Nutrient effects on working memory across the adult lifespan.

OBJECTIVE: To identify the nutrients that influence the performance of working memory, which is greatly affected as age progresses. METHOD: A total of 1646 healthy adults between 21 and 80 years old participated in the study. The daily consumption of 64 nutrients was examined using a food frequency questionnaire that assessed food intake during the previous year. Working memory was measured in the verbal and spatial domains using a computerized task. We examined which nutrients influence working memory across the entire adult lifespan and whether the influence of any of these nutrients on working memory is moderated by individuals' ages. RESULTS: Working memory, across the entire adult lifespan, benefits from the intake of cholesterol, alcohol, gamma- and delta-tocopherol, vitamin B6, and palmitoleic, oleic, alpha linoleic and linoleic acids. Moderator analyses revealed that fats, energy, lactose and sodium negatively influenced working memory in middle-aged and older adults, whereas vitamin D and vitamin C had positive effects on memory beyond 70 years of age. CONCLUSION: Nutrients have the ability to positively or negatively affect working memory, which varies as a function of age.

Metamemory Mediates the Effects of Age on Episodic and Working Memory across the Adult Lifespan.

BACKGROUND: Previous studies have examined the direct relationship between metamemory and memory performance in young and older adults, but the results of these studies have been inconsistent. Therefore, we examined whether metamemory mediates the effects of age on memory performance. METHODS: We examined episodic memory and working memory through computerized tasks performed by a lifespan sample of 1554 healthy adults. Seven metamemory traits were measured with the Metamemory in Adulthood (MIA) questionnaire. Separate structural equation modeling analyses were conducted to investigate potential metamemory mediators that intervened between age and the accuracy and speed of accessing information from episodic and working memory. RESULTS: The use of internal or external strategies mediated the effects of age on episodic memory and spatial working memory performance. The perception of one's own memory capacity and the experience of anxiety when using memory functions mediated the effects of age on working memory performance in both domains. CONCLUSIONS: Metamemory traits have the power to strengthen or weaken the course of episodic and working memory decline throughout adulthood.

Effects of hypotension and hypertension on source memory and working memory.

OBJECTIVES: The effects of chronic low and high blood pressure on memory are unclear due to divergent results, originating in part due to participant misclassifications. The aim of this study was to compare source memory and working memory performance in individuals diagnosed with hypotension or hypertension with the performance of normotensive participants. Hypertensive and hypotensive individuals were receiving medical treatment. METHOD: From a sample of 1656 participants, 219 were identified as hypertensive, and 37 were identified as hypotensive. Each of these two groups was compared with normotensive individuals matched by age, education and sex. Source memory performance and working memory performance were assessed through computerized tasks. RESULTS: Source memory accuracy was poorer in hypotensive and hypertensive individuals than in normotensive individuals, and spatial working memory discrimination was inferior in hypertensive participants compared to normotensive individuals. CONCLUSION: Blood pressure impairment should be considered a major concern because it has been linked to severe cardiovascular and cerebrovascular diseases. Furthermore, here we show that it has negative effects on the two types of memory that are most essential for preserving a self-sufficient lifestyle.

Influence of Dietary Nutrient Intake on Episodic Memory Across the Adult Life Span.

The aim of the study was to identify nutrients that have the ability to impact brain functioning and, as a consequence, influence episodic memory. In particular, we examined recollection, the ability to recall details of previous experiences, which is the episodic memory process most affected as age advances. A sample of 1,550 healthy participants between 21 and 80 years old participated in the study. Nutritional intake was examined through a food frequency questionnaire and software developed to determine the daily consumption of 64 nutrients based on food intake during the last year. Recollection was measured through a computerized source memory paradigm. First, we identified which nutrients influence recollection across the entire adult life span. Then, moderator analyses were conducted by dividing the sample into young (21-40 years old), middle-aged (41-60 years old) and older (61-80 years old) adults to establish in which life stage nutrients influence episodic memory. Across the adult life span, recollection accuracy was shown to benefit from the intake of sodium, heme, vitamin E, niacin, vitamin B6, cholesterol, alcohol, fat, protein, and palmitic, stearic, palmitoleic, oleic, gadoleic, alpha-linoleic and linoleic acid. The effects of energy, maltose, lactose, calcium and several saturated fatty acids on recollection were modulated by age; in older adults, the consumption of these nutrients negatively influenced episodic memory performance, and in middle-aged adults, only lactose had negative effects. Several brain mechanisms that support episodic memory were influenced by specific nutrients, demonstrating the ability of food to enhance or deteriorate episodic memory.

