biodiversity: Margalef Richness, Simpson dominance, Shannon diversity and Pielou uniformity. The results showed lower abundance of individuals in Naked soil, while the Native Forest presented the best Biodiversity indices. With eight years of implantation of eucalyptus there was recovered the biological quality of the soil expressed by the population of springtails. The population of oribatídeos mites increased expressively from the six years of implantation of eucalyptus.


Resumo Na implantação de florestas, o revolvimento do solo pode simplificar a fauna edáfica, porém com o passar dos anos é possível que o desenvolvimento florestal possa recompor os indicadores biológicos de qualidade do solo. O objetivo deste trabalho foi avaliar a influência de diferentes períodos de desenvolvimento de eucalipto sobre a comunidade da fauna edáfica. O experimento foi realizado em área florestal no município de Ametista do Sul, RS. O delineamento experimental foi inteiramente casualizado com 6 tratamentos, sendo 4 tratamentos com diferentes períodos de implantação de Eucalyptus grandis (dois, quatro, seis e oito anos após o transplante - YAT) + 2 tratamentos controle - Mata Nativa e Solo Desnudo, com 7 pontos de coleta. A coleta da fauna edáfica foi por meio de armadilhas do tipo PROVID e amostras centrais de solo na profundidade de 0-5 cm para ácaros. Realizou-se a contagem de indivíduos em nível de classe ou ordem e de família para ácaros, as médias dos grupos foram submetidas ao teste de Tukey e comparações por Contrastes Ortogonais e calculados os índices de biodiversidade: Riqueza de Margalef, dominância de Simpson, Diversidade de Shannon e uniformidade de Pielou. Os resultados demonstram menor abundância de indivíduos no solo Desnudo, enquanto a Mata Nativa apresentou os melhores índices de Biodiversidade. Com oito anos de implantação de eucalipto ha recuperação da qualidade biológica do solo expressa pela população de Colêmbolos. A população de ácaros oribatídeos aumenta expressivamente a partir dos seis anos de implantação de eucalipto.

8.
J Anim Sci ; 94(4): 1472-81, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27136006

RESUMO

We aimed to evaluate the expression of genes related to the regulation of muscle protein turnover in the longissimus dorsi (LD) muscle of Angus and Nellore bulls and to estimate the within-breed correlations of gene expression and performance traits. Thirteen genes related to the IGF-1 and myostatin pathways were studied. Thirteen animals, with an initial average BW of 381.2 ± 11.8 kg, from each breed were used in a completely randomized 2 × 2 factorial design (2 breeds and 2 feeding levels). The diet consisted of corn silage and a corn-soybean meal concentrate in a roughage-to-concentrate ratio of 30:70. Cattle were fed ad libitum (with 9 animals from each breed) or feed restricted (a 55% restriction of total DMI of ad libitum-fed animals, calculated as percentage of metabolic BW, with 4 animals of each breed). The experimental period lasted for 82 d and it was preceded by a 28-d adaptation period. The performance traits evaluated were slaughter body weight, total ADG (from d 1 to 82 of the trial), initial ADG (from d 1 to 41 of the trial), final ADG (from d 42 to 82 of the trial), total DMI (from d 1 to 82 of the trial), initial DMI (from d 1 to 41 of the trial), final DMI (from d 42 to 82 of the trial), HCW, LD weight (LDW), and rib eye area (REA). After slaughter, samples were taken from the LD muscle between the 12th and 13th ribs for gene expression analysis by quantitative reverse transcription PCR. There was no difference ( > 0.05) in the expression of any of the genes studied between ad libitum-fed Angus and ad libitum-fed Nellore, whereas feed restriction increased the expression of (; < 0.001), (; = 0.05), and (; = 0.04) and decreased the expression of ( < 0.01). The REA was negatively correlated to (; = 0.01), (; = 0.02), and ( = 0.05). The HCW was negatively correlated to ( = 0.01) and ( = 0.01) and tended to be negatively correlated to ( = 0.07), whereas the LDW tended to be negatively correlated to ( = 0.08). The genes , , and seem to be important for muscle growth and may be worthy of further investigation as future strategies for increasing muscle in livestock.


