Special thanks to Sarah Kossak, Mitchell Guanzon, Sung Yeun Yang and Li Guo Jia, for their collaboration during the endoscopic assessment of their experimental animals.

1. Setting up the Endoscopy System
<ol>
	<li>Set up the endoscopy system before anesthetizing the mice, following the manufacturer&#39;s instructions. Use a video ureteroscope designed for humans for this protocol (Figure 1). The outer diameter of the insertion tube is 9.9 Fr (3.3 mm), its distal end is 8.5 Fr (2.8 mm), and the inner diameter of the instrumentation channel is 6 Fr (1.2 mm).</li>
	<li>Although the use of endoscopes have not been linked to disease transmission [9], sterilize the endoscop...

<ol>
	<li>Huang, E. H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Colonoscopy+in+mice.">Colonoscopy in mice.</a> Surg. Endosc. 16, 22-24 (2002).</li><li>Wirtz, S., Becker, C., Blumberg, R., Galle, P. R., Neurath, M. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Treatment+of+T+cell-dependent+experimental+colitis+in+SCID+mice+by+local+administration+of+an+adenovirus+expressing+IL-18+antisense+mRNA.">Treatment of T cell-dependent experimental colitis in SCID mice by local administration of an adenovirus expressing IL-18 antisense mRNA.</a> J. Immunol. 168, 411-420 (2002).</li><li>Funovics, M. A., Alencar, H., Su, H. S., Khazaie, K., Weissleder, R., Mahmood, U. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Miniaturized+multichannel+near+infrared+endoscope+for+mouse+imaging.">Miniaturized multichannel near infrared endoscope for mouse imaging.</a> Mol Imaging. 2, 350-357 (2003).</li><li>Becker, C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+vivo+imaging+of+colitis+and+colon+cancer+development+in+mice+using+high+resolution+chromoendoscopy.">In vivo imaging of colitis and colon cancer development in mice using high resolution chromoendoscopy.</a> Gut. 54, 950-954 (2005).</li><li>Ravnic, D. J., Konerding, M. A., Huss, H. T., Wolloscheck, T., Pratt, J. P., Mentzer, S. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Murine+microvideo+endoscopy+of+the+colonic+microcirculation.">Murine microvideo endoscopy of the colonic microcirculation.</a> J. Surg. Res. 142, 97-103 (2007).</li><li>Hamilton, M. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Essential+role+for+mast+cell+tryptase+in+acute+experimental+colitis.">Essential role for mast cell tryptase in acute experimental colitis.</a> Proc. Natl. Acad. Sci. U.S.A. 108, 290-295 (2011).</li><li>Becker, C., Fantini, M. C., Neurath, M. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High+resolution+colonoscopy+in+live+mice.">High resolution colonoscopy in live mice.</a> Nat. Protoc. 1, 2900-2904 (2006).</li><li>Hensley, H. H., Merkel, C. E., Chang, W. C., Devarajan, K., Cooper, H. S., Clapper, M. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Endoscopic+imaging+and+size+estimation+of+colorectal+adenomas+in+the+multiple+intestinal+neoplasia+mouse.">Endoscopic imaging and size estimation of colorectal adenomas in the multiple intestinal neoplasia mouse.</a> Gastrointest. Endosc. 69, 742-749 (2009).</li><li>Banerjee, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Infection+control+during+GI+endoscopy.">Infection control during GI endoscopy.</a> Gastrointest. Endosc. 67, 781-790 (2008).</li><li>. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cleaning+and+disinfection+of+equipment+for+gastrointestinal+endoscopy.+Report+of+a+Working.">Cleaning and disinfection of equipment for gastrointestinal endoscopy. Report of a Working.</a> Party of the British Society of Gastroenterology Endoscopy Committee. Gut. 42, 585-593 (1998).</li><li>Sano, Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=New+diagnostic+method+based+on+color+imaging+using+narrow+band+imaging+(NBI)+system+for+gastrointestinal+tract.">New diagnostic method based on color imaging using narrow band imaging (NBI) system for gastrointestinal tract.</a> Gastrointest. Endosc. 53, 125-12 (2001).</li><li>Davies, J., Burke, D., Olliver, J. R., Hardie, L. J., Wild, C. P., Routledge, M. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Methylene+blue+but+not+indigo+carmine+causes+DNA+damage+to+colonocytes+in+vitro+and+in+vivo+at+concentrations+used+in+clinical+chromoendoscopy.">Methylene blue but not indigo carmine causes DNA damage to colonocytes in vitro and in vivo at concentrations used in clinical chromoendoscopy.</a> Gut. 56, 155-156 (2007).</li><li>Chiang, N., Schwab, J. M., Fredman, G., Kasuga, K., Gelman, S., Serhan, C. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Anesthetics+impact+the+resolution+of+inflammation.">Anesthetics impact the resolution of inflammation.</a> PLoS One. 3, e1879 (2008).</li><li>Zilberman, D. E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+digital+flexible+ureteroscope:+in+vitro+assessment+of+optical+characteristics.">The digital flexible ureteroscope: in vitro assessment of optical characteristics.</a> J. Endourol. 25, 519-522 (2011).</li><li>Machida, H., Sano, Y., Hamamoto, Y., Muto, M., Kozu, T., Tajiri, H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Narrow-band+imaging+in+the+diagnosis+of+colorectal+mucosal+lesions:+a+pilot+study.">Narrow-band imaging in the diagnosis of colorectal mucosal lesions: a pilot study.</a> Endoscopy. 36, 1094-1098 (2004).</li><li>Dohoo, I., Martin, W., Stryhn, H., McPike, S. 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There are several considerations regarding modification and troubleshooting of the endoscopic technique in mice. Critical aspects of the procedure that need to be mastered during the use of flexible endoscopy include the adjustment of the air volume needed to prevent abdominal distension and respiratory compromise of the mouse, and minor technical aspects of view control with coordination of the angulation and torque controls. Torque control is important to minimize the risk of intestinal perforation. When handled proper...

