We would like to thank the Vanderbilt University Institute of Imaging Science MRI technologists David Pennell, Leslie McIntosh, and Kristen George-Durrett, and the team of Vanderbilt University Medical Center PET/CT technologists led by Martha D. Shone. This work was supported by the following grants from the NIH: NCATS/NIH UL1 RR024975, NIDDK/NIH R21DK096282, NCI/NIH R25CA136440, and NIBIB/NIH T32EB014841.

The authors declare that they have no competing financial interests or other conflicts of interests.

O protocolo do estudo descrito foi projetado para usar tanto termoneutro e frio ativado PET / CT para automaticamente segmento depósitos de bastão em uma base específica assunto. Estas regiões geradas automaticamente de interesse pode então ser aplicada a ambos os exames de ressonância magnética termoneutras e frios-ativado que foram co-registradas para os exames de PET / CT do mesmo assunto. Para o melhor de nosso conhecimento, esta é a primeira pesquisa para executar tanto ressonância magnética e PET / CT ap...

Devido ao aumento acentuado da obesidade em todo o mundo, há um aumento do interesse em áreas de pesquisa voltados à compreensão balanço energético. A obesidade pode resultar em condições médicas caras e devastadoras, como a diabetes, doenças do fígado, doenças cardiovasculares e câncer, tornando-se uma área significativa de preocupação para a saúde pública 1. Uma área de pesquisa tem como objetivo compreender o equilíbrio da ingestão de energia versus gasto energético é o estudo do tecido adiposo marrom ou BAT. Embora denominado um tecido adiposo, BAT difere do tecido branco adiposo mais comum (WAT) em muitos aspectos 2. A função de adipócitos brancos é armazenar triglicéridos em uma única grande vacúolo lipídico por célula, e para libertar estes triglicerídeos como uma fonte de energia para a corrente sanguínea quando necessário. De uma forma muito diferente, a função de adipócitos castanhos é produzir calor. Um mecanismo pelo qual isso ocorre é através da exposição ao frio. Isto provoca um aumento no sympathetic atividade do sistema nervoso, que por sua vez ativa BAT. Quando activados, os adipócitos castanhos gerar calor. Para isso, eles usam os triglicéridos contidos em muitos vacúolos pequenos lipídicos por célula, e por meio da presença de desacoplamento da proteína 1 (UCP1) na mitocôndria abundante, converter os triglicéridos de substratos metabólicos, sem a produção de ATP, resultando em perda entrópica como a geração de calor. Como os triglicéridos armazenados nos vacúolos pequenos lipídicos estão esgotados, o adipócitos leva-se a glicose e triglicéridos presentes na corrente sanguínea 3. O interesse em estudar BAT aumentou dramaticamente nos últimos anos devido à sua contribuição para a termogênese sem calafrios, o seu papel na modulação do gasto energético do corpo, e a relação inversa entre o potencial BAT e obesidade 3-9. Além disso, estudos recentes em animais indicam BAT desempenha um papel crítico na compensação triglicérides e glicose from na corrente sanguínea, especialmente após a ingestão de uma refeição rica em gordura 10,11. No entanto, a maior parte do que sabemos sobre BAT é resultado de uma pesquisa em pequenos mamíferos, que contêm muitos depósitos de BAT 4,9,12 - 15. Não obstante alguns estudos iniciais de 16-18, a presença da BAT em ​​humanos foi amplamente pensado para diminuir com a idade, até recentemente, quando o interesse em estudar BAT humano foi renovado. Pesquisas recentes sugerem que quantidades relativamente pequenas de BAT persistir na idade adulta 19-24. Um fator limitante adicional para estudar BAT é que além de biópsia e coloração histológica, o método inequívoco atualmente aceito para detectar BAT é de 18 F-fluorodeoxyglucose (18 F-FDG) a tomografia por emissão de pósitrons (PET). Scanners PET modernos são normalmente combinada com um scanner de tomografia computadorizada (TC). Quando ativado por exposição ao frio, BAT ocupa o 18 </saté&gt; radiofármaco F-FDG, que é um análogo metabólica de glucose, e torna-se visível em imagens de PET, em comparação com o nível muito mais baixo de 18F-FDG quando MTD é 20,21,23,25 inactivo. CT imagens adquiridas durante um exame de PET em um PET-CT do scanner ajuda a diferenciar entre os tecidos com alta de 18 F-FDG, fornecendo informações anatômicas. Este uso de PET-CT imagem expõe o indivíduo a radiação ionizante (predominantemente a partir de PET, embora a dose do TC não é negligenciável), e é, portanto, um método desejável para a detecção de MTD. Embora o número de estudos sobre BAT em ​​humanos adultos saudáveis ​​está aumentando, estudos recentes de BAT humano principalmente têm sido limitados a retrospectiva PET-CT estuda 19,25, cadáveres humanos 26,27 infantis, adolescentes humanos que já foram internados em hospitais para outras razões 27-30, e alguns estudos em humanos de adultos saudáveis31-35. Um dos desafios com ambos os estudos das crianças e dos estudos retrospectivos é a possibilidade de resultados alterados