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1.
J Microbiol Biol Educ ; : e0001124, 2024 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-39058038

RESUMO

Studies document difficulties undergraduate pre-nursing and allied health students face when learning human anatomy and physiology (A&P) course content. A comprehensive synthesis exploring the teaching practices within the course and how those practices are evaluated is warranted. This scoping literature review identified 78 journal articles investigating teaching practices, and we charted their research methods, student outcomes, and institutional contexts. Content analysis found the teaching practices described most frequently in A&P education research literature involved multiple aligned changes across the curriculum, including student activities, course delivery, and assessments. Critical appraisal of study methodologies revealed that most studies in undergraduate A&P were longitudinal, included comparison groups, and used simple inferential statistics. In contrast, few studies listed limitations of their research, collected data from multiple institutions, or reported student demographic data. We believe these factors pose notable limitations to the interpretation of A&P education studies across institutional contexts. The results of this review identify future lines of inquiry to enrich existing evidence about pedagogical interventions in A&P courses.

2.
Pediatr Res ; 2024 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-38368498

RESUMO

BACKGROUND: A combination of budesonide and surfactant decreases the rates of BPD in infants and lung injury in preterm sheep. Whether this combination will show benefit in the setting of chorioamnionitis and antenatal steroids is not known. METHODS: Ewes at 123 ± 1 day gestational age received intra-amniotic (IA) injections of 10 mg LPS before being randomized to receive either 0.25 mg/kg maternal betamethasone phosphate and acetate or saline by intramuscular (IM) injection at 48 and 24 h prior to delivery at 125 ± 1 day. Lambs (N = 6-9/group) underwent intentionally injurious ventilation for 15 min, then lambs received surfactant mixed with either: (1) saline; or (2) Budesonide 0.25 mg/kg and were ventilated for 4 h. RESULTS: Compared with LPS-exposed animals that received no IM steroid treatment, betamethasone exposed fetuses had improved hemodynamic stability, lung compliance, and ventilation efficiency. The addition of budesonide to surfactant further improved markers of injury and pro-inflammatory cytokine mRNA in both betamethasone IM or no IM lambs exposed to LPS IA. Antenatal betamethasone and IA LPS exposures decreased budesonide levels in the fetal lung and plasma. CONCLUSION: Antenatal betamethasone stabilizes physiologic parameters in LPS treated lambs. Budesonide mixed with surfactant further decreases injury and improves respiratory physiology in betamethasone treated animals. IMPACT: Antenatal betamethasone improved lung and systemic physiology in the setting of intra-amniotic LPS. The addition of budesonide to the surfactant further improved lung function. Budesonide levels in the plasma and lung were lower in lambs exposed to either LPS or LPS and Betamethasone animals, and these findings were not explained by increased esterification in the lungs. The combination of antenatal steroids and budesonide with surfactant had the lowest markers of pro-inflammatory cytokines in the lung of LPS exposed animals.

3.
Am J Physiol Lung Cell Mol Physiol ; 324(6): L815-L824, 2023 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-37096911