Assuntos
Composição Corporal/fisiologia , Bovinos/genética , Regulação da Expressão Gênica/fisiologia , Proteínas Musculares/metabolismo , Ração Animal/análise , Animais , Composição Corporal/genética , Peso Corporal , Bovinos/fisiologia , Dieta/veterinária , Fibras na Dieta/metabolismo , Comportamento Alimentar/fisiologia , Fator de Crescimento Insulin-Like I/metabolismo , Masculino , Proteínas Musculares/genética , Silagem/análise
9.
J Anim Sci ; 94(3): 1105-9, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27065272

RESUMO

The traditional techniques to measure heat production (HP) are calorimetry (direct and indirect) and comparative slaughter. Both methods are expensive and require extensive amounts of time and infrastructure. Infrared thermography (IRT) could be a faster and less expensive alternative to estimate cattle HP. The objective of this project was to evaluate the use of the IRT technique as an indicator of HP in cattle. A total of 24 bulls (12 Nellore and 12 Black Angus) with initial BW of 380 ± 7 kg were used. Initially, 4 animals of each breed were harvested (baseline animals) and simple regressions were developed for each breed from these baseline animals to estimate the initial chemical composition of the remaining bulls. Eight animals of each breed were fed a silage/concentrate diet for ad libitum intake in individual stalls. On the 25th, 50th, and 75th experimental day, infrared thermal images (Fluke Ti 55ft; Fluke Corporation) were taken of each animal's face to access skin and ocular surface temperatures. A metabolism trial was conducted to estimate the ME intake (MEI). After 84 experimental days, the cattle were harvested and retained energy (RE) and HP were calculated. The data were analyzed using the MIXED and REG procedures of SAS adopting a significance level of 0.05. Angus cattle had a greater daily MEI, HP, and skin and eye temperatures than Nellore. We found significant correlations ( ≤ 0.005) between daily HP and maximum ( = 0.65) and average skin temperatures ( = 0.65) and maximum ( = 0.65) and average ocular surface ( = 0.69) temperatures recorded on d 50. Infrared thermography has potential to be used to evaluate HP in cattle.


Assuntos
Bovinos/fisiologia , Metabolismo Energético/fisiologia , Termogênese , Termografia , Animais , Masculino
10.
Arq. bras. med. vet. zootec ; 68(1): 141-146, jan.-fev. 2016. tab
Artigo em Português | LILACS | ID: lil-771882

RESUMO

Objetivou-se com este trabalho determinar o poder dióptrico da lente intraocular (LIO) em miniporco e as dimensões do bulbo do olho. Foram utilizados 17 miniporcos, sadios, adultos, machos e fêmeas, com peso médio de 70kg. Em todos os olhos foram realizadas a ultrassonografia modo A, a ceratometria e a medida da distância limbo a limbo. O cálculo do poder dióptrico da LIO foi obtido utilizando-se as fórmulas Haigis, Hoffer Q, SRK/T, Holladay I e Holladay II e o software Holladay IOL Consultant(r). Na comparação entre o sexo e a lateralidade do olho, não houve diferença nas variáveis biométricas e poder da LIO. A aplicação das fórmulas (Haigis, Holladay II, Holladay I, SRK/T e Hoffer Q) possibilitou o cálculo do poder da LIO. A Holladay II, fórmula que melhor individualiza o bulbo do olho do miniporco, estima valor dióptrico ao redor de 41 D. Os miniporcos têm potencial como modelo experimental em oftalmologia, relacionado ao seu menor porte e à facilidade no manejo, especialmente em experimentos de longa duração.


The aim of this study was to determine the refractive power of intraocular lens (IOL) of mini pigs and the dimensions of the eyeball. A total of 17 (34 eyes) healthy, adult, males and female animals, with average weight of 70kg were used. For every eye, A-mode ultrasound, keratometry and the measurement of limbo-to-limbo distance were conducted, all variables for calculating the refractive power of the IOL. The value was obtained using different formulas and Holladay IOL Consultant(r) Software. Additionally, the ocular measurements were compared per sex, laterality of the eye and the different formulas used in this study (Haigis, Hoffer Q, SRK / T, Holladay I and Holladay II). In the comparison between sex and laterality of the eye, there was no difference in biometric variables and power of the IOL. The application of the employed formulas (Haigis, Holladay II, Holladay I, SRK / T and Hoffer Q) allowed the IOL power calculation for this specie, and the observed value ranged between 39.58±2.15 and 46.60±2.81 diopters. Mini pigs play an important and growing role as an experimental model for study and practice of ophthalmic procedures, specially related to their smaller size and easy management in long-term experiments.