quando se estuda uma população paciente que está doente, o que pode afetar BAT. Além disso, porque a glicose não é a fonte de combustível preferido de BAT 36, estudos de PET pode nem sempre detectar BAT ativado e, portanto, pode sub-representar a presença de BAT. Outra dificuldade em estudar BAT com imagens biomédicas está relacionada com a realização de segmentação de imagem para definir os limites de depósitos de tecido. Atualmente, a segmentação da BAT em estudos humanos muitas vezes se baseia em algum grau de segmentação de imagem manual e é, portanto, vulnerável a erros de identificação de depósitos MTD, bem como a variabilidade inter-observador. Devido a estes desafios, técnicas de mapeamento espaciais fiáveis ​​que podem distinguir BAT a partir de distribuições Wat, juntamente com métodos de segmentação automatizados, iria fornecer aos investigadores com um novo e poderoso paraol com que estudar BAT. A ressonância magnética (MRI) tem a capacidade de identificação, mapeamento espacial, e quantificação volumétrica de BAT, e ao contrário de abordagens de imagem existentes híbridos PET-CT, que incluem uma dose radioactiva para o assunto com imagens, a RM não envolve radiação ionizante e pode ser usado com segurança e repetidamente. A capacidade de identificar e quantificar BAT usando ressonância magnética pode ter um impacto positivo dramático em endocrinologia clínica e à busca de novos caminhos de pesquisa da obesidade. -Água gordura Anterior RM (FWMRI) estudos de MTD em ratos e em humanos mostram que a gordura-sinal-fracção (FSF) de MTD é na gama de 40-80% de gordura, enquanto que WAT é acima de 90% de gordura 15,26 , 27. Por conseguinte, a hipótese de que esta FWMRI métrica quantitativa, em conjunto com outras métricas quantitativas MRI, pode ser utilizado em trabalhos futuros para visualizar e quantificar depósitos MTD em seres humanos. Isso proporcionaria a comunidade de pesquisa com uma ferramenta poderosa para estudar a influência da BAT em atendidasabolism e gasto de energia sem o uso de radiação ionizante. Nosso grupo de pesquisa vem estudando BAT em humanos adultos, nos últimos três anos. Nossa primeira apresentação pública sobre o uso de ressonância magnética para investigar suspeitas de BAT no sujeito humano um adulto ocorreu em fevereiro de 2012, a Sociedade Internacional de Ressonância Magnética na Oficina Medicine (ISMRM) Separação Fat-água em Long Beach, California 37. Dois meses mais tarde, o nosso grupo apresentou valores FSF na suspeita de BAT em ​​dois adultos no 20º encontro anual da ISMRM em abril de 2012, em Melbourne, Austrália 38. Um ano depois, no 21º encontro anual da ISMRM em abril de 2013, em Salt Lake City, Utah, o protocolo descrito neste manuscrito foi utilizado para o primeiro (com o melhor de nosso conhecimento) apresentação pública do MRI quantificação do PET-confirmado BAT no ser humano adulto 39 indivíduos. Especificamente, apresentou provas de que o previously suspeita BAT foi confirmado para ser BAT activatable usando tanto frio ativado e thermoneutral imaging 18 F-FDG PET-CT. Desde 2013, o nosso grupo de seres humanos adultos saudáveis ​​fotografada com tanto ressonância magnética e PET / CT em conforto térmico e frio ativado se expandiu para mais de 20 indivíduos com resultados mais recentemente apresentado em Fevereiro de 2014, o workshop &quot;Explorando o papel da gordura Brown em seres humanos &quot;, patrocinado pelo NIH NIDDK 40. Especificamente, nós informamos FWMRI FSF e R2 * propriedades de relaxamento nas regiões de BAT supraclavicular confirmados por 18 F-FDG PET-CT em humanos adultos, com as ROIs MTD delineado usando algoritmos de segmentação automatizados com base no frio ativado e thermoneutral PET-CT scans. Mais recentemente, apresentou os resultados de mapeamento de temperatura em 18 F-FDG PET-CT confirmado BAT em ​​humanos adultos que usam avançado FWMRI termometria 41,42. O procedimento aqui apresentado adquirirs tanto MRI e 18 F-FDG PET-CT scans sobre o mesmo assunto, cada um após a exposição a ambas as condições frias ativados e termoneutras. Os 18 scans F-FDG PET-CT frio ativado e termoneutras são usados ​​para criar regiões segmentadas automaticamente MTD de interesse (ROI), em uma base específica assunto. Estas ROIs MTD são então aplicadas aos exames de ressonância magnética co-registrada para medir as propriedades de ressonância magnética no PET-CT confirmado BAT. Uma limitação deste protocolo é que a temperatura do ar usado ao expor assuntos, quer o estímulo quente ou fria é consistente para cada assunto. Esta é uma limitação, porque a temperatura à qual cada sujeito experimenta sensação de calor refrigerados ou pode ser diferente. Portanto, pela execução de uma sessão de ensaio durante o qual a temperatura do ar é ajustado de acordo com a resposta do indivíduo, e, em seguida, utilizando estas temperaturas durante os protocolos termoneutras e-activação frio, pode ser possível obter melhores respostasa partir do tecido adiposo castanho.

