24 research outputs found
Interconectividade: professores do Norte e do Sul do Brasil compreendendo saberes pedagógicos
O presente estudo propiciou entendermos como"saberes - o conjunto de conhecimentos e modos"de fazer enraizados no cotidiano das comunidades"- expressam-se nos mais diversos locais,"como mercados, feiras, santuários, praças, escolas"e demais espaços onde se forjam as mentalidades."Tais saberes englobam os rituais e festas"que marcam a vivência coletiva do trabalho, da"religiosidade, da ludicidade, das diversas formas"de expressão artÃstica: literária, musical, cênica,"visual e de outras práticas da vida social. Por"uma atitude cientÃfica, somos levados a compreender"as várias dimensões das respostas dos"professores do projeto de pesquisa, realizado em"três municÃpios da região do Salgado paraense"e articulamos o artigo em tópicos para que cada"um dos saberes fosse aprofundado teoricamente"e entrelaçado com as falas coletadas, assim"chegamos aos subtÃtulos: Saberes ambientais -"sustentabilidade no nosso planeta; O lúdico na"vida e na escola; O saber poético - sensibilidade"e autoconhecimento; Religiosidade, religião e"espiritualidade. Com aproximações e distanciamentos,"fomos nos reconhecendo nas falas dos"professores da Amazônia paraense, evidenciando"a inseparabilidade de dois contextos, aparentemente"tão distantes e diversos. Professores do"norte do paÃs foram ouvidos por professores do"sul, realidades diversas e semelhantes ao mesmo"tempo. Semelhança em ser professor, semelhança"na busca pelo conhecimento, semelhança no"acolhimento à s diferenças, semelhança no amor"pelo ser humano. Semelhanças e diferenças nos"uniram em um mesmo projeto de pesquisa, em"um mesmo projeto de profissão e em um mesmo"projeto de vida. Desta forma, nas considerações"finais, percebemos que estávamos compreendendo"sobre a interconectividade entre professores"do sul e professores do norte e contribuindo para"a construção de saberes em diferentes processos"educativos.Palavras-Chave: Interconectividade - Saberes pedagógicos - Formação de ProfessoresInterconnectivity: teachers of Northern and Southern Brazil understanding pedagogical knowledge" " ""This study led us to understand how knowledge - the set of knowledge and ways of doing rooted in everyday communities - are expressed in various places, such as markets, fairs, sanctuaries, playgrounds, schools and other places where attitudes are forged. Such knowledge encompass rituals and dances which mark the collective experience of work, religiosity, playfulness and other various forms of artistic expression: literary, musical, scenic, visual and other practices of social life. For a scientific attitude, we are driven to understand the various dimensions of teachers' responses to such research project, performed in three municipalities in the region of Salgado Paraense, then we articulated this article on topics for each knowledge were examined theoretically and interlaced with the collected speeches, so we came to the subtitles: Environmental Knowledge - sustainability on our planet; The Playful in Life and in School; Poetic Knowledge - sensitivity and self-awareness; Religion, Religion and Spirituality. Considering similarities and differences, we began to recognize ourselves in the speeches of the teachers of Amazon Paraense, demonstrating the inseparability of these two contexts, seemingly so distant and so diverse. Teachers from the North were heard by teachers from the South, realities which are different and similar at the same time. Similarities in being a teacher, similarities in pursuit of knowledge, similarities to host differences, similarities in love for the human being. Similarities and differences brought us together in a same research project, in a same professional project and in the same project of life. Thus, in concluding remarks, we realized we were comprehending about the interconectivity between Southern and Northern teachers and contributing to the construction of knowledge in different educational processes.Key-words: Interconnectivity - Pedagogical Knowledge - Teacher Training
Alcohol exposure during late gestation: Multiple developmental outcomes in sheep