Assuntos
Animais , Experimentação Animal , Oftalmologia , Porco Miniatura/anatomia & histologia , Biometria , Lentes Intraoculares/veterinária , Modelos Animais
11.
Braz J Biol ; 75(4): 812-20, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26675900

RESUMO

Uniform rapid seed germination generally forms a great risk for the plant population if subsequent intermittent precipitation causes desiccation and seedling death. Handroanthus impetiginosus can be found commonly in a wide range of biomes within Brazil including those that are semi-arid. Germination and early growth was studied to understand how germinated seeds survive under these stringent conditions. Accessions were sampled from four seasonally dry biomes in Brazil. Precipitation at the start of the rainy season in the Caatinga, a semi-arid biome, is less predictable and the number of successive dry days per dry interval in the first four months of the rainy season was higher than in the other studied biomes. Plants from the Caatinga produced thicker seeds and this trait concurred with slow germination and stronger osmotic inhibition of germination across the accessions, forming a stress avoidance mechanism in the Caatinga. Post-germination desiccation tolerance was high in the Caatinga accession, could be re-induced in accessions from biomes with more regular precipitation (Cerrado and transition zone), but remained poor in the Cerradão accession; thus forming a stress tolerance mechanism. Production of adventitious roots ascertained survival of all tested individuals from all four locations, even if protruded radicles did not survive desiccation, forming an additional stress tolerance mechanism. A sequence of stress avoidance and stress tolerance mechanisms in seeds and germinated seeds was associated with precipitation patterns in different biomes. These mechanisms purportedly allow rapid seedling establishment when conditions are suitable and enable survival of the young seedling when conditions are adverse.


Assuntos
Bignoniaceae/crescimento & desenvolvimento , Dessecação , Germinação , Chuva , Sementes/crescimento & desenvolvimento , Brasil , Plântula/crescimento & desenvolvimento
12.
Braz. j. biol ; 75(4): 812-820, Nov. 2015. tab, graf
Artigo em Inglês | LILACS | ID: lil-768205

RESUMO

Abstract Uniform rapid seed germination generally forms a great risk for the plant population if subsequent intermittent precipitation causes desiccation and seedling death. Handroanthus impetiginosus can be found commonly in a wide range of biomes within Brazil including those that are semi-arid. Germination and early growth was studied to understand how germinated seeds survive under these stringent conditions. Accessions were sampled from four seasonally dry biomes in Brazil. Precipitation at the start of the rainy season in the Caatinga, a semi-arid biome, is less predictable and the number of successive dry days per dry interval in the first four months of the rainy season was higher than in the other studied biomes. Plants from the Caatinga produced thicker seeds and this trait concurred with slow germination and stronger osmotic inhibition of germination across the accessions, forming a stress avoidance mechanism in the Caatinga. Post-germination desiccation tolerance was high in the Caatinga accession, could be re-induced in accessions from biomes with more regular precipitation (Cerrado and transition zone), but remained poor in the Cerradão accession; thus forming a stress tolerance mechanism. Production of adventitious roots ascertained survival of all tested individuals from all four locations, even if protruded radicles did not survive desiccation, forming an additional stress tolerance mechanism. A sequence of stress avoidance and stress tolerance mechanisms in seeds and germinated seeds was associated with precipitation patterns in different biomes. These mechanisms purportedly allow rapid seedling establishment when conditions are suitable and enable survival of the young seedling when conditions are adverse.