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			<td height="100" style="height:100px;width:363px;">Name of Material/ Equipment</td>
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			<td style="width:392px;">Philips</td>
			<td style="width:375px;">Achieva 3T</td>
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			<td height="68" style="height:68px;width:363px;">MRI Torso-XL coil</td>
			<td style="width:392px;">Philips</td>
			<td style="width:375px;">Philips SENSE XL Torso coil 16-elements</td>
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		<tr height="68">
			<td height="68" style="height:68px;width:363px;">MRI X-tend Table</td>
			<td style="width:392px;">X-Tend</td>
			<td style="width:375px;">X-tend table, Acieva 3T compatible</td>
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		<tr height="34">
			<td height="34" style="height:34px;width:363px;">X-tend armsupport</td>
			<td style="width:392px;">X-Tend</td>
			<td style="width:375px;">X-tend, accessories</td>
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			<td height="34" style="height:34px;width:363px;">X-tend fabricsling</td>
			<td style="width:392px;">X-Tend</td>
			<td style="width:375px;">X-tend, accessories</td>
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			<td height="38" style="height:39px;width:363px;">PET/CT</td>
			<td style="width:392px;">GE</td>
			<td style="width:375px;">Discovery STE</td>
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		<tr height="38">
			<td height="38" style="height:39px;width:363px;">Portable A/C Unit</td>
			<td style="width:392px;">Soleus Air</td>
			<td style="width:375px;">XL-140, 14000 BTU</td>
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		<tr height="38">
			<td height="38" style="height:39px;width:363px;">Floor fan</td>
			<td style="width:392px;">Lasko Pedestal Fan</td>
			<td style="width:375px;">2527</td>
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		<tr height="38">
			<td height="38" style="height:39px;width:363px;">Portable Heater</td>
			<td style="width:392px;">Lasko Ceramic Air</td>
			<td style="width:375px;">5536</td>
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		<tr height="38">
			<td height="38" style="height:39px;width:363px;">Chair</td>
			<td style="width:392px;">Winco Lifecare Recliner</td>
			<td style="width:375px;">585</td>
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			<td height="38" style="height:39px;width:363px;">Sublingual Thermometer</td>
			<td style="width:392px;">WelchAllyn</td>
			<td style="width:375px;">SureTemp Plus 690</td>
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		<tr height="38">
			<td height="38" style="height:39px;width:363px;">Cold vest</td>
			<td style="width:392px;">Polar Products</td>
			<td style="width:375px;">Cool58 #PCVZ</td>
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		<tr height="38">
			<td height="38" style="height:39px;width:363px;">Thermal IR Camera</td>
			<td style="width:392px;">FLUKE</td>
			<td style="width:375px;">TIR-125</td>
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human brown adipose tissue depots automatically segmented by positron emission tomography/computed tomography and registered magnetic resonance images

