NRASQ61R mutation drives elevated angiopoietin-2 expression in human endothelial cells and a genetic mouse model.

BACKGROUND: Angiopoietin-2 (Ang-2) is increased in the blood of patients with kaposiform lymphangiomatosis (KLA) and kaposiform hemangioendothelioma (KHE). While the genetic causes of KHE are not clear, a somatic activating NRASQ61R mutation has been found in the lesions of KLA patients. PROCEDURE: Our study tested the hypothesis that the NRASQ61R mutation drives elevated Ang-2 expression in endothelial cells. Ang-2 was measured in human endothelial progenitor cells (EPC) expressing NRASQ61R and a genetic mouse model with endothelial targeted NRASQ61R. To determine the signaling pathways driving Ang-2, NRASQ61R EPC were treated with signaling pathway inhibitors. RESULTS: Ang-2 levels were increased in EPC expressing NRASQ61R compared to NRASWT by Western blot analysis of cell lysates and ELISA of the cell culture media. Ang-2 levels were elevated in the blood of NRASQ61R mutant mice. NRASQ61R mutant mice also had reduced platelet counts and splenomegaly with hypervascular lesions, like some KLA patients. mTOR inhibitor rapamycin attenuated Ang-2 expression by NRASQ61R EPC. However, MEK1/2 inhibitor trametinib was more effective blocking increases in Ang-2. CONCLUSIONS: Our studies show that the NRASQ61R mutation in endothelial cells induces Ang-2 expression in vitro and in vivo. In cultured human endothelial cells, NRASQ61R drives elevated Ang-2 through MAP kinase and mTOR-dependent signaling pathways.

NRASQ61R mutation in human endothelial cells causes vascular malformations.

Somatic mutations in NRAS drive the pathogenesis of melanoma and other cancers but their role in vascular anomalies and specifically human endothelial cells is unclear. The goals of this study were to determine whether the somatic-activating NRASQ61R mutation in human endothelial cells induces abnormal angiogenesis and to develop in vitro and in vivo models to identify disease-causing pathways and test inhibitors. Here, we used mutant NRASQ61R and wild-type NRAS (NRASWT) expressing human endothelial cells in in vitro and in vivo angiogenesis models. These studies demonstrated that expression of NRASQ61R in human endothelial cells caused a shift to an abnormal spindle-shaped morphology, increased proliferation, and migration. NRASQ61R endothelial cells had increased phosphorylation of ERK compared to NRASWT cells indicating hyperactivation of MAPK/ERK pathways. NRASQ61R mutant endothelial cells generated abnormal enlarged vascular channels in a 3D fibrin gel model and in vivo, in xenografts in nude mice. These studies demonstrate that NRASQ61R can drive abnormal angiogenesis in human endothelial cells. Treatment with MAP kinase inhibitor U0126 prevented the change to a spindle-shaped morphology in NRASQ61R endothelial cells, whereas mTOR inhibitor rapamycin did not.

Constitutively active PIK3CA mutations are expressed by lymphatic and vascular endothelial cells in capillary lymphatic venous malformation.

Capillary lymphatic venous malformations (CLVM) are complex vascular anomalies characterized by aberrant and enlarged lymphatic and blood vessels. CLVM appear during fetal development and enlarge after birth, causing life-long complications such as coagulopathy, pulmonary embolism, chronic pain, and disfigurement. Treatment includes surgical debulking, amputation, and recurrent sclerotherapy. Somatic, mosaic mutations in the 110-kD catalytic α-subunit of phosphoinositide-3-kinase (PIK3CA) gene have been previously identified in affected tissues from CLVM patients; however, the cell population harboring the mutation is still unknown. In this study, we hypothesized that endothelial cells (EC) carry the PIK3CA mutations and play a major role in the cellular origin of CLVM. We isolated EC from the lesions of seven patients with CLVM and identified PIK3CA hotspot mutations. The CLVM EC exhibited constitutive phosphorylation of the PI3K effector AKT as well as hyperproliferation and increased resistance to cell death compared to normal EC. Inhibitors of PIK3CA (BYL719) and AKT (ARQ092) attenuated the proliferation of CLVM EC in a dose-dependent manner. A xenograft model of CLVM was developed by injecting patient-derived EC into the flanks of immunocompromised mice. CLVM EC formed lesions with enlarged lymphatic and vascular channels, recapitulating the patient histology. EC subpopulations were further obtained by both immunomagnetic separation into lymphatic EC (LEC) and vascular EC (VEC) and generation of clonal populations. By sequencing these subpopulations, we determined that both LEC and VEC from the same patient express the PIK3CA mutation, exhibit increased AKT activation and can form lymphatic or vascular lesions in mouse.