Microglial synaptic pruning on axon initial segment spines of dentate granule cells: Sexually dimorphic effects of early-life stress and consequences for adult fear response.

Axon initial segments (AIS) of dentate granule cells in the hippocampus exhibit prominent spines (AISS) during early development that are associated with microglial contacts. In the present study, we investigated whether developmental changes in AISS could be modified by early-life stress (ELS), specifically neonatal maternal separation (MS), through stress hormones and microglial activation and examined the potential behavioural consequences. We examined AISS at postnatal day (PND)5, 15 and 50, using Golgi-Cox staining and anatomical analysis. Neurone-microglial interaction was assessed using antibodies against ankyrin-G, PSD-95 and Iba1, for AIS, AISS and microglia visualisation, respectively, in normally reared and neonatal maternally separated male and female rats. We observed a higher density of AISS in ELS rats at both PND15 and PND50 compared to controls. Effects were more pronounced in females than males. AIS-associated microglia in ELS rats showed a hyper-ramified morphology and less co-localisation with PSD-95 compared to controls at PND15. ELS-associated alteration in microglial morphology and synaptic pruning was mimicked by treatment of acute hippocampal slices of normally reared rats with vasopressin. ELS rats exhibited increased freezing behaviour during auditory fear memory testing, which was more pronounced in female subjects and corresponded with increased Fos expression in dorsal and ventral dentate granule cells. Thus, microglial synaptic pruning in dentate AIS of hippocampus is influenced by ELS, with demonstrable sex bias regarding its anatomical characteristics and subsequent fear-induced defensive behaviours.

Predictors of Working Memory Maintenance and Decline in Older Adults.

The aging process is associated with the gradual decline of several cognitive functions, and working memory is particularly affected. Although the majority of older adults experience a deterioration of their working memory, some individuals maintain their working memory in older age, and some suffer an extreme deterioration of their working memory. The purpose of the present study was to identify, among a total of 120 potential predictors, those that significantly contributed to these two extreme outcomes in working memory. A sample of 588 healthy adults was examined with the n-back task in the spatial and verbal domains using a 2-back level of difficulty. Individuals were classified as working memory maintainers or decliners if their discrimination level in the two domains was superior to the 80th percentile or inferior to the 20th percentile, respectively. Logistic regression identified eight and six significant predictors of working memory maintenance and decline, respectively. High vocabulary scores and smoking more were significant predictors of working memory maintenance; however, in the opposite direction, these same variables predicted working memory decline. Several consumption habits that influenced cerebrovascular function were found in both models. Psychological traits and everyday activities were present in both models. We identified specific predictors that contribute to extremely high or low working memory performance in older age.

Contributions of Cognitive Aging Models to the Explanation of Source Memory Decline across the Adult Lifespan.

Background: A number of cognitive aging models have been proposed to explain the age-related decline in several cognitive functions, but these models have rarely been examined together. We analyzed the contributions of four main models - processing resources, speed of processing, cognitive reserve and knowledge - to source memory decay related to the aging process.Methods: A total of 1554 healthy adults between 21 and 80 years old participated in the study. Structural equation modeling was conducted on data from the whole sample and separately in the data from young, middle-aged and older adult age groups. To estimate each cognitive model, we measured working memory discrimination levels (processing resources), working memory reaction times (speed of processing), education (cognitive reserve) and vocabulary (knowledge).Results: Processing resources mediate the effects of age on source memory across the adult lifespan, whereas speed of processing mediates these effects only in young adults, cognitive reserve only in middle-aged adults and knowledge only in older adults.Conclusions: Processing resources was the cognitive model that most contributes to explaining source memory decay. The fact that the other models are relevant to specific age groups provides useful information to exploit their benefits to preserve source memory in specific life stages.