Reliably diferenciação entre tecido adiposo marrom (BAT) de outros tecidos utilizando um método de imagem não-invasivo é um passo importante para estudar BAT em seres humanos. Detectando BAT é tipicamente confirmada pela captação do marcador radioativo injetado 18 F-Fluorodeoxyglucose (18 F-FDG) em depósitos de tecido adiposo, medida pela tomografia por emissão de pósitrons / tomografia computadorizada (PET-CT) scans depois de expor o assunto ao estímulo frio . -Água gordura separada ressonância magnética (MRI) tem a capacidade de distinguir MTD sem a utilização de um marcador radioactivo. Até à data, a RM de BAT em humanos adultos não tem sido co-registradas com frio ativado PET-CT. Portanto, este protocolo utiliza 18 scans F-FDG PET-CT para gerar automaticamente uma máscara BAT, que é então aplicada a co-registrada exames de ressonância magnética do mesmo assunto. Esta abordagem permite a medição de propriedades de ressonância magnética quantitativos da BAT sem segmentação manual. Máscaras MTD são criados a partir de dois PEScans t-CT: após exposição durante 2 h, quer termicamente neutro (TN) (24 ° C) ou a frio activado (AC) (17 ° C) condições. Os TN e CA PET-CT scans são registrados, e os valores de PET captação padronizado e CT Hounsfield são usados ​​para criar uma máscara contendo apenas BAT. CA e TN ressonância magnética também são adquiridos sobre o mesmo assunto e registrado para os exames PET-CT, a fim de estabelecer as propriedades de ressonância magnética quantitativas dentro da máscara BAT automaticamente definida. Uma vantagem dessa abordagem é que a segmentação é totalmente automatizado e é baseado em métodos aceitos para identificação de BAT ativado (PET-CT). As propriedades de ressonância magnética quantitativos da BAT estabelecida utilizando este protocolo pode servir como base para uma ressonância magnética somente exame BAT que evita a radiação associada com PET-CT.

Adquirir tanto de ressonância magnética e PET-CT scans sobre o mesmo assunto, e realizar co-registo em todas as varreduras permite uma medição confiável de métricas quantitativas de ressonância magnética de BAT. A Figura 1 mostra a quente não transformados (TN) e frio (CA) PET-TC e RM scans de um assunto. Com a aquisição de dados tanto TN e CA PET-CT, é possível distinguir claramente os depósitos MTD frio ativado pelo aumento da captação de 18 F-FDG. Após o co-registo de todo...

Watch this Scientific Journal Video about Human Brown Adipose Tissue Depots Automatically Segmented by Positron Emission Tomography/Computed Tomography and Registered Magnetic Resonance Images at JoVE

Human Brown Adipose Tissue Depots Automatically Segmented by Positron Emission Tomography/Computed Tomography and Registered Magnetic Resonance Images

O método aqui apresentado utiliza 18 F-Fluorodeoxyglucose (18 F-FDG) tomografia por emissão de pósitrons / tomografia computadorizada (PET-CT) e água gordura separada ressonância magnética (MRI), cada digitalizada seguinte 2 exposição hr para termoneutro (24 ° C ) e condições de frio (17 ° C), a fim de mapear tecido adiposo castanho (BAT) em seres humanos adultos.

Brown Human Tissue adiposo Depots automaticamente segmentada por Positron Emission Tomography / Tomografia Computadorizada e registrado ressonância magnética

Reliably differentiating brown adipose tissue (BAT) from other tissues using a non-invasive imaging method is an important step toward studying BAT in ...

human-brown-adipose-tissue-depots-automatically-segmented-positron

Research

JoVE Journal

Medicine

12.1K visualizações.  Vanderbilt University.  O método aqui apresentado utiliza 18 F-Fluorodeoxyglucose (18 F-FDG) tomografia por emissão de pósitrons / tomografia computadorizada (PET-CT) e água gordura separada ressonância magnética (MRI), cada digitalizada seguinte 2 exposição hr para termoneutro (24 ° C ) e condições de frio (17 ° C), a fim de mapear tecido adiposo castanho (BAT) em seres humanos adultos. 

Vídeo: Human Brown Adipose Tissue Depots Automatically Segmented by Positron Emission Tomography/Computed Tomography and Registered Magnetic Resonance Images

Basic Surgical Techniques in the G&ouml;ttingen Minipig: Intubation, Bladder Catheterization, Femoral Vessel Catheterization, and Transcardial Perfusion

The emergence of the G&ouml;ttingen minipig in research of topics such as neuroscience, toxicology, diabetes, obesity, and experimental surgery reflects the close resemblance of these animals to human anatomy and physiology 1-6.The size of the G&ouml;ttingen minipig permits the use of surgical equipment and advanced imaging modalities similar to those used in humans 6-8. The aim of this instructional video is to increase the awareness on the value of minipigs in biomedical research, by demonstrating how to perform tracheal intubation, transurethral bladder catheterization, femoral artery and vein catheterization, as well as transcardial perfusion. 
Endotracheal Intubation should be performed whenever a minipig undergoes general anesthesia, because it maintains a patent airway, permits assisted ventilation and protects the airways from aspirates. Transurethral bladder catheterization can provide useful information about about hydration state as well as renal and cardiovascular function during long surgical procedures. Furthermore, urinary catheterization can prevent contamination of delicate medico-technical equipment and painful bladder extension which may harm the animal and unnecessarily influence the experiment due to increased vagal tone and altered physiological parameters. Arterial and venous catheterization is useful for obtaining repeated blood samples and monitoring various physiological parameters. Catheterization of femoral vessels is preferable to catheterization of the neck vessels for ease of access, when performing experiments involving frame-based stereotaxic neurosurgery and brain imaging. When performing vessel catheterization in survival studies, strict aseptic technique must be employed to avoid infections6. Transcardial perfusion is the most effective fixation method, and yields preeminent results when preparing minipig organs for histology and histochemistry2,9. For more information about anesthesia, surgery and experimental techniques in swine in general we refer to Swindle 2007. Supplementary information about premedication and induction of anesthesia, assisted ventilation, analgesia, pre- and postoperative care of G&ouml;ttingen minipigs are available via the internet at <a href="http://www.minipigs.com">http://www.minipigs.com</a>10. For extensive information about porcine anatomy we refer to Nickel et al. Vol. 1-511.

