Name: murine oropharyngeal aspiration model of ventilator-associated and hospital-acquired bacterial pneumonia
Uploaded: 2018-06-28T14:00:00
Description: Watch this Scientific Journal Video about Murine Oropharyngeal Aspiration Model of Ventilator-associated and Hospital-acquired Bacterial Pneumonia at JoVE.com

This work was supported by the National Institute of Allergy and Infectious Diseases at the National Institutes of Health [Grant Numbers R01 AI117211, R01 AI130060, R21 AI127954, and R42 AI106375 to BS] and US Food and Drug Administration [Contract HHSF223201710199C to BML].

All procedures involving animals must be approved by the researcher&#8217;s Institutional Animal Care and Use Committee (IACUC).
1. Preparation of Bacterial Inoculum
<ol>
	<li>Isolate bacterial colonies.
	<ol>
		<li>Streak a bacterial strain (e.g., A. baumannii &#8220;HUMC1&#8221;) on appropriate sterile agar medium (e.g., Tryptic soy agar), being careful to generate isolated colonies.</li>
		<li>Incubate at appropriate conditions (e.g., overnight at 37 &#...

<ol>
	<li>Spellberg, B., Talbot, G. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Recommended+Design+Features+of+Future+Clinical+Trials+of+Antibacterial+Agents+for+Hospital-Acquired+Bacterial+Pneumonia+and+Ventilator-Associated+Bacterial+Pneumonia.">Recommended Design Features of Future Clinical Trials of Antibacterial Agents for Hospital-Acquired Bacterial Pneumonia and Ventilator-Associated Bacterial Pneumonia.</a> Clinical Infectious Diseases. 51 (S1), S150-S170 (2010).</li><li>Kalil, A. 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=Management+of+Adults+With+Hospital-acquired+and+Ventilator-associated+Pneumonia:+2016+Clinical+Practice+Guidelines+by+the+Infectious+Diseases+Society+of+America+and+the+American+Thoracic+Society.">Management of Adults With Hospital-acquired and Ventilator-associated Pneumonia: 2016 Clinical Practice Guidelines by the Infectious Diseases Society of America and the American Thoracic Society.</a> Clinical Infectious Diseases. 63 (5), e61-e111 (2016).</li><li>Medina, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Murine+model+of+pneumococcal+pneumonia.">Murine model of pneumococcal pneumonia.</a> Methods in Molecular Biology. , 405-410 (2010).</li><li>Azoulay-Dupuis, 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=In+vivo+efficacy+of+a+new+fluoroquinolone,+sparfloxacin,+against+penicillin-susceptible+and+-resistant+and+multiresistant+strains+of+Streptococcus+pneumoniae+in+a+mouse+model+of+pneumonia.">In vivo efficacy of a new fluoroquinolone, sparfloxacin, against penicillin-susceptible and -resistant and multiresistant strains of Streptococcus pneumoniae in a mouse model of pneumonia.</a> Antimicrobial Agents and Chemotherapy. 36 (12), 2698-2703 (1992).</li><li>Mizgerd, J. P., Skerrett, 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=Animal+models+of+human+pneumonia.">Animal models of human pneumonia.</a> American Journal of Physiology-Lung Cellular and Molecular Physiology. 294 (3), L387-L398 (2008).</li><li>Rayamajhi, M., 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=Non-surgical+intratracheal+instillation+of+mice+with+analysis+of+lungs+and+lung+draining+lymph+nodes+by+flow+cytometry.">Non-surgical intratracheal instillation of mice with analysis of lungs and lung draining lymph nodes by flow cytometry.</a> Journal of Visualized Experiments. (51), (2011).</li><li>Nielsen, T. B., Bruhn, K. W., Pantapalangkoor, P., Junus, J. L., Spellberg, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cryopreservation+of+virulent+Acinetobacter+baumannii+to+reduce+variability+of+in+vivo+studies.">Cryopreservation of virulent Acinetobacter baumannii to reduce variability of in vivo studies.</a> BMC Microbiology. 15, 252 (2015).</li><li>Trammell, R. A., Toth, L. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Markers+for+predicting+death+as+an+outcome+for+mice+used+in+infectious+disease+research.">Markers for predicting death as an outcome for mice used in infectious disease research.</a> Comparative Medicine. 61 (6), 492-498 (2011).</li><li>Bast, D. 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=Novel+murine+model+of+pneumococcal+pneumonia:+use+of+temperature+as+a+measure+of+disease+severity+to+compare+the+efficacies+of+moxifloxacin+and+levofloxacin.">Novel murine model of pneumococcal pneumonia: use of temperature as a measure of disease severity to compare the efficacies of moxifloxacin and levofloxacin.</a> Antimicrobial Agents and Chemotherapy. 48 (9), 3343-3348 (2004).</li><li>Hankenson, F. 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=Weight+loss+and+reduced+body+temperature+determine+humane+endpoints+in+a+mouse+model+of+ocular+herpesvirus+infection.">Weight loss and reduced body temperature determine humane endpoints in a mouse model of ocular herpesvirus infection.</a> Journal of the American Association for Laboratory Animal Science. 52 (3), 277-285 (2013).</li><li>Adamson, T. W., Diaz-Arevalo, D., Gonzalez, T. M., Liu, X., Kalkum, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hypothermic+endpoint+for+an+intranasal+invasive+pulmonary+aspergillosis+mouse+model.">Hypothermic endpoint for an intranasal invasive pulmonary aspergillosis mouse model.</a> Comparative Medicine. 63 (6), 477-481 (2013).</li><li>Nielsen, T. B., 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=Diabetes+Exacerbates+Infection+via+Hyperinflammation+by+Signaling+through+TLR4+and+RAGE.">Diabetes Exacerbates Infection via Hyperinflammation by Signaling through TLR4 and RAGE.</a> mBio. 8 (4), (2017).</li><li>Nielsen, T. B., 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=Monoclonal+Antibody+Protects+Against+Acinetobacter+baumannii+Infection+by+Enhancing+Bacterial+Clearance+and+Evading+Sepsis.">Monoclonal Antibody Protects Against Acinetobacter baumannii Infection by Enhancing Bacterial Clearance and Evading Sepsis.</a> Journal of Infectious Diseases. 216 (4), 489-501 (2017).</li><li>Cheng, B. L., 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=Evaluation+of+serotypes+5+and+8+capsular+polysaccharides+in+protection+against+Staphylococcus+aureus+in+murine+models+of+infection.">Evaluation of serotypes 5 and 8 capsular polysaccharides in protection against Staphylococcus aureus in murine models of infection.</a> Human Vaccine Immunotherapy. 13 (7), 1609-1614 (2017).</li><li>Wong, D., 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=Clinical+and+Pathophysiological+Overview+of+Acinetobacter+Infections:+a+Century+of+Challenges.">Clinical and Pathophysiological Overview of Acinetobacter Infections: a Century of Challenges.</a> Clinical Microbiology Reviews. 30 (1), 409-447 (2017).</li></ol>