Resumo A germinação rápida e uniforme geralmente pode apresentar riscos para a população de plantas caso a precipitação ocorra de maneira intermitente, provocando seca e morte das plântulas. Handroanthus impetiginosus pode ser encontrado em uma grande variedade de biomas no Brasil. A germinação e o crescimento inicial das plântulas de Handroanthus impetiginosus foram estudadas para compreender como as sementes germinadas sobrevivem nestas condições. Acessos de quatro biomas que apresentam secas sazonais foram amostrados. A precipitação, no início da estação chuvosa na Caatinga, um bioma semi-árido, é menos previsível e o número de dias secos consecutivos por intervalo de seca, nos primeiros quatro meses da estação chuvosa, foi maior do que nos outros biomas estudados. Plantas do bioma Caatinga produzem sementes mais espessas e essa característica está associada com uma germinação lenta e com a inibição osmótica maior da germinação através dos acessos, formando um mecanismo para evitar o estresse. Tolerância à dessecação em sementes germinadas foi superior no bioma Caatinga e que podem ser reinduzida em acesso com uma precipitação mais regular (Cerrado e na zona de transição), mas manteve-se baixa no acesso Cerradão, formando assim um mecanismo para evitar o estresse. Produção de raízes adventícias foi observada nos indivíduos estudados de todos os quatro biomas, mesmo quando as raízes primárias não sobreviveram à dessecação, formando um mecanismo adicional de tolerância ao estresse. Assim, foi observado estratégias para evitar o estresse e mecanismos de tolerância ao estresse em sementes e sementes germinadas associada com padrões de precipitação nos diferentes biomas estudados. Estes mecanismos podem favorecer o estabelecimento das plântulas de forma rápida quando as condições são adequadas e permitirem a sobrevivência de plântulas quando as condições são adversas.


Assuntos
Bignoniaceae/crescimento & desenvolvimento , Dessecação , Germinação , Chuva , Sementes/crescimento & desenvolvimento , Brasil , Plântula/crescimento & desenvolvimento
13.
Arq. bras. med. vet. zootec ; 67(5): 1295-1303, tab, graf
Artigo em Português | LILACS | ID: lil-764442

RESUMO

O objetivo deste estudo foi avaliar o efeito do tratamento da superfície de lentes intraoculares acrílicas utilizando-se plasma de flúor ou polietilenoglicol na prevenção da opacidade de cápsula posterior. Foram analisados 40 olhos de coelhos, submetidos à cirurgia de facoemulsificação e distribuídos em quatro grupos experimentais (n=10), sendo estes: grupo controle, coelhos sem implante de lente intraocular; grupo com lente intraocular tratada com plasma de polietilenoglicol; grupo com lente intraocular tratada com plasma de flúor; e grupo com lente intraocular comercial. As cápsulas posteriores das lentes dos grupos foram avaliadas por meio de análise histopatológica (morfometria e imuno-histoquímica). Os grupos com lente intraocular tratada com polietilenoglicol e com lente intraocular comercial apresentaram menor espessura da cápsula posterior na avaliação inicial (12 semanas) em relação ao grupo controle. No período final de avaliação (6 meses), os tratamentos da superfície da lente intraocular à base de plasma de flúor e polietilenoglicol não reduziram o desenvolvimento das alterações histológicas associadas à opacidade de cápsula posterior. O tratamento das superfícies das lentes intraoculares com plasma de flúor e polietilenoglicol pode ser realizado como adjuvante na prevenção da opacidade de cápsula posterior, pois não causa alterações na morfologia da lente após facoemulsificação.


The aim of this study was to evaluate the effect of surface treatment of acrylic intraocular lens using Fluorine plasma or polyethylene glycol in the prevention of posterior capsule opacification. Forty rabbit eyes that underwent phacoemulsification were analyzed and distributed into four experimental groups (n=10): Control group, composed of rabbits without intraocular lens implantation; intraocular lens group treated with Polyethylene glycol plasma, intraocular lens group treated with Fluoride plasma, and commercial intraocular lens group. The posterior capsule of the lens was evaluated by histopathological analysis, including morphometric and immunohistochemical studies. Groups with intraocular lens treated with polyethylene glycol and commercial intraocular lens presented thinner posterior capsule at initial assessment (12 weeks) compared to the control group. At the end of the evaluation (six months), the treatment of surface intraocular lens with fluorine and polyethylene glycol plasma did not reduce the development of histological changes associated with posterior capsule opacification. The surface treatment of the intraocular lens with Fluoride and Polyethylene glycol can be performed as an adjuvant in preventing posterior capsule opacification, because it does not cause changes in the morphology of lens after phacoemulsification surgery.