Predictors of Source Memory Success and Failure in Older Adults.

Source memory decline has been identified as one of the types of memory most seriously affected during older age. It refers to our capacity to recollect the contextual information in which our experiences take place. Although most elderly adults will be affected by progressive source memory decline, a subset of individuals will not follow this average pattern; instead, their source memory capabilities will remain functional. Likewise, a minority of individuals will manifest an extreme decay of their source memory abilities. The objective of the present study was to identify among 120 potential predictors that significantly contributed to these two extreme source memory outcomes. Spatial source memory was measured in a sample of 519 healthy individuals between 61 and 80 years old. Individuals who performed below the 20th and above the 80th percentiles in the source memory task were defined as individuals whose episodic memory failed and succeeded, respectively. Logistic models identified five and six significant predictors of source memory success and failure in older age, respectively. High source memory performance was mainly predicted by healthy cardiovascular markers and psychological traits, whereas low source memory performance was primarily predicted by consumption habits and by less engagement in mental activities. The models identified relevant biological and life experiences that underlie these unusual source memory outcomes in older age.

Multidimensional Patterns of Sexual Risk Behavior and Psychiatric Disorders in Men with Substance Use Disorders.

Previous evidence links substance use disorders (SUD) to STI/HIV risk and suggests that comorbid psychiatric disorders increase the probability to engage in sexual risk behaviors. This study had two aims: (1) to identify subgroups based on sexual risk behavior using a person-centered approach in a sample of substance users and (2) to measure the association of psychiatric and SUD with subgroup membership. We assessed 402 male adults with SUD, reporting sexual intercourse in the previous 12 months using the HIV-Risk Behavior Scale and the Mini International Neuropsychiatric Interview. Latent class analysis was performed to determine multidimensional patterns of sexual risk behaviors and multinomial logistic regression was utilized to associate classes with disorders. The three-class model showed the best fit, and the classes were labeled: Relationship-Based (31.34% of the sample), Condom-Based (39.55%), and Multiple Risks (29.10%). Controlling for age and marital status, major depressive disorders, antisocial personality disorder, and any psychiatric disorder were associated with the Multiple Risks class. Results stress the importance of developing a personalized assessment and counseling for sexual risk behaviors in individuals with SUD, particularly when they endorse criteria for comorbid psychiatric disorders. Future studies should focus on evaluating differential response to preventive interventions.

Presence of unreported carcinogens, Aflatoxins and their hydroxylated metabolites, in industrialized Oaxaca cheese from Mexico City.

Aflatoxins (AFs) are toxic secondary metabolites of the fungi Aspergillus flavus, A. parasiticus and A. nomius. The fungi produce these AFs in cereals, oilseeds and spices. AFs have damaging effects on all organisms, including humans, and their symptoms can be classified as acute (vomiting, hemorrhage and death) or chronic (immunodepression, Reye syndrome, Kwashiorkor, teratogenesis, hepatitis, cirrhosis, and various cancers). Basic AFs (AFB1, AFB2, AFG1, and AFG2) are metabolized in the liver or by microbes that produce hydroxylated metabolites (AFM1, AFM2, and AFP1) and aflatoxicol (AFL), soluble in water and easy to dispose. Thus, AFs can be excreted in fluids, such as milk. AFs are not destroyed in the process of making cheese. The purpose of this study was to identify and quantify the AFs present in 30 samples of industrialized Oaxaca-type cheese sold in Mexico City. The average concentrations of AFs detected in the 30 samples of industrialized cheese were as follows: AFB1 (0.1 µg kg-1) in 20% (6/30); a trace amount of AFB2 (0.01 < LOD) in only 3% (1/30); AFG1 (0.14 µg kg-1) in 10% (3/30); AFG2 (0.6 µg kg-1) in 30% (9/30); AFM1 (1.7 µg kg-1) in 57% (17/30); AFP1 (0.03% µg kg-1) in 3% (1/30); and AFL (13.1 µg kg-1) in 97% (29/30). AFB1 and AFL were the most abundant aflatoxins in Oaxaca-type cheese. However, eight aflatoxins were present, contributing an average of 15.7 µg kg-1 AFs distributed among the 30 samples. The risk assessment analysis showed that there was no substantial risk for cancer due to AFs in industrialized Oaxaca cheese from Mexico City.