Murine endoscopy has been performed as a useful research tool for over a decade1-3. To date, most studies employing murine endoscopy have used rigid endoscopes, although some have also used flexible sigmoidoscopy. Murine endoscopy provides immediate results and a more objective estimate of the extent of intestinal normalcy, severity of inflammation, and tumor progression compared to indirect measures, such as body weight loss, diarrhea, and histology (which is suboptimal when lesions are patchy), while offering insights on the overall health of the colon. Most notably, endoscopy allows for the repeated assessment of laboratory animal models over time, as opposed to traditional histological examination that requires the animal to be euthanized and colons to be harvested for analysis1. Despite these advantages, the use of murine endoscopic technology has not been widespread and is limited by the lack of standardized protocols for implementation and scoring of pathological findings. Properly implemented, murine endoscopy holds great promise to further facilitate our understanding and characterization of animal models of multiple chronic gastrointestinal disease states, including inflammatory bowel diseases, colitis, and colorectal tumors.
The utility of murine endoscopic technology hinges upon its reproducibility and objectivity, which requires the existence of standardized examination procedures and a consistent, non-redundant, and reliable scoring system for intestinal pathologies. At least three descriptive scoring systems for endoscopic assessment of colitis4-6, as well as for colonic tumors4,7,8 in mice have been published. However, these reported approaches and scoring systems are not readily comparable across studies. In many cases, there is no clear definition of the criteria used for classification of lesions, and when criteria are given, they vary widely. Moreover, there are no reported scoring systems that integrate the assessment of both colitis and tumors, two of the most common colonic pathologies that can occur simultaneously and have interactive effects on outcome, into a single measurement tool. Finally, the endoscopic scoring systems that do exist for colitis often have inflammatory categories with limited discrimination (i.e.&#160;narrow scoring options over short integer scales, often 1-4) to properly represent disease progression scenarios and enable the use of parametric statistical analysis.
In this paper, we describe the use of a flexible endoscope to assess the severity of murine colitis and colonic tumors&#160;and describe a standardized protocol for employing this technology in the anatomical assessment of the perianal region, rectum, and distal colon. We illustrate effective troubleshooting during endoscopy to minimize trauma and image artifacts, and we describe a reproducible scoring system based on validated published clinical parameters. The scoring system integrates evaluation of both intestinal inflammation and tumors using a high level of discrimination with 12 possible grades of inflammation, tumor mapping and plotting options, and a novel decimal unit system (i.e., decimal identifiers) to highlight findings with specific diagnostic value (i.e. tumor development, complications during endoscopy, etc.). The use of decimal identifiers allows for rapid tracking of relevant data sets for further downstream analysis. Finally, we perform reliability and validity testing of the scoring system in multiple murine models of colitis and colitis-associated cancer (dextran sulfate sodium (DSS) induced-colitis, Clostridium difficile infection, and azoxymethane/DSS-induced colonic cancer).

