GaAs 904-nm laser irradiation improves myofiber mass recovery during regeneration of skeletal muscle previously damaged by crotoxin.

This work investigated the effect of gallium arsenide (GaAs) irradiation (power: 5 mW; intensity: 77.14 mW/cm(2), spot: 0.07 cm(2)) on regenerating skeletal muscles damaged by crotoxin (CTX). Male C57Bl6 mice were divided into six groups (n = 5 each): control, treated only with laser at doses of 1.5 J or 3 J, CTX-injured and, CTX-injured and treated with laser at doses of 1.5 J or 3 J. The injured groups received a CTX injection into the tibialis anterior (TA) muscle. After 3 days, TA muscles were submitted to GaAs irradiation at doses of 1.5 or 3 J (once a day, during 5 days) and were killed on the eighth day. Muscle histological sections were stained with hematoxylin and eosin (H&E) in order to determine the myofiber cross-sectional area (CSA), the previously injured muscle area (PIMA) and the area density of connective tissue. The gene expression of MyoD and myogenin was detected by real-time PCR. GaAs laser at a dose of 3 J, but not 1.5 J, significantly increased the CSA of regenerating myofibers and reduced the PIMA and the area density of intramuscular connective tissue of CTX-injured muscles. MyoD gene expression increased in the injured group treated with GaAs laser at a dose of 1.5 J. The CTX-injured, 3-J GaAs laser-treated, and the CTX-injured and treated with 3-J laser groups showed an increase in myogenin gene expression when compared to the control group. Our results suggest that GaAs laser treatment at a dose of 3 J improves skeletal muscle regeneration by accelerating the recovery of myofiber mass.

Neuroplasticity induced by the retention period of a complex motor skill learning in rats.

Learning complex motor skills is an essential process in our daily lives. Moreover, it is an important aspect for the development of therapeutic strategies that refer to rehabilitation processes since motor skills previously acquired can be transferred to similar tasks (motor skill transfer) or recovered without further practice after longer delays (motor skill retention). Different acrobatic exercise training (AE) protocols induce plastic changes in areas involved in motor control and improvement in motor performance. However, the plastic mechanisms involved in the retention of a complex motor skill, essential for motor learning, are not well described. Thus, our objective was to analyze the brain plasticity mechanisms involved in motor skill retention in AE . Motor behavior tests, and the expression of synaptophysin (SYP), synapsin-I (SYS), and early growth response protein 1 (Egr-1) in brain areas involved in motor learning were evaluated. Young male Wistar rats were randomly divided into 3 groups: sedentary (SED), AE, and AE with retention period (AER). AE was performed three times a week for 8 weeks, with 5 rounds in the circuit. After a fifteen-day retention interval, the AER animals was again exposed to the acrobatic circuit. Our results revealed motor performance improvement in the AE and AER groups. In the elevated beam test, the AER group presented a lower time and greater distance, suggesting retention period is important for optimizing motor learning consolidation. Moreover, AE promoted significant plastic changes in the expression of proteins in important areas involved in control and motor learning, some of which were maintained in the AER group. In summary, these data contribute to the understanding of neural mechanisms involved in motor learning in an animal model, and can be useful to the construction of therapeutics strategies that optimize motor learning in a rehabilitative context.

Motor improvement requires an increase in presynaptic protein expression and depends on exercise type and age.

The aging process is associated with structural and functional changes in the nervous system. Considering that exercise can improve the quality of life of the elderly, the aim of this study was to evaluate the effects of exercise protocols with different motor demands on synaptic protein expression (i.e., synapsin-I and synaptophysin). Cognitive and motor brain areas and the motor performance of adult and aged animals were analyzed. Adult (7 months old) and aged (18 months old) male Wistar rats were used. Animals were divided into the following groups: treadmill exercise (TE, rhythmic motor activity), acrobatic exercise (AE, complex motor activity) and sedentary (SED, control). The animals were exposed to exercise 3 times per week for 8 weeks. The brains were collected for immunohistochemistry and immunoblotting assays. Our results showed that both types of exercise induced changes in motor performance and synaptic protein expression in adult and aged animals. However, acrobatic exercise promoted a greater number of changes, mainly in the aged animals. In addition, protein expression changes occurred in a greater number of brain areas in the aged animals than in adult animals. There were clear increases in synapsin-I expression in all areas analyzed of aged animals only after acrobatic exercises. On the other hand, synaptophysin increased in the same areas but with both types of exercise. Thus, in general, our data suggest that even at advanced ages, when the aging process is already in progress, initiating physical training may be beneficial to generate neuroplasticity that can improve motor performance.