Alasdair MacIntyre's writings on medicine and medical ethics / Escritos de Alasdair MacIntyre sobre medicina y ética médica / Escritos de Alasdair MacIntyre sobre medicina e ética médica

Abstract Alasdair MacIntyre is a contemporary philosopher of Ethics and Politics best known for his book "After virtue", 1981. The originality and relevance of this work lie in the presentation of his articles from the 1970's about medicine and medical ethics, which are unexplored in Bioethics. In these articles, MacIntyre criticizes changes in society transforming the physician-patient relationship: fragmentary moral views, individualism, misunderstanding of scientism and fallibility of the practice, as well as the lost background of common values and medical authority. From a teleological perspective, MacIntyre describes internal goods of medicine and physician's virtues: reliability, fairness, courage, humility and even, friendship.

Resumen Alasdair MacIntyre es un filósofo contemporáneo de Ética y Política, mejor conocido por su libro "Tras la virtud", de 1981. La originalidad y relevancia de este trabajo se encuentran en la presentación de sus artículos de la década de 1970 sobre medicina y ética médica, que no han sido explorados en Bioética. En estos artículos, MacIntyre critica los cambios en la sociedad que transforman la relación médico-paciente: visiones morales fragmentarias, individualismo, incomprensión del cientificismo y la falibilidad de la práctica, además de las pérdidas de la base en valores comunes y la autoridad médica. En una perspectiva teleológica, MacIntyre describe los bienes internos de la medicina y las virtudes de los médicos: fiabilidad, justicia, coraje, humildad e incluso amistad.

Resumo Alasdair MacIntyre é um filósofo contemporâneo de ética e política, mais conhecido por seu livro "Depois da virtude", 1981. A originalidade e a relevância deste trabalho estão na apresentação de artigos escritos por ele nos anos 1970 sobre medicina e ética médica, inexplorados no campo da bioética. Nestes artigos, MacIntyre critica as mudanças na sociedade que transformam a relação médico-paciente: visões morais fragmentárias, individualismo, a incompreensão da cientificidade e falibilidade da prática, além das perdas do embasamento em valores comuns e da autoridade médica. Em perspectiva teleológica, MacIntyre define bens internos à medicina e virtudes que os médicos devem possuir: confiabilidade, justiça, coragem, humildade e até amizade.

Do Burnout à Estratégia de Grupo na Perspectiva Balint: Experiência com Residentes de Pediatria de um Hospital Terciário / From Burnout to the "Balint Group" Strategy: Experience with Pediatric Residents of a Tertiary Care Hospital

RESUMO A síndrome de burnout (esgotamento) atinge mais de 70% dos médicos residentes em todo o mundo. Apesar dos dados alarmantes, ainda podemos caracterizá-la como uma doença negligenciada. Alguns trabalhos descrevem estratégias de enfrentamento do problema, porém poucos serviços as adotam na prática. Objetivo Determinar a prevalência da síndrome entre residentes de Pediatria de um hospital terciário brasileiro e descrever a estratégia de grupo psicodinâmico implementada localmente com base nos resultados. Metodologia Estudo de prevalência transversal com aplicação da escala Maslach Burnout Inventory aos residentes, seguida de planejamento e execução de um projeto piloto de intervenção, de grupo, na perspectiva Balint. Resultados De 23 residentes de primeiro e segundo ano de Pediatria em dezembro de 2016, 95% eram do sexo feminino, a média de idade era de 27 anos, e a média da carga horária trabalhada era de 75 horas semanais, sendo que apenas três residentes se dedicavam exclusivamente à residência médica. Encontramos uma prevalência de 87% de residentes que apresentavam critérios para síndrome de burnout, sendo 74% com exaustão, 57% com baixa realização profissional e 39% despersonalizados. O grupo de intervenção ocorreu entre maio e dezembro de 2017 com outros seis residentes de primeiro ano que atendiam no Ambulatório Geral de Pediatria às sextas-feiras. A periodicidade foi de uma hora a cada 15 dias. A participação foi voluntária, e os encontros aconteciam segundo o conceito de "espaço protegido". As discussões eram baseadas em casos clínicos e abordavam também a relação médico-família e as dinâmicas hospitalares. Conclusão A elevada prevalência da síndrome de burnout deste trabalho não foi uma novidade frente aos dados da literatura nacional e internacional. Estabelecemos, porém, uma discussão local que resultou numa estratégia que visa ao bem-estar dos residentes e proporciona oportunidade de aprendizado do reconhecimento das reações pessoais, dos pacientes e de toda a equipe de saúde. Entendemos que os benefícios se dão, finalmente, na qualidade da assistência oferecida aos pacientes.

