Tracheal tube fusion in Drosophila involves release of extracellular vesicles from multivesicular bodies.

Extracellular vesicles (EVs) comprise diverse types of cell-released membranous structures that are thought to play important roles in intercellular communication. While the formation and functions of EVs have been investigated extensively in cultured cells, studies of EVs in vivo have remained scarce. We report here that EVs are present in the developing lumen of tracheal tubes in Drosophila embryos. We define two distinct EV subpopulations, one of which contains the Munc13-4 (also known as UNC13D) homolog Staccato (Stac) and is spatially and temporally associated with tracheal tube fusion (anastomosis) events. The formation of Stac-positive luminal EVs depends on the tracheal tip-cell-specific GTPase Arl3 (also known as Dnd in Drosophila), which is also required for the formation of Stac-positive multivesicular bodies (MVBs), suggesting that Stac-positive EVs derive from fusion of Stac-positive MVBs with the luminal membrane in tip cells during anastomosis formation. The GTPases Rab27 and Rab35 cooperate downstream of Arl3 to promote Stac-positive MVB formation and tube fusion. We propose that Stac-positive MVBs act as membrane reservoirs that facilitate tracheal lumen fusion in a process regulated by Arl3, Rab27, Rab35 and Stac. This article has an associated First Person interview with the first author of the paper.

Opi1p translocation to the nucleus is regulated by hydrogen peroxide in Saccharomyces cerevisiae.

During exposure of yeast cells to low levels of hydrogen peroxide (H2 O2 ), the expression of several genes is regulated for cells to adapt to the surrounding oxidative environment. Such adaptation involves modification of plasma membrane lipid composition, reorganization of ergosterol-rich microdomains and altered gene expression of proteins involved in lipid and vesicle traffic, to decrease permeability to exogenous H2 O2 . Opi1p is a transcriptional repressor that is inactive when present at the nuclear membrane/endoplasmic reticulum, but represseses transcription of inositol upstream activating sequence (UASINO )-containing genes, many of which are involved in the synthesis of phospholipids and fatty acids, when it is translocated to the nucleus. We investigated whether H2 O2 in concentrations inducing adaptation regulates Opi1p function. We found that, in the presence of H2 O2 , GFP-Opi1p fusion protein translocates to the nucleus and, concomitantly, the expression of UASINO -containing genes is affected. We also investigated whether cysteine residues of Opi1p were implicated in the H2 O2 -mediated translocation of this protein to the nucleus and identified cysteine residue 159 as essential for this process. Our work shows that Opi1p is redox-regulated and establishes a new mechanism of gene regulation involving Opi1p, which is important for adaptation to H2 O2 in yeast cells. Copyright © 2017 John Wiley & Sons, Ltd.

Acute manipulation and real-time visualization of membrane trafficking and exocytosis in Drosophila.

Intracellular trafficking of secretory proteins plays key roles in animal development and physiology, but so far, tools for investigating the dynamics of membrane trafficking have been limited to cultured cells. Here, we present a system that enables acute manipulation and real-time visualization of membrane trafficking through the reversible retention of proteins in the endoplasmic reticulum (ER) in living multicellular organisms. By adapting the "retention using selective hooks" (RUSH) approach to Drosophila, we show that trafficking of GPI-linked, secreted, and transmembrane proteins can be controlled with high temporal precision in intact animals and cultured organs. We demonstrate the potential of this approach by analyzing the kinetics of ER exit and apical secretion and the spatiotemporal dynamics of tricellular junction assembly in epithelia of living embryos. Furthermore, we show that controllable ER retention enables tissue-specific depletion of secretory protein function. The system is broadly applicable to visualizing and manipulating membrane trafficking in diverse cell types in vivo.

Cells into tubes: Molecular and physical principles underlying lumen formation in tubular organs.

Tubular networks, such as the vascular and respiratory systems, transport liquids and gases in multicellular organisms. The basic units of these organs are tubes formed by single or multiple cells enclosing a luminal cavity. The formation and maintenance of correctly sized and shaped lumina are fundamental steps in organogenesis and are essential for organismal homeostasis. Therefore, understanding how cells generate, shape and maintain lumina is crucial for understanding normal organogenesis as well as the basis of pathological conditions. Lumen formation involves polarized membrane trafficking, cytoskeletal dynamics, and the influence of intracellular as well as extracellular mechanical forces, such as cortical tension, luminal pressure or blood flow. Various tissue culture and in vivo model systems, ranging from MDCK cell spheroids to tubular organs in worms, flies, fish, and mice, have provided many insights into the molecular and cellular mechanisms underlying lumenogenesis and revealed key factors that regulate the size and shape of cellular tubes. Moreover, the development of new experimental and imaging approaches enabled quantitative analyses of intracellular dynamics and allowed to assess the roles of cellular and tissue mechanics during tubulogenesis. However, how intracellular processes are coordinated and regulated across scales of biological organization to generate properly sized and shaped tubes is only beginning to be understood. Here, we review recent insights into the molecular, cellular and physical mechanisms underlying lumen formation during organogenesis. We discuss how these mechanisms control lumen formation in various model systems, with a special focus on the morphogenesis of tubular organs in Drosophila.

