Modelo transcontextual de la motivación en la predicción de estilos de vida saludables / Transcontextual Model of Motivation in the Preaching of Healthy Lifestyles

El presente trabajo examinó la aplicación del Modelo Transcontextual de la Motivación en la predicción de estilos de vida saludables de atletas veteranos. Se utilizó una muestra de 682 atletas veteranos portugueses de ambos géneros, de edades comprendidas entre los 30 y los 76 años (M=43.64; DT=8.25), dónde a través de cuestionarios se ha medido: la satisfacción de las necesidades psicológicas básicas, la motivación, las variables del comportamiento planeado y los estilos de vida saludables. De las conclusiones alcanzadas en este trabajo, son de destacar la relevancia de fomentar la necesidad psicológica básica de relación social, ya que ésta favorecerá la motivación intrínseca, promoviendo un mayor control del comportamiento sobre las intenciones de los practicantes, generando así mejores hábitos alimenticios, hábitos de descanso y menor consumo de tabaco

The present paper has examined the application of the Transcontextual Model of motivation in the prediction of healthy lifestyles of veteran athletes. A sample of 682 Portuguese veteran athletes of both sexes, aged between 30 and 76 years (M = 43.64; SD = 8.25), were administered the following questionnaires: satisfaction of needs basic psychological, self-determination motivation, planned behavioral variables and healthy lifestyles. From the conclusions reached in this work, it is important to emphasize the importance of fostering the basic psychological need of relatedness, since this will favor the intrinsic motivation, promoting greater control of behavior over the intentions of practitioners, thus generating more healthy eating habits, rest habits and lower tobacco consumption

Validación del cuestionario del modelo transteórico del cambio de ejercicio físico / Validation of the questionnaire of the transtheoretical model of change of physical exercice

El objetivo de este estudio fue traducir y validar al español el Cuestionario del Modelo Transteórico del Cambio de Ejercicio Físico de Prochaska y DiClemente (1983). Se utilizó una muestra de 812 personas, entre los 14 y los 88 años (29,5±21,7). Se realizó un análisis factorial confirmatorio, análisis de consistencia interna y validez predictiva. Los resultados del Cuestionario del Modelo Transteórico del Cambio de Ejercicio Físico presentaron valores adecuados (χ2/g.l = 4,3, CFI = 0,92, IFI = 0,92, TLI = 0,90, RMSEA = 0,06, SRMR = 0,05). La consistencia interna mostró valores encima de .70. Se halló una predicción positiva y significativa de los estadios más activos del Modelo Transteórico sobre la intención de ser físicamente activo. Este estudio ha permitido proporcionar un cuestionario válido y fiable para evaluar el estadio en el que se encuentran las personas con respecto a la práctica de ejercicio físico, en el ámbito español

The aim of this study was to translate and validate in Spanish the Questionnaire of the Transtheoretical Model of Change of Physical Exercise, of Prochaska and DiClemente (1983), and also to make adaptations and modifications as needed. The sample was composed of 812 people, aged between 14 and 88 years (29.5+21.7). Confirmative factorial analysis, analysis of internal consistency and of predictive validity were carried out. After the confirmative factorial analysis, the Questionnaire of the Theoretical Model of Change of Physical Exercise showed acceptable results (x2/g.1=4,3, CFI=0,92, IFI= 0.92, TLI = 0.90, RMSEA = 0.06, SRMR = 0,05). Similarly, internal consistency obtained from the respective dimensions showed values above .70. A positive and significant prediction of the most active stages of the Transtheoretical Model (action and maintenance) was found on the 'intention to be physically active'. This study has enabled the provision of a valid and reliable questionnaire

Implicancias del marco legal chileno en la prevención del embarazo adolescente: conflicto e inseguridad en los profesionales de la salud / Implications of chilean legal framework in teen pregnancy prevention: conflict and insecurity in health professionals

Background: Teenage pregnancy is a psychosocial and multifactorial problem described as a lack of exercise of rights in sexual and reproductive health. There are important aspects in the doctor-patient relationship and confidentiality that directly affect the continuity and quality of care. There are controversies in the laws relating to the provision of contraception and confidentiality, and those that protect the sexual indemnity, especially in adolescents under 14 years. Aim: To describe the implications of the legal framework for professional midwives in the care of adolescents younger than 14 years in sexual and reproductive health. Material and Methods: In-depth interviews were conducted to 13 female and 2 male midwives working at Primary Health Care Centers in the Metropolitan Region. Results: The attention of adolescents younger than 14 years in sexual and reproductive health involves medical-legal issues for health professionals. All professionals recognize that mandatory reporting sexual activity is a complex situation. All professionals notify pregnancies. In relation to the delivery of contraception, clinical care is problematic since professionals should take shelter from a legal standpoint. Conclusions: The medical-legal context of pregnant women under 14 years of age care generates a context of uncertainty and fear for professionals and becomes a source of conflict and insecurity in the exercise of the profession.