Salud ocupacional en el trabajo de estiba: los trabajadores de mercados mayoristas de Huancayo, 2006 / Occupational health in high altitude stevedores: the workers of the wholesale markets from Huancayo, 2006

Objetivo. Conocer las condiciones de higiene y seguridad del proceso de trabajo de estiba y su relación con el estado de salud de los trabajadores que realizan esta actividad. Materiales y métodos. Se realizó un estudio observacional en trabajadores de estiba de papa de los mercados mayoristas de Huancayo, Perú (3350 msnm). Se realizó una valoración antropométrica según parámetros internacionales, se evaluaron las condiciones laborales por observación directa y ergonómicas usando el método REBA y OWAS. Se realizó un examen clínico y traumatológico, y se evaluó la satisfacción laboral y los niveles de ansiedad y depresión con la escala de Zung. Resultados. Se evaluaron 105 trabajadores, 72,4 por ciento fueron estibadores, 25,7 por ciento cabeceadores y 1,9 por ciento transportistas manuales de carga, su estatura promedio fue de 159,9 mas menos 5,8 cm, manipulan sacos de 150 kg y diariamente pueden movilizar entre 10 a 20 toneladas. Se encontraron posturas inadecuadas como flexión de cuello mayor 60º, flexión elevada de brazos, flexión de tronco mayor 60º y flexión de tronco con movimientos de rotación, calificando esta actividad de riesgo ergonómico muy alto. 55 por ciento presentaron lumbalgia, 42 por ciento hiperxifosis dorsal, 62 por ciento refirieron estar satisfechos con su trabajo, no tenían síntomas depresivos 77 por ciento y de ansiedad 62 por ciento. Conclusiones. El proceso de trabajo de estiba es riesgoso para la salud de los trabajadores, debido al peso extremadamente excesivo que manejan, por lo que se debe reglamentar la reducción del peso de la carga a estándares internacionales (55 kg). Es necesario adoptar medidas, especialmente en lo que concierne a la capacitación de buenas técnicas en el transporte y manejo de carga.

Objectives. Knowing the conditions of hygiene and safety of the stowage work process and their relationship with the health of workers engaged in this activity. Materials and methods. Observational study was performed in potato stevedores from wholesale markets of Huancayo, Peru (3350 m). Anthropometric evaluation was using international parameters; working conditions were assessed by direct observation, and ergonomic using the REBA and OWAS methods. We performed a clinical and traumatological examination, and assessed the job satisfaction and levels of anxiety and depression with the Zung scale. Results. We evaluated 105 workers, stevedores were 72.4 per cent, 25.7 per cent cabeceadores and 1.9 per cent manual carriers of load, their average height was 159.9 more less 5.8 cm, handled bags of 150 kg daily and can mobilize between 10 to 20 tons. We found positions as inadequate bending neck great 60º, high bending arms, trunkflexion great 60º and bending movements with trunk rotation, qualifying this activity ergonomic as very high risk. 55 per cent had low back pain, 42 per cent dorsal hyperkyphosis, 62 per cent referred satisfaction with their work, did not have depressive symptoms 77 per cent and 62 per cent anxiety symptoms. Conclusions. The process of stevedoring work is risky for the health of workers, due to extremely excessive weight managing, and therefore should be regulated reducing the weight of cargo to international standards (55 kg). Action is needed, especially in terms of good technical training in transport and handling load.

Conocimientos y actividades de los padres de niños asmáticos en relación al asma de Costa Rica / Knowledge and activities of childhood asthma in of parents in relation asthma in Costa Rica

Este es un estudio prospectivo con 100 niños entre 1 y 2 años de edad y diagnóstico de asma bronquial (57 niñas y 53 varones), realizado en el mes de marzo de 1999 en la Sala de Nebulización del Hospital Nacional de Niños de Costa Rica. Se aplicó entrevista estructurada a los padres. El 52 por ciento fueron diagnosticados a edades entre 1 y 3 años y sólo el 40 por ciento ha tenido control médico regular. Aunque el 93 por ciento de los padres nunca asistió a cursos de prevención y educación sobre asma, muchos de ellos conocen sobre signos y síntomas de la enfermedad y desean adquirir más conocimiento al respecto. El estudio demuestra la necesidad de fortalecer el control de los niños asmáticos en el nivel primario de atención en salud

Infecciones: nosocomiales: características del problema en el Instituto Nacional de la Nutrición Salvador Zubirán y en México / Nosocomical infections: characteristics of the problem at the Instituto Nacional de la Nutrición \"Dr Salvador Zubián\" and in México

Se presentan los resultados de la vigilancia realizada en el INNSZ durante los años de 1982 y 1984. En nuestra experiencia, la frecuencia de infecciones nosocomiales en hospitales de tercer nivel es mucho mayor a la reconocida en otros hospitales del país, en donde se ha estudiado el problema. En promedio la tasa de incidencia (número de pacientes infectados/número de pacientes en riesgo) en el INNSZ es de 14.6% y la razón de infecciones nosocomiales (N§ de episodios de infección/100 egresos) es del 18.9%. Estos resultados se obtienen de un programa de vigilancia intenso y rutinario que se describe con detalle y se discuten los posibles motivos de la discrepancia con otras publicaciones nacionales previas. En vista de que existe alguna confusión en relación a algunos términos, se trata de delimitar con exactitud los significados de razón, incidencia y prevalencia y finalmente se señalan las características sobresalientes de este problema en nuestro hospital