Observation of geometric structure of collagen molecules by atomic force microscopy

Atomic force microscopy was used to study the geometric structure of collagen fibrils and molecules of rat calcanean tendon tissues. The authors found that the diameter of the fibrils ranged from 124 to 170 nm, and their geometric form suggested a helical winding with spectral period from 59.4 to 61.7 nm, close to the band dimensions reported by electron microscopy. At high magnification, the surface of these bands revealed images that probably correspond to the almost crystalline array of collagen molecules, with the triple helix structure almost visible. The typical helix width is 1.43 nm, with main periods of 1.15 and 8.03 nm, very close to the dimensions reported by X-ray diffraction.692919

Observation of baker's yeast strains used in biotransformation by atomic force microscopy

Different strains of baker's yeast (Saccharomyces cerevisiae) were imaged with an atomic force microscope (AFM). The images of uncoated and nonfixed samples were reproducible with high-constrast and nanometer-resolution. Molecules from the polysaccharide surface of the cell wall were pictured and the distance of atoms was measured. The preparation of samples was easy, suggesting that AFM is a useful tool in this type of analyses.59213514

The effect of therapeutic ultrasound on repair of the Achilles tendon (Tendo calcaneus) of the rat

The purpose of this study was to evaluate the effects of therapeutic ultrasound (US) on the healing process in the Achilles tendon (Tendo calcaneus) of Wistar rats after tenotomy. Sonication was performed at a frequency of 1 MHz, an intensity of 0.5 W/cm(2) (SATA), for 5 min, over a period of 14 consecutive days in two modalities (n = 15); in both continuous and pulsed modes. The control group was divided into tenotomized, mock-sonicated and nontenotomized tendons (it = 15). On the 15th postoperative day, the tendons were removed and analyzed by using the polarized light microscopy, with the purpose of detecting and measuring the organization of collagen fibers through birefringence. The results showed a high birefringence for the tendons treated using the pulsed mode (p < 0.001), revealing the best organization and aggregation of collagen bundles. Sonication in the continuous mode induced a decrease (p = 0.047) in the ability to quicken the healing process. These findings suggest that US therapy is beneficial in the early healing process of tendons when the pulsed mode is used. (E-mail: [email protected]) (C) 2002 World Federation for Ultrasound in Medicine Biology.27121691169

Low-level laser therapy (LLLT) (660 nm) alters gene expression during muscle healing in rats

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Introduction: The effects of LLLT were studied during muscle regeneration through gene expression. Methods: It was evaluated 10 and 50 J/cm(2) doses during 7, 14 and 21 days post cryoinjury, through histopathological analysis and mRNA MyoD, Myogenin, Vegf and Cox-2 expression. Results: Irradiated groups presented less inflammatory process than control group after 14 and 21 days. Cox-2 levels were downregulated in all irradiated groups after 7, 14 and 21 days. On day 7, both treated groups had a downregulation of Vegf levels, and an upregulation after 14 and 21 days, mainly with 50 J/cm(2). The MyoD levels were upregulated with high dose in all periods and with low dose after 21 days. Myogenin expression was downregulated in both treated groups after 7 days, and was upregulated with 10 J/cm(2) after 21 days. Conclusion: These responses suggest that LLLT can improve the skeletal muscle regeneration through the gene expression stimulation. (C) 2013 Elsevier B.V. All rights reserved.1202935Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Comparative study using 685-nm and 830-nm lasers in the tissue repair of tenotomized tendons in the mouse

Objective: The objective of this study was to evaluate the effects of 685- and 830-nm laser irradiations, at different fluences on the healing process of Achilles tendon (Tendon calcaneo) of mice after tenotomy. Background Data: Some authors have shown that low-level laser therapy (LLLT) is able to accelerate the healing process of tendinuos tissue after an injury, increasing fibroblast cell proliferation and collagen synthesis. However, the mechanism by which LLLT acts on healing process is not fully understood. Methods: Forty-eight male mice were divided into six experimental groups: group A, tenomized animals, treated with 685 nm laser, at the dosage of 3 J/cm(2); group B, tenomized animals, treated with 685-nm laser, at the dosage of 10 J/cm(2); group C, tenomized animals, treated with 830-nm laser, at dosage of 3 J/cm(2); group D, tenomized animals, treated with 830-nm laser, at the dosage of 10 J/cm(2); group E, injured control (placebo treatment); and group F, non-injured standard control. Animals were killed on day 13 post-tenotomy, and their tendons were surgically removed for a quantitative analysis using polarization microscopy, with the purpose of measuring collagen fibers organization trough the birefringence (optical retardation [OR]). Results: All treated groups showed higher values of OR when compared to injured control group. The best organization and aggregation of the collagen bundles were shown by the animals of group A (685 run, 3 J/cm(2)), followed by the animals of group C and B, and finally, the animals of group D. Conclusion: All wavelengths and fluences used in this study were efficient at accelerating the healing process of Achilles tendon post-tenotomy, particularly after the 685-nm laser irradiation, at 3 J/cm(2). It suggests the existence of wavelength tissue specificity and dose dependency. Further studies are required to investigate the physiological mechanisms responsible for the effects of laser on tendinuos repair.o TEXTO COMPLETO DESTE ARTIGO, ESTARÁ DISPONÍVEL À PARTIR DE AGOSTO DE 2015.24675475

Infrared LED irradiation applied during high-intensity treadmill training improves maximal exercise tolerance in postmenopausal women: a 6-month longitudinal study

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Reduced aerobic fitness is associated with an increased risk of cardiovascular diseases among the older population. The aim of this study was to investigate the effects of LED irradiation (850 nm) applied during treadmill training on the maximal exercise tolerance in postmenopausal women. At the beginning of the study, 45 postmenopausal women were assigned randomly to three groups, and 30 women completed the entire 6 months of the study. The groups were: (1) the LED group (treadmill training associated with phototherapy, n = 10), (2) the exercise group (treadmill training, n = 10), and (3) the sedentary group (neither physical training nor phototherapy, n = 10). The training was performed for 45 min twice a week for 6 months at intensities between 85% and 90% maximal heart rate (HRmax). The irradiation parameters were 39 mW/cm(2), 45 min and 108 J/cm(2). The cardiovascular parameters were measured at baseline and after 6 months. As expected, no significant differences were found in the sedentary group (p a parts per thousand yenaEuro parts per thousand 0.05). The maximal time of tolerance (Tlim), metabolic equivalents (METs) and Bruce stage reached significantly higher values in the LED group and the exercise group (p < 0.01). Furthermore, the HR, double product and Borg score at isotime were significantly lower in the LED group and in the exercise group (p < 0.05). However, the time of recovery showed a significant decrease only in the LED group (p = 0.003). Moreover, the differences between before and after training (delta values) for the Tlim, METs and HR at isotime were greater in the LED group than in the exercise group with a significant intergroup difference (p < 0.05). Therefore, the infrared LED irradiation during treadmill training can improve maximal performance and post-exercise recovery in postmenopausal women.282415422Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)FAPESP [98/14270-8, 09/01842-0]CNPq [150949/2011-1