Dopamine cross-sensitization between psychostimulant drugs and stress in healthy male volunteers.

Dysregulation of the stress response system is a potential etiological factor in the development of and relapse to multiple neuropsychiatric disorders. Previously we reported that repeated intermittent d-amphetamine administration can lead to progressively greater dopamine release, thereby providing evidence of drug-induced neurochemical sensitization. Here, we test the hypothesis that repeated exposure to d-amphetamine increases dopaminergic responses to stress; that is, produces cross-sensitization. Using positron emission tomography, we measured in 17 healthy male volunteers (mean ± s.d. = 22.1 ± 3.4 years) [(11)C]raclopride binding responses to a validated psychosocial stress task before and 2 weeks after a regimen of repeated d-amphetamine (3 × 0.3 mg kg(-1), by mouth; n = 8) or placebo (3 × lactose, by mouth; n = 9). Mood and physiological measurements were recorded throughout each session. Before the d-amphetamine regimen, exposure to the stress task increased behavioral and physiological indices of stress (anxiety, heart rate, cortisol, all P ⩽ 0.05). Following the d-amphetamine regimen, the stress-induced cortisol responses were augmented (P < 0.04), and voxel-based analyses showed larger stress-induced decreases in [(11)C]raclopride non-displaceable binding potential across the striatum. In the placebo group, re-exposure to stress led to smaller clusters of decreased [(11)C]raclopride binding, primarily in the sensorimotor striatum (P < 0.05). Together, this study provides evidence for drug × stress cross-sensitization; moreover, random exposure to stimulants and/or stress cumulatively, while enhancing dopamine release in striatal areas, may contribute to a lowered set point for psychopathologies in which altered dopamine neurotransmission is invoked.

[Implications of chilean legal framework in teen pregnancy prevention: conflict and insecurity in health professionals]. / Implicancias del marco legal chileno en la prevención del embarazo adolescente: conflicto e inseguridad en los profesionales de la salud.

BACKGROUND: Teenage pregnancy is a psychosocial and multifactorial problem described as a lack of exercise of rights in sexual and reproductive health. There are important aspects in the doctor-patient relationship and confidentiality that directly affect the continuity and quality of care. There are controversies in the laws relating to the provision of contraception and confidentiality, and those that protect the sexual indemnity, especially in adolescents under 14 years. AIM: To describe the implications of the legal framework for professional midwives in the care of adolescents younger than 14 years in sexual and reproductive health. MATERIAL AND METHODS: In-depth interviews were conducted to 13 female and 2 male midwives working at Primary Health Care Centers in the Metropolitan Region. RESULTS: The attention of adolescents younger than 14 years in sexual and reproductive health involves medical-legal issues for health professionals. All professionals recognize that mandatory reporting sexual activity is a complex situation. All professionals notify pregnancies. In relation to the delivery of contraception, clinical care is problematic since professionals should take shelter from a legal standpoint. CONCLUSIONS: The medical-legal context of pregnant women under 14 years of age care generates a context of uncertainty and fear for professionals and becomes a source of conflict and insecurity in the exercise of the profession.

Variables motivacionales predictoras de las barreras para la práctica de ejercicio físico en adolescents / Variáveis motivacionais preditoras das barreiras para a prática de exercício físico em adolescentes / Predictors of barriers to physical exercise in adolescents motivational variables