Assuntos
Animais , Coelhos , Opacificação da Cápsula , Olho , Lentes Intraoculares/efeitos adversos , Facoemulsificação , Histologia , Imuno-Histoquímica
14.
Scand J Med Sci Sports ; 24 Suppl 1: 57-65, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24944132

RESUMO

We evaluated the effects of recreational football training combined with calorie-restricted diet (football + diet) vs calorie-restricted diet alone (diet) on aerobic fitness, lipid profile, and insulin resistance indicators in type 2 diabetes (T2D) patients. Forty-four T2D patients aged 48-68 years (27 females, 17 males) were randomly allocated to the football + diet group (FDG; n = 22) or to the diet group (DG; n = 22), of whom 19 FDG and 15 DG subjects completed the study. The football training was performed for 3 × 40 min/week for 12 weeks. Dual-energy X-ray absorptiometry scanning, treadmill testing, and fasting blood samplings were performed pre and post-intervention. After 12 weeks, maximal oxygen uptake (VO2max ) was elevated (P < 0.05) by 10 ± 4% in FDG but not in DG (-3 ± 4%, P < 0.05). After 12 weeks, reductions in blood triglycerides (0.4 ± 0.1 mmol/L), total cholesterol (0.6 ± 0.2 mmol/L), low-density lipoprotein, and very low-density lipoprotein levels were observed only in FDG. Fat mass decreased (P < 0.05) by 3.4 ± 0.4 kg in FDG and 3.7 ± 0.4 kg in DG. The lower (P < 0.05) glucagon and homeostatic model assessment of insulin resistance indicated an improvement in insulin sensitivity in FDG. In conclusion, football combined with restricted diet was effective in enhancing VO2max , reducing total cholesterol and triglycerides, and increasing insulin sensitivity, potentially providing better tools for the prevention of T2D complications than diet alone.


Assuntos
Colesterol/sangue , Diabetes Mellitus Tipo 2/terapia , Terapia por Exercício/métodos , Resistência à Insulina , Aptidão Física , Futebol/fisiologia , Triglicerídeos/sangue , Idoso , Biomarcadores/sangue , Glicemia/metabolismo , Brasil , Restrição Calórica , Terapia Combinada , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/fisiopatologia , Feminino , Frequência Cardíaca , Humanos , Masculino , Pessoa de Meia-Idade , Consumo de Oxigênio , Resultado do Tratamento
16.
Mol Pharm ; 11(1): 112-30, 2014 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-24215236

RESUMO

Amorphous S-flurbiprofen was obtained by the melt quench/cooling method. Dielectric measurements performed in the isochronal mode, conventional and temperature modulated differential scanning calorimetry (TMDSC) studies showed a glass transition, recrystallization, and melting. The different parameters characterizing the complex molecular dynamics of amorphous S-flurbiprofen that can have influence on crystallization and stability were comprehensively characterized by dielectric relaxation spectroscopy experiments (isothermal mode) covering a wide temperature (183 to 408 K) and frequency range (10(-1) to 10(6) Hz): width of the α-relaxation (ßKWW), temperature dependence of α-relaxation times (τα), fragility index (m), relation of the α-relaxation with the ß-secondary relaxation, and the breakdown of the Debye-Stokes-Einstein (DSE) relationship between the structural relaxation time and dc-conductivity (σdc) at deep undercooling close to Tg. The ß-relaxation, observed in the glassy as well as in the supercooled state was identified as the genuine Johari-Goldstein process, attributed to localized motions and regarded as the precursor of the α-relaxation as suggested in the coupling model. A separation of about 6 decades between the α- and ß-relaxation was observed at Tg; this decoupling decreased on increasing temperature, and both processes merged at Tαß = 295 K. The temperature dependence of the α-relaxation time, τα, was described by two Vogel-Fulcher-Tammann-Hesse equations, which intercept at a crossover temperature, TB = 290 K, close to the splitting temperature between the α- and ß-relaxation. From the low temperature VFTH equation, a Tg(DRS) = 265.2 was estimated (at τα =100 s) in good agreement with the calorimetric value (Tg,onset,TMDSC = 265.6 K), and a fragility or steepness index m = 113 was calculated allowing to classify S-flurbiprofen as a fragile glass former. The α-relaxation spectra were found to be characterized by a relatively large degree of nonexponentiality (ßKWW = 0.52). A breakdown of the DSE log10 σdc - log10 τ relation was observed revealing an enhancement of translational ionic motions in comparison with the orientational molecular motions as the glass transition temperature Tg is approached from above.