To be sure, mice are not miniature humans. Results obtained from mouse models must be considered in context and subsequently interpreted for applicability to humans, based on differences and similarities between the two species6. It is also important to choose the appropriate mouse strain as certain are more susceptible to some infections than others; the same applies to the pathogen strain of choice16.
It is essential to perform infections in an...

Lower respiratory infection is the world&#39;s deadliest communicable disease and the most common cause of death in developing countries1. Globally, these infections account for more than 3.2 million deaths1. In addition, nosocomial pneumonia is among the most common and deadly forms of healthcare acquired infections, and is caused by the most antibiotic-resistant pathogens2,3. The typical route of acquisition of bacterial pneumonia for both community-acquired and nosocomial pneumonia is the aspiration of oropharyngeal contents into the alveoli. Murine models used to study these diseases often use intranasal inoculation4, depositing much of the bacteria outside the lung, causing off-target complications and symptoms like sinusitis and physical trauma, which are incongruent with the disease progression in human that the models were designed to emulate. Other models may use inhalation chambers and micromisting devices, which more accurately mimic viral, tuberculous, and fungal pneumonias, but do not accurately recapitulate the normal route of acquisition for typical bacterial pneumonias.
The murine oropharyngeal aspiration pneumonia model may be utilized to simulate the natural route and pathogenesis of bacterial pneumonia. By inoculating 50 &#181;L of the bacterial suspension into the oropharynx of anesthetized mice using a pipette, reflexive aspiration ensues, which results in infectious pneumonia. Using this model, one can examine the pathogenesis of pneumonia-causing pathogens and new treatments to combat these diseases with a higher fidelity model, more analogous to aspiration pneumonia infections observed in human. Additionally, unlike similar models that infect through the oral cavity5,6, this model ensures that the full inoculum reaches the lungs instead of the gut, where it can cause off-site inflammation and infections, such as gastritis and enteritis. Finally, unlike another published model that requires a laryngoscope and inoculates through the trachea7, this model does not obstruct the airway with a gavage needle and does not require injection for inoculum delivery. Instead, inoculation relies on the natural aspiration reflex of the mouse.