RESUMO

Mechanical ventilation causes airway injury, respiratory epithelial cell proliferation, and lung inflammation in preterm sheep. Whether preterm epithelial cells respond similarly to adult epithelial cells or are altered by mechanical ventilation is unknown. We test the hypothesis that mechanical ventilation alters the responses of preterm airway epithelium to stimulation in culture. Respiratory epithelial cells from the trachea, left mainstem bronchi (LMSB), and distal bronchioles were harvested from unventilated preterm lambs, ventilated preterm lambs, and adult ewes. Epithelial cells were grown in culture or on air-liquid interface (ALI) and challenged with combinations of either media only, lipopolysaccharide (LPS; 10 ng/mL), bronchoalveolar fluid (BALF), or interleukin-13 (IL-13). Cell lysates were evaluated for mRNA changes in cytokine, cell type markers, Notch pathway, and acute phase markers. Mechanical ventilation altered preterm respiratory epithelium cell types. Preterm respiratory epithelial cells responded to LPS in culture with larger IL-8 induction than adults, and mechanical ventilation further increased cytokines IL-1ß and IL-8 mRNA induction at 2 h. IL-8 protein is detected in cell media after LPS stimulation. The addition of BALF from ventilated preterm animals increased IL-1ß mRNA to LPS (fivefold) in both preterm and adult cells and suppressed IL-8 mRNA (twofold) in adults. Preterm respiratory epithelial cells, when grown on ALI, responded to IL-13 with an increase in goblet cell mRNA. Preterm respiratory epithelial cells responded to LPS and IL-13 with responses similar to adults. Mechanical ventilation or exposure to BALF from mechanically ventilated animals alters the responses to LPS.NEW & NOTEWORTHY Preterm lamb respiratory epithelial cells can be extracted from the trachea and bronchi and frozen, and the preterm cells can respond in culture to stimulation with LPS or IL-13. Brief mechanical ventilation changes the distribution and cell type of preterm respiratory cells toward an adult phenotype, and mechanical ventilation alters the response to LPS in culture. Bronchoalveolar lavage fluid from preterm lambs receiving mechanical ventilation also alters unventilated preterm and adult responses to LPS.


Assuntos
Interleucina-13 , Respiração Artificial , Animais , Ovinos , Feminino , Respiração Artificial/efeitos adversos , Interleucina-13/metabolismo , Lipopolissacarídeos/farmacologia , Lipopolissacarídeos/metabolismo , Interleucina-8/metabolismo , Células Epiteliais/metabolismo , RNA Mensageiro/metabolismo , Pulmão/metabolismo
4.
Pediatr Res ; 90(2): 328-334, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33177678

RESUMO

BACKGROUND: Chorioamnionitis is associated with increased rates of bronchopulmonary dysplasia (BPD) in ventilated preterm infants. Budesonide when added to surfactant decreased lung and systemic inflammation from mechanical ventilation in preterm lambs and decreased the rates and severity of BPD in preterm infants. We hypothesized that the addition of budesonide to surfactant will decrease the injury from mechanical ventilation in preterm lambs exposed to intra-amniotic (IA) lipopolysaccharide (LPS). METHODS: Lambs at 126 ± 1 day GA received LPS 10 mg IA 48 h prior to injurious mechanical ventilation. After 15 min, lambs received either surfactant mixed with: (1) saline or (2) Budesonide 0.25 mg/kg, then ventilated with normal tidal volumes for 4 h. Injury markers in the lung, liver, and brain were compared. RESULTS: Compared with surfactant alone, the addition of budesonide improved blood pressures, dynamic compliance, and ventilation, while decreasing mRNA for pro-inflammatory cytokines in the lung, liver, and multiple areas of the brain. LPS caused neuronal activation and structural changes in the brain that were not altered by budesonide. Budesonide was not retained within the lung beyond 4 h. CONCLUSIONS: In preterm lambs exposed to IA LPS, the addition of budesonide to surfactant improved physiology and markers of lung and systemic inflammation. IMPACT: The addition of budesonide to surfactant decreases the lung and systemic responses to injurious mechanical ventilation preterm lambs exposed to fetal LPS. Budesonide was present in the plasma by 15 min and the majority of the budesonide is no longer in the lung at 4 h of ventilation. IA LPS and mechanical ventilation caused structural changes in the brain that were not altered by short-term exposure to budesonide. The budesonide dose of 0.25 mg/kg being used clinically seems likely to decrease lung inflammation in preterm infants with chorioamnionitis.