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			<td height="21" style="height:21px;width:240px;">Isoflurane, USP</td>
			<td style="width:160px;">Webster Veterinary&#160;</td>
			<td style="width:217px;"></td>
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			<td height="20" style="height:20px;width:240px;">Surgical lubricant</td>
			<td style="width:160px;">Savage laboratories</td>
			<td style="width:217px;">surgilube, 0281-0205-45</td>
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			<td height="20" style="height:20px;width:240px;">Phosphate Buffered Saline</td>
			<td style="width:160px;">Thermo Scientific&#160;</td>
			<td style="width:217px;">SH30256</td>
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			<td height="20" style="height:20px;width:240px;">RNAlater</td>
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			<td height="20" style="height:20px;width:240px;">Methylene Blue 1% Aqueous Solution</td>
			<td style="width:160px;">Fisher Science Education</td>
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			<td height="21" style="height:21px;width:240px;">Flexible digital ureteroscope</td>
			<td style="width:160px;">Olympus America</td>
			<td style="width:217px;">URF-V</td>
			<td style="width:79px;"></td>
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			<td height="21" style="height:21px;width:240px;">Video system center</td>
			<td style="width:160px;">Olympus America</td>
			<td style="width:217px;">VISERA Pro OTV-S7 Pro</td>
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			<td height="21" style="height:21px;width:240px;">Xenon light source</td>
			<td style="width:160px;">Olympus America</td>
			<td style="width:217px;">VISERA Pro CLV-S40 Pro</td>
			<td style="width:79px;"></td>
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		<tr height="21">
			<td height="21" style="height:21px;width:240px;">Video recorder</td>
			<td style="width:160px;">MediCapture, Inc.</td>
			<td style="width:217px;">MediCap USB200</td>
			<td style="width:79px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:240px;">Flexible biopsy cup forceps</td>
			<td style="width:160px;">Olympus America</td>
			<td style="width:217px;">FBC-3115</td>
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			<td height="21" style="height:21px;width:240px;">Anesthesia machine</td>
			<td style="width:160px;">Euthanex Corporation</td>
			<td style="width:217px;">EZ-7000 Classic System</td>
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flexible colonoscopy in mice to evaluate the severity of colitis and colorectal tumors using a validated endoscopic scoring system

The use of modern endoscopy for research purposes has greatly facilitated our understanding of gastrointestinal pathologies. In particular, experimental endoscopy has been highly useful for studies that require repeated assessments in a single laboratory animal, such as those evaluating mechanisms of chronic inflammatory bowel disease and the progression of colorectal cancer. However, the methods used across studies are highly variable. At least three endoscopic scoring systems have been published for murine colitis and published protocols for the assessment of colorectal tumors fail to address the presence of concomitant colonic inflammation. This study develops and validates a reproducible endoscopic scoring system that integrates evaluation of both inflammation and tumors simultaneously. This novel scoring system has three major components: 1) assessment of the extent and severity of colorectal inflammation (based on perianal findings, transparency of the wall, mucosal bleeding, and focal lesions), 2) quantitative recording of tumor lesions (grid map and bar graph), and 3) numerical sorting of clinical cases by their pathological and research relevance based on decimal units with assigned categories of observed lesions and endoscopic complications (decimal identifiers). The video and manuscript presented herein were prepared, following IACUC-approved protocols, to allow investigators to score their own experimental mice using a well-validated and highly reproducible endoscopic methodology, with the system option to differentiate distal from proximal endoscopic colitis (D-PECS).

The protocol and images presented in this study were prepared with an Olympus URF-V flexible endoscope14&#160;and NBI11,15. Video images were saved in MPEG-2 format and pictures in JPG, TIF, PNG,&#160;or DICOM format with maximum 1,280 x 1,024 pixels, transferable to standard USB flash portable memories. NBI enhances the visual contrast of hemoglobin-containing tissues. Normal light and NBI imaging are key features to illustrate the normal anatomy of the colorectal mucosa and the differences between...

Watch this Scientific Journal Video about Flexible Colonoscopy in Mice to Evaluate the Severity of Colitis and Colorectal Tumors Using a Validated Endoscopic Scoring System at JoVE.com

Flexible Colonoscopy in Mice to Evaluate the Severity of Colitis and Colorectal Tumors Using a Validated Endoscopic Scoring System

Over the past few years, new generation endoscopes have emerged as important diagnostic research aids for evaluating murine colitis and colorectal tumors. We present herein a detailed protocol for endoscopic assessment of inflammation and colorectal tumors in mice, as well as a novel scoring system that uses decimal identifiers to document the endoscopic severity of colitis and colorectal tumors.

The use of modern endoscopy for research purposes has greatly facilitated our understanding of gastrointestinal pathologies. In particular, experimental ...

flexible-colonoscopy-mice-to-evaluate-severity-colitis-colorectal

Research

JoVE Journal

Medicine

31.4K visualizações.  Case Western Reserve University School of Medicine, Cleveland.  Ao longo dos últimos anos, novas endoscópios geração surgiram como importantes auxiliares de pesquisa de diagnóstico para a avaliação de colite murina e tumores colorectais. Apresentamos aqui um protocolo detalhado para a avaliação endoscópica de inflamação e tumores colo-rectal em ratos, bem como um novo sistema de pontuação que utiliza identificadores decimais para documentar a gravidade endoscópico de colite e tumores colorectais. 