ABSTRACT Burnout syndrome affects more than 70% of resident physicians worldwide. Despite his alarming statistic, it can still be characterized as a neglected disease. Some studies have described coping strategies, but few services adopt them in practice. The aims of this study were to determine the prevalence of Burnout syndrome among pediatric residents of a Brazilian tertiary hospital, and to describe a psychodynamic group strategy that was implemented locally, based on the results. Methodology a cross-sectional prevalence study using the Maslach Burnout Inventory scale, followed by the planning and execution of a pilot intervention group, from the Balint perspective. Results of 23 first and second year pediatric residents in December 2016, 95% were female; the mean age was 27 years, and the average workload was 75 hours per week. Only 3 residents were exclusively dedicated to the medical residency. The prevalence of burnout syndrome was 87%, with exhaustion in 74%, low professional achievement in 57%, and depersonalization in 39%. The intervention group took place between May and December 2017, with six other first-year residents attending the General Pediatric Outpatient Clinic on Fridays. Meetings of the group took place every 15 days, lasted one hour, and adhered to the concept of "protected space". Participation in the meetings was voluntary. The discussions were based on clinical cases, also addressing the doctor-family relationship and the hospital dynamics. Conclusion The high prevalence of burnout syndrome found in this study was comparable to data from national and international literature. However, our study established a local discussion that resulted in a strategy aimed at the well-being of residents and provided an opportunity to learn to recognize personal reactions, as well as those of patients and the whole healthcare team. We also hope this study will bring benefits for the quality of care provided to patients.

Signaling pathways and inhibitors of cells from patients with kaposiform lymphangiomatosis.

BACKGROUND: Kaposiform lymphangiomatosis (KLA) is a rare lymphatic anomaly with significant morbidity and mortality. KLA is characterized by diffuse multifocal lesions comprised of focal areas of "kaposiform" spindled cells accompanying malformed lymphatic channels. The goal of this study was to identify activated signaling pathways in cells isolated from three KLA patients for the purpose of testing new therapies. PROCEDURE: Cells were obtained from the lungs of one patient isolated at autopsy and the spleen of two patients removed in surgery due to disease complications. A protein kinase array was performed on the KLA cell lysates and normal lymphatic endothelial cells. RESULTS: Higher activation of key signaling pathways in the KLA cells, including PRAS40, AKT1/2/3, and ERK-1/2, was identified by protein kinase array and confirmed by Western blot analysis. This indicated a role for highly activated PI3K-AKT and MAPK-ERK-1/2 signaling pathways in KLA cells. Cell proliferation studies assessed PI3K inhibitors (LY294002; BYL719), AKT inhibitor ARQ092, mTOR inhibitor rapamycin, and MAPK inhibitor U0126. These studies demonstrated that PI3K-AKT-mTOR and MAPK signaling are important mediators of KLA cell proliferation. BYL719 and rapamycin were more effective at inhibiting KLA cell proliferation than U0126. CONCLUSIONS: Our studies using cells from KLA patient lesions demonstrate that these cells are highly proliferative and the PI3K-AKT-mTOR and MAPK pathways are promising therapeutic targets. Development and clinical trials of PI3K, AKT, and MAPK inhibitors for cancer treatment and the data in this study lend support for early clinical trials assessing the efficacy of these inhibitors in KLA patients.

Ponatinib Combined With Rapamycin Causes Regression of Murine Venous Malformation.