Basic Surgical Techniques in the G&amp;#246;ttingen Minipig: Intubation, Bladder Catheterization, Femoral Vessel Catheterization, and Transcardial Perfusion

The use of domestic and miniature pigs in science has increased significantly in recent years. By demonstrating how to perform intubation, transurethral bladder catheterization, femoral artery and vein catheterization, as well as transcardial perfusion, we aim to further increase the value of G&ouml;ttingen minipigs in biomedical research.

Básico Técnicas Cirúrgicas na Minipig Göttingen: Intubação, cateterismo vesical, cateterização veia femoral e perfusão Transcardial

The emergence of the G&ouml;ttingen minipig in research of topics such as neuroscience, toxicology, diabetes, obesity, and experimental surgery reflects ...

Medicina

Quantification of Atherosclerotic Plaque Activity and Vascular Inflammation using [18-F] Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography (FDG-PET/CT)

Conventional non-invasive imaging modalities of atherosclerosis such as coronary artery calcium (CAC)1 and carotid intimal medial thickness (C-IMT)2 provide information about the burden of disease. However, despite multiple validation studies of CAC3-5, and C-IMT2,6, these modalities do not accurately assess plaque characteristics7,8, and the composition and inflammatory state of the plaque determine its stability and, therefore, the risk of clinical events9-13.
[18F]-2-fluoro-2-deoxy-D-glucose (FDG) imaging using positron-emission tomography (PET)/computed tomography (CT) has been extensively studied in oncologic metabolism14,15. Studies using animal models and immunohistochemistry in humans show that FDG-PET/CT is exquisitely sensitive for detecting macrophage activity16, an important source of cellular inflammation in vessel walls. More recently, we17,18 and others have shown that FDG-PET/CT enables highly precise, novel measurements of inflammatory activity of activity of atherosclerotic plaques in large and medium-sized arteries9,16,19,20. FDG-PET/CT studies have many advantages over other imaging modalities: 1) high contrast resolution; 2) quantification of plaque volume and metabolic activity allowing for multi-modal atherosclerotic plaque quantification; 3) dynamic, real-time, in vivo imaging; 4) minimal operator dependence. Finally, vascular inflammation detected by FDG-PET/CT has been shown to predict cardiovascular (CV) events independent of traditional risk factors21,22 and is also highly associated with overall burden of atherosclerosis23. Plaque activity by FDG-PET/CT is modulated by known beneficial CV interventions such as short term (12 week) statin therapy24 as well as longer term therapeutic lifestyle changes (16 months)25.
The current methodology for quantification of FDG uptake in atherosclerotic plaque involves measurement of the standardized uptake value (SUV) of an artery of interest and of the venous blood pool in order to calculate a target to background ratio (TBR), which is calculated by dividing the arterial SUV by the venous blood pool SUV. This method has shown to represent a stable, reproducible phenotype over time, has a high sensitivity for detection of vascular inflammation, and also has high inter-and intra-reader reliability26. Here we present our methodology for patient preparation, image acquisition, and quantification of atherosclerotic plaque activity and vascular inflammation using SUV, TBR, and a global parameter called the metabolic volumetric product (MVP). These approaches may be applied to assess vascular inflammation in various study samples of interest in a consistent fashion as we have shown in several prior publications.9,20,27,28

Quantification of Atherosclerotic Plaque Activity and Vascular Inflammation using [18-F] Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography FDG-PET/CT

There is great need to identify atherosclerosis non-invasively, and here we demonstrate how FDG-PET/CT can be used to detect and quantify atherosclerotic plaque activity and vascular inflammation.