Assuntos
Produtos Biológicos/farmacologia , Displasia Broncopulmonar/prevenção & controle , Budesonida/farmacologia , Corioamnionite/tratamento farmacológico , Doenças Fetais/prevenção & controle , Glucocorticoides/farmacologia , Pulmão/efeitos dos fármacos , Fosfolipídeos/farmacologia , Pneumonia/prevenção & controle , Surfactantes Pulmonares/farmacologia , Síndrome de Resposta Inflamatória Sistêmica/prevenção & controle , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Encéfalo/fisiopatologia , Displasia Broncopulmonar/etiologia , Displasia Broncopulmonar/metabolismo , Displasia Broncopulmonar/fisiopatologia , Corioamnionite/induzido quimicamente , Corioamnionite/metabolismo , Corioamnionite/fisiopatologia , Citocinas/metabolismo , Modelos Animais de Doenças , Quimioterapia Combinada , Feminino , Doenças Fetais/etiologia , Doenças Fetais/metabolismo , Doenças Fetais/fisiopatologia , Idade Gestacional , Mediadores da Inflamação/metabolismo , Lipopolissacarídeos , Pulmão/metabolismo , Pulmão/fisiopatologia , Pneumonia/etiologia , Pneumonia/metabolismo , Pneumonia/fisiopatologia , Gravidez , Respiração Artificial/efeitos adversos , Carneiro Doméstico , Síndrome de Resposta Inflamatória Sistêmica/etiologia , Síndrome de Resposta Inflamatória Sistêmica/metabolismo , Síndrome de Resposta Inflamatória Sistêmica/fisiopatologia
5.
CBE Life Sci Educ ; 19(3): ar47, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32870084

RESUMO

Epistemological beliefs about science (EBAS) or beliefs about the nature of science knowledge, and how that knowledge is generated during inquiry, are an essential yet difficult to assess component of science literacy. Leveraging learning analytics to capture and analyze student practices in simulated or game-based authentic science activities is a potential avenue for assessing EBAS. Our previous work characterized inquiry practices of experts and novices engaged in simulated authentic science inquiry and suggested that practices may reflect EBAS. Here, we extend our prior qualitative work to quantitatively examine differences in practices and EBAS between non-science majors, biology majors, and biology graduates. We observed that inquiry practices of non-science majors and biology graduates were similar to the novice and expert practices, respectively, in our prior work. However, biology majors sometimes appeared to act like their undergraduate peers (e.g., performing fewer planning actions) but other times were more similar to biology graduates (e.g., performing complex investigations). We noted that cognitive constructs like metacognition were also important for understanding which practices were most likely to be reflective of EBAS. This work advances how to assess EBAS using learning analytics and raises questions regarding the development of cognitive processes like EBAS among aspiring biologists.


Assuntos
Ciência , Produtos Biológicos , Cultura , Avaliação Educacional , Humanos , Aprendizagem
6.
Pediatr Res ; 88(5): 726-732, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32066138

RESUMO

BACKGROUND: The addition of budesonide (Bud) 0.25 mg/kg to surfactant decreased the lung and systemic responses to mechanical ventilation in preterm sheep and the rates and severity of bronchopulmonary dysplasia (BPD) in preterm infants. We hypothesized that lower budesonide concentrations in surfactant will decrease injury while decreasing systemic corticosteroid exposure. METHODS: Preterm lambs received either (1) protective tidal volume (VT) ventilation with surfactant from birth or (2) injurious VT ventilation for 15 min and then surfactant treatment. Lambs were further assigned to surfactant mixed with (i) Saline, (ii) Bud 0.25 mg/kg, (iii) Bud 0.1 mg/kg, or (iv) Bud 0.04 mg/kg. All lambs were then ventilated with protective VT for 6 h. RESULTS: Plasma Bud levels were proportional to the dose received and decreased throughout ventilation. In both protective and injurious VT ventilation, <4% of Bud remained in the lung at 6 h. Some of the improvements in physiology and markers of injury with Bud 0.25 mg/kg were also found with 0.1 mg/kg, whereas 0.04 mg/kg had only minimal effects. CONCLUSIONS: Lower doses of Bud were less effective at decreasing lung and systemic inflammation from mechanical ventilation. The plasma Bud levels were proportional to dose given and the majority left the lung.