Factors that positively or negatively mediate the effects of age on working memory across the adult life span.

Working memory abilities significantly decrease with advancing age; hence, the search for factors that may increase or mitigate this decline is critical. Several factors have been identified that influence working memory; however, their effects have been mainly assessed separately and rarely together with other factors in the same sample. We examined 120 variables to search for factors that jointly act as mediators of working memory decay across the adult life span. A sample of 1652 healthy adults was assessed in spatial and verbal working memory domains. Structural equation modeling analyses were conducted to search for potential mediators that intervened between age and working memory. Only 14 and 10 variables reliably mediated spatial and verbal working memory, respectively. Factors from several domains remained in the models, such as individual characteristics, physiological traits, consumption habits, and regular activities. These factors are sufficiently powerful to influence working memory decline when they jointly interact, as in everyday living.

Mediators of episodic memory decay across the adult life span.

The ability to remember the details of our own experiences declines gradually as we get old. The reason for this decay has been attributed to several factors besides age, such as education, nutrient intake and health status. However, the influence of these factors has mainly been examined individually and rarely together. Here we identify those factors that jointly act as mediators of episodic memory decay across the adult life span. We examined source memory in a lifespan sample of 1557 healthy adults. A total of 70 physical, biological and lifestyle variables were measured and introduced into a structural equation model as potential mediators that intervene between age and source memory. Only 14 mediator variables reliably mediated source memory decay; notably, eight of these variables have an effect on the cardiovascular system. The model unequivocally highlights that the mediators that may impair cardiovascular functioning also impact brain resources involved in episodic memory. We identified the factors that are relevant to episodic memory decline when they interact together as occurs in real life.

Quantitative analysis of ventricular ectopic beats in short-term RR interval recordings to predict imminent ventricular tachyarrhythmia.

BACKGROUND: Most approaches to predict ventricular tachyarrhythmias which are based on RR intervals consider only sinus beats, excluding premature ventricular complexes (PVCs). The method known as heartprint, which analyses PVCs and their characteristics, has prognostic value for fatal arrhythmias on long recordings of RR intervals (>70,000 beats). OBJECTIVE: To evaluate characteristics of PVCs from short term recordings (around 1000 beats) and their prognostic value for imminent sustained tachyarrhythmia. MATERIALS AND METHODS: We analyzed 132 pairs of short term RR interval recordings (one before tachyarrhythmia and one control) obtained from 78 patients. Patients were classified into two groups based on the history of accelerated heart rate (HR) (HR>90bpm) before a tachyarrhythmia episode. Heartprint indexes, such as mean coupling interval (meanCI) and the number of occurrences of the most prevalent form of PVCs (SNIB) were calculated. The predictive value of all the indexes and of the combination of different indexes was calculated. RESULTS: MeanCI shorter than 482ms and the occurrence of more repetitive arrhythmias (sNIB≥2.5), had a significant prognostic value for patients with accelerated heart rate: adjusted odds ratio of 2.63 (1.33-5.17) for meanCI and 2.28 (1.20-4.33) for sNIB. Combining these indexes increases the adjusted odds ratio: 10.94 (3.89-30.80). CONCLUSIONS: High prevalence of repeating forms of PVCs and shorter CI are potentially useful risk markers of imminent ventricular tachyarrhythmia. Knowing if a patient has history of VT/VF preceded by accelerated HR, improves the prognostic value of these risk markers.

Dopamine receptor dysregulation in hippocampus of aged rats underlies chronic pulsatile L-Dopa treatment induced cognitive and emotional alterations.