A quantificação da atividade da placa aterosclerótica e Inflamação Vascular utilizando [18-F] Positron fluorodesoxiglicose Tomografia por Emissão / tomografia computadorizada (FDG-PET/TC)

Conventional non-invasive imaging modalities of atherosclerosis such as coronary artery calcium (CAC)1 and carotid intimal medial thickness (C-IMT)2 ...

Non-invasive Imaging and Analysis of Cerebral Ischemia in Living Rats Using Positron Emission Tomography with 18F-FDG

Stroke is the third leading cause of death among Americans 65 years of age or older1. The quality of life for patients who suffer from a stroke fails to return to normal in a large majority of patients2, which is mainly due to current lack of clinical treatment for acute stroke. This necessitates understanding the physiological effects of cerebral ischemia on brain tissue over time and is a major area of active research. Towards this end, experimental progress has been made using rats as a preclinical model for stroke, particularly, using non-invasive methods such as 18F-fluorodeoxyglucose (FDG) coupled with Positron Emission Tomography (PET) imaging3,10,17. Here we present a strategy for inducing cerebral ischemia in rats by middle cerebral artery occlusion (MCAO) that mimics focal cerebral ischemia in humans, and imaging its effects over 24 hr using FDG-PET coupled with X-ray computed tomography (CT) with an Albira PET-CT instrument. A VOI template atlas was subsequently fused to the cerebral rat data to enable a unbiased analysis of the brain and its sub-regions4. In addition, a method for 3D visualization of the FDG-PET-CT time course is presented. In summary, we present a detailed protocol for initiating, quantifying, and visualizing an induced ischemic stroke event in a living Sprague-Dawley rat in three dimensions using FDG-PET.

Non-invasive Imaging and Analysis of Cerebral Ischemia in Living Rats Using Positron Emission Tomography with 18F-FDG

Brain damage resulting from cerebral ischemia may be non-invasively imaged and studied in rats using pre-clinical positron emission tomography coupled with the injectable radioactive probe, 18F-fluorodeoxyglucose. Further, the use of modern software tools that include volume of interest (VOI) brain templates dramatically increase the quantitative information gleaned from these studies.

Imagem não invasivo e Análise de Isquemia Cerebral em Ratos de Vida Usando Positron Emission Tomography com<sup&gt; 18</sup&gt; F-FDG

Stroke is the third leading cause of death among Americans 65 years of age or older1. The quality of life for patients who suffer from a stroke fails to ...

Cerenkov Luminescence Imaging of Interscapular Brown Adipose Tissue

Brown adipose tissue (BAT), widely known as a &#8220;good fat&#8221; plays pivotal roles for thermogenesis in mammals. This special tissue is closely related to metabolism and energy expenditure, and its dysfunction is one important contributor for obesity and diabetes. Contrary to previous belief, recent PET/CT imaging studies indicated the BAT depots are still present in human adults. PET imaging clearly shows that BAT has considerably high uptake of 18F-FDG under certain conditions. In this video report, we demonstrate that Cerenkov luminescence imaging (CLI) with 18F-FDG can be used to optically image BAT in small animals. BAT activation is observed after intraperitoneal injection of norepinephrine (NE) and cold treatment, and depression of BAT is induced by long anesthesia. Using multiple-filter Cerenkov luminescence imaging, spectral unmixing and 3D imaging reconstruction are demonstrated. Our results suggest that CLI with 18F-FDG is a practical technique for imaging BAT in small animals, and this technique can be used as a cheap, fast, and alternative imaging tool for BAT research.

In this video report, we show the application of Cerenkov Luminescence Imaging (CLI) for interscapular brown adipose tissue in mice under activated and depressed conditions.

Cerenkov luminescência imagem de Interscapular Brown tecido adiposo

Brown adipose tissue (BAT), widely known as a &#8220;good fat&#8221; plays pivotal roles for thermogenesis in mammals. This special tissue is closely ...

Localization, Identification, and Excision of Murine Adipose Depots

Obesity has increased dramatically in the last few decades and affects over one third of the adult US population. The economic effect of obesity in 2005 reached a staggering sum of $190.2 billion in direct medical costs alone. Obesity is a major risk factor for a wide host of diseases. Historically, little was known regarding adipose and its major and essential functions in the body. Brown and white adipose are the two main types of adipose but current literature has identified a new type of fat called brite or beige adipose. Research has shown that adipose depots have specific metabolic profiles and certain depots allow for a propensity for obesity and other related disorders. The goal of this protocol is to provide researchers the capacity to identify and excise adipose depots that will allow for the analysis of different factorial effects on adipose; as well as the beneficial or detrimental role adipose plays in disease and overall health. Isolation and excision of adipose depots allows investigators to look at gross morphological changes as well as histological changes. The adipose isolated can also be used for molecular studies to evaluate transcriptional and translational change or for in vitro experimentation to discover targets of interest and mechanisms of action. This technique is superior to other published techniques due to the design allowing for isolation of multiple depots with simplicity and minimal contamination.

