Synergism between phorbol myristate acetate and calcium ionophore in inducing proliferation of in vitro γ-irradiated murine lymphocytes.

The objective of this study was to analyze the in vitro effects of γ-irradiation (0-5 Gy) on lymphocyte proliferation in animals sensitive to radiation as BALB/c mice. Lymphocytes were irradiated and underwent different treatments: quiescent cells were cultured with calcium ionophore A23187 (5 min or 48 h) with or without phorbol myristate acetate (PMA); lymphocytes (control cells or incubated with A23187 and PMA) were also cultured with four mitogens that are specific to the different subpopulations to determine the degree of inhibition of the response to radiation. Results obtained indicated that in quiescent cells, A23187 and PMA treatment had a mitogenic effect, which peaked with long A23187 treatment (48 h); synergism was further demonstrated between both drugs and was enhanced with higher ionizing radiation doses. However, in both irradiated and non-irradiated mitogen-stimulated cells, A23187 (48 h) and PMA had a strong inhibitory effect on cell proliferation. In conclusion these results indicate that irradiated BALB/c mice lymphocytes respond to treatment with A23187 and PMA more actively than controls. Inhibition of the post-exposure mitogen-induced proliferative response and the synergic effect between A23187 and PMA also suggest altered PKC activation mechanisms in cell membranes. Comparing with previous studies with in vivo irradiated mice, the effects of IR in vitro were less intense.

Immediate and short-, mid- and long-term effects of in vivo ionizing radiation exposure in BALB/c mice: II. activation of phorbol myristate acetate and/or calcium ionophore on lymphocyte proliferation.

AIM: To study the effects of whole-body irradiation (WBI) on lymphocyte proliferation at different times (0, 7, 15, 30, 90 and 180 days) in an animal sensitive to radiation, BALB/c-mice. MATERIALS AND METHODS: Mice were irradiated (4 Gy) and euthanized at different times, and lymphocytes underwent different treatments: quiescent cells were cultured with calcium ionophore (5 min or 48 h) with/without phorbol myristate acetate (PMA). Lymphocytes were cultured with mitogens and underwent the same treatment. Cell proliferation was measured by a tritiated thymidine assay. RESULTS: The results obtained varied at different time points: at 15 days post-irradiation, quiescent cells and PMA-treated cells showed a significantly decreased proliferation, but increased at 90 days; moreover, when cells were treated with ionophore, a significant stimulation was noted at all times. When cells were exposed to mitogens, they behaved according to its nature: thus, concanavalin A (ConA) and phytohaemaglutinin A (PHA) behaved differently with PMA, while lipopolysaccharide (LPS) had an inhibitory effect at 30 days post-irradiation, and pokeweed (PWM) stimulated proliferation at both 90 and 180 days. Accordingly, there were very few variations in the test results when mitogen concanavalin A (ConA) and calcium ionophore with/without PMA were used. CONCLUSION: Our model is based on BALB/c mice. Cells induced to proliferate by the PKC enzyme and calcium ionophore are more resistant to irradiation than the same cells treated with specific T- and B-cells mitogen.

Disminución del riesgo cardiovascular en adolescentes. Aplicación del programa de prevención PATH (Physical Activity and Teenage Health) / Cardiovascular risk decrease in teenagers. Aplication of the preventive program path (Physical activity and teenage health)

Las enfermedades cardiovasculares representan hoy en día una de las principales causas de mortalidad en los países desarrollados. Parece que el proceso se inicia en la infancia y la adolescencia, con la adquisición de estilos de vida no saludables que conducirán a la enfermedad cardiovascu- lar en la edad adulta. Por ello, se piensa que una de las mejores estrategias para combatir estas enfermedades sería iniciar las actividades preventivas a edades muy tempranas. Con esta intención se desarrolló el Programa PATH (Phy- sical Activity and Teenage Health) , programa destinado a mejorar la salud cardiovascular y disminuir el riesgo futuro de estas enfermedades mediante el aumento de conoci- mientos relacionados con la salud, la modificación de los estilos de vida y el entrenamiento físico. La aplicación de este programa en escolares norteamericanos tuvo como resultado la disminución de la tensión arterial y el aumento de la capacidad aeróbica de los individuos, junto con el importante aumento de los conocimientos de salud. En este trabajo se estudian los resultados de la primera aplicación del Programa PATH en adolescentes españoles. La aplicación del programa disminuyó significativamente la tensión arterial y aumentó de forma significativa la capacidad aeróbica de los escolares medida en términos de VO 2 máx. Estos resultados se acompañaron de un aumento muy importante en los conocimientos de salud. Los resultados de este trabajo sugieren que el Programa PATH es de gran interés para la prevención de la enferme- dad cardiovascular, y su aplicación en el entorno escolar es plenamente viable(AU)

Cardiovascular illnesses represent today one of the main causes of mortality in the developed countries. It seems that the process begins in childhood and adolescence, with the acquisition of non healthy lifestyles that will lead to the cardiovascular illness in the adult age. So, it is thought that one of the best strategies to combat these illnesses would be to begin the preventive activities to very early ages. In this way, the PATH Program (Physical Activity and Teenage Health) was developed to improve the cardiovas- cular health and diminish the future risk of these illnesses by means of the increase of knowledge related with the health, the modification of the lifestyles and the physical training. The application of this program in North Ameri- can scholars had the decrease of the arterial pressure and the increase of the aerobic capacity of the individuals as a result, together with the important increase of the knowled- ge of health. In this work the results of the first application of the PATH Program in Spanish adolescents are evaluated. The appli- cation of the program diminished significantly arterial pres- sure. Furthermore, aerobic capacity of the scholars measure increased in a significant way in terms of VO 2 max. These results were accompanied of a very important increase in the knowledge of health. The results of this work suggest that the PATH Program is of great interest for the prevention of the cardiovascular illness, and its application in our school environment is fully viable (AU)