Type IV collagen conforms to the organization of polylaminin adsorbed on planar substrata.

Tissue engineering demands the development of scaffolds that mimic natural extracellular matrices (ECM). Despite the success in obtaining synthetic interstitial ECM, the production of an artificial basement membrane (BM), the specialized thin sheet of ECM that is pivotal for the functional organization of most tissues and internal organs, is still not achieved. With the long-term aim of developing a flat BM-like structure here we investigated the behavior of acid-soluble Col IV during simultaneous assembly with laminin (LM) in acidic conditions. The underlying rationale was the previously observed phenomenon of acid-triggered LM polymerization, giving rise to biomimetic polylaminin (polyLM) that can be adsorbed on the substrate. Unexpectedly, we found that Col IV (that does not polymerize in acidic conditions) readily incorporated into the polyLM layer, forming a network that mimics to a great extent the characteristic polygonal morphology of single polyLM observable at micrometric scale. Scanning calorimetry and light scattering measurements supported the notion that polyLM and Col IV could directly interact. The biological properties of the proposed artificial BM-like structure were characterized using human keratinocytes (HACAT) and umbilical vein endothelial cells (HUVEC). HACAT formed stratified cell layers on the hybrid polyLM/Col IV layer, but not on Matrigel, nor on LM or Col IV alone, while HUVEC improved cortical F-actin and tight juctions organization on polyLM/Col IV. Thus, the proposed artificial BM reproduces not only morphological but also some functional properties of the natural BM. STATEMENT OF SIGNIFICANCE: Basement membranes (BMs) are flat biological matrices separating tissue compartments in the body. Their peculiar sheet-like structure is thought to result from the association of two independent protein networks of laminin and collagen IV. While pursuing the development of an artificial BM, we found that, when mixed with acid-induced polymerized laminin, collagen IV immediately conformed to the laminin shape. This implies that the protein networks may not be independently assembled as believed so far, but instead that laminin may command the assembly of collagen IV. Our hybrid matrix was structurally more stable than the commercial BM extract Matrigel and, unlike the latter, supported in vitro formation of a stratified layer of keratinocytes that approximated the organization of the natural epidermis.

[Effects of physical activity on women's morphology]. / Efectos de la actividad física en la morfología de mujeres.

Objective To analyze the effect of 12 weeks of physical activity on the morphology of the women enrolled in the Family Health Program in the city of Patos, Paraíba, Brazil. During these weeks, different physical activity programs were applied. Methods A quasi-experimental study, in which 28 women were analyzed. All were volunteers, aged between 42 and 56 years and divided into groups: G1 (n=15, recreational activities) and G2 (n=13, dance activities). For data analysis, the Student t-test for independent samples was used with a significance level of p<0.05. Results The comparison of body composition variables showed no difference between the two groups. However, when the pre- and post-exercise moments are compared, it is seen that the two different physical activity programs produce significant changes in the morphology of women. Conclusion The results indicate that the applied physical activity programs produce significant changes in the morphology of women. On the other hand, we consider that the comparison between a physical exercise program and recreational physical activity program and their effects on the morphology of women could be good.

Ascorbic acid reduces gentamicin-induced nephrotoxicity in rats through the control of reactive oxygen species.

BACKGROUND & AIM: Oxidative stress has been implicated in the pathophysiology of many forms of acute renal failure. The aim was examine the effect of vitamin C on oxidative stress and its relationship with nitric oxide on gentamicin-induced nephrotoxicity in rats. METHODS: We utilized 32 Wistar rats allocated in four groups of eight animals each: control (CTL), vitamin C (VIT C), gentamicin (GENTA), and GENTA + VIT C; all groups were treated during seven days. RESULTS: Serum urea and creatinine, serum and renal tissue malondialdehyde, blood superoxide anion and hydrogen peroxide in GENTA were increased vs CTL and vs VIT C, and decreased in GENTA + VIT C vs GENTA (all P < 0.05). Serum nitric oxide increased in GENTA vs CTL and vs VIT C, and reduced in GENTA + VIT C vs GENTA (P < 0.001). Urinary nitric oxide was reduced in GENTA vs CTL and vs VIT C and increased in GENTA + VIT C vs GENTA (P < 0.001). Severe degeneration of proximal tubules was present in GENTA, but only mild lesions were observed in GENTA + VIT C. CONCLUSION: This study suggests that VIT C is a valuable tool to protect against GENTA-induced nephrotoxicity, by reducing reactive oxygen species and increasing the nitric oxide.

Efectos de la actividad física en la morfología de mujeres / Effects of physical activity on women's morphology

Objetivo Analizar el efecto de 12 semanas de actividad física en la morfología de las mujeres inscritas en el programa de salud familiar de la ciudad de Patos, Paraíba - Brasil. Durante estas semanas se aplicaron diferentes programas de actividad física. Métodos Investigación cuasi experimental, en la cual fueron analizadas 28 mujeres, voluntarias, con edades entre 42 y 56 años, divididas en los grupos: G1 (n=15, actividades lúdicas) y G2 (n=13, actividad de danza). Para el análisis de datos se empleó la prueba t student para muestras independientes con un nivel de significancia de p<0.05. Resultados La comparación de las variables de la composición corporal no mostró diferencia entre los grupos. Sin embargo, cuando se comparan los momentos pre y post, se observa que los dos programas de actividad física distintos producen modificaciones significativas en la morfología de las mujeres. Conclusión Los resultados obtenidos indican que los programas de actividad física aplicados producen modificaciones significativas en la morfología de las mujeres. Por otro lado, se considera que podría ser buena la comparación de un programa de ejercicio físico y de actividades físicas lúdicas y sus efectos en la morfología de mujeres.(AU)

Objective To analyze the effect of 12 weeks of physical activity on the morphology of the women enrolled in the Family Health Program in the city of Patos, Paraíba, Brazil. During these weeks, different physical activity programs were applied. Methods A quasi-experimental study, in which 28 women were analyzed. All were volunteers, aged between 42 and 56 years and divided into groups: G1 (n=15, recreational activities) and G2 (n=13, dance activities). For data analysis, the Student t-test for independent samples was used with a significance level of p<0.05. Results The comparison of body composition variables showed no difference between the two groups. However, when the pre- and post-exercise moments are compared, it is seen that the two different physical activity programs produce significant changes in the morphology of women. Conclusion The results indicate that the applied physical activity programs produce significant changes in the morphology of women. On the other hand, we consider that the comparison between a physical exercise program and recreational physical activity program and their effects on the morphology of women could be good.(AU)