Assuntos
Produtos Biológicos/administração & dosagem , Displasia Broncopulmonar/prevenção & controle , Budesonida/administração & dosagem , Glucocorticoides/administração & dosagem , Pulmão/efeitos dos fármacos , Fosfolipídeos/administração & dosagem , Surfactantes Pulmonares/administração & dosagem , Animais , Animais Recém-Nascidos , Displasia Broncopulmonar/etiologia , Displasia Broncopulmonar/metabolismo , Displasia Broncopulmonar/fisiopatologia , Budesonida/farmacocinética , Citocinas/genética , Citocinas/metabolismo , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Quimioterapia Combinada , Idade Gestacional , Glucocorticoides/farmacocinética , Fígado/efeitos dos fármacos , Fígado/metabolismo , Pulmão/metabolismo , Pulmão/fisiopatologia , Nascimento Prematuro , Respiração Artificial , Carneiro Doméstico , Distribuição Tecidual
7.
Am J Physiol Lung Cell Mol Physiol ; 318(1): L41-L48, 2020 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-31617728

RESUMO

Mechanical ventilation from birth with normal tidal volumes (VT) causes lung injury and systemic responses in preterm sheep. The addition of budesonide to surfactant therapy decreases these injury markers. Budesonide and surfactant will decrease the injury from injurious VT ventilation in preterm sheep. Lambs at 126 ± 1 day gestational age were ventilated from birth with either: 1) Normal VT [surfactant 200 mg/kg before ventilation, positive end expiratory pressure (PEEP) 5 cmH2O, VT 8 mL/kg] or 2) Injury VT (high pressure, 100% oxygen, no PEEP) for 15 min, then further randomized to surfactant + saline or surfactant + 0.25 mg/kg budesonide with Normal VT for 6 h. Lung function and lung, liver, and brain tissues were evaluated for indicators of injury. Injury VT + saline caused significant injury and systemic responses, and Injury VT + budesonide improved lung physiology. Budesonide decreased lung inflammation and decreased pro-inflammatory cytokine mRNA in the lung, liver, and brain to levels similar to Normal VT + saline. Budesonide was present in plasma within 15 min of treatment in both ventilation groups, and less than 5% of the budesonide remained in the lung at 6 h. mRNA sequencing of liver and periventricular white matter demonstrated multiple pathways altered by both Injury VT and budesonide and the combination exposure. In lambs receiving Injury VT, the addition of budesonide to surfactant improved lung physiology and decreased pro-inflammatory cytokine responses in the lung, liver, and brain to levels similar to lambs receiving Normal VT.


Assuntos
Budesonida/farmacologia , Lesão Pulmonar/tratamento farmacológico , Pulmão/efeitos dos fármacos , Surfactantes Pulmonares/farmacologia , Respiração Artificial/efeitos adversos , Animais , Animais Recém-Nascidos/metabolismo , Citocinas/metabolismo , Feminino , Idade Gestacional , Humanos , Recém-Nascido , Fígado/efeitos dos fármacos , Fígado/metabolismo , Pulmão/metabolismo , Lesão Pulmonar/metabolismo , Pneumonia/tratamento farmacológico , Pneumonia/metabolismo , Respiração com Pressão Positiva/métodos , Gravidez , Nascimento Prematuro/metabolismo , RNA Mensageiro/metabolismo , Respiração/efeitos dos fármacos , Ovinos , Volume de Ventilação Pulmonar/efeitos dos fármacos
8.
J Leukoc Biol ; 106(1): 95-103, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30924969

RESUMO

Gut immune system homeostasis involves diverse structural interactions among resident microbiota, the protective mucus layer, and a variety of cells (intestinal epithelial, lymphoid, and myeloid). Due to the substantial surface area in direct contact with an "external" environment and the diversity of xenobiotic, abiotic, and self-interactions coordinating to maintain gut homeostasis, there is enhanced potential for the generation of endogenous danger signals when this balance is lost. Here, we focus on the potential generation and reception of damage in the gut resulting from exposure to nanoparticles (NPs), common food and drug additives. Specifically, we describe recent evidence in the literature showing that certain NPs are potential generators of damage-associated molecular patterns, as well as potential immune-stimulating molecular patterns themselves.