Objective- Venous malformations (VMs) arise from developmental defects of the vasculature and are characterized by massively enlarged and tortuous venous channels. VMs grow commensurately leading to deformity, obstruction of vital structures, bleeding, and pain. Most VMs are associated with the activating mutation L914F in the endothelial cell (EC) tyrosine kinase receptor TIE2. Therapeutic options for VM are limited and ineffective while therapy with the mammalian target of rapamycin inhibitor rapamycin shows moderate efficacy. Here, we investigated novel therapeutic targets promoting VM regression. Approach and Results- We performed an unbiased screen of Food and Drug Administration-approved drugs in human umbilical vein ECs expressing the TIE2-L914F mutation (HUVEC-TIE2-L914F). Three ABL (Abelson) kinase inhibitors prevented cell proliferation of HUVEC-TIE2-L914F. Moreover, c-ABL, common target of these inhibitors, was highly phosphorylated in HUVEC-TIE2-L914F and VM patient-derived ECs with activating TIE2 mutations. Knockdown of c-ABL/ARG in HUVEC-TIE2-L914F reduced cell proliferation and vascularity of murine VM. Combination treatment with the ABL kinase inhibitor ponatinib and rapamycin caused VM regression in a xenograft model based on injection of HUVEC-TIE2-L914F. A reduced dose of this drug combination was effective in this VM murine model with minimal side effects. The drug combination was antiproliferative, enhanced cell apoptosis and vascular channel regression both in vivo and in a 3-dimensional fibrin gel assay. Conclusions- This is the first report of a combination therapy with ponatinib and rapamycin promoting regression of VM. Mechanistically, the drug combination enhanced AKT inhibition compared with single drug treatment and reduced PLCγ (phospholipase C) and ERK (extracellular signal-regulated kinase) activity.

Hypoxia-induced Pulmonary Hypertension in Different Mouse Strains: Relation to Transcriptome.

Patients with pulmonary arterial hypertension (PAH) can harbor mutations in several genes, most commonly in BMPR2. However, disease penetrance in patients with BMPR2 mutations is low. In addition, most patients do not carry known PAH gene mutations, suggesting that other factors determine susceptibility to PAH. To begin to identify additional genomic factors contributing to PAH pathogenesis, we exposed 32 mouse strains to chronic hypoxia. We found that the PL/J strain has extremely high right ventricular systolic pressure (RVSP; 86.58 mm Hg) but minimal lung remodeling. To identify potential genomic factors contributing to the high RVSP, RNAseq analysis of PL/J lung mRNAs and microRNAs (miRNAs) after hypoxia was performed, and it demonstrated that 4 of 43 upregulated miRNAs in the Dlk1-Dio3 imprinting region are predicted to target T cell marker mRNAs. These target mRNAs, as well as the numbers of T cells were downregulated. In addition, C5a and its receptor, C5AR1, were increased. Analysis of Rho-associated protein kinase (Rock) 2 mRNA expression, in the RhoA/Rock pathway, demonstrated a significant increase in PL/J. Inhibition of Rock2 ameliorated a portion of the elevated RVSP. In addition, we identified miR-150-5p as a potential regulator of Rock2 expression. In conclusion, we identified two possible pathways contributing to the hypoxia pulmonary hypertension phenotype of extreme RVSP elevation: aberrant T cell expression driven by hypoxia-induced miRNAs and increased expression of C5a and C5AR1. We suggest that the PL/J mouse will be a good model for seeking mechanism(s) of RVSP elevation in hypoxia-induced PAH.

CHILDREN WITH MULTIPLE CONGENITAL DEFECTS: WHAT ARE THE LIMITS BETWEEN THERAPEUTIC OBSTINACY AND THE TREATMENT OF UNCERTAIN BENEFIT? / CRIANÇAS COM MÚLTIPLAS MALFORMAÇÕES CONGÊNITAS: QUAIS SÃO OS LIMITES ENTRE OBSTINAÇÃO TERAPÊUTICA E TRATAMENTO DE BENEFÍCIO DUVIDOSO?

OBJECTIVE: Therapeutic approach of children with multiple malformations poses many dilemmas, making it difficult to build a line between the treatment of uncertain benefit and therapeutic obstinacy. The aim of this paper was to highlight possible sources of uncertainty in the decision-making process, for this group of children. CASE DESCRIPTION: An 11-month-old boy, born with multiple birth defects and abandoned by his parents, has never been discharged home. He has complex congenital heart disease, main left bronchus stenosis and imperforate anus. He is under technological support and has gone through many surgical procedures. The complete correction of the cardiac defect seems unlikely, and every attempt to wean the ventilator has failed. COMMENTS: The first two main sources of uncertainty in the management of children with multiple birth defects are related to an uncertain prognosis. There is a lack of empirical data, due to the multiple possibilities of anatomic or functional organ involvement, with few similar cases described. Prognosis is also unpredictable for neuro-developmental evolution, as well as the capacity for the development and regeneration of other organs. Another source of uncertainty is how to qualify the present and future life as worth living, by weighing the costs and benefits. The fourth source of uncertainty is who has the decision: physicians or parents? Finally, if a treatment is defined futile then, how to limit support? No single framework exists to help these delicate decision-making processes. We propose, then, that physicians should be committed to develop their own perception skills in order to understand patient's manifestations of needs and family values.