<table>
	<tbody>
		<tr>
			<td>Agar</td>
			<td>BD</td>
			<td>214530</td>
			<td>Combine with TSB to make TSA</td>
		</tr>
		<tr>
			<td>Beads, Borosilicate Glass</td>
			<td>Kimble</td>
			<td>135003</td>
			<td>Sterilize by baking or autoclaving before each use</td>
		</tr>
		<tr>
			<td>Beaker, 250 mL</td>
			<td>Pyrex</td>
			<td>1003</td>
			<td>Used during precise aliquoting of concentrated bacterial inocula</td>
		</tr>
		<tr>
			<td>Centrifuge</td>
			<td>Sorvall</td>
			<td>ST 40R</td>
			<td>Capable of 4,000&#215;g at 4&#176;C</td>
		</tr>
		<tr>
			<td>Chamber for Anesthesia</td>
			<td>Kent Scientific Corporation</td>
			<td>VetFlo-0720</td>
			<td>Accommodates up to 5 mice</td>
		</tr>
		<tr>
			<td>Cryomold, Intermediate Size</td>
			<td>Sakura Tissue-Tek</td>
			<td>4566</td>
			<td>Disposable vinyl specimen molds, 15&#215;15&#215;5 mm</td>
		</tr>
		<tr>
			<td>Dental Floss</td>
			<td>Oral-B</td>
			<td>37000469537</td>
			<td>Tie to stable post approx. 6&#34; above table height</td>
		</tr>
		<tr>
			<td>Forceps</td>
			<td>VWR</td>
			<td>82027-440</td>
			<td>Used to gently pull tongue out of mouse&#39;s mouth</td>
		</tr>
		<tr>
			<td>Homogenizer for Lung Tissue</td>
			<td>Omni International</td>
			<td>TM125-115</td>
			<td>Autoclave before first use; rinse between samples</td>
		</tr>
		<tr>
			<td>Isoflurane for Anesthesia</td>
			<td>Abbott</td>
			<td>10015516</td>
			<td>Alternative drug can be used; modify procedure accordingly</td>
		</tr>
		<tr>
			<td>iSTAT Cartridge</td>
			<td>Abbott</td>
			<td>03P79-25</td>
			<td>Various cartridges are available to suit your needs</td>
		</tr>
		<tr>
			<td>Ketamine, 100 mg/mL</td>
			<td>Western Medical Supply</td>
			<td>4165</td>
			<td>Dilute 1:10 in PBS to 1 mg/mL and combine with Xylazine at 1 mg/mL</td>
		</tr>
		<tr>
			<td>Ointment for Eyes</td>
			<td>Akorn</td>
			<td>Tears Renewed</td>
			<td>Avoid touching eye with tip of dispenser</td>
		</tr>
		<tr>
			<td>Optimal Cutting Temperature (O.C.T.) Compound</td>
			<td>Fisher Scientific</td>
			<td>23-730-571</td>
			<td>Used to freeze lung samples at -80 &#176;C to prepare for pathology sectioning</td>
		</tr>
		<tr>
			<td>Petri Dish</td>
			<td>VWR</td>
			<td>25384-302</td>
			<td>Polystyrene, disposable, sterilized, 100&#215;15 mm</td>
		</tr>
		<tr>
			<td>Phosphate-Buffered Saline (PBS)</td>
			<td>Corning</td>
			<td>21-031-CM</td>
			<td>Dulbecco&#39;s PBS without calcium and magnesium</td>
		</tr>
		<tr>
			<td>Pipette Tips, 200-&#956;L</td>
			<td>VWR</td>
			<td>10017-044</td>
			<td>Autoclave before use</td>
		</tr>
		<tr>
			<td>Pipetter, 200-&#956;L</td>
			<td>Gilson</td>
			<td>Pipetman P200</td>
			<td>Autoclave and calibrate before use</td>
		</tr>
		<tr>
			<td>Spreader, Bacterial Cell</td>
			<td>Bel-Art</td>
			<td>F377360006</td>
			<td>Sterilize by baking or autoclaving before each use</td>
		</tr>
		<tr>
			<td>Stir Bar, Magnetic, 7.9 mm Diameter &#215; 38.1 mm Length</td>
			<td>VWR</td>
			<td>58948-150</td>
			<td>Used for stiring concentrated bacterial inocula during aliquoting</td>
		</tr>
		<tr>
			<td>Stir Plate, Magnetic</td>
			<td>Corning</td>
			<td>PC-620D</td>
			<td>Used for stiring concentrated bacterial inocula during aliquoting</td>
		</tr>
		<tr>
			<td>Tryptic Soy Broth (TSB)</td>
			<td>BD</td>
			<td>211822</td>
			<td>Combine with Agar to make TSA</td>
		</tr>
		<tr>
			<td>Vial, Conical, Sterile, 50 mL</td>
			<td>Corning</td>
			<td>431720</td>
			<td>Used for preparing bacterial inocula</td>
		</tr>
		<tr>
			<td>Vial, Conical, Sterile, 500 mL</td>
			<td>Corning</td>
			<td>431123</td>
			<td>Used to concentrate inocula for preparing frozen inocula</td>
		</tr>
		<tr>
			<td>Vial, Cryogenic, 2.0 mL</td>
			<td>Corning</td>
			<td>430659</td>
			<td>Used for cryogenic storage of concentrated bacterial inocula</td>
		</tr>
		<tr>
			<td>Xylazine, 20 mg/mL</td>
			<td>Akorn</td>
			<td>AnaSed Injection</td>
			<td>Dilute 1:20 in PBS to 1 mg/mL and combine with Ketamine at 1 mg/mL</td>
		</tr>
	</tbody>
</table>