Assuntos
Alarminas/fisiologia , Mucosa Intestinal/efeitos dos fármacos , Nanopartículas/toxicidade , Trifosfato de Adenosina/metabolismo , Administração Oral , Animais , DNA Mitocondrial/fisiologia , Homeostase , Humanos , Mucosa Intestinal/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/fisiologia , Nanopartículas/metabolismo , Estresse Oxidativo/efeitos dos fármacos
9.
Am J Physiol Lung Cell Mol Physiol ; 316(5): L888-L893, 2019 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-30838863

RESUMO

Mechanical ventilation with normal tidal volumes (VT) causes lung and systemic inflammation in preterm sheep. Mechanical ventilation is associated with bronchopulmonary dysplasia (BPD) in preterm infants, and the addition of budesonide to surfactant decreases BPD in clinical trials. Budesonide with surfactant will decrease the lung injury from mechanical ventilation for 24 h in preterm sheep. Lambs at 126 ± 1 day gestational age were delivered and randomized to either: 1) surfactant (200 mg/kg) or 2) surfactant mixed with budesonide (0.25 mg/kg) before mechanical ventilation with VT of 7-8 ml/kg for 2, 6, or 24 h (n = 6 or 7/group). Lung physiology and budesonide levels in the plasma and the lung were measured. Lung tissue, bronchoalveolar lavage fluid (BALF), liver, and brain tissues were evaluated for indicators of injury. High initial budesonide plasma levels of 170 ng/ml decreased to 3 ng/ml at 24 h. Lung tissue budesonide levels were less than 1% of initial dose by 24 h. Although physiological variables were generally similar, budesonide-exposed lambs required lower mean airway pressures, had higher hyperoxia responses, and had more stable blood pressures. Budesonide decreased proinflammatory mRNA in the lung, liver, and brain. Budesonide also decreased total protein and proinflammatory cytokines in BALF, and decreased inducible nitric oxide synthase activation at 24 h. In ventilated preterm lambs, most of the budesonide left the lung within 24 h. The addition of budesonide to surfactant improved physiology, decreased markers of lung injury, and decreased systemic responses in liver and brain.


Assuntos
Budesonida , Pulmão , Pneumonia , Surfactantes Pulmonares , Respiração Artificial , Animais , Animais Recém-Nascidos , Encéfalo/metabolismo , Encéfalo/patologia , Encéfalo/fisiopatologia , Budesonida/farmacocinética , Budesonida/farmacologia , Inflamação/metabolismo , Inflamação/patologia , Inflamação/fisiopatologia , Inflamação/terapia , Fígado/metabolismo , Fígado/patologia , Fígado/fisiopatologia , Pulmão/metabolismo , Pulmão/patologia , Pulmão/fisiopatologia , Pneumonia/metabolismo , Pneumonia/patologia , Pneumonia/fisiopatologia , Pneumonia/terapia , Surfactantes Pulmonares/farmacocinética , Surfactantes Pulmonares/farmacologia , Ovinos
10.
PLoS One ; 13(7): e0200713, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30005089