En el presente trabajo se realizó una predicción de las barreras para la práctica de ejercicio físico en 356 adolescentes, con edades comprendidas entre los 11 y los 17 años (M = 13,56; DT = 1,39), empleando como marco teórico el modelo jerárquico de la motivación de Vallerand, para ello, a través de cuestionarios se midió: la percepción del clima motivacional que implica a la tarea de los padres, la creencia incremental de habilidad, la necesidad de competencia, la motivación intrínseca y las barreras para la práctica de ejercicio físico. El modelo de ecuaciones estructurales mostró que la percepción del clima motivacional que implica a la tarea de los padres predecía positivamente la creencia incremental, ésta a su vez, predecía de forma positiva la necesidad de competencia, dicho mediador predijo positivamente la motivación intrínseca, y por último, la motivación más autodeterminada predecía de forma negativa las barreras para la práctica de ejercicio físico. De los hallazgos de este trabajo destacar la relevancia de fomentar la necesidad psicológica básica de competencia para reducir el número de barreras percibidas por los sujetos a la hora de realizar ejercicio físico, y en consecuencia evitar el abandono de la práctica físico-deportiva de los adolescentes (AU)

In this work we were done a prediction of barriers to physical exercise in 356 adolescents, aged between 11 and 17 years (M = 13,56; DT = 1,39), using it as a theoretical framework of the hierarchical model of motivation Vallerand for this, through questionnaires was measured: the perceived motivational climate involving the task of the parents, the incremental ability belief, the need for competence, intrinsic motivation and barriers to physical exercise. The structural equation modeling showed that the perceived motivational climate involving the task of the parents positively predicted incremental belief, this in turn positively predicted the need for competition, said mediator positively predicted intrinsic motivation and finally, the most self-determined motivation negatively predicted barriers to physical exercise. From the findings of this study highlight the importance of improve basic psychological need of competence to reduce the number of barriers perceived by the subjects at the time of physical exercise, and thus avoid the abandonment of the practice of physical and sporting teenagers (AU)

No presente trabalho realizou-se uma predição das barreiras para a prática de exercício físico em 356 adolescentes, com idades compreendidas entre os 11 e os 17 anos (M = 13,56; DP = 1,39), empregando como marco teórico o modelo hierárquico da motivação de Vallerand, onde através de questionários se mediu: a perceção do clima motivacional que implica à tarefa dos pais, a crença incremental de habilidade, a necessidade de competência, a motivação intrínseca e as barreiras para a prática de exercício físico. O modelo de equações estruturais mostrou que a perceção do clima motivacional que implica à tarefa dos pais predizia positivamente a crença incremental, esta por sua vez, predizia de forma positiva a necessidade de competência, onde tal mediador prediz positivamente a motivação intrínseca e, por último, a motivação mais auto-determinada predizia de forma negativa as barreiras para a prática de exercício físico. Das conclusões alcançadas neste trabalho, são de destacar a relevância de fomentar a necessidade psicológica básica da competência para reduzir o número de barreiras percebidas pelos sujeitos no momento de praticar exercício físico e, como consequência, evitar o abandono da prática físico-desportiva dos adolescentes (AU)

Limbic system mGluR5 availability in cocaine dependent subjects: a high-resolution PET [(11)C]ABP688 study.

Cocaine self-administration decreases type 5 metabotropic glutamate receptor (mGluR5) tissue concentrations in laboratory rats during early abstinence. These changes are thought to influence the drug's reinforcing properties and the ability of drug-related cues to induce relapse. Here, our goal was to measure brain regional mGluR5 availability in recently abstinent cocaine dependent humans. Participants meeting DSM-IV diagnostic criteria for current cocaine dependence (n=9) were recruited from the general population. mGluR5 availability (binding potential, non-displaceable; BPND) was measured with high-resolution positron emission tomography (PET HRRT) and [(11)C]ABP688. Compared to age- and sex-matched healthy controls (n=9), cocaine dependent subjects showed significantly lower BPND values in the ventral (bilateral: -28.2%, p=0.011), associative (right: -21.4%, p=0.043), and sensorimotor striatum (bilateral: -21.7%, p=0.045), amygdala (left: -26%, p=0.046) and insula (right: -23.3%, p=0.041). Among the cocaine users, receptor availabilities were related to abstinence (range: 2 to 14days). The longer the duration of abstinence, the lower the BPND values in the sensorimotor striatum (r=-0.71, p=0.034), left amygdala (r=-0.73, p=0.026) and right insula (r=-0.67, p=0.046). Compared to healthy controls, BPND values were significantly reduced in those who tested negative for cocaine on the PET test session in the ventral (p=0.018) and sensorimotor striatum (p=0.017), left amygdala (p=0.008), and right insula (p=0.029), but not in those who tested positive. Together, these results provide evidence of time-related mGluR5 alterations in striatal and limbic regions in humans during early cocaine abstinence.