Alcohol consumption during pregnancy remains common in many countries. Exposure to even low amounts of alcohol (i.e. ethanol) in pregnancy can lead to the heterogeneous fetal alcohol spectrum disorders (FASD), while heavy alcohol consumption can result in the fetal alcohol syndrome (FAS). FAS is characterized by cerebral dysfunction, growth restriction and craniofacial malformations. However, the effects of lower doses of alcohol during pregnancy, such as those that lead to FASD, are less well understood. In this article, we discuss the findings of recent studies performed in our laboratories on the effects of fetal alcohol exposure using sheep, in which we investigated the effects of late gestational alcohol exposure on the developing brain, arteries, kidneys, heart and lungs. Our studies indicate that alcohol exposure in late gestation can (1) affect cerebral white matter development and increase the risk of hemorrhage in the fetal brain, (2) cause left ventricular hypertrophy with evidence of altered cardiomyocyte maturation, (3) lead to a decrease in nephron number in the kidney, (4) cause altered arterial wall stiffness and endothelial and smooth muscle function and (5) result in altered surfactant protein mRNA expression, surfactant phospholipid composition and pro-inflammatory cytokine mRNA expression in the lung. These findings suggest that fetal alcohol exposure in late gestation can affect multiple organs, potentially increasing the risk of disease and organ dysfunction in later life
Early biomarkers and potential mediators of ventilation-induced lung injury in very preterm lambs
BACKGROUND: Bronchopulmonary dysplasia (BPD) is closely associated with ventilator-induced lung injury (VILI) in very preterm infants. The greatest risk of VILI may be in the immediate period after birth, when the lungs are surfactant deficient, still partially filled with liquid and not uniformly aerated. However, there have been very few studies that have examined this immediate post-birth period and identified the initial injury-related pathways that are activated. We aimed to determine if the early response genes; connective tissue growth factor (CTGF), cysteine rich-61 (CYR61) and early growth response 1 (EGR1), were rapidly induced by VILI in preterm lambs and whether ventilation with different tidal volumes caused different inflammatory cytokine and early response gene expression. METHODS: To identify early markers of VILI, preterm lambs (132 d gestational age; GA, term approximately 147 d) were resuscitated with an injurious ventilation strategy (V(T) 20 mL/kg for 15 min) then gently ventilated (5 mL/kg) for 15, 30, 60 or 120 min (n = 4 in each). To determine if early response genes and inflammatory cytokines were differentially regulated by different ventilation strategies, separate groups of preterm lambs (125 d GA; n = 5 in each) were ventilated from birth with a V(T) of 5 (VG5) or 10 mL/kg (VG10) for 135 minutes. Lung gene expression levels were compared to levels prior to ventilation in age-matched control fetuses. RESULTS: CTGF, CYR61 and EGR1 lung mRNA levels were increased approximately 25, 50 and 120-fold respectively (p < 0.05), within 30 minutes of injurious ventilation. VG5 and VG10 caused significant increases in CTGF, CYR61, EGR1, IL1- , IL-6 and IL-8 mRNA levels compared to control levels. CTGF, CYR61, IL-6 and IL-8 expression levels were higher in VG10 than VG5 lambs; although only the IL-6 and CYR61 mRNA levels reached significance. CONCLUSION: CTGF, CYR61 and EGR1 may be novel early markers of lung injury and mechanical ventilation from birth using relatively low tidal volumes may be less injurious than using higher tidal volumes
cAMP Response Element Binding Protein Is Required for Differentiation of Respiratory Epithelium during Murine Development
The cAMP response element binding protein 1 (Creb1) transcription factor regulates cellular gene expression in response to elevated levels of intracellular cAMP. Creb1−/− fetal mice are phenotypically smaller than wildtype littermates, predominantly die in utero and do not survive after birth due to respiratory failure. We have further investigated the respiratory defect of Creb1−/− fetal mice during development. Lungs of Creb1−/− fetal mice were pale in colour and smaller than wildtype controls in proportion to their reduced body size. Creb1−/− lungs also did not mature morphologically beyond E16.5 with little or no expansion of airway luminal spaces, a phenotype also observed with the Creb1−/− lung on a Crem−/− genetic background. Creb1 was highly expressed throughout the lung at all stages examined, however activation of Creb1 was detected primarily in distal lung epithelium. Cell differentiation of E17.5 Creb1−/− lung distal epithelium was analysed by electron microscopy and showed markedly reduced numbers of type-I and type-II alveolar epithelial cells. Furthermore, immunomarkers for specific lineages of proximal epithelium including ciliated, non-ciliated (Clara), and neuroendocrine cells showed delayed onset of expression in the Creb1−/− lung. Finally, gene expression analyses of the E17.5 Creb1−/− lung using whole genome microarray and qPCR collectively identified respiratory marker gene profiles and provide potential novel Creb1-regulated genes. Together, these results demonstrate a crucial role for Creb1 activity for the development and differentiation of the conducting and distal lung epithelium
Bronchiolar remodeling in adult mice following neonatal exposure to hyperoxia: relation to growth.