RESUMO

BACKGROUND: Epidermal growth factor receptor (EGFR) is important for airway branching and lung maturation. Mechanical ventilation of preterm lambs causes increases in EGFR and EGFR ligand mRNA in the lung. Abnormal EGFR signaling may contribute to the development of bronchopulmonary dysplasia. HYPOTHESIS: Inhibition of EGFR signaling will decrease airway epithelial cell proliferation and lung inflammation caused by mechanical ventilation in preterm, fetal sheep. METHODS: Following exposure of the fetal head and chest at 123±1 day gestational age and with placental circulation intact, fetal lambs (n = 4-6/group) were randomized to either: 1) Gefitinib 15 mg IV and 1 mg intra-tracheal or 2) saline IV and IT. Lambs were further assigned to 15 minutes of either: a) Injurious mechanical ventilation (MV) or b) Continuous positive airway pressure (CPAP) 5 cmH2O. After the 15 minute intervention, the animals were returned to the uterus and delivered after i) 6 or ii) 24 hours in utero. RESULTS: MV caused lung injury and inflammation, increased lung mRNA for cytokines and EGFR ligands, caused airway epithelial cell proliferation, and decreased airway epithelial phosphorylated ERK1/2. Responses to MV were unchanged by Gefitinib. Gefitinib altered expression of EGFR mRNA in the lung and liver of both CPAP and MV animals. Gefitinib decreased the liver SAA3 mRNA response to MV at 6 hours. There were no differences in markers of lung injury or inflammation between CPAP animals receiving Gefitinib or saline. CONCLUSION: Inhibition of the EGFR pathway did not alter acute lung inflammation or injury from mechanical ventilation in preterm sheep.


Assuntos
Displasia Broncopulmonar/patologia , Receptores ErbB/antagonistas & inibidores , Desenvolvimento Fetal/efeitos dos fármacos , Gefitinibe/uso terapêutico , Pulmão/crescimento & desenvolvimento , Inibidores de Proteínas Quinases/uso terapêutico , Animais , Proliferação de Células/efeitos dos fármacos , Modelos Animais de Doenças , Família de Proteínas EGF/metabolismo , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/patologia , Receptores ErbB/fisiologia , Feminino , Gefitinibe/farmacologia , Humanos , Pulmão/citologia , Pulmão/patologia , Gravidez , Inibidores de Proteínas Quinases/farmacologia , Respiração Artificial/efeitos adversos , Carneiro Doméstico , Resultado do Tratamento
11.
Am J Physiol Lung Cell Mol Physiol ; 315(2): L193-L201, 2018 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-29671605

RESUMO

Mechanical ventilation causes lung injury and systemic inflammatory responses in preterm sheep and is associated with bronchopulmonary dysplasia (BPD) in preterm infants. Budesonide added to surfactant decreased BPD by 20% in infants. We wanted to determine the effects of budesonide and surfactant on injury from high tidal volume (VT) ventilation in preterm lambs. Ewes at 125 ± 1 days gestational age had fetal surgery to expose fetal head and chest with placental circulation intact. Lambs were randomized to 1) mechanical ventilation with escalating VT to target 15 ml/kg by 15 min or 2) continuous positive airway pressure (CPAP) of 5 cmH2O. After the 15-min intervention, lambs were given surfactant 100 mg/kg with saline, budesonide 0.25 mg/kg, or budesonide 1 mg/kg. The fetuses were returned to the uterus for 24 h and then delivered and ventilated for 30 min to assess lung function. Budesonide levels were low in lung and plasma. CPAP groups had improved oxygenation, ventilation, and decreased injury markers compared with fetal VT lambs. Budesonide improved ventilation in CPAP lambs. Budesonide decreased lung weights and lung liquid and increased lung compliance and surfactant protein mRNA. Budesonide decreased proinflammatory and acute-phase responses in lung. Airway thickness increased in animals not receiving budesonide. Systemically, budesonide decreased monocyte chemoattractant protein-1 mRNA and preserved glycogen in liver. Results with 0.25 and 1 mg/kg budesonide were similar. We concluded that budesonide with surfactant matured the preterm lung and decreased the liver responses but did not improve lung function after high VT injury in fetal sheep.


