Facilitation of macrofaunal assemblages in marinas by the habitat-forming invader Amathia verticillata (Bryozoa: Gymnolaemata) across a spatiotemporal scale.

Widespread habitat-forming invaders inhabiting marinas, such as the spaghetti bryozoan Amathia verticillata, allow exploring facilitation processes across spatiotemporal contexts. Here we investigate the role of this bryozoan as habitat for native and exotic macrofaunal assemblages across different ecoregions of Western Mediterranean and East Atlantic coasts, and a monthly variation over a year. While only 7 (all peracarid crustaceans) of the 54 associated species were NIS, they dominated macrofaunal assemblages in terms of abundance, raising the potential for invasional meltdown. NIS richness and community structure differed among marinas but not among ecoregions, highlighting the importance of marina singularities in modulating facilitation at spatial scale. Despite facilitation did not depend on bryozoan abundance fluctuations, it was affected by its deciduous pattern, peaking in summer and disappearing in late winter. Monitoring A. verticillata in marinas, especially in summer periods, may improve the detection and management of multiple associated NIS.

Assessment of depressive symptoms in severe smokers with minimal-mild depressive symptomatology receiving pre-smoking abstinence for integrated treatment: a randomized clinical trial / Evaluación de síntomas de depresión en fumadores graves con sintomatología depresiva mínima-leve en preabstinencia para un tratamiento integrado: un ensayo clínico aleatorizado

INTRODUCTION: Smoking and depression have a long-history documented of comorbidity. OBJECTIVE: The objective of this study was to develop and test a treatment that could simultaneously achieve smoking abstinence and decrease depressive symptoms in a group of heavy smokers with minimal/mild depressive symptomatology. METHOD: Sixty smokers were randomly assigned to three different treatment settings. Treatment included a pre-abstinence phase, a psychological treatment phase, a pharmacotherapy phase and a follow-up stage. Smokers began the psychological treatment and the pharmacotherapy two weeks before the day they chosen to quit smoking, and monitoring was conducted over a year. Abstinence was confirmed by assessing the levels of urinary cotinine. RESULTS: Using a linear mixed model with individual random effect, baseline data was compared with subsequent assessments; 46% of the patients achieved abstinence. For men, the three treatment settings significantly reduced depressive symptoms and helped smokers to achieve abstinence. For women, only the nicotine patch showed to be effective in the reducing depressive symptoms. DISCUSSION AND CONCLUSION: Integral pre-abstinence treatment is effective in aiding smokers to achieve smoking abstinence and improve depressive symptoms.

INTRODUCCIÓN: El fumar y la depresión tienen una larga y documentada historia de comorbilidad. OBJETIVO: El objetivo de este estudio fue desarrollar y probar un tratamiento que lograra, simultáneamente, la abstinencia del consumo de tabaco y los síntomas depresivos en un grupo de fumadores graves con sintomatología depresiva mínima/leve. MÉTODO: Sesenta fumadores fueron asignados al azar a tres diferentes situaciones de tratamiento. El tratamiento incluyó una fase de preabstinencia, una fase de tratamiento psicológico, una fase de farmacoterapia y una fase de seguimiento. Los fumadores comenzaron el tratamiento psicológico y farmacológico dos semanas antes de iniciar la abstinencia y el seguimiento se realizó durante un año. La abstinencia se confirmó evaluando los niveles de cotinina en orina. RESULTADOS: Por medio de un modelo lineal mixto con efecto aleatorio individual, los datos de la línea base se compararon con las evaluaciones subsequentes; el 46% de los pacientes lograron la abstinencia. Para los hombres, las tres situaciones de tratamiento redujeron significativamente sus síntomas de depresión y les ayudaron a lograr la abstinencia, mientras que en las mujeres sólo el parche de nicotina mostró ser efectivo para reducir de los síntomas depresivos. DISCUSIÓN Y CONCLUSIÓN: El tratamiento integral de preabstinencia es efectivo para ayudar a los fumadores a lograr la abstinencia y mejorar los síntomas depresivos.

Temporary morphological changes in plus disease induced during contact digital imaging.