Deterioro del reflejo acústico en pacientes con diabetes mellitus tipo I / Acoustics reflex decay in patients with type 1 diabetes mellitus

Introducción: Diversas investigaciones tratan de explicar la asociación entre Diabetes Mellitus (DM) y alteraciones auditivas, relacionándola con el tiempo de evolución, control metabólico, entre otros, encontrando variados resultados. El parámetro menos investigado es el deterioro del reflejo acústico (ARD). Objetivo: Caracterizar el ARD en pacientes con DM tipo 1. Asimismo, relacionar el ARD con el tiempo de evolución de la enfermedad, el grado de control metabólico y la edad. Material y método: Estudio transversal de tipo descriptivo correlacional Se evaluaron 92 oídos en 500 Hz y 99 oídos en 1.000 Hz, con edades entre 4y 68 años, de ambos géneros, con un tiempo de evolución de la enfermedad entre un mes y 44 años. Se realizó un análisis frecuencial del ARD y estadística no paramétrica mediante el coeficiente Rho de Spearman. Resultados: En ambas frecuencias la mayoría no presenta ARD, mientras que 2,2% en 500 Hz y 3,0% en 1.000 Hz presenta ARD patológico. No existiendo correlación entre el ARD con tiempo de evolución de la enfermedad, el grado de control metabólico y la edad de los sujetos. Conclusión: Existe un bajo porcentaje de ARD patológico y una ausencia de correlación con características propias de la enfermedad coincidiendo con otras investigaciones que han utilizado otras herramientas evaluativas.

Introduction: Various studies try to explain the association between diabetes mellitus (DM) and impaired hearing, relating it to the time of evolution, metabolic control, among others, finding mixed results. The parameter under investigation is the acoustic reflex decay (ARD). Aim: To characterize the ARD in patients with type 1 DM. Also relate the ARD with time of evolution of the disease, metabolic control and age. Material and method: Cross-sectional descriptive correlational study. 92 ears were evaluated in 50 0Hz and 99 ears in 1000 Hz, with ages between 4 and 68 years, of both genders, with a time of evolution of the disease from one month to 44 years. Frequency analysis of the ARD were performed and nonparametric statistics by Spearman's Rho coefficient. Results: In both frequencies most ears do not have ARD, while 2.2% in 500 Hz and 3.0% in 1000 Hz showed ARD pathological features. No correlation exists between the ARD with time of evolution of the disease, metabolic control and age of subjects. Conclusion: There is a low percentage of ARD pathological and lack of correlation with disease characteristics, coinciding with other studies that have used differents assessment tools.

Perfil epidemiológico de adolescentes mujeres con antecedentes de agresión sexual consultantes en el área de salud mental de un centro de salud sexual y reproductiva / Characteristic of child sexual aggression in adolescent women admitted to the mental health unit of an adolescent sexual and reproductive health centre

Objetivo: conocer la frecuencia y describir las características de las agresiones sexuales infantiles en adolescentes mujeres ingresadas a la unidad de salud mental de un Centro de Salud Sexual y Reproductiva Adolescente. Método: estudio de diseño transversal y analítico, se revisaron las fichas clínicas entre enero de 2006 y diciembre de 2009. Las variables estudiadas fueron: edad de la agresión, tipo y frecuencia de ésta; sexo, edad y tipo de relación con el agresor; revelación y persona a la que se le informa de la agresión sexual y denuncia de la agresión. Resultados: la mayor frecuencia de agresión sexual se presenta en la edad pre-escolar (28,1 por ciento) y la más común es el abuso sexual (73,8 por ciento), tipo de agresión que es la más común en todas las edades. La mayoría de las agresiones fue un episodio único (59,3 por ciento). La totalidad de los agresores eran conocidos o familiares de la víctima, todos varones, el 29,1 por ciento eran menores de 18 años. El 36 por ciento nunca reveló la agresión sufrida. El 31,8 por ciento de las agresiones sin revelar ocurrieron en la edad pre-escolar. Sólo un 14,1 por ciento realizó denuncia. Conclusión: la mayoría de las agresiones sexuales ocurridas durante la infancia y adolescencia no son reveladas, ni denunciadas legalmente, manteniendo un alto nivel de silenciamiento y dificultades por parte de los equipos de salud para apoyar y tratar a las víctimas.