OBJETIVO: A abordagem terapêutica de crianças com múltiplas malformações inclui muitos dilemas, tornando difícil diferenciar um tratamento de benefício duvidoso da obstinação terapêutica. O objetivo deste artigo foi destacar as possíveis fontes de incerteza no processo de tomada de decisão para esse grupo de crianças. DESCRIÇÃO DO CASO: Lactente de 11 meses de idade, que nasceu com múltiplas malformações congênitas e foi abandonado por seus pais, nunca recebeu alta hospitalar. Ele tem cardiopatia congênita cianótica, estenose do brônquio fonte esquerdo e imperfuração anal. Passou por muitos procedimentos cirúrgicos e permanece sob suporte tecnológico. A correção total do defeito cardíaco parece improvável, e todas as tentativas de desmame do ventilador falharam. COMENTÁRIOS: As duas principais fontes de incerteza no processo de tomada de decisão para crianças com múltiplos defeitos congênitos estão relacionadas ao prognóstico incerto. Dados empíricos escassos são por conta das múltiplas possibilidades de envolvimento (anatômico ou funcional) de órgãos, com poucos casos semelhantes descritos na literatura. O prognóstico é também imprevisível para a evolução da capacidade cognitiva e para o desenvolvimento de outros órgãos. Outra fonte de incertezas é como qualificar uma vida como valendo a pena ser vivida, ponderando custos e benefícios. A quarta fonte de incerteza é quem tem a decisão: os médicos ou os pais? Finalmente, se um tratamento é definido como fútil, então, como limitar o suporte? Na ausência de um método universal para essa tomada de decisão, ficamos com a responsabilidade dos médicos em desenvolver suas habilidades de percepção das necessidades dos pacientes e dos valores familiares.

CRIANÇAS COM MÚLTIPLAS MALFORMAÇÕES CONGÊNITAS: QUAIS SÃO OS LIMITES ENTRE OBSTINAÇÃO TERAPÊUTICA E TRATAMENTO DE BENEFÍCIO DUVIDOSO? / CHILDREN WITH MULTIPLE CONGENITAL DEFECTS: WHAT ARE THE LIMITS BETWEEN THERAPEUTIC OBSTINACY AND THE TREATMENT OF UNCERTAIN BENEFIT?

RESUMO Objetivo: A abordagem terapêutica de crianças com múltiplas malformações inclui muitos dilemas, tornando difícil diferenciar um tratamento de benefício duvidoso da obstinação terapêutica. O objetivo deste artigo foi destacar as possíveis fontes de incerteza no processo de tomada de decisão para esse grupo de crianças. Descrição do caso: Lactente de 11 meses de idade, que nasceu com múltiplas malformações congênitas e foi abandonado por seus pais, nunca recebeu alta hospitalar. Ele tem cardiopatia congênita cianótica, estenose do brônquio fonte esquerdo e imperfuração anal. Passou por muitos procedimentos cirúrgicos e permanece sob suporte tecnológico. A correção total do defeito cardíaco parece improvável, e todas as tentativas de desmame do ventilador falharam. Comentários: As duas principais fontes de incerteza no processo de tomada de decisão para crianças com múltiplos defeitos congênitos estão relacionadas ao prognóstico incerto. Dados empíricos escassos são por conta das múltiplas possibilidades de envolvimento (anatômico ou funcional) de órgãos, com poucos casos semelhantes descritos na literatura. O prognóstico é também imprevisível para a evolução da capacidade cognitiva e para o desenvolvimento de outros órgãos. Outra fonte de incertezas é como qualificar uma vida como valendo a pena ser vivida, ponderando custos e benefícios. A quarta fonte de incerteza é quem tem a decisão: os médicos ou os pais? Finalmente, se um tratamento é definido como fútil, então, como limitar o suporte? Na ausência de um método universal para essa tomada de decisão, ficamos com a responsabilidade dos médicos em desenvolver suas habilidades de percepção das necessidades dos pacientes e dos valores familiares.