L-Dopa is the major symptomatic therapy for Parkinson's disease, which commonly occurs in elderly patients. However, the effects of chronic use on mood and cognition in old subjects remain elusive. In order to compare the effects of a chronic pulsatile L-Dopa treatment on emotional and cognitive functions in young (3 months) and old (18 months) intact rats, an L-Dopa/carbidopa treatment was administered every 12 h over 4 weeks. Rats were assessed for behavioural despair (repeated forced swimming test, RFST), anhedonia (sucrose preference test, SPT) and spatial learning (Morris water maze, MWM) in the late phase of treatment (T). Neuronal expression of Fos in the hippocampus at the early and late phases of T, as well as after MWM was studied. The density and ratio of dopamine D5r, D3r and D2r receptors were also evaluated in the hippocampus using immunohistochemistry and confocal microscopy. Young rats showed similar patterns during behavioural tests, whereas aged treated rats showed increased immobility counts in RFST, diminished sucrose liquid intake in SPT, and spatial learning impairment during MWM. Fos expression was significantly blunted in the aged treated group after MWM. The density of D5r, D3r and D2r was increased in both aged groups. The treatment reduced the ratio of D5r/D3r and D5r/D2r in both groups. Moreover, aged treated subjects had significant lower values of D5r/D3r and higher values of D5r/D2r when compared with young treated subjects. These results indicate that chronic L-Dopa treatment in itself could trigger emotional and cognitive dysfunctions in elderly subjects through dopamine receptor dysregulation.

Benthic bacterial diversity from freshwater tufas of the Iberian Range (Spain).

Aiming to characterize the bacterial diversity of modern tufa systems of the Iberian Range (Spain), we surveyed the 16S rRNA gene sequence diversity from 24 sites within three rivers (Añamaza, Mesa and Piedra). These tufas record substantial calcareous growth under different physicochemical conditions and are part of an important, regional landscape-building system. The bacterial community structure and composition, richness and diversity were quantified from denaturing gradient gel electrophoresis fingerprints. Retrieved DNA sequences could be assigned to 10 bacterial phyla and included a variety of phototrophic and heterotrophic groups. Cyanobacteria, mainly filamentous taxa, constituted 43% of all the retrieved sequences, followed by Firmicutes (11%), Gammaproteobacteria (10%), Alphaproteobacteria (7%), Acidobacteria (6%), Bacteroidetes (5%), Betaproteobacteria (4%), Planctomycetes (4%), Actinobacteria (3%) and Deltaproteobacteria (2%). Diatom and Xanthophyceae chloroplast sequences were also detected. Physicochemical variables measured at each site were modelled with multivariate statistics. Principal component analyses yielded the highest variance for salinity-related variables (conductivity; Na(+) , Cl(-) and SO4(2-) concentrations), which correlated negatively and significantly with diversity indices. However, the highest variance explained by individual principal components was relatively low (< 34%). Overall, we show that these young fluvial tufas are inhabited by a large variety of bacteria in diverse and widespread communities.

[Bullying and its association with psychiatric disorders in a Mexican students sample]. / El acoso escolar (bullying) y su asociación con trastornos psiquiátricos en una muestra de escolares en México.

OBJECTIVE: To study the relationship between bullying behavior and psychopathology. MATERIALS AND METHODS: A total of 1 092 students identified their peers' bullying status based on the Bull-S questionnaire. Parents completed the Child Behavior Checklist (CBCL) to determine psychopathology levels. RESULTS: The bullying group had associations with anxiety, somatic symptoms, oppositionalism and behavior problems; the bully-victims group had associations with attention, oppositionalism and behavior problems; victims had higher anxiety scores.These differences were significant compared with the control group. CONCLUSIONS: Bullying is associated with psychopathology, which requires timely psychiatric attention.