murine oropharyngeal aspiration model of ventilator-associated and hospital-acquired bacterial pneumonia

Murine infection models are critical for understanding disease pathogenesis and testing the efficacy of novel therapeutics designed to combat causative pathogens. Infectious pneumonia is among the most common infections presented by patients in the clinic and thus warrants an appropriate in vivo model. Typical pneumonia models use intranasal inoculation, which deposits excessive organisms outside the lung, causing off-target complications and symptoms, such as sinusitis, gastritis, enteritis, physical trauma, or microparticle misting to mimic aerosol spread more typical of viral, tuberculous, or fungal pneumonia. These models do not accurately reflect the pathogenesis of typical community- or healthcare-acquired bacterial pneumonia. In contrast, this murine model of oropharyngeal aspiration pneumonia mimics the droplet route in healthcare-acquired pneumonia. Inoculating 50 &#181;L of the bacteria suspension into the oropharynx of anesthetized mice causes reflexive aspiration, which results in pneumonia. With this model, one can examine the pathogenesis of pneumonia-causing pathogens and new treatments to combat these diseases.

By carefully following the protocol, reproducible and robust data can be easily obtained. It is critical to strictly adhere to one&#39;s customized inoculum preparation protocol for experiments to be compared to one each other. It is also important to properly handle mice during the infection procedure. Be sure to place mice into an anesthesia chamber devoid of isoflurane. Mice will panic if they are placed into a chamber that has been pre-filled with isoflurane and may experience excess ...

Watch this Scientific Journal Video about Murine Oropharyngeal Aspiration Model of Ventilator-associated and Hospital-acquired Bacterial Pneumonia at JoVE.com

Murine Oropharyngeal Aspiration Model of Ventilator-associated and Hospital-acquired Bacterial Pneumonia

Infectious pneumonia is among the most common infections in human. An appropriate in vivo model is critical for understanding disease pathogenesis and testing the efficacy of novel therapeutics. With this murine oropharyngeal aspiration pneumonia model, one can examine the pathogenesis and new treatments against these deadly infections.

Murine infection models are critical for understanding disease pathogenesis and testing the efficacy of novel therapeutics designed to combat causative ...