ABSTRACT Objective: Therapeutic approach of children with multiple malformations poses many dilemmas, making it difficult to build a line between the treatment of uncertain benefit and therapeutic obstinacy. The aim of this paper was to highlight possible sources of uncertainty in the decision-making process, for this group of children. Case description: An 11-month-old boy, born with multiple birth defects and abandoned by his parents, has never been discharged home. He has complex congenital heart disease, main left bronchus stenosis and imperforate anus. He is under technological support and has gone through many surgical procedures. The complete correction of the cardiac defect seems unlikely, and every attempt to wean the ventilator has failed. Comments: The first two main sources of uncertainty in the management of children with multiple birth defects are related to an uncertain prognosis. There is a lack of empirical data, due to the multiple possibilities of anatomic or functional organ involvement, with few similar cases described. Prognosis is also unpredictable for neuro-developmental evolution, as well as the capacity for the development and regeneration of other organs. Another source of uncertainty is how to qualify the present and future life as worth living, by weighing the costs and benefits. The fourth source of uncertainty is who has the decision: physicians or parents? Finally, if a treatment is defined futile then, how to limit support? No single framework exists to help these delicate decision-making processes. We propose, then, that physicians should be committed to develop their own perception skills in order to understand patient’s manifestations of needs and family values.

A perspectiva da ética das virtudes para o processo de tomada de decisão médica / The perspective of virtue ethics regarding the process of medical decision-making / La perspectiva de la ética de las virtudes para la toma de decisiones médicas

A bioética é vista por muitos médicos como disciplina que deve substanciar decisões e condutas em situações dilemáticas, indicando regras de ação racionais e universais. Nesse cenário, a perspectiva da ética das virtudes propõe substituição da pergunta de “como agir” para “como se constituir”; e, formando o próprio caráter, permitir que a pessoa seja capaz de tomar as decisões da vida, inclusive profissionais, de forma sábia e prudente. Neste ensaio, apresentar-se-á a perspectiva da ética aristotélica, seus autores contemporâneos e as respostas às principais críticas, explicitando vantagens que esse referencial oferece à deliberação médica – suas características valorativa, particularista e teleológica. Mais do que proclamar um paciente autônomo e um profissional que busca regras externamente estabelecidas, a ética das virtudes reconhece que paciente e profissional estão inseridos em comunidades, tradições e culturas, respeitando valores e virtudes, em busca do fim determinado de suas práticas e vidas.

Many doctors understand bioethics as the discipline that should substantiate decisions and conduct in dilemmatic cases, indicating rational and universal rules of action. In this scenario, the perspective of Virtue Ethics proposes the modification of the question “what to do” to “how to be” and, how to constitute one’s own character in order to take wise and prudent decisions in life, including professional ones. This theoretical essay will present the Aristotelian Ethics perspective, its contemporary authors, the answers to the main criticisms and will underline the advantages this framework offers to medical decision-making processes - its evaluative, particularistic and teleological characteristics. It will lead to a conclusion that more than proclaiming an autonomous patient and a profefssional who seeks externally established rules, Virtue Ethics recognizes that both patient and professional are integrated in communities, traditions and cultures, respecting values and virtues, in the pursuit of a particular purpose for their practices and lives.

La bioética es vista por muchos médicos como la disciplina que debe justificar las decisiones y conductas en casos dilemáticos indicando reglas de acción racionales y universales. En este escenario, la perspectiva de la Ética de las Virtudes propone la modificación de la cuestión de “qué hacer” al “cómo ser” – cómo construir su propio carácter con el objetivo de tomar decisiones sabias y prudentes, incluyendo las profesionales. En este ensayo teórico, se presentará la perspectiva ética aristotélica, algunos autores contemporáneos, las respuestas a las principales críticas, destacando las ventajas que ofrece este marco para las decisiones médicas – sus características evaluativa, particularista y teleológica. Más que proclamar un paciente autónomo y un profesional que busca reglas establecidas externamente, se concluye que la Ética de las Virtudes reconoce que ambos se insertan en comunidades, tradiciones y culturas, con valores y virtudes, en busca de los fines particulares de sus prácticas y vidas.