OBJECTIVE: To compare and quantify the retinal vascular changes induced by non-intentional pressure contact by digital handheld camera during retinopathy of prematurity (ROP) imaging by means of a computer-based image analysis system, Retinal Image multiScale Analysis. METHODS: A set of 10 wide-angle retinal pairs of photographs per patient, who underwent routine ROP examinations, was measured. Vascular trees were matched between 'compression artifact' (absence of the vascular column at the optic nerve) and 'not compression artifact' conditions. Parameters were analyzed using a two-level linear model for each individual parameter for arterioles and venules separately: integrated curvature (IC), diameter (d), and tortuosity index (TI). RESULTS: Images affected with compression artifact showed significant vascular d (P<0.01) changes in both arteries and veins, as well as in artery IC (P<0.05). Vascular TI remained unchanged in both groups. CONCLUSIONS: Non-adverted corneal pressure with the RetCam lens could compress and decrease intra-arterial diameter or even collapse retinal vessels. Careful attention to technique is essential to avoid absence of the arterial blood column at the optic nerve head that is indicative of increased pressure during imaging.

Breastfeeding and asthma among Brazilian children.

We examined the association of breastfeeding and the presence of chronic respiratory symptoms among 5,182 Brazilian schoolchildren 7-14 years of age who were participants in the International Study on Asthma and Allergies in Childhood (ISAAC). The prevalence of medically diagnosed asthma and current wheeze were respectively 4.6% (95% confidence interval [CI] 4.0%-5.2%) and 11.9% (95% CI 11.0%-12.8%). Ninety percent of the mothers in our study population had breastfed their child. After adjusting for potential confounding factors, we found that children who had not been breastfed were more likely to have a medical diagnosis of asthma (odds ration [OR] = 1 .51, 95% CI 1.00-2.51), experience current wheeze (OR = 1.29, 95% CI 0.96-1.74), and wheeze after exercise (OR = 1.51, 95% CI 1.01-2.27) than children who had been breastfed for more than 6 months. This effect was only present among children with no family history of asthma (OR = 1.54, 95% CI 0.90-2.42 for medical diagnosis of asthma; OR = 1.27, 95% CI 0.93-1.75 for current wheezing; and OR = 1.74, 95% CI 1.12-2.6 for wheeze after exercise). We conclude that the low prevalence of asthma and wheeze observed in our population may be partly related to the high level of breastfeeding.

Daily respiratory mortality and PM10 pollution in Mexico City: importance of considering place of death.

Significant associations have been reported between particles with a 50% cut-off aerodynamic diameter of 10 mm (PM10) and ozone ambient concentrations, and daily number of deaths from respiratory causes. The aim of the present study was to assess such associations among elderly (> or =65 yrs) residents of Mexico City. Ambient air pollution data were provided by the Metropolitan Monitoring Network. During the study period, the average daily PM10 ranged 23.4-175.3 microg x m(-3), and ozone 1 h daily maximums ranged 39.4-216.7 ppb. Information was compiled on the primary and underlying causes of death. The analyses were conducted separately according to place of death (within or out of a hospital unit) using time-series methodology. The total number of deaths from all respiratory causes and mortality for chronic obstructive pulmonary diseases (COPD) were significantly related to PM10 over different lags: an increase of 10 microg x m(-3) was related to a 2.9% (95% (CI): 0.9-4.9%) increase and to a 4.1% (95% CI: 1.3%-6.9%) increase with a 3-day lag when death occurred out of medical units, respectively. For deaths occurring in medical units, a longer lag and smaller risk estimate was observed. An interactive effect between PM10 and ozone was detected. This study confirms that there is an important impact of PM10 on respiratory morbidity among elderly subjects. It also indicates that accounting for primary and underlying causes of death, and considering place of death may reduce misclassification and provide more accurate estimates of the adverse impact of PM10 on mortality.

Limits of variation of fiber distribution in the sural nerve of man.

Although the sural nerve is the most extensively studied nerve in man, there is a dearth of data regarding the normal variations in the size-frequency distribution of axons in normal subjects; criteria for assessing the normality of a given individual are not available. Therefore, in everyday practice, the surgical pathologist may meet with difficulty in interpreting the biopsy of one particular individual, in whom the distribution is slightly different from the curves published. The object of this work is to detect the normal limits of variation in the distribution of diameters of myelinated and unmyelinated fibers in normal subjects and to establish the criteria that permit the calculated curves to be used in everyday clinical practice. Normal sural nerves of 19 patients were analyzed. Ages ranged between 18 months and 55 years. Morphometric analysis was performed with the Histoscan X automatic image processing analyzer, and, for statistical analysis, mixtures of lognormal distributions were fitted and tested with Pearson's statistics. Nerves of three diabetic patients were used for testing the method. They were clearly classified as abnormal. The curves, therefore, have been proven useful for everyday surgical pathology practice.

[Effect of environmental pollution on medical visits for respiratory infections in children in Mexico City]. / Efecto de la contaminación ambiental sobre las consultas por infecciones respiratorias en niños de la Ciudad de México.