This method can help answer key questions in the field of antibiotic resistance about novel therapeutics with a treatment of ventilator-associated pneumonia. The main advantage of this technique is that it accurately replicates clinical infection in a quick and easily reproducible manner. To inoculate the mice, hang the first anesthetized animal by its top incisors on a strong thin string.Secure it to a fixed object above the operating surface, at a height approximately twice the mouse's body length. Use sterile blunt-handed forceps to gently pull out the tongue, and transfer the tongue to sterile, gloved fingers to allow access to the oral pharynx. Depress the plunger of a micro pipette to the first stop to place 50 microliters of the inoculum into the oral pharynx, until the mouse inhales the bacterial suspension, by reflexive aspiration.The mouse will stop breathing for a few seconds when the inoculum is placed in the oral pharynx, and eventually reflexive aspiration will cause the bacterial suspension to be inhaled, indicative by the distinctive crackling noise of liquid entering the lungs. Then return the animal to its cage, with monitoring, until full recumbency. At the appropriate experimental endpoint, cut the trachea, pulmonary artery, and pulmonary vein, to allow removal of the lung tissue.For histopathological analysis of the disease progression, place the lungs into a specimen mold. And fill the mold with optimal cutting temperature compound, until the tissue is completely submerged. Then freeze the samples at minus 80 degrees Celsius, until their sectioning and analysis.To estimate the bacterial burden, transfer the harvested lung tissue to a 50 milliliter conical vial, and determine its mass with an analytical balance. Then transfer five milliliters of sterile PBS to the vial. Homogenize the lung tissue with a tissue homogenizer.And perform serial dilutions in the homogenate and sterile PBS, to achieve approximately 1000 colony forming units, or CFU, per millimeter, based on the expected bacterial burden in the infected lungs. Plate 100 microliters of each dilution onto individual tryptic soy agar plates. And use glass beads to evenly distribute the homogenates.Then store the plates in a humidified, 37 degree Celsius incubator over night. Before calculating the number of colony forming units per dilution. It is necessary to infect the mice with various inoculum concentrations, to determine the LD 100.Under these representative experimental conditions, two times 10 to the eighth CFU per mouse was too high. Five times 10 to the seventh and two times 10 to the seventh, were too low. And one times 10 to the eighth was just right Hematoxylin and ee-ah-zin staining of lung sections before and 24 hours after oral pharyngeal aspiration of the bacterial species commonly encountered in ventilator-associated pneumonia in humans, typically results in substantial alveolar inflammation.While attempting this procedure, it's important to remember the inoculum must be prepared and atomy surd identically from experiment to experiment to obtain reproducible results. After watching this video, you should have a good understanding of how to recapitulate ventilator-associated pneumonia using a mouse model.

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Medicine

Murine Bioluminescent Hepatic Tumour Model

This video describes the establishment of liver metastases in a mouse model that can be subsequently analysed by bioluminescent imaging. Tumour cells are administered specifically to the liver to induce a localised liver tumour, via mobilisation of the spleen and splitting into two, leaving intact the vascular pedicle for each half of the spleen. Lewis lung carcinoma cells that constitutively express the firefly luciferase gene (luc1) are inoculated into one hemi-spleen which is then resected 10 minutes later. The other hemi-spleen is left intact and returned to the abdomen. Liver tumour growth can be monitored by bioluminescence imaging using the IVIS whole body imaging system. Quantitative imaging of tumour growth using IVIS provides precise quantitation of viable tumour cells. Tumour cell death and necrosis due to drug treatment is indicated early by a reduction in the bioluminescent signal. This mouse model allows for investigating the mechanisms underlying metastatic tumour-cell survival and growth and can be used for the evaluation of therapeutics of liver metastasis. 

This article describes a procedure for the induction of orthotopic bioluminescent liver tumours in mice, and subsequent analysis of tumour growth confined to the liver using live whole body luminescence imaging.

This video describes the establishment of liver metastases in a mouse model that can be subsequently analysed by bioluminescent imaging. Tumour cells are ...

An Orthotopic Model of Murine Bladder Cancer

In this straightforward procedure, bladder tumors are established in female C57 mice through the use of catheterization, local cauterization, and subsequent cell adhesion. After their bladders are transurethrally catheterized and drained, animals are again catheterized to permit insertion of a platinum wire into bladders without damaging the urethra or bladder. The catheters are made of Teflon to serve as an insulator for the wire, which will conduct electrical current into the bladder to create a burn injury. An electrocautery unit is used to deliver 2.5W to the exposed end of the wire, burning away extracellular layers and providing attachment sites for carcinoma cells that are delivered in suspension to the bladder through a subsequent catheterization. Cells remain in the bladder for 90 minutes, after which the catheters are removed and the bladders allowed to drain naturally. The development of tumor is monitored via ultrasound. Specific attention is paid to the catheterization technique in the accompanying video.

Bladder tumors are established in female mice in a minimally invasive fashion through catheterization, local cauterization, and subsequent adhesion of carcinoma cells to the burn sites.

In this straightforward procedure, bladder tumors are established in female C57 mice through the use of catheterization, local cauterization, and ...