Due to the drastic and negative connection between obesity and other comorbidities, research on the role adipose plays in disease and overall health is warranted. We present a protocol for the isolation and excision of adipose depots allowing for the study of adipose using in situ and in vitro methods.

Localização, identificação e excisão de Depots Murino adiposo

Obesity has increased dramatically in the last few decades and affects over one third of the adult US population. The economic effect of obesity in 2005 ...

Encapsulation Thermogenic Preadipocytes for Transplantation into Adipose Tissue Depots

Cell encapsulation was developed to entrap viable cells within semi-permeable membranes. The engrafted encapsulated cells can exchange low molecular weight metabolites in tissues of the treated host to achieve long-term survival. The semipermeable membrane allows engrafted encapsulated cells to avoid rejection by the immune system. The encapsulation procedure was designed to enable a controlled release of bioactive compounds, such as insulin, other hormones, and cytokines. Here we describe a method for encapsulation of catabolic cells, which consume lipids for heat production and energy dissipation (thermogenesis) in the intra-abdominal adipose tissue of obese mice. Encapsulation of thermogenic catabolic cells may be potentially applicable to the prevention and treatment of obesity and type 2 diabetes. Another potential application of catabolic cells may include detoxification from alcohols or other toxic metabolites and environmental pollutants.

Here, we present a protocol for encapsulation of catabolic cells, which consume lipids for heat production in intra-abdominal adipose tissue and increase energy dissipation in obese mice.

Encapsulation termogênico pré-adipócitos para transplante em adiposo Depots Tissue

Cell encapsulation was developed to entrap viable cells within semi-permeable membranes. The engrafted encapsulated cells can exchange low molecular ...

Assessment of Human Adipose Tissue Microvascular Function Using Videomicroscopy

While obesity is closely linked to the development of metabolic and cardiovascular disease, little is known about mechanisms that govern these processes. It is hypothesized that pro-atherogenic mediators released from fat tissues particularly in association with central/visceral adiposity may promote pathogenic vascular changes locally and systemically, and the notion that cardiovascular disease may be the consequence of adipose tissue dysfunction continues to evolve. Here, we describe a unique method of videomicroscopy that involves analysis of vasodilator and vasoconstrictor responses of intact small human arterioles removed from the adipose depot of living human subjects. Videomicroscopy is used to examine functional properties of isolated microvessels in response to pharmacological or physiological stimuli using a pressured system that mimics in vivo conditions. The technique is a useful approach to gain understanding of the pathophysiology and molecular mechanisms that contribute to vascular dysfunction locally within the adipose tissue milieu. Moreover, abnormalities in the adipose tissue microvasculature have also been linked with systemic diseases. We applied this technique to examine depot-specific vascular responses in obese subjects. We assessed endothelium-dependent vasodilation to both increased flow and acetylcholine in adipose arterioles (50 - 350 &#181;m internal diameter, 2 - 3 mm in length) isolated from two different adipose depots during bariatric surgery from the same individual. We demonstrated that arterioles from visceral fat exhibit impaired endothelium-dependent vasodilation compared to vessels isolated from the subcutaneous depot. The findings suggest that the visceral microenvironment is associated with vascular endothelial dysfunction which may be relevant to clinical observation linking increased visceral adiposity to systemic disease mechanisms. The videomicroscopy technique can be used to examine vascular phenotypes from different fat depots as well as compare findings across individuals with different degrees of obesity and metabolic dysfunction. The method can also be used to examine vascular responses longitudinally in response to clinical interventions.

Videomicroscopy systems are used to examine functional properties of isolated adipose tissue arterioles in response to physiological and pharmacological stimuli. This technique can be used to examine microvascular phenotypes in different adipose tissue domains in obese humans.

Avaliação da função Microvascular de tecido adiposo humano usando tele-microscopia

While obesity is closely linked to the development of metabolic and cardiovascular disease, little is known about mechanisms that govern these processes. ...

