Early-childhood social reticence predicts SCR-BOLD coupling during fear extinction recall in preadolescent youth.

Social Reticence (SR) is a temperament construct identified in early childhood that is expressed as shy, anxiously avoidant behavior and, particularly when stable, robustly associated with risk for anxiety disorders. Threat circuit function may develop differently for children high on SR than low on SR. We compared brain function and behavior during extinction recall in a sample of 11-to-15-year-old children characterized in early childhood on a continuum of SR. Three weeks after undergoing fear conditioning and extinction, participants completed a functional magnetic resonance imaging extinction recall task assessing memory and threat differentiation for conditioned stimuli. Whereas self-report and psychophysiological measures of differential conditioning, extinction, and extinction recall were largely similar across participants, SR-related differences in brain function emerged during extinction recall. Specifically, childhood SR was associated with a distinct pattern of hemodynamic-autonomic covariation in the brain when recalling extinguished threat and safety cues. SR and attention focus impacted associations between trial-by-trial variation in autonomic responding and in brain activation. These interactions occurred in three main brain areas: the anterior insular cortex (AIC), the anterior subdivision of the medial cingulate cortex (aMCC), and the dorsolateral prefrontal cortex (dlPFC). This pattern of SCR-BOLD coupling may reflect selective difficulty tracking safety in a temperamentally at-risk population.

[Prevalence of symptoms related to asthma in school children of Campos Gerais, Brazil]. / Prevalencia de síntomas relacionados con el asma en escolares de Campos Gerais (MG), Brasil.

Asthma is the most common chronic disease among children and adolescents, and in recent decades dramatic increases in its prevalence have been reported around the world. However, previous studies have been based on a variety of methodological approaches, making it difficult to compare the results. That situation led a group of international researchers to prepare a standardized self-administered questionnaire to carry out cooperative international studies for the International Study of Asthma and Allergies in Childhood (ISAAC). During April 1996 a cross-sectional study using the ISAAC questionnaire was performed in the city of Campos Gerais, Minas Gerais, Brazil, to determine the prevalence of wheezing and other signs and symptoms related to bronchial asthma among schoolchildren. Two medical students interviewed a randomly selected sample of 200 adolescents 13-14 years old registered in public schools in the city. The sample was equally distributed by sex and age. Of the schoolchildren, 28.5% (95% CI: 22.3%-35.3%) had had wheezing or whistling in the chest at some point in the past. In the preceding 12 months, 6% of them (95% CI: 3.1%-10.5%) had had at least one wheezing episode. A comparison of these results with ones from larger Brazilian cities studied showed that higher prevalence rates were associated with higher population densities and greater urbanization and industrialization. These results strengthen theories supporting an association between asthma and environmental factors. From this it follows that it is necessary to deal with asthma as an important public health problem in Brazil.

Neoplasms of the peripheral nervous system.

Neoplasms of the peripheral nervous system arise from the cellular sheath surrounding the nerve trunks, that is, the pluripotential Schwann cells and related cells, and rarely affect the feet. When present, they are most frequently associated with the autosomal dominantly inherited neurofibromatosis 1. This condition has been related to chromosome 17, and it appears, from in vitro experiments, to involve defects in tyrosine metabolism. Hence, the most common neoplasm is the neurofibroma. Distinct criteria have been established for a diagnosis of neurofibromatosis 1, so that a single pedal neurofibroma may not represent this complex. However, if the complex is present, it is necessary to consider the possibility of malignant transformation to a neurofibrosarcoma. Although malignant peripheral nerve neoplasms are extremely rare in the feet, they may arise in the context of neurofibromatosis 1, or independently. Other benign or malignant schwannomas may (rarely) also arise in the feet. Surgical excision of benign lesions, according to established standards for tumor surgery, is usually curative, but a detailed personal and familial history, along with adjunctive radiologic procedures and biopsy, is necessary to determine the nature of the lesion. Since (endocrine and) other abnormalities may complicate neurofibromatosis 1, surgical procedures must not be undertaken until the patient has been medically cleared and is carefully monitored. A high mortality rate is associated with malignant peripheral neurogenic tumors, especially those arising in the context of neurofibromatosis 1. It should be recalled that neurologic manifestations in the foot may represent non-neoplastic conditions as well as peripheral nerve tumors (or other tumors involving those nerves) that are proximal to the foot and ankle area.