A Murine Closed-chest Model of Myocardial Ischemia and Reperfusion

Surgical trauma by thoracotomy in open-chest models of coronary ligation induces an immune response which modifies different mechanisms involved in ischemia and reperfusion. Immune response includes cytokine expression and release or secretion of endogenous ligands of innate immune receptors. Activation of innate immunity can potentially modulate infarct size. We have modified an existing murine closed-chest model using hanging weights which could be useful for studying myocardial pre- and postconditioning and the role of innate immunity in myocardial ischemia and reperfusion. This model allows animals to recover from surgical trauma before onset of myocardial ischemia.
Volatile anesthetics have been intensely studied and their preconditioning effect for the ischemic heart is well known. However, this protective effect precludes its use in open chest models of coronary artery ligation. Thus, another advantage could be the use of the well controllable volatile anesthetics for instrumentation in a chronic closed-chest model, since their preconditioning effect lasts up to 72 hours. Chronic heart diseases with intermittent ischemia and multiple hit models are other possible applications of this model.
For the chronic closed-chest model, intubated and ventilated mice undergo a lateral blunt thoracotomy via the 4th intercostal space. Following identification of the left anterior descending a ligature is passed underneath the vessel and both suture ends are threaded through an occluder. Then, both suture ends are passed through the chest wall, knotted to form a loop and left in the subcutaneous tissue. After chest closure and recovery for 5 days, mice are anesthetized again, chest skin is reopened and hanging weights are hooked up to the loop under ECG control.
At the end of the ischemia/reperfusion protocol, hearts can be stained with TTC for infarct size assessment or undergo perfusion fixation to allow morphometric studies in addition to histology and immunohistochemistry.

Surgical trauma induces an inflammatory response. Cytokines and endogenous ligands are known to modulate myocardial infarct size following ischemia and reperfusion. We present a modified closed-chest model of murine ischemia and reperfusion using hanging weights to minimize effects of thoracotomy.

Surgical trauma by thoracotomy in open-chest models of coronary ligation induces an immune response which modifies different mechanisms involved in ...

Murine Model of Wound Healing

Wound healing and repair are the most complex biological processes that occur in human life. After injury, multiple biological pathways become activated. Impaired wound healing, which occurs in diabetic patients for example, can lead to severe unfavorable outcomes such as amputation. There is, therefore, an increasing impetus to develop novel agents that promote wound repair. The testing of these has been limited to large animal models such as swine, which are often impractical. Mice represent the ideal preclinical model, as they are economical and amenable to genetic manipulation, which allows for mechanistic investigation. However, wound healing in a mouse is fundamentally different to that of humans as it primarily occurs via contraction. Our murine model overcomes this by incorporating a splint around the wound. By splinting the wound, the repair process is then dependent on epithelialization, cellular proliferation and angiogenesis, which closely mirror the biological processes of human wound healing. Whilst requiring consistency and care, this murine model does not involve complicated surgical techniques and allows for the robust testing of promising agents that may, for example, promote angiogenesis or inhibit inflammation. Furthermore, each mouse acts as its own control as two wounds are prepared, enabling the application of both the test compound and the vehicle control on the same animal. In conclusion, we demonstrate a practical, easy-to-learn, and robust model of wound healing, which is comparable to that of humans.

A murine model of cutaneous wound healing that can be used to assess therapeutic compounds in physiological and pathophysiological settings.

Wound healing and repair are the most complex biological processes that occur in human life. After injury, multiple biological pathways become activated. ...

Osteopathic Manipulative Treatment as a Useful Adjunctive Tool for Pneumonia

Pneumonia, the inflammatory state of lung tissue primarily due to microbial infection, claimed 52,306 lives in the United States in 20071 and resulted in the hospitalization of 1.1 million patients2. With an average length of in-patient hospital stay of five days2, pneumonia and influenza comprise significant financial burden costing the United States $40.2 billion in 20053. Under the current Infectious Disease Society of America/American Thoracic Society guidelines, standard-of-care recommendations include the rapid administration of an appropriate antibiotic regiment, fluid replacement, and ventilation (if necessary). Non-standard therapies include the use of corticosteroids and statins; however, these therapies lack conclusive supporting evidence4. (Figure 1)

Osteopathic Manipulative Treatment (OMT) is a cost-effective adjunctive treatment of pneumonia that has been shown to reduce patients&#8217; length of hospital stay, duration of intravenous antibiotics, and incidence of respiratory failure or death when compared to subjects who received conventional care alone5. The use of manual manipulation techniques for pneumonia was first recorded as early as the Spanish influenza pandemic of 1918, when patients treated with standard medical care had an estimated mortality rate of 33%, compared to a 10% mortality rate in patients treated by osteopathic physicians6. When applied to the management of pneumonia, manual manipulation techniques bolster lymphatic flow, respiratory function, and immunological defense by targeting anatomical structures involved in the these systems7,8, 9, 10.