Using migrating cells as probes to illuminate features in live embryonic tissues.

The biophysical and biochemical properties of live tissues are important in the context of development and disease. Methods for evaluating these properties typically involve destroying the tissue or require specialized technology and complicated analyses. Here, we present a novel, noninvasive methodology for determining the spatial distribution of tissue features within embryos, making use of nondirectionally migrating cells and software we termed "Landscape," which performs automatized high-throughput three-dimensional image registration. Using the live migrating cells as bioprobes, we identified structures within the zebrafish embryo that affect the distribution of the cells and studied one such structure constituting a physical barrier, which, in turn, influences amoeboid cell polarity. Overall, this work provides a unique approach for detecting tissue properties without interfering with animal's development. In addition, Landscape allows for integrating data from multiple samples, providing detailed and reliable quantitative evaluation of variable biological phenotypes in different organisms.

Intraosseous anomalous drainage: a rare case of pretibial varicose vein.

Valve failure with reflux and post-thrombotic syndrome are the factors most commonly correlated with varicose disease. Other rare etiologies can be put forward when these two main causes are ruled out. We report a case in which a young man presented chronic pain in the left tibia, varicose veins in the lower limbs and frequent occurrences of erysipelas. During investigation of the etiology of the varicose veins, radiographs and magnetic resonance imaging of the left leg were requested. These showed images suggestive of an osteolytic lesion in the tibia, but led us to the diagnosis of an intraosseous vein with anomalous drainage. This was confirmed through vascular examinations comprising Doppler venous flow measurement and phlebography. Recognition of this rare intraosseous anomaly is fundamental for proper patient management, but an intraosseous surgical approach is unnecessary.

Incompetência valvar com refluxo e síndrome pós-trombótica são os fatores mais comumente relacionados à doença varicosa. Outras raras etiologias podem ser levantadas quando essas duas principais causas são descartadas. Relatamos o caso de um homem jovem com dor crônica na tíbia esquerda, varizes em membros inferiores e erisipela de repetição. Durante investigação da etiologia das varizes foram solicitadas radiografias e ressonância da perna esquerda, que evidenciaram imagens sugestivas de uma lesão osteolítica na tíbia, mas que nos levaram ao diagnóstico de veia intraóssea com drenagem anômala, confirmado pelos exames vasculares de dopplerfluxometria venosa e flebografia. O reconhecimento dessa rara anomalia intraóssea é fundamental para o manejo adequado do paciente, não necessita de abordagem cirúrgica intraóssea.

Intraosseous anomalous drainage: a rare case of pretibial varicose vein / Drenagem anômala intraóssea: um caso raro de varizes pré-tibiais

ABSTRACT Valve failure with reflux and post-thrombotic syndrome are the factors most commonly correlated with varicose disease. Other rare etiologies can be put forward when these two main causes are ruled out. We report a case in which a young man presented chronic pain in the left tibia, varicose veins in the lower limbs and frequent occurrences of erysipelas. During investigation of the etiology of the varicose veins, radiographs and magnetic resonance imaging of the left leg were requested. These showed images suggestive of an osteolytic lesion in the tibia, but led us to the diagnosis of an intraosseous vein with anomalous drainage. This was confirmed through vascular examinations comprising Doppler venous flow measurement and phlebography. Recognition of this rare intraosseous anomaly is fundamental for proper patient management, but an intraosseous surgical approach is unnecessary.

RESUMO Incompetência valvar com refluxo e síndrome pós-trombótica são os fatores mais comumente relacionados à doença varicosa. Outras raras etiologias podem ser levantadas quando essas duas principais causas são descartadas. Relatamos o caso de um homem jovem com dor crônica na tíbia esquerda, varizes em membros inferiores e erisipela de repetição. Durante investigação da etiologia das varizes foram solicitadas radiografias e ressonância da perna esquerda, que evidenciaram imagens sugestivas de uma lesão osteolítica na tíbia, mas que nos levaram ao diagnóstico de veia intraóssea com drenagem anômala, confirmado pelos exames vasculares de dopplerfluxometria venosa e flebografia. O reconhecimento dessa rara anomalia intraóssea é fundamental para o manejo adequado do paciente, não necessita de abordagem cirúrgica intraóssea.

Aortic thrombosis in a patient with a late of Behcet's disease / Trombose aórtica em paciente com diagnóstico tardio de doença de Behçet

Behcet's disease is form of systemic vasculitis of unknown etiology. One surprising feature is that arterial involvement is less common in this disease than venous forms, accounting for 1 to 7% of patients. In 7 to 30% of cases the vascular symptoms precede the clinical diagnosis of Behcet. We describe the case of a patient with Thromboangiitis Obliterans who was treated with lumbar sympathectomy and an aortobiiliac bypass. Around 1 year later he was diagnosed with Behcet's disease after presenting with oral ulcers, genital ulcers and scaling lesions on the hands.