Preterm infants who receive supplemental oxygen for prolonged periods are at increased risk of impaired lung function later in life. This suggests that neonatal hyperoxia induces persistent changes in small conducting airways (bronchioles). Although the effects of neonatal hyperoxia on alveolarization are well documented, little is known about its effects on developing bronchioles. We hypothesized that neonatal hyperoxia would remodel the bronchiolar walls, contributing to altered lung function in adulthood. We studied three groups of mice (C57BL/6J) to postnatal day 56 (P56; adulthood) when they either underwent lung function testing or necropsy for histological analysis of the bronchiolar wall. One group inhaled 65% O2 from birth until P7, after which they breathed room air; this group experienced growth restriction (HE+GR group). We also used a group in which hyperoxia-induced GR was prevented by dam rotation (HE group). A control group inhaled room air from birth. At P56, the bronchiolar epithelium of HE mice contained fewer Clara cells and more ciliated cells, and the bronchiolar wall contained ∼25% less collagen than controls; in HE+GR mice the bronchiolar walls had ∼13% more collagen than controls. Male HE and HE+GR mice had significantly thicker bronchiolar epithelium than control males and altered lung function (HE males: greater dynamic compliance; HE+GR males: lower dynamic compliance). We conclude that neonatal hyperoxia remodels the bronchiolar wall and, in adult males, affects lung function, but effects are altered by concomitant growth restriction. Our findings may partly explain the reports of poor lung function in ex-preterm children and adults
Altered lung function at mid-adulthood in mice following neonatal exposure to hyperoxia.
Infants born very preterm are usually exposed to high oxygen concentrations but this may impair lung function in survivors in later life. However, the precise changes involved are poorly understood. We determined how neonatal hyperoxia alters lung function at mid-adulthood in mice. Neonatal C57BL/6J mice inhaled 65% oxygen (HE group) from birth for 7 days. They then breathed room air until 11 months of age (P11mo); these mice experienced growth restriction. Controls breathed only room air. To exclude the effects of growth restriction, a group of dams was rotated between hyperoxia and normoxia during the exposure period (HE+DR group). Lung function was measured at P11mo. HE mice had increased inspiratory capacity, work of breathing and tissue damping. HE+DR mice had further increases in inspiratory capacity and work of breathing, and reduced FEV100/FVC. Total lung capacity was increased in HE+DR males. HE males had elevated responses to methacholine. Neonatal hyperoxia alters lung function at mid-adulthood, especially in males
Early Postnatal Hyperoxia in Mice Leads to Severe Persistent Vitreoretinopathy
Purpose: To describe a mouse model of hyperoxia-induced vitreoretinopathy that replicated some of the clinical and pathologic features encountered in infants with severe retinopathy of prematurity and congenital ocular conditions such as persistent hyperplastic primary vitreous. Methods: Experimental mice (C57BL/6J) were exposed to 65% oxygen between postnatal days (P)0 to P7 and studied at P10, P14, and 3, 5, 8, 20, and 40 weeks. Controls were exposed to normoxic conditions. Fundus imaging and fluorescein angiography were performed at all time points, and spectral-domain optical coherence tomography (SD-OCT) and electroretinography were performed at 8- and 20-week time points. Eyes were processed for resin histology, frozen sections, and retinal whole mounts. Immunostaining was performed to visualize vasculature isolectin B4 (Ib4), collagen type IV, glial fibrillary acidic protein, and α-smooth muscle actin. Results: Early exposure to hyperoxia resulted in bilateral vitreous hemorrhages at 3 weeks. From 5 weeks onward there were extensive zones of retinal degeneration, scarring or gliosis, retinal folding, and detachments caused by traction of α-smooth muscle actin-positive vitreous membranes. Tortuous retinal vessels, together with hyperplastic and persistence of hyaloid vessels are evident into adulthood. In the early stages (P10-3 weeks), branches from the tunica vasculosa lentis (TVL) supplied the marginal retina until retinal vessels were established. The peripheral retina remained poorly vascularized into adulthood. Electroretinography revealed 50% to 60% diminution in retinal function in adult mice that strongly correlated with vitreal changes identified using SD-OCT. Conclusions: This animal model displays a mixture of vitreoretinal pathologic changes that persist into adulthood. The model may prove valuable in experimental investigations of therapeutic approaches to blinding conditions caused by vitreous and retinal abnormalities