OBJECTIVE: To model the variability of medical visits by children for respiratory reasons as a consequence of the daily changes in environmental pollution observed in the emergency and family medicine departments of a hospital of the Instituto Mexicano del Seguro Social located in the southwest of Mexico City during 1993. MATERIALS AND METHODS: The correlation between the presence of upper and lower respiratory tract infections and exposure to ozone and nitrogen dioxide was studied. To model this association, the authors used multivariate Poisson regression models with linear and non-linear risk, with lag periods between the environmental measurements and the medical visits of one, two and three days, as well as the average of the measurements of three, five and seven days previous to the visit. RESULTS: The model estimates that an increment of 50 ppb in the daily average of ozone would cause an increase of 9.9% in emergency visits due to high respiratory tract infections during the winter, which could rise to 30% if the increment would last five consecutive days in average. CONCLUSIONS: Results suggest that exposure of children younger than 15 years of age to ozone and nitrogen dioxide significantly affect the number of medical visits for respiratory causes in this part of Mexico City.

[Prevalence of asthma, rhinitis and eczema in school children in the city of Cuernavaca, Mexico]. / Prevalencia de asma, rinitis y eczema en escolares de la ciudad de Cuernavaca, México.

OBJECTIVE: The measurement of asthma, rhinitis and eczema have been subject of controversy due to lack of a standardized methodology. To test the applicability of a standardized methodology for comparisons of time and space we determined the prevalence of asthma and other allergic diseases in a random sample of schoolchildren (n = 6,238) from 6 to 8 and 11 to 14 years of age living in Cuernavaca, Morelos, Mexico. MATERIAL AND METHODS: The methodology proposed by the International Study of Asthma and Allergies in Childhood (ISAAC) to determine prevalence and severity of asthma, rhinitis and eczema was applied. Current and accumulated information on prevalence was obtained by means of a standardized questionnaire answered by the children's parents. RESULTS: The accumulated prevalence of asthma by medical diagnosis and wheezing was 5.8% (5.2-6.4) and 21.8% (20.7-22.9) respectively; prevalence of wheezing in the last 12 months was 8.9% in the group of 6 to 8 years against 6.6% in the 11 to 14 year old group p < 0.001. Prevalence of the medical diagnosis of rhinitis was 4.9% (4.3-5.5). Regarding the typical symptoms of rhinitis, in the last 12 months prevalence was 9.6% (6-8 years) and 10.1% (11-14 years). Prevalence of eczema by medical diagnosis was 4.1% (3.6-4.6). Prevalence of eczema symptoms in the last 12 months was 10.1% (6-8 years) and 10.6% (11-14 years). Prevalence of severe asthma symptoms was significantly higher in the 6 to 8 year olds and in the autumn. CONCLUSIONS: Prevalence of asthma by medical diagnosis and by symptoms is relatively low with respect to other studies performed with the same methodology. The benefits of using a standardized methodology were analyzed.

[Asthma in a population of children and its relation to airborne environmental pollutants in Mexico City. A cohort study. Mexico, 1991. Experimental design]. / Asma en población infantil y su relación con los contaminantes ambientales aéreos de la ciudad de México. Un estudio de cohorte. México, 1991 Diseño metodológico.

We developed a panel study to evaluate the association between intermittent exposure to ozone and acute attack of asthma. The population study consists in 136 asthmatic children residents in the southwest and northeast of Mexico City. They were attended in the allergic services of the two main Pediatric Hospital of Mexico City. In this paper we present the methodological issues following in the study and the results of the descriptive analysis of the relation between ozone exposure and acute attack of asthma.

Acute effects of ozone on the pulmonary function of exercising schoolchildren from Mexico City.

The acute effects of ozone (O3) on the change in lung function before and after exercise was assessed in 22 boys and 18 girls from 7 1/2 to 11 yr of age tested up to eight times over a 1 1/2-yr period outdoors (under a tarpaulin) at a school in Mexico City. Ozone and particulates were monitored at an adjacent government station, in the school yard, and under the tarp. Subjects were selected to oversample children with chronic respiratory symptoms, although children with active asthma under regular medication or FEV1 < 80% predicted were excluded. Of the participants, 21 had chronic cough, chronic phlegm, or ever wheeze with colds or apart from colds. Children performed two cycles of treadmill exercise (15 min) and rest (15 min) for a total of 1 h of intermittent exercise. Most subjects attained the target minute ventilation of 35 L/min/m2. Subjects exercised alternately during low ozone hours (8:00-10:00 A.M.) and during peak O3 hours (12:00-2:00 P.M.), to assure a range of exposures. On 85% of exercise days, the maximum daily 1-h average for ambient O3 exceeded the Mexican guideline of 110 parts per billion (ppb). O3 exposure during the hour of exercise was divided into quintiles, and the response was adjusted for repeated measures, subject having a cold, and prior outdoor exercise. Ambient O3 in the fifth quintile (mean = 229 ppb) was associated with a percentage change in FVC (-1.43% +/- 0.70), FEV1 (-2.85% +/- 0.79), FEF25-75% (-6.32 +/- 1.87) and FEV1 (-1.41% +/- 0.46).(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of urban air pollutants on emergency visits for childhood asthma in Mexico City.