Objective: to describe the frequency and characteristic of child sexual aggression in adolescent women admitted to the Mental Health Unit of an Adolescent Sexual and Reproductive Health Centre. Method: this is a cross-sectional and analytical study, clinical records were reviewed the between january 2006 and december 2009. The variables studied were: age of aggression, type and frequency of this aggression, sex, age and type of relationship with the perpetrator; disclosure and person who is informed and judicial complaint of sexual aggression. Results: the highest frequency of sexual aggression occurs in the preschool age (28.1 percent) and the most common is sexual abuse (73.8 percent), type of aggression is the most common in all ages. Most of the attacks were a single episode (59.3 percent). All the attackers were males and acquaintances or relatives of victims, 29.1 percent were under 18 years old. 36 percent never disclosure the assault. The 31.8 percent of unveiled attacks occurred in preschool. Only 14.1 percent made a judicial complaint. Conclusion: the majority of sexual assaults that occurred during childhood and adolescence are unveiled, nor legally reported maintaining a high level of silencing and difficulties by health equipment to support and treat victims.

Tryptophan hydroxylase(2) gene polymorphisms predict brain serotonin synthesis in the orbitofrontal cortex in humans.

Brain regional serotonin synthesis can be estimated in vivo using positron emission tomography (PET) and α-[((11))C]methyl-L-tryptophan ((11)C-AMT) trapping (K*) as a proxy. Recently, we reported evidence of lower normalized (11)C-AMT trapping in the orbitofrontal cortex (OBFC) of subjects meeting the criteria for an impulsive and/or aggressive behavioral phenotype. In this study, we examined whether part of the variance in OBFC serotonin synthesis is related to polymorphisms of the gene that encodes for the indoleamine's rate-limiting enzyme in the brain, tryptophan hydroxylase-2 (TPH(2)). In all, 46 healthy controls had PET (11)C-AMT scans and were genotyped for 11 single-nucleotide polymorphisms (SNPs) distributed across the TPH(2) gene and its 5' upstream region. Several TPH(2) SNPs were associated with lower normalized blood-to-brain clearance of (11)C-AMT in the OBFC. Dose-effect relationships were found for two variants (rs6582071 and rs4641527, respectively, located in the 5' upstream region and intron 1) that have previously been associated with suicide. Associations in the OBFC remained statistically significant in a mixed larger sample of patients and controls. These results suggest that in humans, genetic factors might partly account for variations in serotonin synthesis in the OBFC.

Características y consecuencias de las agresiones sexuales en adolescentes consultantes en un centro de salud sexual y reproductiva / Characteristics of sexual assault and its consequences in adolescents at a sexual and reproductive health center

Antecedentes: La agresión sexual es un evento traumático y doloroso que afecta de manera transversal, a las víctimas de ambos sexos, de todos los niveles socioeconómicos con graves consecuencias para la salud física, psicológica y social para quienes la sufren. Objetivo: Determinar las características de las agresiones sexuales y sus consecuencias en adolescentes consultantes en un centro de atención en Salud Sexual y Reproductiva. Método: Estudio analítico de corte transversal de 573 adolescentes atendidas en un centro de medicina reproductiva (CEMERA) en el período 2003-2010 y que reportaron antecedente de abuso sexual. Se estudiaron tanto las características como las consecuencias del abuso, datos que se obtuvieron desde las fichas clínicas. Resultados: En el 86,5 por ciento de los casos se reportó abuso sexual y en un 13,5 por ciento violación. El 48,5 por ciento de los agresores son familiares. La edad más vulnerable fue entre 5-9 años con un 41,2 porciento. En el 39,2 por ciento el abuso sexual fue reiterado. En un 43,4 por ciento el lugar fue el propio hogar de la víctima. Un 70 por ciento reveló y de estos el 45,9 por ciento lo hizo en forma tardía. Sólo en un 19 por ciento se hizo la denuncia legal. De las adolescentes que iniciaron actividad sexual voluntaria (83,3 por ciento), un 35,4 por ciento tenía menos de 15 años. Un 11,8 por ciento reportó 3 y más parejas sexuales. Conclusión: El antecedente de abuso sexual debe ser considerado en la atención de adolescentes que consultan por salud sexual y reproductiva. El equipo de salud debe estar preparado para atender sus múltiples necesidades.