A Doença de Behçet é uma vasculite sistêmica de etiologia desconhecida. O inusitado é que o acometimento arterial nesta doença é menos comum que o venoso, correspondendo a 1 a 7% dos pacientes. Já os sintomas vasculares precedem o diagnóstico clínico de Behçet em 7 a 30%. Relatamos o caso de um paciente portador de Tromboangeíte Obliterante que foi submetido a simpatectomia lombar e derivação aorto-bi-ilíaca. Após cerca de um ano, diagnosticou-se Doença de Behçet, devido a quadro clínico de úlceras orais, genitais e lesões descamativas nas mãos.

Síndrome de Lemierre: relato de caso / Lemierre syndrome: a case report

A tromboflebite supurativa da veia jugular interna ou síndrome de Lemierre foi descrita pela primeira vez em 1900. O evento inicial mais frequente é a infecção de orofaringe associada à trombose da veia jugular interna. Embora uma entidade rara, a síndrome de Lemierre continua a ser uma doença de morbidade e mortalidade consideráveis devido à sua progressão e atrasos de diagnóstico.

Suppurative thrombophlebitis of the internal jugular vein, or Lemierre syndrome, was described for the first time in 1900. The most common initial event is an infection of the oropharynx associated with thrombosis of the internal jugular vein. While it is a rare entity, Lemierre syndrome remains a disease that causes considerable morbidity and mortality, due to its progression and to delays in diagnosis.

Dramatização como instrumento de informação a respeito do tabagismo entre escolares / Dramatization as an instrument for smoking information among schoolchildren

O tabaco é a segunda droga mais utilizada entre adolescentes e seu uso contínuo causa cerca de 200.000 mortes por ano no Brasil, dessa forma, é relevante investigar com frequência a extensão do tabagismo e o conhecimento dessa população sobre o tema, para assim orientar estratégias preventivas e de combate ao fumo dentro do próprio ambiente escolar. Avaliar a extensão do tabagismo nas escolas públicas de Goiânia ? GO e o conhecimento do jovem a respeito do tabagismo. Trata-se de um estudo experimental, analítico com 343 alunos da sexta série do ensino fundamental de 10 escolas públicas de Goiânia que foram submetidos à aplicação de um questionário antes e após assistirem a uma dramatização sobre tabagismo criada por alunos da Liga do Pulmão da Faculdade de Medicina - UFG. Média de idade de 12,5±1,0 anos, 42,1% do sexo masculino e 57,9% feminino; 1,5% fumantes, 11,6% ex-fumantes e 21,2% experimentaram cigarro por pelo menos uma vez. A média de idade de experimentação do cigarro foi de 11,1±1,6 anos. A maior parte dos alunos tem parentes (79%) ou amigos (51,9%) que fumam; 28,9% relataram que alguém em casa fuma perto deles. Os alunos apresentaram elevado grau de conhecimento prévio a respeito dos malefícios do tabaco. Após assistirem a dramatização houve aumento do conhecimento frente às questões referentes aos benefícios de se parar de fumar e síndrome de abstinência (p<0,05). As escolas avaliadas em Goiânia apresentaram baixas taxas de experimentação e de tabagismo entre os escolares de 6ª série do ensino fundamental. Os escolares apresentaram bom nível de esclarecimento sobre os malefícios do cigarro, no entanto, informações como benefícios de se interromper o hábito devem ser reforçadas nessa população. Dramatização pode ser uma ferramenta útil para esclarecimento de escolares e combate ao tabagismo.

Tobacco is the second most used drug among adolescents and its continued use causes about 200.000 deaths per year in Brazil. Thus, it is relevant to investigate the extent of smoking and the knowledge of this population on the topic, and to provide preventive and anti-smoking strategies within the school environment. Therefore, the objective of this paper is to evaluate the extension of smoking throughout public schools in Goiania as well as the youngsters? awareness on this issue. This is an experimental analytic study, with 343 sixth-graders from 10 public schools in Goiania, who have been submitted to a questionnaire before and after watching a dramatization about smoking created by the Lung League from the Medicine Faculty at UFG. The average age was of 12.5±1.0 year old, with 42.1% male and 57.9% female; 1.5% smokers, 11.6% former smokers and 21.2% have tried cigarettes at least once. The average age for first-timers was 11.1±1.6 years of age. Most of the students have relatives (79%) or friends (51%) who are smokers; 28.9% reported that a member of their family smokes near them (second-hand smokers). The students have shown a high level of knowledge regarding the harms of tobacco. There has been an increase in knowledge towards the benefits of quitting smoking and withdrawal symptoms after seeing the dramatization (p<0.05). The schools evaluated in Goiania presented low experimentation and smoking rates among sixth-graders. The students have shown reasonable awareness regarding the harms of cigarette; however, relevant information such as the benefits of quitting should be reinforced in this population. Dramatization may be a useful tool for raising awareness among schoolchildren as well as fighting smoking.