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EMBO Rep ; 20(8): e47047, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31379129


We identify a novel endothelial membrane behaviour in transgenic zebrafish. Cerebral blood vessels extrude large transient spherical structures that persist for an average of 23 min before regressing into the parent vessel. We term these structures "kugeln", after the German for sphere. Kugeln are only observed arising from the cerebral vessels and are present as late as 28 days post fertilization. Kugeln do not communicate with the vessel lumen and can form in the absence of blood flow. They contain little or no cytoplasm, but the majority are highly positive for nitric oxide reactivity. Kugeln do not interact with brain lymphatic endothelial cells (BLECs) and can form in their absence, nor do they perform a scavenging role or interact with macrophages. Inhibition of actin polymerization, Myosin II, or Notch signalling reduces kugel formation, while inhibition of VEGF or Wnt dysregulation (either inhibition or activation) increases kugel formation. Kugeln represent a novel Notch-dependent NO-containing endothelial organelle restricted to the cerebral vessels, of currently unknown function.

Cochrane Database Syst Rev ; 10: CD005154, 2017 10 12.
Artigo em Inglês | MEDLINE | ID: mdl-29025197


BACKGROUND: People with supraventricular tachycardia (SVT) frequently are symptomatic and present to the emergency department for treatment. Although vagal manoeuvres may terminate SVT, they often fail, and subsequently adenosine or calcium channel antagonists (CCAs) are administered. Both are known to be effective, but both have a significant side effect profile. This is an update of a Cochrane review previously published in 2006. OBJECTIVES: To review all randomised controlled trials (RCTs) that compare effects of adenosine versus CCAs in terminating SVT. SEARCH METHODS: We identified studies by searching CENTRAL, MEDLINE, Embase, and two trial registers in July 2017. We checked bibliographies of identified studies and applied no language restrictions. SELECTION CRITERIA: We planned to include all RCTs that compare adenosine versus a CCA for patients of any age presenting with SVT. DATA COLLECTION AND ANALYSIS: We used standard methodological procedures as expected by Cochrane. Two review authors independently checked results of searches to identify relevant studies and resolved differences by discussion with a third review author. At least two review authors independently assessed each included study and extracted study data. We entered extracted data into Review Manager 5. Primary outcomes were rate of reversion to sinus rhythm and major adverse effects of adenosine and CCAs. Secondary outcomes were rate of recurrence, time to reversion, and minor adverse outcomes. We measured outcomes by calculating odds ratios (ORs) and assessed the quality of primary outcomes using the GRADE approach through the GRADEproGDT website. MAIN RESULTS: We identified two new studies for inclusion in the review update; the review now includes seven trials with 622 participants who presented to an emergency department with SVT. All included studies were RCTs, but only three described the randomisation process, and none had blinded participants, personnel, or outcome assessors to the intervention given. Moderate-quality evidence shows no differences in the number of people reverting to sinus rhythm who were treated with adenosine or CCA (89.7% vs 92.9%; OR 1.51, 95% confidence interval (CI) 0.85 to 2.68; participants = 622; studies = 7; I2 = 36%). Low-quality evidence suggests no appreciable differences in major adverse event rates between CCAs and adenosine. Researchers reported only one case of hypotension in the CCA group and none in the adenosine group (0.66% vs 0%; OR 3.09, 95% CI 0.12 to 76.71; participants = 306; studies = 3; I2 = 0%). Included trials did not report length of stay in hospital nor patient satisfaction. AUTHORS' CONCLUSIONS: Moderate-quality evidence shows no differences in effects of adenosine and calcium channel antagonists for treatment of SVT on reverting to sinus rhythm, and low-quality evidence suggests no appreciable differences in the incidence of hypotension. A study comparing patient experiences and prospectively studied adverse events would provide evidence on which treatment is preferable for management of SVT.

Adenosina/uso terapêutico , Antiarrítmicos/uso terapêutico , Bloqueadores dos Canais de Cálcio/uso terapêutico , Taquicardia Supraventricular/tratamento farmacológico , Adenosina/efeitos adversos , Adulto , Antiarrítmicos/efeitos adversos , Bloqueadores dos Canais de Cálcio/efeitos adversos , Serviço Hospitalar de Emergência/estatística & dados numéricos , Humanos , Hipotensão/induzido quimicamente , Ensaios Clínicos Controlados Aleatórios como Assunto , Verapamil/efeitos adversos , Verapamil/uso terapêutico
Expert Opin Drug Discov ; 12(4): 379-389, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28277839


INTRODUCTION: Patients with metastatic cancer suffer the highest rate of cancer-related death, but existing animal models of metastasis have disadvantages that limit our ability to understand this process. The zebrafish is increasingly used for cancer modelling, particularly xenografting of human cancer cell lines, and drug discovery, and may provide novel scientific and therapeutic insights. However, this model system remains underexploited. Areas covered: The authors discuss the advantages and disadvantages of the zebrafish xenograft model for the study of cancer, metastasis and drug discovery. They summarise previous work investigating the metastatic cascade, such as tumour-induced angiogenesis, intravasation, extravasation, dissemination and homing, invasion at secondary sites, assessing metastatic potential and evaluation of cancer stem cells in zebrafish. Expert opinion: The practical advantages of zebrafish for basic biological study and drug discovery are indisputable. However, their ability to sufficiently reproduce and predict the behaviour of human cancer and metastasis remains unproven. For this to be resolved, novel mechanisms must to be discovered in zebrafish that are subsequently validated in humans, and for therapeutic interventions that modulate cancer favourably in zebrafish to successfully translate to human clinical studies. In the meantime, more work is required to establish the most informative methods in zebrafish.

Antineoplásicos/farmacologia , Descoberta de Drogas/métodos , Neoplasias/tratamento farmacológico , Animais , Humanos , Metástase Neoplásica , Neoplasias/patologia , Células-Tronco Neoplásicas/metabolismo , Neovascularização Patológica/patologia , Especificidade da Espécie , Ensaios Antitumorais Modelo de Xenoenxerto/métodos , Peixe-Zebra