Daily ethanol exposure during late ovine pregnancy: physiological effects in the mother and fetus in the apparent absence of overt fetal cerebral dysmorphology
High levels of ethanol (EtOH) consumption during pregnancy adversely affect fetal development; however, the effects of lower levels of exposure are less clear. Our objectives were to assess the effects of daily EtOH exposure (3.8 USA standard drinks) on fetal-maternal physiological variables and the fetal brain, particularly white matter. Pregnant ewes received daily intravenous infusions of EtOH (0.75 g/kg maternal body wt over 1 h, 8 fetuses) or saline (8 fetuses) from 95 to 133 days of gestational age (DGA; term ∼145 DGA). Maternal and fetal arterial blood was sampled at 131-133 DGA. At necropsy (134 DGA) fetal brains were collected for analysis. Maternal and fetal plasma EtOH concentrations reached similar maximal concentration (∼0.11 g/dl) and declined at the same rate. EtOH infusions produced mild reductions in fetal arterial oxygenation but there were no changes in maternal oxygenation, maternal and fetal PaCO2, or in fetal mean arterial pressure or heart rate. Following EtOH infusions, plasma lactate levels were elevated in ewes and fetuses, but arterial pH fell only in ewes. Fetal body and brain weights were similar between groups. In three of eight EtOH-exposed fetuses there were small subarachnoid hemorrhages in the cerebrum and cerebellum associated with focal cortical neuronal death and gliosis. Overall, there was no evidence of cystic lesions, inflammation, increased apoptosis, or white matter injury. We conclude that daily EtOH exposure during the third trimester-equivalent of ovine pregnancy has modest physiological effects on the fetus and no gross effects on fetal white matter development
The therapeutic effect of mesenchymal stem cells on pulmonary myeloid cells following neonatal hyperoxic lung injury in mice
Abstract Background Exposure to high levels of oxygen (hyperoxia) after birth leads to lung injury. Our aims were to investigate the modulation of myeloid cell sub-populations and the reduction of fibrosis in the lungs following administration of human mesenchymal stem cells (hMSC) to neonatal mice exposed to hyperoxia. Method Newborn mice were exposed to 90% O2 (hyperoxia) or 21% O2 (normoxia) from postnatal days 0–4. A sub-group of hyperoxia mice were injected intratracheally with 2.5X105 hMSCs. Using flow cytometry we assessed pulmonary immune cells at postnatal days 0, 4, 7 and 14. The following markers were chosen to identify these cells: CD45+ (leukocytes), Ly6C+Ly6G+ (granulocytes), CD11b+CD11c+ (macrophages); macrophage polarisation was assessed by F4/80 and CD206 expression. hMSCs expressing enhanced green fluorescent protein (eGFP) and firefly luciferase (fluc) were administered via the trachea at day 4. Lung macrophages in all groups were profiled using next generation sequencing (NGS) to assess alterations in macrophage phenotype. Pulmonary collagen deposition and morphometry were assessed at days 14 and 56 respectively. Results At day 4, hyperoxia increased the number of pulmonary Ly6C+Ly6G+ granulocytes and F4/80lowCD206low macrophages but decreased F4/80highCD206high macrophages. At days 7 and 14, hyperoxia increased numbers of CD45+ leukocytes, CD11b+CD11c+ alveolar macrophages and F4/80lowCD206low macrophages but decreased F4/80highCD206high macrophages. hMSCs administration ameliorated these effects of hyperoxia, notably reducing numbers of CD11b+CD11c+ and F4/80lowCD206low macrophages; in contrast, F4/80highCD206high macrophages were increased. Genes characteristic of anti-inflammatory ‘M2’ macrophages (Arg1, Stat6, Retnla, Mrc1, Il27ra, Chil3, and Il12b) were up-regulated, and pro-inflammatory ‘M1’ macrophages (Cd86, Stat1, Socs3, Slamf1, Tnf, Fcgr1, Il12b, Il6, Il1b, and Il27ra) were downregulated in isolated lung macrophages from hyperoxia-exposed mice administered hMSCs, compared to mice without hMSCs. Hydroxyproline assay at day 14 showed that the 2-fold increase in lung collagen following hyperoxia was reduced to control levels in mice administered hMSCs. By day 56 (early adulthood), hMSC administration had attenuated structural changes in hyperoxia-exposed lungs. Conclusions Our findings suggest that hMSCs reduce neonatal lung injury caused by hyperoxia by modulation of macrophage phenotype. Not only did our cell-based therapy using hMSC induce structural repair, it limited the progression of pulmonary fibrosis