El acoso escolar (bullying) y su asociación con trastornos psiquiátricos en una muestra de escolares en México / Bullying and its association with psychiatric disorders in a Mexican students sample

OBJETIVO: Estudiar la relación entre el tipo de psicopatología y el acoso escolar en una muestra de niños de las escuelas públicas de la Ciudad de México. MATERIAL Y MÉTODOS: Un total de 1 092 escolares identificó por medio del Test Bull-S a un grupo de agresores,víctimas,víctima-agresores y neutros. Los padres contestaron la Lista de Síntomas del Niño (Child Behavior Checklist, CBCL) para determinar el rango clínico de psicopatología. RESULTADOS: El grupo de agresores tuvo asociación con las escalas de ansiedad, síntomas somáticos, oposicionismo y de conducta. El grupo de víctima-agresores presentó asociación con los problemas de atención,oposicionismo y de conducta.En el grupo de víctimas las asociaciones encontradas fueron con los problemas de ansiedad.Estas diferencias fueron significativas frente al grupo control (neutros). CONCLUSIÓN: El acoso escolar se asocia con psicopatología que requiere de atención psiquiátrica oportuna.

OBJECTIVE: To study the relationship between bullying behavior and psychopathology. MATERIALS AND METHODS: A total of 1 092 students identified their peers' bullying status based on the Bull-S questionnaire. Parents completed the Child Behavior Checklist (CBCL) to determine psychopathology levels. RESULTS: The bullying group had associations with anxiety, somatic symptoms, oppositionalism and behavior problems; the bully-victims group had associations with attention, oppositionalism and behavior problems; victims had higher anxiety scores.These differences were significant compared with the control group. CONCLUSIONS: Bullying is associated with psychopathology, which requires timely psychiatric attention.

Association between smoking and minimal-mild depressive symptomatology in heavy smokers / Asociación entre el hábito de fumar y la sintomatología depresiva mínima leve en fumadores fuertes

The World Health Organization (WHO) estimates that by the year 2020 tobacco addiction will be responsible for 10 million deaths, seventy percent of which will occur in underdeveloped countries. On the other hand, depression affects about 121 million people worldwide, and is projected to reach a second place in the ranking of Disability Adjusted Life Years (DALYs) calculated for all ages and both sexes by the year 2020. In Mexico, 14 million people are current smokers and 9.6 million are former smokers, according to the 2002 National Addictions Survey, and almost four million people are diagnosed with depression. Both disorders are classified among the main causes of mortality and disability in Mexico. By gender, major depression in females is the second most prevalent disorder. Two percent of the Mexican population (two million people) present at least one major depressive episode before reaching the age of 18. Several studies have found an important link between depression and smoking. More recently, it was reported that the manifestation of depressive symptomatology predicts smoking addiction. Although the strong association between affective disorders and drug abuse has been documented, they are generally treated independently. For this reason, the need for integral management of comorbid diseases has been highlighted. Little is known about specific populations of patients that simultaneously manifest both disorders, and more knowledge is needed in order to design precise integral treatments for this kind of patients, taking into consideration the gender, severity of depression and level of nicotine dependence. The aim of this study was to describe the association between depressive symptoms, sociodemographic characteristics, and pattern of tobacco consumption of heavy smokers with minimal-mild depressive symptomatology in order to adjust for these relations in a later longitudinal regression analysis after these subjects have been assigned to different conditions of a new integral treatment to quit smoking. A total of 89 heavy smokers were assessed; 74 of them (83%) had minimal-mild depressive symptomatology; there were 35 females and 39 males, with an average age of 44.3 yrs. Level of tobacco addiction was determined by the Fagerström Test for Nicotine Dependence, and the Beck Depression Inventory was used to assess depressive symptomatology. By means of regression models, we found an increase of the depressive symptomatology related to the severity of tobacco addiction (p= .025). Those with a bachelor's educational level, had less depressive symptomatology (p= .025). The high frequency of depressive symptomatology and the protective factor of schooling concur with findings reported in other studies. The better understanding of the characteristics of smokers with different levels of tobacco consumption and depressive symptomatology is suggested. It is important to gain knowledge on the particular characteristics of specific groups of smokers for the development of new treatments that can simultaneously treat smoking addiction and depression, and can also help to norm criteria for their treatment.