The metropolitan area of Mexico City, Mexico, has serious air pollution problems. Although air contaminants may contribute to clinical asthma, there are at present no data on the relation between air pollution exposure and childhood asthma in Mexico City. The authors reviewed data on emergency visits from January to June 1990 at one major pediatric hospital in Mexico City. They used a Poisson regression model to study the relation between the number of daily emergency visits for asthma and air pollutant levels. The levels of ozone and sulfur dioxide-exposure were significantly associated with the number of emergency visits for asthma. After adjustment for potential confounding factors, the multivariate regression model predicted that an increase of 50 ppb in the 1-hour maximum ozone level would lead to a 43% increase in the number of emergency visits for asthma on the following day. Exposure to high ozone levels (> 110 ppb) for 2 consecutive days increased the number of asthma-related emergency visits by 68 percent. The results of this study suggest that ozone exposure is positively associated with the number of children's emergency visits for asthma in Mexico City.

PIP: A retrospective analysis of records of emergency visits during January-June 1990 at the Hospital Infantil de Mexico Federico Gomez in the northern section of Mexico City was conducted to examine the association between the 395 children's (16 years) emergency visits for asthma (2.5% of all emergency visits) and daily levels of different air pollutants. Most emergency visits for asthma (67%) included children aged less than 5. The mean ozone daily one-hour maximum level was 90 ppb (range: 10-250 ppb). The ozone level exceeded the Mexican ozone standard (110 ppb) on 49 days (28%). Concentrations of ozone and sulfur dioxide exposure were linked to the number of emergency visits for asthma (p = 0.001 for 1-hour maximum with 1-day lag and p = 0.07 for 1-hour maximum on same day). When the researchers controlled for confounding factors, they found that a rise in the ozone level of 50 ppb was related to a 43% increase in the number of emergency visits for asthma with a one-day lag period. 133% of these visits were made after two consecutive days of ozone levels of at least 110 ppb. Exposure to such high ozone levels increased the number of emergency visits for asthma by 68%. These findings demonstrate a positive relationship between ozone exposure and the number of children living in Mexico City who were treated for asthma. In fact, they suggest that cumulative exposure to ozone strengthens this association.

Short-term projections of AIDS cases in Mexico.

We attempt to analyze and predict the behavior of the AIDS epidemic in Mexico. The reporting delay is corrected by using a cluster analysis, and the corrected data are used to make short-term projections by extrapolation, by fitting linear and log-linear models, and by back-calculation. The incubation period is assumed to have a Weibull distribution, and step functions are used for the infection functions. Most of the methods predict a mean of 25,000 accumulated cases by the end of 1993, and a comparison of the predictions with actual data up to November 1990 shows good agreement in all cases except the log-transformation linear model. The data for 1990 also show the reporting delay correction to be adequate in most cases.

[AIDS: the risk that must be predicted]. / El SIDA. Frente al riesgo hay que prevenir.

PIP: 9356 cases of AIDS were reported in Mexico through March 1992. Although 7971 were in men and 1385 in women, the ratio of male to female cases has declined. In 1985, 1 woman was infected for every 20 men, but by 1991 the proportion was 1 for every 5. The annual numbers of reported cases through 1992 indicate that the epidemic is abating, but reporting of AIDS cases may be delayed for up to 4 years in Mexico. The groups considered at greatest risk of AIDS have changed over time. The proportion of new cases in homosexuals has declined from 80% in the early 1980s to 40% at present. Heterosexually transmitted cases now account for around 23%. Another 17% are transmitted parenterally through transfusions or use of contaminated needles by addicts. The homosexual population has become aware of the danger, but greater attention to prevention is required for the general heterosexual population. Cases are concentrated in the Federal District, which has a rate of 30/100,000. Four states, Baja California, Jalisco, Morelos, and Yucatan, have rates of over 10/100,000, and rates in 10 states exceed 5/100,000. The mean age of reported cases is 33 years.^ieng