O aprendizado melhorado por provas / Test-enhanced learning

Provas não são neutras em termos de aprendizagem. Não têm apenas caráter avaliativo. A utilização de testes repetidamente traz um benefício mnemônico, estudado em psicologia cognitiva no chamado "efeito de ser testado". A utilização de testes repetidos em cenários de educação caracteriza a metodologia do "aprendizado melhorado por provas". Estudos experimentais e aplicados em cursos extracurriculares têm demonstrado melhor desempenho na retenção de conteúdos e em habilidades de alunos submetidos a testes repetidos em comparação aos de grupos controle. Embora caracterize uma metodologia ativa e o incremento de conteúdo factual seja necessário ao desenvolvimento do raciocínio clínico, a crítica que se faz ao método é de ser baseado em memorização e retenção, na era das evidências. Os estudos aplicados não podem, até o momento, estabelecer se há melhor organização dos conteúdos adquiridos para utilização na resolução de problemas e se isto interfere positivamente no cuidado aos pacientes.

Tests are not neutral in terms of learning. They are not only evaluative, but summative too. There is a mnemonic benefit of testing - called the testing effect, in cognitive psychology studies. In educational settings, test-enhanced learning methodology has been associated with improved cognitive skills and performance of students repetitively tested on a specific content. Although it is an active learning method and despite the fact that the development of clinical reasoning depends upon increased factual contents, there has been criticism of memorization and retention in the era of evidence-based medicine. In fact, available studies have been unable to prove the benefits of using this method in problem solving abilities and patient care.

Rapamycin decreases airway remodeling and hyperreactivity in a transgenic model of noninflammatory lung disease.

Airway hyperreactivity (AHR) and remodeling are cardinal features of asthma and chronic obstructive pulmonary disease. New therapeutic targets are needed as some patients are refractory to current therapies and develop progressive airway remodeling and worsening AHR. The mammalian target of rapamycin (mTOR) is a key regulator of cellular proliferation and survival. Treatment with the mTOR inhibitor rapamycin inhibits inflammation and AHR in allergic asthma models, but it is unclear if rapamycin can directly inhibit airway remodeling and AHR, or whether its therapeutic effects are entirely mediated through immunosuppression. To address this question, we utilized transforming growth factor-α (TGF-α) transgenic mice null for the transcription factor early growth response-1 (Egr-1) (TGF-α Tg/Egr-1(ko/ko) mice). These mice develop airway smooth muscle thickening and AHR in the absence of altered lung inflammation, as previously reported. In this study, TGF-α Tg/Egr-1(ko/ko) mice lost body weight and developed severe AHR after 3 wk of lung-specific TGF-α induction. Rapamycin treatment prevented body weight loss, airway wall thickening, abnormal lung mechanics, and increases in airway resistance to methacholine after 3 wk of TGF-α induction. Increases in tissue damping and airway elastance were also attenuated in transgenic mice treated with rapamycin. TGF-α/Egr-1(ko/ko) mice on doxycycline for 8 wk developed severe airway remodeling. Immunostaining for α-smooth muscle actin and morphometric analysis showed that rapamycin treatment prevented airway smooth muscle thickening around small airways. Pentachrome staining, assessments of lung collagen and fibronectin mRNA levels, indicated that rapamycin also attenuated fibrotic pathways induced by TGF-α expression for 8 wk. Thus rapamycin reduced airway remodeling and AHR, demonstrating an important role for mTOR signaling in TGF-α-induced/EGF receptor-mediated reactive airway disease.

Epithelial EGF receptor signaling mediates airway hyperreactivity and remodeling in a mouse model of chronic asthma.

Increases in the epidermal growth factor receptor (EGFR) have been associated with the severity of airway thickening in chronic asthmatic subjects, and EGFR signaling is induced by asthma-related cytokines and inflammation. The goal of this study was to determine the role of EGFR signaling in a chronic allergic model of asthma and specifically in epithelial cells, which are increasingly recognized as playing an important role in asthma. EGFR activation was assessed in mice treated with intranasal house dust mite (HDM) for 3 wk. EGFR signaling was inhibited in mice treated with HDM for 6 wk, by using either the drug erlotinib or a genetic approach that utilizes transgenic mice expressing a mutant dominant negative epidermal growth factor receptor in the lung epithelium (EGFR-M mice). Airway hyperreactivity (AHR) was assessed by use of a flexiVent system after increasing doses of nebulized methacholine. Airway smooth muscle (ASM) thickening was measured by morphometric analysis. Sensitization to HDM (IgG and IgE), inflammatory cells, and goblet cell changes were also assessed. Increased EGFR activation was detected in HDM-treated mice, including in bronchiolar epithelial cells. In mice exposed to HDM for 6 wk, AHR and ASM thickening were reduced after erlotinib treatment and in EGFR-M mice. Sensitization to HDM and inflammatory cell counts were similar in all groups, except neutrophil counts, which were lower in the EGFR-M mice. Goblet cell metaplasia with HDM treatment was reduced by erlotinib, but not in EGFR-M transgenic mice. This study demonstrates that EGFR signaling, especially in the airway epithelium, plays an important role in mediating AHR and remodeling in a chronic allergic asthma model.

