Effects of skin temperature on lesion size in fractional photothermolysis.

BACKGROUND AND OBJECTIVES: Fractional photothermolysis is a new concept in cutaneous re-modeling whereby laser-induced microscopic zones of thermal injury (MTZ-Microscopic Treatment Zones) are surrounded by normal, viable tissue. This unique thermal damage pattern allows re-epithelialization in less than 24 hours. To increase patient comfort level during the procedure of fractional photothermolysis, simultaneous skin cooling has been proposed and is now extensively used. The purpose of this in vitro study was to examine the influence of skin temperature on the diameter of the epidermal microthermal zone and the extent of thermal injury per unit area. The determination of the changes in these parameters that are due to skin temperature will allow the better control and understanding of fractional photothermolysis at different skin temperatures. MATERIALS AND METHODS: Fractional photothermolysis was performed with a 1,550 nm fiber laser (Fraxel SR Laser) with 10 mJ per pulse on full-thickness cadaver skin. The skin samples were brought prior to exposure to temperatures that ranged from 0 to 45 degrees C. The epidermis of the skin samples was separated by dispase treatment, stained for thermal damage by NBTC stain, and lesion diameter was assessed by a blinded investigator. RESULTS: The average MTZ diameter exhibits a positive, linear relationship with skin temperature (R(2) = 0.904, P < 0.0001). As the skin temperature increases from 0 to 45 degrees C. The MTZ diameter increases from 93 to 147 microm (58%), and the MTZ area from 6,870 to 17,050 microm(2) (148%). CONCLUSION: The skin temperature affects the size of epidermal MTZs during fractional photothermolysis and is an important variable factor. The use of simultaneous skin cooling increases patient comfort; however, as it also decreases MTZ size, it may interfere with treatment efficacy. The control of skin temperature is necessary to provide a consistent outcome and to be able to compare treatments.

S-adenosyl-L-methionine prevents 5-HT(1A) receptors up-regulation induced by acute imipramine in the frontal cortex of the rat.

S-adenosyl-L-methionine (SAM) has shown efficacy in speeding the onset of the antidepressant effect of imipramine in depressed patients. This effect may be related to their interactions at the serotonin(1A) (5-HT(1A)) receptors. Acute imipramine up-regulated the frontal cortex 5-HT(1A) receptors (B(max), 51.5 +/- 8.4 fmol/mg protein) vs. saline (B(max), 27.5 +/- 5.9 fmol/mg protein), and did not show antidepressant effect. Acute SAM and imipramine+SAM did not modify frontal cortex 5-HT(1A) receptors, and showed antidepressant effects (decrease of the immobility response of 26%, P<0.01; and 47%, P<0.001) vs. saline. All the chronic treatments showed antidepressant effects and up-regulated the hippocampus 5-HT(1A) receptors. SAM prevents the 5-HT(1A) receptor up-regulation induced by acute imipramine in the frontal cortex. This mechanism may contribute to imipramine's antidepressant effect.

Modulación emocional de la respuesta de sobresalto / Emotional modulation of startle reflex

Se presentan los resultados sobre el reflejo parpebral de sobresalto evocado por un estímulo auditivo intenso y su modulación mediante la visualización de diapositivas afectivas. El objeto del estudio fue poner a prueba la adaptación española de la metodología y los instrumentos desarrollados por Lang y colaboradores en la Universidad de Florida y aportar datos que confirmaran o desconfirmaran su modelo de 'priming' motivacional. Se estudiaron a 78 estudiantes de 2° de Psicología de la Universidad de Málaga. Los resultados confirman que los sujetos universitarios estudiados modulan la amplitud de la respuesta de sobresalto en función de la valencia de las imágenes observadas, potenciándola ante las desagradables e inhibiéndolas antes las agradables. Estos resultados confieren validez a la adaptación española del paradigma del reflejo de sobresalto y al modelo teórico propuesto por Lang (AU)

We present the results on the startle-probe reflex evoked by an intense auditory stimulus and its modulation through affective slide visualization. The aim was to test the validity of the Spanish adaptation of the methodology and instruments developed by Lang and colleagues at Florida University and to confirm his model of motivational priming. 78 students in the second year of Psychology from Málaga University participated in the study. The results confirm that the university students modulated the magnitude of the startle-probe reflex according to the emotional valence of the image: it was largest when the subject was viewing unpleasant slides and smallest when viewing pleasant ones. These results confer validity on the Spanish adaptation of the startle-probe reflex paradigm and Lang’s theoretical model (AU)