Blood glucose kinetics during concentric and eccentric muscle contractions

Studies comparing the two classes of stimuli (concentric and eccentric) have shown differences in the improvement of cardiovascular, metabolic, and muscle strength gain. This is an experimental, quantitative, and prospective study that aimed to verify the effect of eccentric exercise on glycolytic consumption and kinetics. The blood glucose kinetics of 17 male subjects was evaluated during a treadmill exercise with a 10% declined floor and velocity that required a 60% metabolic activity of VO2max, for 30 minutes. Seventy-two hours later, the same subjects exercised on the treadmill with a 10% inclined floor and 60% VO2max, for 30 minutes. To quantify glucose, blood samples were collected before the exercise, every three minutes along the 30 minutes of physical activity, and five and 10 minutes after finishing the exercise. For the downward slope, there was a homogeneous group behavior for blood glucose dynamics during the exercise, which was characterized by a monotonic decrease of glucose levels until reaching a minimum value at experimental times between 20 and 30 min, followed by a progressive recovery toward initial values. For the acclivity condition, blood glucose dynamics did not follow such a homogeneous behavior. A set of different types of dynamics could be identified. Experimental data showed that the type of dynamics could be predicted, to some extent, by the basal blood glucose level of subjects. The type of floor slope (upward or downward) directly affected glycolytic consumption and kinetics for the individuals analyzed.

Efeitos da radiação laser sobre a fase inicial do processo de cicatrização tendinosa em ratos / Effects of laser irradiation at the initial stage of the tendon healing process in rats

A laserterapia de baixa intensidade vem sendo empregada para diminuir o processo inflamatório e promover uma aceleração na cicatrização de diferentes tecidos lesionados. Visando verificar os efeitos da radiação laser sobre a fase inicial do processo de cicatrização tendinosa de lesões parciais induzidas cirurgicamente, vinte ratos machos da raça wistar clinicamente sadios provenientes do Biotério da Universidade de Passo Fundo foram aleatoriamente divididos em dois grupos e subdivididos e 2 subgrupos contendo cinco ratos cada. Todos os animais sofreram lesão parcial no corpo do tendão de Aquiles esquerdo de dois milímetros com sutura imediata da pele e início do tratamento estabelecido. Pelo período de sete dias, as lesões tendinosas foram submetidas a uma aplicação diária do laser Índio gálio fósforo com comprimento de onda de 670 nm na faixa do vermelho visível no modo pontual com dose de 4 joules com a caneta em contato direto com a pele do animal. A avaliação microscópica foi feita mediante acompanhamento histopatológico após biópsia tecidual efetuada em todas as lesões tendíneas ao término do 3° e 7° dias. O tecido removido foi fixado, preparado e corado com Hematoxilina-Eosina e Tricômico Masson para observar as células inflamatórias, fibroblastos, deposição de colágeno e neovascularização. Através dos resultados obtidos pode-se concluir que o laser de baixa intensidade é um método não evasivo eficiente e altamente significativo no tratamento de lesões parciais tendíneas induzidas em ratos na fase inicial quando comparados com o grupo controle, por diminuir o processo inflamatório e incrementar a produção de fibroblastos, depositação de colágeno e formação de novos vasos no sítio da lesão.

The low intensity laser therapy has been used to reduce the inflammation process and to promote acceleration of lesions healing. Aiming at verifying the effects of laser irradiation at first stage of the tendon healing process of partial lesions induced surgically, twenty male Wistar rats, clinically healthy, from the Vivarium of Passo Fundo University were randomly divided into two groups and subdivided and 2 subgroups with five rats each. All animals suffered partial lesion in the left Achilles tendon body of 0.2 mm with immediate skin suture and beginning of the treatment. During seven days, the tendon lesions were submitted to a daily application of laser InGaP with wavelength of 670 nm in the visible red, dosage of 4 joules, with the pen in direct contact with animal skin. The microscopic evaluation was performed through tissue biopsy made in all tendon lesions at the end of the third and seventh days. The removed tissue was fixed, prepared and stained with hematoxylin-eosin and Masson’s trichrome to observe inflammatory cells, fibroblasts, collagen deposition and new vascularization. The results showed that low intensity laser is a non invasive and efficient method and highly significant to treat tendon partial lesions induced in rats at first stage when compared with control group, as it reduces inflammatory process and increases the fibroblasts production, collagen deposition and formation of new vessels in the lesions site.

In vitro assessment of the effectiveness of whitening dentifrices for the removal of extrinsic tooth stains

This in vitro study evaluated the effectiveness of whitening dentifrices for the removal of extrinsic tooth stains. Twenty dental blocks (4 x 4 mm), including enamel and dentine, removed from freshly extracted bovine incisors, were randomly divided into 4 groups: G1 - distilled water, G2 - Colgate, G3 - Crest Extra Whitening and G4 - Rapid White. In all specimens, the dentin was covered with colorless nail polish, and the enamel was left exposed. Next, the specimens were immersed in a solution of black tea, which was changed every 24 h, for a period of 6 days. After this period, a photo-reflectance reading was taken (Time 1) with a spectrometer. The stained specimens were then submitted to linear brushing movements (5,000 cycles) using brushes (Oral B-Soft) coupled to an automatic toothbrushing machine, under a static axial load of 200 g and with a speed of 4 movements/second, at 37°C, with the dentifrice or water being injected every 60 s. When toothbrushing ended, a second photo-reflectance reading was taken (Time 2). The results were submitted to two-criteria analysis of variance (ANOVA) and to the Tukey test ( = 0.05). When the two times for a same group were compared, Time 2 presented the highest reflectance values with statistical difference only for G3 and G4. Among the dentifrices tested, only the Rapid White group differed from the control group, presenting the highest reflectance values. Only the whitening dentifrice Rapid White was effective for the removal of extrinsic stains.

Estudo do aumento de temperatura intra-pulpar gerado pelo clareamento dental / Intra-pulpar temperature increase generated by dental bleaching

Neste trabalho foi estudado in-vitro o aumento de temperatura intra-pulpar de um grupo de 15 dentes (três passagens cada), geradas pela técnica de clareamento dental utilizando-se um aparelho Fotopolimerizador e dois sistemas conjugados de LEDs com Laser de marcas comerciais distintas, com um mesmo agente clareador. Um dos principais fatores limitantes para os procedimentos de clareamento dental fotoassistido é o aumento de temperatura gerado no elemento dental em decorrência da técnica. Em virtude disso foram avaliados os equipamentos e submetidos a uma comparação sob o aspecto de aumento de temperatura intra-pulpar in vitro. Os resultados foram compilados e mostraram que o equipamento denominado LEDs B, foi o maior gerador de aumento de temperatura, apresentando uma média aritmética de 5,98°C, inclusive ultrapassando os limites propostos por ZACH e COHEN em 1965. O equipamento Fotopolimerizador foi o segundo maior gerador de aumento de temperatura, com um aumento médio de 5,19°C, apresetando-se em uma posição limítrofe, aos limites propostos. O equipamento denominado LEDs A apresentou o menor aumento de temperatura gerado em decorrência da técnica, com uma média aritmética de 0,54°C, podendo ser considerada como desprezível