Characterization of Immune Cells in Human Adipose Tissue by Using Flow Cytometry

Infiltration of immune cells in the subcutaneous and visceral adipose tissue (AT) deposits leads to a low-grade inflammation contributing to the development of obesity-associated complications such as type 2 diabetes. To quantitatively and qualitatively investigate the immune cell subsets in human AT deposits, we have developed a flow cytometry approach. The stromal vascular fraction (SVF), containing the immune cells, is isolated from subcutaneous and visceral AT biopsies by collagenase digestion. Adipocytes are removed after centrifugation. The SVF cells are stained for multiple membrane-bound markers selected to differentiate between immune cell subsets and analyzed using flow cytometry. As a result of this approach, pro- and anti-inflammatory macrophage subsets, dendritic cells (DCs), B-cells, CD4+ and CD8+ T-cells, and NK cells can be detected and quantified. This method gives detailed information about immune cells in AT and the amount of each specific subset. Since there are numerous fluorescent antibodies available, our flow cytometry approach can be adjusted to measure various other cellular and intracellular markers of interest.

This article describes a method to analyze immune cell content of adipose tissue by isolation of immune cells from adipose tissue and subsequent analysis using flow cytometry.

Caracterização de células imunes no tecido adiposo humano usando citometria de fluxo

Infiltration of immune cells in the subcutaneous and visceral adipose tissue (AT) deposits leads to a low-grade inflammation contributing to the ...

Whole Body and Regional Quantification of Active Human Brown Adipose Tissue Using 18F-FDG PET/CT

In endothermic animals, brown adipose tissue (BAT) is activated to produce heat for defending body temperature in response to cold. BAT&#39;s ability to expend energy has made it a potential target for novel therapies to ameliorate obesity and associated metabolic disorders in humans. Though this tissue has been well studied in small animals, BAT&#39;s thermogenic capacity in humans remains largely unknown due to the difficulties of measuring its volume, activity, and distribution. Identifying and quantifying active human BAT is commonly performed using 18F-Fluorodeoxyglucose (18F-FDG) positron emission tomography and computed tomography (PET/CT) scans following cold-exposure or pharmacological activation. Here we describe a detailed image-analysis approach to quantify total-body human BAT from 18F-FDG PET/CT scans using an open-source software. We demonstrate the drawing of user-specified regions of interest to identify metabolically active adipose tissue while avoiding common non-BAT tissues, to measure BAT volume and activity, and to further characterize its anatomical distribution. Although this rigorous approach is time-consuming, we believe it will ultimately provide a foundation to develop future automated BAT quantification algorithms.

Whole Body and Regional Quantification of Active Human Brown Adipose Tissue Using 18F-FDG PET/CT

Using free, open-source software, we have developed an analytical approach to quantify total and regional brown adipose tissue (BAT) volume and metabolic activity of BAT using 18F-FDG PET/CT.

Todo o corpo e quantificação Regional de ativo humano marrom tecido adiposo usando 18F-FDG PET-CT

In endothermic animals, brown adipose tissue (BAT) is activated to produce heat for defending body temperature in response to cold. BAT&#39;s ability to ...

Continuous Blood Sampling in Small Animal Positron Emission Tomography/Computed Tomography Enables the Measurement of the Arterial Input Function

For quantitative analysis and bio-kinetic modeling of positron emission tomography/computed tomography (PET/CT) data, the determination of the temporal blood time-activity concentration also known as arterial input function (AIF) is a key point, especially for the characterization of animal disease models and the introduction of newly developed radiotracers. The knowledge of radiotracer availability in the blood helps to interpret PET/CT-derived data of tissue activity. For this purpose, online blood sampling during the PET/CT imaging is advisable to measure the AIF. In contrast to manual blood sampling and image-derived approaches, continuous online blood sampling has several advantages. Besides the minimized blood loss, there is an improved resolution and a superior accuracy for the blood activity measurement. However, the major drawback of online blood sampling is the costly and time-consuming preparation to catheterize the femoral vessels of the animal. Here, we describe an easy and complete workflow for catheterization and continuous blood sampling during small animal PET/CT imaging and compared it to manual blood sampling and an image-derived approach. Using this highly-standardized workflow, the determination of the fluorodeoxyglucose ([18F]FDG) AIF is demonstrated. Further, this procedure can be applied to any radiotracer in combination with different animal models to create fundamental knowledge of tracer kinetic and model characteristics. This allows a more precise evaluation of the behavior of pharmaceuticals, both for diagnostic and therapeutic approaches in the preclinical research of oncological, neurodegenerative and myocardial diseases.

Here a protocol for continuous blood sampling during PET/CT imaging of rats to measure the arterial input function (AIF) is described. The catheterization, the calibration and setup of the system and the data analysis of the blood radioactivity are demonstrated. The generated data provide input parameters for subsequent bio-kinetic modeling.

A amostragem contínua do sangue no tomography de emissão de Positron animal pequeno/tomography computado permite a medida da função de entrada arterial

For quantitative analysis and bio-kinetic modeling of positron emission tomography/computed tomography (PET/CT) data, the determination of the temporal ...