Assuntos
Flurbiprofeno/química , Vidro/química , Varredura Diferencial de Calorimetria , Cristalização , Espectroscopia Dielétrica , Condutividade Elétrica , Modelos Moleculares , Simulação de Dinâmica Molecular , Transição de Fase , Termogravimetria , Temperatura de Transição
17.
Braz J Biol ; 74(3 Suppl 1): S177-83, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25627383

RESUMO

A general analysis of the behaviour of "Cebus" shows that when this primate moves position to feed or perform another activity, it presents different ways of locomotion. This information shows that the brachial biceps muscle of this animal is frequently used in their locomotion activities, but it should also be remembered that this muscle is also used for other development activities like hiding, searching for objects, searching out in the woods, and digging in the soil. Considering the above, it was decided to research the histoenzimologic characteristics of the brachial biceps muscle to observe whether it is better adpted to postural or phasic function. To that end, samples were taken from the superficial and deep regions, the inserts proximal (medial and lateral) and distal brachial biceps six capuchin monkeys male and adult, which were subjected to the reactions of m-ATPase, NADH-Tr. Based on the results of these reactions fibres were classified as in Fast Twitch Glycolitic (FG), Fast Twitch Oxidative Glycolitic (FOG) and Slow Twitc (SO). In general, the results, considering the muscle as a whole, show a trend of frequency FOG> FG> SO. The data on the frequency were studied on three superficial regions FOG=FG>SO; the deep regions of the inserts proximal FOG=FG=SO and inserting the distal FOG>FG=SO. In conclusion, the biceps brachii of the capuchin monkey is well adapted for both postural and phasic activities.


Assuntos
Braço/fisiologia , Cebus/metabolismo , Fibras Musculares Esqueléticas/enzimologia , Animais , Braço/inervação , Cebus/classificação , Cebus/fisiologia , Histocitoquímica , Locomoção , Masculino , Fibras Musculares de Contração Rápida/enzimologia , Fibras Musculares de Contração Rápida/fisiologia , Fibras Musculares Esqueléticas/fisiologia , Fibras Musculares de Contração Lenta/enzimologia , Fibras Musculares de Contração Lenta/fisiologia
18.
Arq. bras. med. vet. zootec ; 65(3): 715-721, June 2013. ilus, tab
Artigo em Inglês | LILACS | ID: lil-679104

RESUMO

The objective of this study was to evaluate whether demineralized bovine bone (Gen-ox®) alters bone neoformation in rats submitted to alcoholism. Forty male rats were separated into two groups of 20 rats and distributed as follows: Group E1, which received 25% ethanol and a surgical cavity filled only by a blood clot, and Group E2, which received 25% ethanol and a surgical cavity filled with Gen-ox®. The animals were euthanized at 10, 20, 40 and 60 days after surgery and necropsy was performed. The histomorphological and histometric analyses of the area of connective tissue and bone neoformation showed that the reorganization of the bone marrow and full repair of the surgical cavity in Group E1 occurred more quickly than in Group E2. It was also noted that in the final period the animals in Group E2 showed areas of connective tissue and thick bone trabeculae around the particles of the implant. It can be concluded that the use of Gen-ox® delayed the process of bone repair in alcoholic rats, although it can be used as filling material because it shows osteoconductive activity, as evidenced by bone tissue formation around the graft particles.


O objetivo deste trabalho foi avaliar se a matriz óssea bovina desmineralizada (Gen-ox®) altera a neoformação óssea em ratos submetidos ao alcoolismo. Foram utilizados 40 ratos machos, separados em dois grupos de 20 animais cada, assim distribuídos: Grupo E1, que recebeu etanol a 25% e cavidade cirúrgica preenchida por coágulo sanguíneo, e Grupo E2, que recebeu etanol a 25% e cavidade cirúrgica preenchida por Gen-ox®. Os animais foram eutanasiados aos 10, 20, 40 e 60 dias após a cirurgia. Os estudos histomorfológico e histométrico da quantidade de tecido conjuntivo presente e a quantidade de tecido ósseo neoformado demostraram que a reorganização da medula óssea e a reparação total da cavidade cirúrgica no Grupo E1 ocorreram em menor espaço de tempo do que no Grupo E2. Observou-se também que, no período final do experimento, os animais do Grupo E2 apresentaram áreas de tecido conjuntivo e trabéculas ósseas espessas ao redor das partículas do material implantado. Concluiu-se que a utilização do Gen-ox® retardou o processo de reparação óssea em ratos alcoolizados, muito embora o Gen-ox® possa ser utilizado como material de preenchimento, pois demonstra atividade osteocondutiva, com a formação de tecido ósseo ao redor das partículas do enxerto.


