Socioeconomic development, family income, and psychosocial risk factors: a study of families with children in public elementary school

This article aims to evaluate the effects of Brazil's recent economic growth on the monetary income, consumption patterns, and risk exposures of families with children enrolled in the public elementary school system in São Gonçalo, Rio de Janeiro State, Brazil. The article analyzes the following information on families of 447 children that participated in two waves in a longitudinal study: social stratum, per capita family income, evolution in income over a three-year period, and psychosocial factors. The findings showed a 74.8% increase in the families' income, accompanied by an increase in the consumption of material assets and access to health services. This increase should not be interpreted as a guarantee of improved living and health conditions, since it was spent on basic products and needs that do not substantially affect the families' form of social inclusion. Psychosocial risk factors were frequent among the families, but decreased during the study period, which may either reflect the improved family situation or result from the later stage in child development.O objetivo deste artigo é avaliar os reflexos do recente crescimento econômico brasileiro sobre o rendimento monetário, o padrão de consumo familiar e os riscos em que vivem famílias da rede pública do Ensino Fundamental do Município de São Gonçalo, Rio de Janeiro, Brasil. São analisadas as seguintes informações sobre as famílias de 447 crianças que participaram de duas ondas de estudo longitudinal: estrato social, renda familiar per capita, evolução de renda no período e fatores psicossociais. Os resultados indicam incremento financeiro em 74,8% das famílias, acompanhado de aumento no consumo de bens materiais e no acesso a serviços de saúde. Esse crescimento não pode ser tomado como garantia de melhoria nas condições de vida e saúde, já que é gasto com a aquisição de produtos e necessidades básicas que não chegam a afetar substancialmente a forma de inserção social em que vivem as famílias. Os fatores de risco psicossociais mostraram-se frequentes, porém decrescentes nas famílias estudadas, o que pode refletir a melhoria da situação de vida familiar ou ser decorrente da etapa do desenvolvimento infantil

Coocorrência de violência física e psicológica entre adolescentes namorados do recife, Brasil: prevalência e fatores associados

Os objetivos foram estimar a prevalência de perpetração de violência física e psicológica entre adolescentes namorados de Recife, identificar fatores associados e a coocorrência de ambos os tipos de violência. Participaram do estudo 302 adolescentes de escolas públicas e particulares, com idade entre 15 e 19 anos, que tiveram algum relacionamento amoroso no último ano e esses preencheram o questionário. Foram realizadas análise univariada e regressão logística e todas as análises estatísticas incorporaram o peso amostral e o desenho da amostra complexa. A prevalência de violência física foi de 19,9%, de 82,8% para violência psicológica e de 18,9% para a coocorrência de violência física e psicológica. Os adolescentes que vivenciaram violência na comunidade e em relacionamentos de mais de um ano de duração apresentaram maiores chances de perpetrar violência psicológica. Enquanto, sofrer violência física do pai, entre irmãos e em namoros anteriores, além de ter perpetrado violência verbal em relacionamentos anteriores, foram variáveis que aumentaram a chance de perpetração de violência física e psicológica no namoro. Conclui-se que a violência psicológica e a coocorrência de violência física e psicológica possuem uma dinâmica distinta da violência física no namoro

Zeb2 is essential for Schwann cell differentiation, myelination and nerve repair

Schwann cell development and peripheral nerve myelination require the serial expression of transcriptional activators, such as Sox10, Oct6 (also called Scip or Pou3f1) and Krox20 (also called Egr2). Here we show that transcriptional repression, mediated by the zinc-finger protein Zeb2 (also known as Sip1), is essential for differentiation and myelination. Mice lacking Zeb2 in Schwann cells develop a severe peripheral neuropathy, caused by failure of axonal sorting and virtual absence of myelin membranes. Zeb2-deficient Schwann cells continuously express repressors of lineage progression. Moreover, genes for negative regulators of maturation such as Sox2 and Ednrb emerge as Zeb2 target genes, supporting its function as an inhibitor of inhibitors in myelination control. When Zeb2 is deleted in adult mice, Schwann cells readily dedifferentiate following peripheral nerve injury and become repair cells. However, nerve regeneration and remyelination are both perturbed, demonstrating that Zeb2, although undetectable in adult Schwann cells, has a latent function throughout life

Zeb2: Inhibiting the inhibitors in Schwann cells

Development of Schwann cells is tightly regulated by concerted action of activating and inhibiting factors. Most of the regulatory feedback loops identified to date are transcriptional activators promoting induction of genes coding for integral myelin proteins and lipids. The mechanisms by which inhibitory factors are silenced during Schwann cell maturation are less well understood. We could recently show a pivotal function for the transcription factor zinc finger E-box binding homeobox 2 (Zeb2) during Schwann cell development and myelination as a transcriptional repressor of maturation inhibitors. Zeb2 belongs to a family of highly conserved 2-handed zinc-finger proteins and represses gene transcription by binding to E-box sequences in the regulatory region of target genes. The protein is known to repress E-cadherin during epithelial to mesenchymal transition (EMT) in tumor malignancy and mediates its functions by interacting with multiple co-factors. During nervous system development, Zeb2 is expressed in neural crest cells, the precursors of Schwann cells, the myelinating glial cells of peripheral nerves. Schwann cells lacking Zeb2 fail to fully differentiate and are unable to sort and myelinate peripheral nerve axons. The maturation inhibitors Sox2, Ednrb and Hey2 emerge as targets for Zeb2-mediated transcriptional repression and show persistent aberrant expression in Zeb2-deficient Schwann cells. While dispensible for adult Schwann cells, re-activation of Zeb2 is essential after nerve injury to allow remyelination and functional recovery. In summary, Zeb2 emerges as an “inhibitor of inhibitors,” a novel concept in Schwann cell development and nerve repair