La Organización Mundial de la Salud (OMS) estima que para el año 2020 la adicción al tabaco será responsable de 10 millones de muertes, 70% de las cuales ocurrirá en los países subdesarrollados. La mitad de los fumadores actuales, aproximadamente 650 millones de personas, morirá debido a una causa relacionada con el consumo de tabaco. Por otro lado, actualmente la depresión afecta a cerca de 121 millones de personas en el mundo, y se ha proyectado que para el año 2020 ocupará el segundo lugar en Años de Vida Ajustados por Discapacidad (AVAD) en todos los grupos de edad y en ambos sexos. En México, 14 millones de personas son fumadores actuales y 9.6 millones son ex fumadores, según la Encuesta Nacional de Adicciones (ENA) 2002, y casi cuatro millones de personas padecen depresión. Ambos trastornos se clasifican entre las principales causas de morbimortalidad en nuestro país. En cuanto a las diferencias por sexo, en las mujeres, la depresión es el segundo trastorno más frecuente. El dos por ciento de la población mexicana (dos millones de personas) ha padecido por lo menos un episodio de depresión importante antes de alcanzar la edad de 18 años. Varios estudios han encontrado una asociación importante entre la depresión y el tabaquismo. Recientemente se reportó que la manifestación de la sintomatología depresiva predice la adicción al tabaco. De acuerdo con varios estudios, se sabe que la nicotina reduce la incidencia y la gravedad de los síntomas depresivos y que la abstinencia del tabaco puede desencadenar síntomas depresivos, por lo que se ha sugerido que las personas con depresión fuman a manera de automedicación contra la sintomatología depresiva. A pesar de que ha sido documentada la fuerte asociación entre los trastornos afectivos y las adicciones, estos trastornos se atienden generalmente de manera independiente. Por esta razón, se ha subrayado la necesidad de generar tratamientos integrales para los trastornos comórbidos. Hasta el momento, se sabe poco sobre poblaciones específicas de pacientes que de manera simultánea son adictos al tabaco y padecen sintomatología depresiva, por lo se requiere de mayor entendimiento de sus características para diseñar tratamientos integrales específicos para este tipo de pacientes. Para ello se debe tomar en consideración el sexo, la gravedad de la depresión y el nivel de dependencia de la nicotina. El objetivo del presente estudio fue describir la relación que existe entre los síntomas depresivos, las características sociodemográficas y el patrón de consumo de tabaco en fumadores fuertes con sintomatología depresiva mínima leve para ajustar dichas relaciones mediante un modelo de regresión longitudinal, en un estudio posterior, donde los pacientes serán asignados a diversas condiciones terapéuticas de un nuevo tratamiento integral contra el tabaquismo. Un total de 89 fumadores fuertes fueron evaluados; 74 de ellos (83%) padecían sintomatología depresiva mínima leve; había 35 mujeres y 39 hombres, con una media de edad de 44.3 años. El nivel de adicción al tabaco fue determinado por la prueba de Fagerström para la dependencia a la nicotina, y se usó el Inventario de Depresión de Beck para determinar el nivel de sintomatología depresiva. Mediante un modelo de regresión, encontramos un aumento de la sintomatología depresiva relacionada con la gravedad de la dependencia al tabaco (p = .025). Aquellos con nivel de enseñanza de licenciatura presentaron menos sintomatología depresiva (p = .025). Los principales resultados de este estudio son la asociación significativa entre el nivel de dependencia al tabaco y la sintomatología depresiva en fumadores fuertes. Tanto la alta incidencia de la sintomatología depresiva como el factor protector de la enseñanza concuerdan con los reportes de otros estudios con fumadores. Es importante conocer las características particulares de grupos específicos de fumadores para desarrollar nuevos tratamientos que pueden tratar simultáneamente la adicción al tabaco y la depresión, así como para ayudar a normar criterios para su tratamiento. Se sugiere continuar ahondando en el conocimiento de las características de los fumadores con diversos niveles de consumo de tabaco y sintomatología depresiva.

Personal exposure to PM2.5 air pollution and heart rate variability in subjects with positive or negative head-up tilt test.