Background: Sexual assault is a traumatic and painful event, which affects victims of both genders, across all socioeconomic levels, with serious consequences for physical, psychological, and social health. Objective: Determine the characteristics of sexual assault and its consequences in adolescents at a sexual and reproductive health center. Method: Analytic and cross-sectional study of 573 adolescents seen at a reproductive medicine center (CEMERA) in the period 2003-2010 and who reported history of sexual abuse. Patient's clinical records were reviewed to study the characteristics as well as the consequences of sexual abuse. Results: The abuse was reported as sexual abuse in 86.5 percent of the cases and as rape in 13.5 percent. In 48.5 percent of the cases, the aggressors were relatives of the victims. The most vulnerable group is between 5-9 of age, representing 41.2 percent of the cases. For 39.2 percent of the cases, the sexual abuse was reiterative, and in 43.4 percent, the abuse took place on the victim's home. 70 percent of the victims told someone about the abuse; 45.9 percent of those revealed their abuse in a delay manner. Only 19 percent of victims filed a legal complaint. Of the adolescents who started voluntary sexual activity (83.3 percent) a 35.4 percent was under de age of 15, and 11,8 percent reported having 3 or more sexual partners. Conclusion: A history of sexual abuse must be considered in the attention of adolescents who consult for reproductive and sexual health. The health team must be prepared to address their multiple needs.

Pioderma gangrenoso de la mama: reporte de un caso y revisión de la literatura / Pyoderma gangrenosum of the breast: a case report and literature review

El pioderma gangrenoso es una rara enfermedad inflamatoria que se caracteriza por una necrosis dolorosa de la piel que no cuenta con un tratamiento gold standard. Generalmente se asocia a enfermedades sistémicas, pero también se puede presentar después de procedimientos quirúrgicos. El diagnóstico es por exclusión, por esta razón es importante el estudio de enfermedades sistémicas e infecciones de la piel. El pioderma gangrenoso de la mama es un fenómeno poco frecuente, sólo se han reportado algunos casos. A continuación presentamos un caso de pioderma gangrenoso de la mama post reducción mamaria.

Pyoderma gangrenosum is a rare inflammatory disease characterized by a painful skin necrosis, and does not have a gold standard treatment. Usually associated with systemic diseases, may occur after surgical procedures. Diagnosis is made by exclusion, therefore it is important to rule out systemic diseases and infections of the skin. Pyoderma gangrenosum of the breast is a rare phenomenon, only few cases have been reported. We present a case of pyoderma gangrenosum of the breast post breast reduction.

Comportamientos sexuales y diferencias de género en adolescentes usuarios de un sistema público de salud universitario / Sexual behavior and gender differencesamong adolescents consultingat a university public health system

Background: The predetermined gender roles and the emphasis on reproductive responsibility on women, excluding men, have negative consequences on their sexual reproductive health and satisfactory sexual practices. Aim: To describe and analyze changes in sexual practices and gender differences in adolescents of the lower-middle socioeconomic level, users of public health system who started their sexual activity. Material and methods: We studied 4,971 adolescents of both sexes aged between 12 and 19 years, who consulted in a clinic for adolescents between the years 1990 and 2005. Several variables related to adolescent sexuality were considered. Uni and bivariate analysis were carried out and a model of stratified lineal regression per sex was fixed to explain the following variables: age at which sexual activity is initiated, number of sexual partners, time period between start of dating and the start of sexual activity along time. Results: The average age when men and women start their sexual activity was 15.7 and 15.5years, respectively. Along years and among women but not men, there was a reduction in the age of start of sexual activity and an increase in the number of sexual partners. The mean íapse between start of dating and the start of sexual activity in men and women was 6.2 and 7.5 months, respectively. This figure had an 11.696 and 13.9 percent reduction per year of study in females and males, respectively. Conclusions: There is an increasing expansion of sexual roles in adolescents, but certain patterns of contradictory conservative reasoning are maintained.

Acute prefrontal cortex TMS in healthy volunteers: effects on brain 11C-alphaMtrp trapping.