The objective of this review video-article is three-fold: a) summarize the findings of randomized controlled studies on the efficacy of OMT in adult patients with diagnosed pneumonia, b) demonstrate established protocols utilized by osteopathic physicians treating pneumonia, c) elucidate the physiological mechanisms behind manual manipulation of the respiratory and lymphatic systems. Specifically, we will discuss and demonstrate four routine techniques that address autonomics, lymph drainage, and rib cage mobility: 1) Rib Raising, 2) Thoracic Pump, 3) Doming of the Thoracic Diaphragm, and 4) Muscle Energy for Rib 1.5,11

Pneumonia is one of the top ten leading causes of death in the U.S. Osteopathic manipulative techniques (OMT) may be utilized as an adjunctive therapy in the treatment of pneumonia to enhance biomechanical and immune function; and ultimately, to reduce hospital stay, duration of antibiotics, incidence of respiratory failure, and mortality. In this video-article, we will review randomized controlled studies on the use of OMT in pneumonia patients, as well as demonstrate specific hands-on techniques that are routinely practiced by osteopathic physicians when treating pulmonary infections.

Pneumonia, the inflammatory state of lung tissue primarily due to microbial infection, claimed 52,306 lives in the United States in 20071 and resulted in ...

A Murine Model of Subarachnoid Hemorrhage

In this video publication a standardized mouse model of subarachnoid hemorrhage (SAH) is presented. Bleeding is induced by endovascular Circle of Willis perforation (CWp) and proven by intracranial pressure (ICP) monitoring. Thereby a homogenous blood distribution in subarachnoid spaces surrounding the arterial circulation and cerebellar fissures is achieved. Animal physiology is maintained by intubation, mechanical ventilation, and continuous on-line monitoring of various physiological and cardiovascular parameters: body temperature, systemic blood pressure, heart rate, and hemoglobin saturation. Thereby the cerebral perfusion pressure can be tightly monitored resulting in a less variable volume of extravasated blood. This allows a better standardization of endovascular filament perforation in mice and makes the whole model highly reproducible. Thus it is readily available for pharmacological and pathophysiological studies in wild type and genetically altered mice.

A standardized mouse model of subarachnoid hemorrhage by intraluminal Circle of Willis perforation is described. Vessel perforation and subarachnoid bleeding are monitored by intracranial pressure monitoring. In addition various vital parameters are recorded and controlled to maintain physiologic conditions.

In this video publication a standardized mouse model of subarachnoid  hemorrhage (SAH) is presented. Bleeding is induced by endovascular Circle of  Willis ...

Femoral Bone Marrow Aspiration in Live Mice

Serial sampling of the cellular composition of bone marrow (BM) is a routine procedure critical to clinical hematology. This protocol describes a detailed step-by-step technical procedure for an analogous procedure in live mice which allows for serial characterization of cells present in the BM. This procedure facilitates studies aimed to detect the presence of exogenously administered cells within the BM of mice as would be done in xenograft studies for instance. Moreover, this procedure allows for the retrieval and characterization of cells enriched in the BM such as hematopoietic stem and progenitor cells (HSPCs) without sacrifice of mice. Given that the cellular composition of peripheral blood is not necessarily reflective of proportions and types of stem and progenitor cells present in the marrow, procedures which provide access to this compartment without requiring termination of the mice are very helpful. The use of femoral bone marrow aspiration is illustrated here for cytological analysis of marrow cells, flow cytometric characterization of the hematopoietic stem/progenitor compartment, and culture of sorted HSPCs obtained by femoral BM aspiration compared with conventional marrow harvest.

This protocol describes a procedure for serial sampling of femoral bone marrow (BM) without requiring the sacrifice of mice. This procedure facilitates longitudinal studies of the BM composition of mice over time and provides serial access to cells within the BM for ex vivo and transplantation studies.

Serial sampling of the cellular composition of bone marrow (BM) is a routine procedure critical to clinical hematology. This protocol describes a detailed ...