Particulate matter air pollution has been related to an increase in cardiopulmonary morbidity and mortality especially in susceptible subjects with a known cardiopulmonary disease. Recent studies suggest that PM(2.5) air pollution was associated with changes in heart rate variability (HRV). The purpose of this study was to identify and compare changes in HRV in positive or negative head-up tilt (HUT) participants. Fifty two subjects, 31 women and 21 men, 20-40 years old, underwent PM(2.5) personal monitoring and Holter-ECG monitoring in supine and orthostatic position, during active standing, in indoor and outdoor environments. All measurements were made between 8 and 11 AM in the same geographical location (southeast of Mexico City). Frequency domain indexes were estimated in absolute (ms(2)) and in normalized units (nu) (low frequencies (LF), high frequencies (HF) and low/high frequency ratio (LF/HF)) in 5 min periods by standard methods. Data were transformed into natural logarithmic scale (ln). Comparisons were made between genders and positive and negative HUT subjects. LF were larger and HF were smaller in negative HUT males. Multivariate analysis with GEE models, adjusted for each index, showed a significant decrease of HRV (LFln -0.194 95% CI, -0.4509, 0.0627, and HFln -0.298 95% CI, -0.5553, -0.0401) associated to an increase in PM(2.5) air pollution in positive and negative HUT subjects which was larger for HFln in outdoor environments. PM(2.5) air pollution was associated with changes in HRV in positive and negative HUT subjects without cardiopulmonary disease.

Susceptibilidad al consumo de tabaco en estudiantes no fumadores de 10 ciudades mexicanas / Susceptibility to use tobacco among non-smoking students in 10 Mexican cities

OBJETIVO: Identificar la susceptibilidad cognitiva a fumar y los factores asociados en estudiantes de 12 a 15 años. MATERIAL Y MÉTODOS: Se analizó la medición basal de una encuesta autoaplicable en 12 293 estudiantes no fumadores de escuelas secundarias, en el ciclo 2005-2006. Susceptible es aquel que contestó que aceptará un cigarrillo de su mejor amigo y cree que el año próximo fumará. Se obtuvieron modelos de regresión logística de multinivel. RESULTADOS: La prevalencia de susceptibilidad fue de 30 por ciento. Los factores asociados fueron autoestima baja (RM = 1.2, IC95 por ciento 1.0-1.5), búsqueda de nuevas sensaciones (RM = 1.6, IC95 por ciento 1.3-2.0) y actitud favorable a fumar (RM = 2.6, IC95 por ciento 2.2-3.2), así como permisividad social reflejada en reglas del hogar (RM = 2.2, IC95 por ciento 1.7-2.8). Sólo en mujeres existió interacción entre permisividad de fumar en el hogar y consumo de tabaco en padres (RM = 2.1, IC95 por ciento 1.1-3.8). CONCLUSIONES: La prevención debe promover la sensibilización de profesores y padres de familia como modelos antitabaco e incentivar hogares libres de tabaco.

OBJECTIVE: To identify the cognitive susceptibility to smoking and associated factors in students between 12 and 15 years of age. MATERIAL AND METHODS: The baseline measurement of a self-administered survey conducted between 2005 and 2006 of 12 293 non-smoking high school students was analyzed. Susceptibility was considered to be a student who would accept a cigarette from his or her best friend and would smoke the following year. Multilevel logistic regression models were obtained. RESULTS: The prevalence of susceptibility was 30 percent. Associated factors were low self-esteem (RM = 1.2, IC95 percent 1.0-1.5), seeking new sensations (RM = 1.6, IC95 percent 1.3-2.0) and a favorable attitude towards smoking (RM = 2.6, IC95 percent 2.2-3.2), as well as the social permissibility reflected in the norms at home (RM = 2.2, IC95 percent 1.7-2.8). The interaction between permissibility of smoking at home and tobacco consumption by parents existed only for females (RM = 2.1, IC95 percent 1.1-3.8). CONCLUSIONS: Prevention should promote the sensitization of the familyÆs parents and teachers as anti-smoking models and encourage tobacco-free homes.