High-frequency repetitive transcranial magnetic stimulation (rTMS) of the left dorsolateral prefrontal cortex (LDLPFC) is a technique with purported efficacy as a treatment for major depression. Here, we assessed in vivo, in healthy volunteers, the effect of acute rTMS of the LDLPFC, relative to the stimulation of the left occipital cortex (LOC), on brain regional serotonin synthesis capacity, using the [(11)C]-alpha-methyl-tryptophan ((11)C-alphaMtrp)/PET method. Ten subjects were studied twice, once following rTMS of the LDLPFC and once following rTMS of the LOC in a randomized counterbalanced order. Three blocks of 15 trains of 10 Hz rTMS were delivered 10 min apart. Behavioural and autonomic measures were recorded before and after each rTMS session. Comparisons of TMS-related changes in regional normalized brain uptake and trapping of (11)C-alphaMtrp (K*) values were carried out using SPM99. Statistically significant regional differences were identified on the basis of an extent threshold of 50 voxels, with a peak threshold of p=0.005 uncorrected. Behavioural and autonomic measures were unaffected by rTMS. Relative to LOC stimulation, LDLPFC rTMS was associated with marked changes in normalized K* in limbic areas, with significantly lower values in the left parahippocampal gyrus (BA 28) and the right insula (BA 13), and higher values in the right cingulate gyrus (BA 31) and cuneus (BA 18). These findings indicate that acute rTMS of the LDLPFC in healthy volunteers modulates aspects of tryptophan/5-HT metabolism in limbic areas. Such adaptive changes may contribute to the mechanism of action of prefrontal rTMS in major depression.

[Sexual behavior and gender differences among adolescents consulting at a university public health system]. / Comportamientos sexuales y diferencias de género en adolescentes usuarios de un sistema público de salud universitario.

BACKGROUND: The predetermined gender roles and the emphasis on reproductive responsibility on women, excluding men, have negative consequences on their sexual reproductive health and satisfactory sexual practices. AIM: To describe and analyze changes in sexual practices and gender differences in adolescents of the lower-middle socioeconomic level, users of public health system who started their sexual activity. MATERIAL AND METHODS: We studied 4,971 adolescents of both sexes aged between 12 and 19 years, who consulted in a clinic for adolescents between the years 1990 and 2005. Several variables related to adolescent sexuality were considered. Uni and bivariate analysis were carried out and a model of stratified lineal regression per sex was fixed to explain the following variables: age at which sexual activity is initiated, number of sexual partners, time period between start of dating and the start of sexual activity along time. RESULTS: The average age when men and women start their sexual activity was 15.7 and 15.5 years, respectively. Along years and among women but not men, there was a reduction in the age of start of sexual activity and an increase in the number of sexual partners. The mean lapse between start of dating and the start of sexual activity in men and women was 6.2 and 7.5 months, respectively. This figure had an 11.696 and 13.9% reduction per year of study in females and males, respectively. CONCLUSIONS: There is an increasing expansion of sexual roles in adolescents, but certain patterns of contradictory conservative reasoning are maintained.

Cortical trapping of alpha-[(11)C]methyl-l-tryptophan, an index of serotonin synthesis, is lower in females than males.

One neural system that may exhibit gender differences is serotonin (5-HT), a neurotransmitter implicated in the regulation of mood, cognitive processes, and impulse-control. However, most of the available evidence of gender-related differences in this system has been indirect and at times contradictory. The objective of the present study was to follow up on preliminary evidence that there are gender differences in brain regional 5-HT synthesis, as measured by trapping of alpha-[(11)C]methyl-l-tryptophan (alpha-[(11)C]MTrp). Sixty-minute dynamic scans were performed in healthy volunteers, 28 women and 31 men. Functional images of the brain trapping constant, used as a proxy for 5-HT synthesis, which correlate in the rat brain with tryptophan's conversion into 5-HT, were transferred to the standardized 3D space. The voxel based comparison was performed by Statistical Parametric Mapping with proportional normalization. There was lower normalized alpha-[(11)C]MTrp trapping in females than males throughout much of the cerebral cortex, including the left middle frontal gyrus, the bilateral inferior frontal gyrus, the bilateral precentral gyrus, the left supramarginal gyrus, the bilateral inferior parietal lobule, the left superior temporal gyrus, the bilateral posterior cingulate gyrus, and the bilateral precuneus. There were no regions in which the normalized trapping was significantly higher in females than in males. Gender differences in sub-cortical sites were not found. Women, compared to men, may have lower rates of this tracer trapping, used as a proxy for 5-HT synthesis, throughout much of the cerebral cortex which is likely related to differences in 5-HT synthesis because relative differences in the normalized trapping should be the same as those in 5-HT synthesis. These differences may be related, at least in part, to previously suggested gender differences in affect, cognitive processes, and susceptibility to 5-HT-related neuropsychiatric and neurological disorders.