Assuntos
Animais , Bovinos , Alcoolismo/complicações , Osso e Ossos , Desmineralização/métodos , Regeneração/fisiologia , Bovinos/classificação , Ratos/classificação
19.
Braz J Med Biol Res ; 46(3): 278-86, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23471360

RESUMO

The antioxidant and free radical scavenger properties of melatonin have been well described in the literature. In this study, our objective was to determine the protective effect of the pineal gland hormone against the DNA damage induced by cyclophosphamide (CP), an anti-tumor agent that is widely applied in clinical practice. DNA damage was induced in rats by a single intraperitoneal injection of CP (20 or 50 mg/kg). Animals received melatonin during the dark period for 15 days (1 mg/kg in the drinking water). Rat bone marrow cells were used for the determination of chromosomal aberrations and of formamidopyrimidine DNA glycosylase enzyme (Fpg)-sensitive sites by the comet technique and of Xpf mRNA expression by qRT-PCR. The number (mean ± SE) of chromosomal aberrations in pinealectomized (PINX) animals treated with melatonin and CP (2.50 ± 0.50/100 cells) was lower than that obtained for PINX animals injected with CP (12 ± 1.8/100 cells), thus showing a reduction of 85.8% in the number of chromosomal aberrations. This melatonin-mediated protection was also observed when oxidative lesions were analyzed by the Fpg-sensitive assay, both 24 and 48 h after CP administration. The expression of Xpf mRNA, which is involved in the DNA nucleotide excision repair machinery, was up-regulated by melatonin. The results indicate that melatonin is able to protect bone marrow cells by completely blocking CP-induced chromosome aberrations. Therefore, melatonin administration could be an alternative and effective treatment during chemotherapy.


Assuntos
Antioxidantes/administração & dosagem , Dano ao DNA/efeitos dos fármacos , Melatonina/administração & dosagem , Animais , Aberrações Cromossômicas , Ciclofosfamida , Injeções Intraperitoneais , Masculino , Mutagênicos , Oxirredução , Ratos Wistar
20.
Braz. j. med. biol. res ; 46(3): 278-286, 15/mar. 2013. tab, graf
Artigo em Inglês | LILACS | ID: lil-670894

RESUMO

The antioxidant and free radical scavenger properties of melatonin have been well described in the literature. In this study, our objective was to determine the protective effect of the pineal gland hormone against the DNA damage induced by cyclophosphamide (CP), an anti-tumor agent that is widely applied in clinical practice. DNA damage was induced in rats by a single intraperitoneal injection of CP (20 or 50 mg/kg). Animals received melatonin during the dark period for 15 days (1 mg/kg in the drinking water). Rat bone marrow cells were used for the determination of chromosomal aberrations and of formamidopyrimidine DNA glycosylase enzyme (Fpg)-sensitive sites by the comet technique and of Xpf mRNA expression by qRT-PCR. The number (mean ± SE) of chromosomal aberrations in pinealectomized (PINX) animals treated with melatonin and CP (2.50 ± 0.50/100 cells) was lower than that obtained for PINX animals injected with CP (12 ± 1.8/100 cells), thus showing a reduction of 85.8% in the number of chromosomal aberrations. This melatonin-mediated protection was also observed when oxidative lesions were analyzed by the Fpg-sensitive assay, both 24 and 48 h after CP administration. The expression of Xpf mRNA, which is involved in the DNA nucleotide excision repair machinery, was up-regulated by melatonin. The results indicate that melatonin is able to protect bone marrow cells by completely blocking CP-induced chromosome aberrations. Therefore, melatonin administration could be an alternative and effective treatment during chemotherapy.


Assuntos
Animais , Masculino , Antioxidantes/administração & dosagem , Dano ao DNA/efeitos dos fármacos , Melatonina/administração & dosagem , Aberrações Cromossômicas , Ciclofosfamida , Injeções Intraperitoneais , Mutagênicos , Oxirredução , Ratos Wistar
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