Zeb2: inhibiting the inhibitors in Schwann cells

Development of Schwann cells is tightly regulated by concerted action of activating and inhibiting factors. Most of the regulatory feedback loops identified to date are transcriptional activators promoting induction of genes coding for integral myelin proteins and lipids. The mechanisms by which inhibitory factors are silenced during Schwann cell maturation are less well understood. We could recently show a pivotal function for the transcription factor zinc finger E-box binding homeobox 2 (Zeb2) during Schwann cell development and myelination as a transcriptional repressor of maturation inhibitors. Zeb2 belongs to a family of highly conserved 2-handed zinc-finger proteins and represses gene transcription by binding to E-box sequences in the regulatory region of target genes. The protein is known to repress E-cadherin during epithelial to mesenchymal transition (EMT) in tumor malignancy and mediates its functions by interacting with multiple co-factors. During nervous system development, Zeb2 is expressed in neural crest cells, the precursors of Schwann cells, the myelinating glial cells of peripheral nerves. Schwann cells lacking Zeb2 fail to fully differentiate and are unable to sort and myelinate peripheral nerve axons. The maturation inhibitors Sox2, Ednrb and Hey2 emerge as targets for Zeb2-mediated transcriptional repression and show persistent aberrant expression in Zeb2-deficient Schwann cells. While dispensible for adult Schwann cells, re-activation of Zeb2 is essential after nerve injury to allow remyelination and functional recovery. In summary, Zeb2 emerges as an “inhibitor of inhibitors,” a novel concept in Schwann cell development and nerve repair

Transcriptional inhibition in Schwann cell development and nerve regeneration

Schwann cells, the myelinating glial cells of the peripheral nervous system are remarkably plastic after nerve trauma. Their transdifferentiation into specialized repair cells after injury shares some features with their development from the neural crest. Both processes are governed by a tightly regulated balance between activators and inhibitors to ensure timely lineage progression and allow re-maturation after nerve injury. Functional recovery after injury is very successful in rodents, however, in humans, lack of regeneration after nerve trauma and loss of function as the result of peripheral neuropathies represents a significant problem. Our understanding of the basic molecular machinery underlying Schwann cell maturation and plasticity has made significant progress in recent years and novel players have been discovered. While the transcriptional activators of Schwann cell development and nerve repair have been well defined, the mechanisms counteracting negative regulation of (re-)myelination are less well understood. Recently, transcriptional inhibition has emerged as a new regulatory mechanism in Schwann cell development and nerve repair. This mini-review summarizes some of the regulatory mechanisms controlling both processes and the novel concept of “inhibiting the inhibitors” in the context of Schwann cell plasticity

Cholesterol: a novel regulatory role in myelin formation

Myelin consists of tightly compacted membranes that form an insulating sheath around axons. The function of myelin for rapid saltatory nerve conduction is dependent on its unique composition, highly enriched in glycosphingolipids and cholesterol. Cholesterol emerged as the only integral myelin component that is essential and rate limiting for the development of CNS and PNS myelin. Experiments with conditional mouse mutants that lack cholesterol biosynthesis in oligodendrocytes revealed that only minimal changes of the CNS myelin lipid composition are tolerated. In Schwann cells of the PNS, protein trafficking and myelin compaction depend on cholesterol. In this review, the authors summarize the role of cholesterol in myelin biogenesis and myelin disease. </jats:p

Cholesterol regulates the endoplasmic reticulum exit of the major membrane protein P0 required for peripheral myelin compaction

Rapid impulse conduction requires electrical insulation of axons by myelin, a cholesterol-rich extension of the glial cell membrane with a characteristic composition of proteins and lipids. Mutations in several myelin protein genes cause endoplasmic reticulum (ER) retention and disease, presumably attributable to failure of misfolded proteins to pass the ER quality control. Because many myelin proteins partition into cholesterol-rich membrane rafts, their interaction with cholesterol could potentially be part of the ER quality control system. Here, we provide in vitro and in vivo evidence that the major peripheral myelin protein P0 requires cholesterol for exiting the ER and reaching the myelin compartment. Cholesterol dependency of P0 trafficking in heterologous cells is mediated by a cholesterol recognition/interaction amino acid consensus (CRAC) motif. Mutant mice lacking cholesterol biosynthesis in Schwann cells suffer from severe hypomyelination with numerous uncompacted myelin stretches. This demonstrates that high-level cholesterol coordinates P0 export with myelin membrane synthesis, which is required for the correct stoichiometry of myelin components and for myelin compaction