Assuntos
Displasia Broncopulmonar , Budesonida , Feto , Nascimento Prematuro/terapia , Surfactantes Pulmonares , Animais , Displasia Broncopulmonar/metabolismo , Displasia Broncopulmonar/patologia , Displasia Broncopulmonar/fisiopatologia , Displasia Broncopulmonar/terapia , Budesonida/farmacocinética , Budesonida/farmacologia , Feminino , Feto/metabolismo , Feto/patologia , Feto/fisiopatologia , Fígado/metabolismo , Fígado/patologia , Fígado/fisiopatologia , Pulmão/metabolismo , Pulmão/patologia , Pulmão/fisiopatologia , Gravidez , Nascimento Prematuro/metabolismo , Nascimento Prematuro/patologia , Nascimento Prematuro/fisiopatologia , Surfactantes Pulmonares/farmacocinética , Surfactantes Pulmonares/farmacologia , Respiração Artificial/efeitos adversos , Respiração Artificial/métodos , Ovinos
12.
PLoS One ; 11(7): e0159754, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27463520

RESUMO

BACKGROUND: Mechanical ventilation at birth causes airway injury and lung inflammation in preterm sheep. Continuous positive airway pressure (CPAP) is being increasingly used clinically to transition preterm infants at birth. OBJECTIVE: To test if distending pressures will activate acute phase reactants and inflammatory changes in the airways of fetal, preterm lambs. METHODS: The head and chest of fetal lambs at 128±1 day GA were surgically exteriorized. With placental circulation intact, fetal lambs were then randomized to one of five 15 minute interventions: PEEP of 0, 4, 8, 12, or 16 cmH2O. Recruitment volumes were recorded. Fetal lambs remained on placental support for 30 min after the intervention. The twins of each 0 cmH2O animal served as controls. Fetal lung fluid (FLF), bronchoalveolar lavage fluid (BAL), right mainstem bronchi and peripheral lung tissue were evaluated for inflammation. RESULTS: Recruitment volume increased from 0.4±0.04 mL/kg at 4 cmH2O to 2.4±0.3 mL/kg at 16 cmH2O. The lambs were surfactant deficient, and all pressures were below the opening inflection pressure on pressure-volume curve. mRNA expression of early response genes and pro-inflammatory cytokines did not increase in airway tissue or lung tissue at any pressure compared to controls. FLF and BAL also did not have increases in early response proteins. No histologic changes or Egr-1 activation was present at the pressures used. CONCLUSION: Distending pressures as high as 16 cmH2O did not recruit lung volume at birth and did not increase markers of injury in the lung or airways in non-breathing preterm fetal sheep.


Assuntos
Reação de Fase Aguda/etiologia , Asfixia Neonatal/terapia , Pulmão/patologia , Respiração com Pressão Positiva/efeitos adversos , Animais , Biomarcadores/metabolismo , Citocinas/genética , Citocinas/metabolismo , Feminino , Pulmão/imunologia , Respiração com Pressão Positiva/métodos , Ovinos
13.
Am J Physiol Lung Cell Mol Physiol ; 311(2): L412-20, 2016 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-27343193

RESUMO

Mechanical ventilation of preterm lambs causes lung inflammation and injury to the airway epithelium, which is repaired by 15 days after ventilation. In mice, activated basal cells (p63+, KRT14+, KRT8+) initiate injury repair to the trachea, whereas club cells coordinate distal airway repair. In both human and sheep, basal cells line the pseudostratified airways to the distal bronchioles with club cells only present in terminal bronchioles. Mechanical ventilation causes airway epithelial injury that is repaired through basal cell activation in the fetal lung. Ewes at 123 ± 1 day gestational age had the head and chest of the fetus exteriorized and tracheostomy placed. With placental circulation intact, fetal lambs were mechanically ventilated with up to 15 ml/kg for 15 min with 95% N2/5% CO2 Fetal lambs were returned to the uterus for up to 24 h. The trachea, left mainstem bronchi, and peripheral lung were evaluated for epithelial injury and cellular response consistent with repair. Peripheral lung tissue had inflammation, pro-inflammatory cytokine production, epithelial growth factor receptor ligand upregulation, increased p63 expression, and proliferation of pro-SPB, TTF-1 positive club cells. In bronchi, KRT14 and KRT8 mRNA increased without increases in Notch pathway mRNA or proliferation. In trachea, mRNA increased for Notch ligands, SAM pointed domain-containing Ets transcription factor and mucin 5B, but not for basal cell markers. A brief period of mechanical ventilation causes differential epithelial activation between trachea, bronchi, and peripheral lung. The repair mechanisms identified in adult mice occur at different levels of airway branching in fetal sheep with basal and club cell activation.


