Utilization of neuromuscular electrical stimulation in the acute phase of ankle immobilization at 90°: Study in rats

Objective: To evaluate the skeletal muscle glycogen content and plasmatic concentration of interleukin -6 (IL-6), interleukin-4 (IL-4), interleukin-10 (IL-10) and tumor necrosis factor-alpha (TNF-α) in rats submitted to electrical stimulation sessions during the first three days of ankle immobilization at the position of 90°. Methods: Albinomale Wistar rats(3-4 months) were maintained in vivarium. conditions with food and water ad libitum, Submitted to 12 h photoperiodic cycles of light/dark, and distributed into 7 experimental groups (n = 6): control(C), immobilized 1 day(I1) immobilized 1 day and electrically stimulated(IE1) immobilized 2 days(12), immobilized 2 days and electrically stimulated(IE2), immobilized 3 days(13) and immobilized 3 days and electrically stimulated(IE3). Groups I utilized an acrylic resin orthesis model and groups electrically stimulated (IE) utilized the orthesis and a session of electrotherapy by a Dualpex 961 (biphasic quadratic pulse, 10 Hz, 0.4 ms, 5.0 mA, one 20 min session a day). After the experimental period, the rats were anesthetized with pentobarbital sodium(40 mg/kg) and a blood sample was colleted to evaluate the plasmatic concentration of interleukins by means of the radioimmunoassay method. The soleus and the white portion of the gastrocnemius muscle were colleted for glycogen reserves analysis(GLY). Other groups of rats were used to apply the glucose tolerance test(GTT) and insulin tolerance test(ITT). For statistical analysis, the Kolmogorov-Smirnov normality test followed by ANOVA and the Tukey tests were utilized, with a critical level established at 5%. Results: In ITT test, groups IE enhanced the skeletal muscle glucose uptake, but no changes were observed in GTT after the therapy session, which indicates that electrical stimulation is a sensibilizing method to augment skeletal muscle glucose uptake. The GLY reserves were reduced in I groups, which indicate that disuse altered insulin sensitivity and compromised energetic homeostasis. However. the IE groups displayed an augment in GLY content, suggesting that electrical stimulation restores the enzymatic pathways altered by immobilization. The improvement in GLY was accompanied by an elevation of the plasmatic concentration of IL-6 and TNF-α, showing the participation of these interleukins in the control of metabolic profile. Plasmatic concentrations of IL-10 were elevated only after 3 days of IE while IL-4 did not display any modifications. Conclusion: The results suggest that neuromuscular electricaf stimulation is an important toot in the maintenance of energetic, conditions of musculature submitted to immobilization, and presents multifactor mechanisms linked to interleukins action that converge to maintain the energetic equilibrium of the tissue in disuse.

Hacia un nuevo modelo de organización industrial: el sector manufacturero argentino en los años 90

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Estabilización macroeconómica, reforma estructural y comportamiento industrial: estructura y funcionamiento del sector manufacturero latinoamericano en los años 90

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Une décennie d'ombres et de lumières: l'Amérique Latine et les Caraibes dans les années 90

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Diffuse Effect of the Tungsten Doped Ba(Zr0.10Ti0.90)O3 Ferroelectric Ceramics

Barium zirconate titanate Ba(Ti0.90Zr0.10)O3 ceramics doped with WO3 (BZT:2W) have been prepared by a traditional solid phase reaction. The effect of temperature on the structural and electrical properties was investigated. X ray diffraction data evidenced formation of secondary phases for the samples sintered at 1300oC end 1350oC while the pure phase was attained at 1200oC. A modified Curie-Weiss law was used to describe the diffuseness of a phase transition. As temperature increases, the maximum dielectric permittivity decreased. The fine-grained sample showed a 'diffuse-like' ferroelectric behavior. The dielectric permittivity reaches a maximum value (εm ~6420 at 10 kHz) for the ceramics sintered at 1200oC for 4 hours.

Pension reform in Europe in the 90's and lessons for Latin America

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Reestructuración de la enseñanza fundamental y gestión del gasto educacional en Brasil: la década de los 90

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El contenido demográfico de la boleta de los censos de población de la década del 90

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La ronda de los censos de los años 90 en América Latina y el Caribe: posibilidades y limitaciones para su utilización en el establecimiento de las metas para la infancia en los años 90

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Concentrações de sacarose no desenvolvimento in vitro e na aclimatização de Cattleya loddigesii Lindley

This work aimed to study the influence of sucrose in the culture medium for in vitro growth and acclimatization of the epiphytic orchid Cattleya loddigesii. Five sucrose treatments (absence, 10, 20, 30 and 40g L-1) were used in a randomic experimental design. Mature seeds were sowed in 1/2 MS culture medium and after 90 days the plantlets (1.0 +/-0.2 cm) were inoculated between the treatments, whereby they were remained more 90 days. After 180 days of the beginning of the experiment the plantlets were removed from the flasks and evaluated the number of roots, shoot length, number of leafs, total dry weight and photosynthetic pigments. Survival percentage was evaluated after 75 days of acclimatization. The data of biometric variables were analyzed by Anovaand polynomial regression (p<0.05). Theothers data were submitted to the Anova and the means compared by the Tukey test (p<0.05). The sucrose concentration of 20g L-1 favored the in vitro growth in all evaluated parameters, showed higher production of chlorophyll a, total chlorophyll and carotenoids, in addition to increased survival under ex vitro condition. The sucrose concentration of 20g L-1 in the culture medium was the most efficient among the tested concentrations both for in vitro growth and ex vitro establishment of Cattleya loddigesii.

Long-term effects of perinatal androgenization on reproductive parameters of male rat offspring androgenization and male rat reproduction

It is known that during sex differentiation, fetal androgens are critical determinants of the male phenotype. Although testosterone is necessary for normal development of male sexual behavior, perinatal androgen treatment can result in disruption of normal male sexual reproduction. Pregnant Wistar rats were administered either corn oil (vehicle) or testosterone propionate at 0.2 mg/kg from gestational day 12 until the end of lactation and the reproductive function of male offspring was evaluated at 90 (adulthood) and 270 (middle age) days of age. Perinatal androgenization in the rat provoked a reduction in sperm production and reserves in adulthood that did not affect fertility and did not persist at more advanced ages, as shown by the results at post-natal day 270. If perinatal androgenization promotes similar effects in humans of reproductive age, the results of the present work can impact male reproduction health, given the less efficient spermatogenesis and lower sperm reserves in the human epididymis, compared to rodents. © Georg Thieme Verlag KG Stuttgart. New York.

Algunas reflexiones sobre los censos del 90: posibles áreas de colaboración = Some thoughts concerning the 1990 censuses: possible areas for co-operation

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