Uso del preservativo en adolescentes nuligestas con uso de anticonconceptivos hormonales / Condom use by in nulliparous adolescent using the hormonal contraceptive method

El propósito del presente estudio es explorar las frecuencias del uso del condón en adolescentes usuarias regulares de un método anticonceptivo, como también conocer las razones de no uso del condón en aquellas que no lo usan. Se incluyó una muestra intencionada de adolescentes varones para conocer diferencias de género. Metodología, estudio exploratorio descriptivo de corte transversal. Se selecciono una muestra de adolescentes usuarias de anticonceptivos consultantes en CEMERA entre el 4 y 30 de Julio del año 2004. La recolección de la información se realizó a través de una encuesta auto administrada a 205 adolescentes. Las variables estudiadas fueron edad, sexo, frecuencia y razones de uso y no uso del condón. La información fue ingresada a una planilla Excel, y se realizó análisis uni y bi variado, a través del programa STATA 8.0. Resultados, un 82,4 por ciento de la muestra corresponde a mujeres y un 17,6 por ciento a hombres. El 52,4 por ciento corresponde a adolescentes entre 16 y 17 años. Un 49,7 por ciento no ocupó nunca el condón durante el último mes y sólo un 7,3 por ciento lo ocupó siempre en sus relaciones sexuales. Las razones de no uso del condón fueron en un 25,8 por ciento por estar utilizando un método anticonceptivo, un 17,5 por ciento por tener pareja única, un 16,4 por ciento por que no le gusta, un 14,4 por ciento por incomodidad. Al analizar las variables por edad y sexo, no se apreciaron diferencias estadísticamente significativas. Se concluye que si bien el uso del condón ha ido aumentando en la población adolescente, aún sigue ligado a la prevención de embarazo y no a la prevención de Infecciones de Transmisión Sexual y que el presente estudio no presenta diferencias de género en los resultados.

The intention of the present study is to explore the frequencies of the use of condom in regular usuary adolescents of a contraceptive method, as also to know the reasons for non use of condom in which they do not use it. A deliberate sample of adolescent men was included to know differences sort. Methodology, descriptive exploratory study of cross section. I select a sample of usuary adolescents of consultants contraceptives in CEMERA between 4 and 30 of Julio of year 2004. The harvesting of the information was made through a survey administered to 205 adolescents. The studied variables were age, sex, frequency and reasons of use and nonuse of condom. The information was entered a list Excel, and analysis was made uni and bi varied, through program STATA 8.0. Results, a 82.4 percent of the sample correspond to women and a 17.6 percent to men. 52.4 percent correspond to adolescents between 16 and 17 years. A 49.7 percent never occupied condom during the last month and only a 7.3 percent always occupied it in their sexual relations. The reasons of use of condom were not in a 25.8 percent to be using a contraceptive method, a 17.5 percent to have unique pair, a 16.4 percent so that it does not like, a 14.4 percent by uncomfortable. When analyzing the variables by age and sex, were not appraised statistically significant differences. One concludes that although the use of condom has been increasing in the adolescent population, still follows bound to the prevention of pregnancy and not the prevention of Infections of Sexual Transmission and that the present study does not present/display differences of sort in the results.

Increasing blood oxygen increases an index of 5-HT synthesis in human brain as measured using alpha-[(11)C]methyl-L-tryptophan and positron emission tomography.

The main objective of this investigation was to test the hypothesis that brain serotonin (5-HT) synthesis, as measured by trapping of alpha-[(11)C]methyl-L-tryptophan (alpha-MTrp) using positron emission tomography (PET), can be modulated by changes in blood oxygen. The study involved six healthy participants (three male and three female), who breathed a 15% or 60% oxygen mixture starting 15 min before the injection of tracer and continuing during the entire acquisition period. Participants were injected with up to 12m Ci of alpha-MTrp. Two sets of PET images were acquired while the participants were breathing each of the oxygen mixtures and, after reconstruction, all images were converted into brain functional images illustrating the brain trapping constant K(*) (microL/g/min). The K(*) values were obtained for 12 regions of interest outlined on the magnetic resonance images. The K(*) values obtained at high and low blood oxygen content were compared by paired statistics using Tukey's post hoc correction. As there were no difference in plasma tryptophan concentrations, these K(*) values are directly related to regional 5-HT synthesis. The results showed highly significant increases (50% on average) in brain serotonin synthesis (K(*) values) at high (mean value of 223+/-41 mmHg) relative to low (mean value 77.1+/-7.7 mmHg) blood oxygen levels. This suggests that tryptophan hydroxylase is not saturated with oxygen in the living human brain and that increases in blood oxygen can elevate brain serotonin synthesis.