Early growth response-1 suppresses epidermal growth factor receptor-mediated airway hyperresponsiveness and lung remodeling in mice.

Transforming growth factor (TGF)-alpha and its receptor, the epidermal growth factor receptor, are induced after lung injury and are associated with remodeling in chronic pulmonary diseases, such as pulmonary fibrosis and asthma. Expression of TGF-alpha in the lungs of adult mice causes fibrosis, pleural thickening, and pulmonary hypertension, in addition to increased expression of a transcription factor, early growth response-1 (Egr-1). Egr-1 was increased in airway smooth muscle (ASM) and the vascular adventitia in the lungs of mice conditionally expressing TGF-alpha in airway epithelium (Clara cell secretory protein-rtTA(+/-)/[tetO](7)-TGF-alpha(+/-)). The goal of this study was to determine the role of Egr-1 in TGF-alpha-induced lung disease. To accomplish this, TGF-alpha-transgenic mice were crossed to Egr-1 knockout (Egr-1(ko/ko)) mice. The lack of Egr-1 markedly increased the severity of TGF-alpha-induced pulmonary disease, dramatically enhancing airway muscularization, increasing pulmonary fibrosis, and causing greater airway hyperresponsiveness to methacholine. Smooth muscle hyperplasia, not hypertrophy, caused the ASM thickening in the absence of Egr-1. No detectable increases in pulmonary inflammation were found. In addition to the airway remodeling disease, vascular remodeling and pulmonary hypertension were also more severe in Egr-1(ko/ko) mice. Thus, Egr-1 acts to suppress epidermal growth factor receptor-mediated airway and vascular muscularization, fibrosis, and airway hyperresponsiveness in the absence of inflammation. This provides a unique model to study the processes causing pulmonary fibrosis and ASM thickening without the complicating effects of inflammation.

Vascular growth and remodeling in compensatory lung growth following right lobectomy.

Studies in animal models have shown that, following lobectomy (LBX), there is compensatory growth in the remaining lung. The vascular growth response following right LBX (R-LBX) is poorly understood. To test the hypothesis that arterial growth and remodeling occur in response to LBX, in proportion to the amount of right lung tissue removed, two (24% of lung mass; R-LBX2 group) or three right lobes (52% of lung mass; R-LBX3 group) were removed via thoracotomy from adult rats. Sham control animals underwent thoracotomy only. Arteriograms were generated 3 wk after surgery. The areas of the left lung arteriogram, arterial branching, length of arterial branches, arterial density, and arterial-to-alveolar ratios were measured. To determine whether R-LBX causes vascular remodeling and pulmonary hypertension, muscularization of arterioles and right ventricular hypertrophy were assessed. Lung weight and volume indexes were greater in R-LBX3. Arterial area of the left lung increased 26% in R-LBX2 and 47% in R-LBX3. The length of large arteries increased in R-LBX3 and to a lesser extent in R-LBX2. The ratio of distal pulmonary arteries to alveoli was similar after R-LBX2 compared with sham but was 30% lower in R-LBX3. Muscularization of arterioles increased after R-LBX3, but not in R-LBX2. Right ventricular hypertrophy increased 50-70% in R-LBX3, but not in R-LBX2. Whereas removal of three right lung lobes induced arterial growth in the left lungs of adult rats, which was proportionate to the number of lobes removed, the ratio of distal pulmonary arteries to alveoli was not normal, and vascular remodeling and pulmonary hypertension developed.

Predictive model for the length of hospital stay of children with hematologic malignancies, neutropenia, and presumed infection.

Few studies have assessed the predictive factors for the length of hospital stay for children with malignancies admitted with a diagnosis of presumed infection. We performed an observational prospective study of children 13 years old or younger with hematologic malignancies and neutropenia admitted for presumed infection to set up a predictive model for the length of stay using variables available at admission. Episodes in which children were on induction chemotherapy were excluded from the study. In a multivariate linear regression model, age 6 years or older, an ill appearance, relapse of the hematologic malignancy, and the presence of a central venous catheter were the factors associated with longer lengths of stay for these children.