Substernal Thyroid Biopsy Using Endobronchial Ultrasound-guided Transbronchial Needle Aspiration

Substernal thyroid goiter (STG) represents about 5.8% of all mediastinal lesions1. There is a wide variation in the published incidence rates due to the lack of a standardized definition for STG. Biopsy is often required to differentiate benign from malignant lesions. Unlike cervical thyroid, the overlying sternum precludes ultrasound-guided percutaneous fine needle aspiration of STG. Consequently, surgical mediastinoscopy is performed in the majority of cases, causing significant procedure related morbidity and cost to healthcare. Endobronchial Ultrasound-guided Transbronchial Needle Aspiration (EBUS-TBNA) is a frequently used procedure for diagnosis and staging of non-small cell lung cancer (NSCLC). Minimally invasive needle biopsy for lesions adjacent to the airways can be performed under real-time ultrasound guidance using EBUS. Its safety and efficacy is well established with over 90% sensitivity and specificity. The ability to perform EBUS as an outpatient procedure with same-day discharges offers distinct morbidity and financial advantages over surgery. As physicians performing EBUS gained procedural expertise, they have attempted to diversify its role in the diagnosis of non-lymph node thoracic pathologies. We propose here a role for EBUS-TBNA in the diagnosis of substernal thyroid lesions, along with a step-by-step protocol for the procedure.

Substernal thyroid lesions are common, and need to be differentiated from malignancy. Obtaining percutaneous fine needle biopsy is not possible due to its retrosternal location. This article proposes a protocol for biopsy of substernal thyroid lesions using Endobronchial Ultrasound-guided Transbronchial Needle Aspiration (EBUS-TBNA).

Substernal thyroid goiter (STG) represents about 5.8% of all mediastinal lesions1. There is a wide variation in the published incidence rates due to the ...

Th17 Inflammation Model of Oropharyngeal Candidiasis in Immunodeficient Mice

Oropharyngeal Candidiasis (OPC) disease is caused not only due to the lack of host immune resistance, but also the absence of appropriate regulation of infection-induced immunopathology. Although Th17 cells are implicated in antifungal defense, their role in immunopathology is unclear. This study presents a method for establishing oral Th17 immunopathology associated with oral candidal infection in immunodeficient mice. The method is based on reconstituting lymphopenic mice with in vitro cultured Th17 cells, followed by oral infection with Candida albicans (C. albicans). Results show that unrestrained Th17 cells result in inflammation and pathology, and is associated with several measurable read-outs including weight loss, pro-inflammatory cytokine production, tongue histopathology and mortality, showing that this model may be valuable in studying OPC immunopathology. Adoptive transfer of regulatory cells (Tregs) controls and reduces the inflammatory response, showing that this model can be used to test new strategies to counteract oral inflammation. This model may also be applicable in studying oral Th17 immunopathology in general in the context of other oral diseases.

Although Candida infection models are available to study host immune resistance, a model to study T cell mediated immunopathology in the context of Candida infection is absent. Here we describe a method to establish Th17 immunopathology associated with oral Candida infection in immunodeficient mice.

Oropharyngeal Candidiasis (OPC) disease is caused not only due to the lack of host immune resistance, but also the absence of appropriate regulation of ...

A Murine Model of Irreversible and Reversible Unilateral Ureteric Obstruction

Obstruction of the kidney may affect native or transplanted kidneys and results in kidney injury and scarring. Presented here is a model of obstructive nephropathy induced by unilateral ureteric obstruction (UUO), which can either be irreversible (UUO) or reversible (R-UUO). In the irreversible UUO model, the ureter may be obstructed for variable periods of time in order to induce increasingly severe renal inflammation and interstitial fibrotic scarring. In the reversible R-UUO model the ureter is obstructed to induce hydronephrosis, tubular dilation and inflammation. After a suitable period of time the ureteric obstruction is then surgically reversed by anastomosis of the severed previously obstructed ureter to the bladder in order to allow complete decompression of the kidney and restoration of urinary flow to the bladder. The irreversible UUO model has been used to investigate various aspects of renal inflammation and scarring including the pathogenesis of disease and the testing of potential anti-inflammatory or anti-fibrotic therapies. The more challenging model of R-UUO has been used by some investigators and does offer significant research potential as it allows the study of inflammatory and immune processes and tissue remodeling in an injured and scarred kidney following the removal of the injurious stimulus. As a result, the R-UUO model offers investigators the opportunity to explore the resolution of kidney inflammation together with key aspects of tissue repair. These experimental models are of relevance to human disease as patients often present with obstruction of the renal tract that requires decompression and are commonly left with significant residual kidney impairment that has no current treatment options and may lead to eventual end stage kidney failure.

The murine model of irreversible unilateral ureteric obstruction (UUO) is presented together with the model of reversible UUO in which the ureteric obstruction is relieved by anastomosis of the severed ureter into the bladder. These models enable the study of renal inflammation and scarring as well as tissue remodeling.

Obstruction of the kidney may affect native or transplanted kidneys and results in kidney injury and scarring. Presented here is a model of obstructive ...