Assuntos
Feto/fisiopatologia , Respiração Artificial/efeitos adversos , Animais , Apoptose , Proliferação de Células , Feminino , Feto/patologia , Humanos , Pulmão/imunologia , Pulmão/patologia , Pulmão/fisiopatologia , Masculino , Camundongos , Mucinas/biossíntese , Mucinas/genética , Pneumonia/imunologia , Pneumonia/fisiopatologia , Gravidez , Receptores Notch/metabolismo , Regeneração , Respiração , Mucosa Respiratória/fisiopatologia , Carneiro Doméstico , Transdução de Sinais , Volume de Ventilação Pulmonar
14.
J Neurosci ; 32(15): 5054-61, 2012 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-22496551

RESUMO

Axonal degeneration is a molecular self-destruction cascade initiated following traumatic, toxic, and metabolic insults. Its mechanism underlies a number of disorders including hereditary and diabetic neuropathies and the neurotoxic side effects of chemotherapy drugs. Molecules that promote axonal degeneration could represent potential targets for therapy. To identify such molecules, we designed a screening platform based on intoxication of Drosophila larvae with paclitaxel (taxol), a chemotherapeutic agent that causes neuropathy in cancer patients. In Drosophila, taxol treatment causes swelling, fragmentation, and loss of axons in larval peripheral nerves. This axonal loss is not due to apoptosis of neurons. Taxol-induced axonal degeneration in Drosophila shares molecular execution mechanisms with vertebrates, including inhibition by both NMNAT (nicotinamide mononucleotide adenylyltransferase) expression and loss of wallenda/DLK (dual leucine zipper kinase). In a pilot RNAi-based screen we found that knockdown of retinophilin (rtp), which encodes a MORN (membrane occupation and recognition nexus) repeat-containing protein, protects axons from degeneration in the presence of taxol. Loss-of-function mutants of rtp replicate this axonal protection. Knockdown of rtp also delays axonal degeneration in severed olfactory axons. We demonstrate that the mouse ortholog of rtp, MORN4, promotes axonal degeneration in mouse sensory axons following axotomy, illustrating conservation of function. Hence, this new model can identify evolutionarily conserved genes that promote axonal degeneration, and so could identify candidate therapeutic targets for a wide-range of axonopathies.


Assuntos
Antineoplásicos Fitogênicos/toxicidade , Axônios/fisiologia , Proteínas de Drosophila/genética , Proteínas de Drosophila/fisiologia , Proteínas do Olho/genética , Proteínas do Olho/fisiologia , Degeneração Neural/genética , Síndromes Neurotóxicas/genética , Paclitaxel/toxicidade , Animais , Antineoplásicos Fitogênicos/efeitos adversos , Apoptose/fisiologia , Axônios/ultraestrutura , Modelos Animais de Doenças , Drosophila , Feminino , Gânglios Espinais/citologia , Gânglios Espinais/fisiologia , Imuno-Histoquímica , Larva , Camundongos , Microscopia Confocal , Degeneração Neural/fisiopatologia , Síndromes Neurotóxicas/fisiopatologia , Paclitaxel/efeitos adversos , Nervos Periféricos/patologia , Nervos Periféricos/ultraestrutura , Interferência de RNA
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