Name: murine salivary functional assessment via pilocarpine stimulation following fractionated radiation
Uploaded: 2018-05-04T14:30:00
Description: Watch this Scientific Journal Video about Murine Salivary Functional Assessment via Pilocarpine Stimulation Following Fractionated Radiation at JoVE.com

Research reported in this publication was supported by the National Institute of Dental and Craniofacial Research (NIDCR) and the National Cancer Institute (NCI) of the National Institutes of Health under Award Number R56 DE025098, UG3 DE027695, and F30 CA206296. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. This work was also supported by the NSF DMR 1206219 and the IADR Innovation in Oral Care Award (2016). 
We would like to thank Dr. Eri Maruyama and Andrew Hollomon for their assistance with saliva collection. We would like to thank Pei-Lun Weng for his assistance with gland dissection. We would like to thank Matthew Ingalls for his assistance in figure preparation. We would like to thank Dr. Elaine Smolock and Emily Wu for critical reading of this manuscript.

All in vivo procedures outlined below were approved by the University Committee on Animal Resources at the University of Rochester, Rochester. NY.
1. Preparation
<ol>
	<li>Using an analytical balance, weigh 20 mg of pilocarpine. Dissolve it in 2 mL of sterile saline in a microcentrifuge tube. 
	NOTE: Because pilocarpine is light sensitive and loses activity over time, this solution should be prepared the day of injection, and protected from light until administered.</li>
	<li>U...

<ol>
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E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Salivary+Glands:+Stem+Cells,+Self-duplication,+or+Both?.">Salivary Glands: Stem Cells, Self-duplication, or Both?.</a> Journal of Dental Research. 94 (11), 1502-1507 (2015).</li><li>Ono, K., 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=Distinct+effects+of+cevimeline+and+pilocarpine+on+salivary+mechanisms,+cardiovascular+response+and+thirst+sensation+in+rats.">Distinct effects of cevimeline and pilocarpine on salivary mechanisms, cardiovascular response and thirst sensation in rats.</a> Archives of Oral Biology. 57 (4), 421-428 (2012).</li><li>Proctor, G. B., Carpenter, G. 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We present a multistep method to assess salivary gland function, which can be applied to study gland injury and therapeutics. Our procedure involves tracheostomy, saliva collection, and gland dissection, each of which has experimental applications that can support an integrated study of salivary gland biology. For example, murine tracheostomy has been used for general airway management during procedures obstructing the oral cavity.
Proper dissection and tracheal incision are required for piloc...

Salivary gland disorders include syndromes of dysregulated or impaired secretion leading to either overproduction (sialorrhea) or underproduction (xerostomia and hyposalivation) of saliva1. In both cases, there is an interest in improving our understanding of salivary gland biology towards the end goal of therapeutic development2.
The salivary glands are highly radiosensitive organs, and are often damaged during head and neck cancer radiotherapy, leading to permanent dry mouth (xerostomia)3,4. Unlike other radiosensitive tissues, however, salivary gland turnover rate is relatively low, and the mechanism of secretory loss is poorly understood5,6. In this unique injury setting, tissue regeneration and radioprotection strategies require salivary functional assessment. Experimentally, murine saliva collection is a particularly valuable tool in evaluating the gland response to both radiation and therapeutic agents.
Here, we present a method for performing and quantifying stimulated saliva secretion using pilocarpine, a potent muscarinic agonist7. Pilocarpine stimulates the autonomic nervous system to induce gland secretion8,9. To complete this test appropriately, a tracheostomy is required to ensure that the mouse maintains a patent airway throughout the procedure, and to reduce the risks of choking and aspiration from pooled secretions in the oral cavity10.
This is a terminal procedure, culminating in the removal of the three major salivary glands: the parotid (PG), the submandibular (SMG), and the sublingual (SLG). For functional studies, gland weights are recorded and are often used to normalize saliva measurement11,12,13. This data is particularly important in radiation studies, wherein gland atrophy is an expected outcome14,15
There is variability in the literature with regards to how stimulated saliva secretion is performed and reported16. For example, pilocarpine doses within the literature span at least three orders of magnitude17,18,19,20,21,22,23. Here, we present an optimized high dose pilocarpine protocol with the intent of improved reproducibility in method execution, as well as providing a modular platform of techniques (tracheostomy, saliva collection, and gland dissection) that can be adapted as needed.
In addition to protocol demonstration, we include representative functional data of saliva flow at 2 weeks following fractionated radiation (4 doses of 6.85 Gy) to the SMG region.

<table border="0" cellpadding="0" cellspacing="0" width="690">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:219px;">Pilocarpine hydrochloride</td>
			<td style="width:128px;">Sigma Aldrich</td>
			<td style="width:119px;">P6503</td>
			<td style="width:225px;">Pilocarpine</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:219px;">Student Vannas Spring Scissors</td>
			<td style="width:128px;">Fine Science Tools</td>
			<td style="width:119px;">91500-9</td>
			<td>Spring Scissors for Tracheostomy</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:219px;">Sterile Saline Solution</td>
			<td style="width:128px;">Medline</td>
			<td style="width:119px;">RDI30296H</td>
			<td>Saline</td>
		</tr>
		<tr height="19">
			<td height="19" style="height:19px;width:219px;">Dumont #7 Forceps</td>
			<td style="width:128px;">Fine Science Tools</td>
			<td style="width:119px;">11274-20</td>
			<td>Curved Forceps</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:219px;">Dumont #5 Forceps</td>
			<td style="width:128px;">Fine Science Tools</td>
			<td style="width:119px;">11251-10</td>
			<td>Straight Forceps</td>
		</tr>
		<tr height="17">
			<td height="17" style="height:17px;width:219px;">Standard Pattern Forceps</td>
			<td style="width:128px;">Fine Science Tools</td>
			<td style="width:119px;">11000-12</td>
			<td>Blunt Forceps</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:219px;">Fine Scissors- Tungsten Carbide</td>
			<td style="width:128px;">Fine Science Tools</td>
			<td style="width:119px;">14568-09</td>
			<td>Dissection Scissors</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:219px;">Microhematocrit Heparinized Capillary Tubes</td>
			<td style="width:128px;">Fisher Scientific</td>
			<td style="width:119px;">22362566</td>
			<td>Capillary tubes</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:219px;">Lubricant Eye Ointment</td>
			<td style="width:128px;">Refresh</td>
			<td style="width:119px;">N/A</td>
			<td>Refresh Lacri-Lube</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:219px;">Goat polyclonal anti-Nkcc1</td>
			<td style="width:128px;">Santa Cruz Biotech</td>
			<td style="width:119px;">SC-21545</td>
			<td>Nkcc1 Antibody</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:219px;">DAPI (4&#39;,6-Diamidino-2-Phenylindole, Dihydrochloride)</td>
			<td style="width:128px;">Thermo Fisher Scientific</td>
			<td style="width:119px;">D1306</td>
			<td>DAPI</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:219px;">GraphPad Prism</td>
			<td style="width:128px;">GraphPad</td>
			<td style="width:119px;">ver6.0</td>
			<td>Statistical Software</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:219px;">Cotton tipped applicator</td>
			<td style="width:128px;">Medline</td>
			<td style="width:119px;">MDS202000</td>
			<td>Applicator for eye ointment</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:219px;">0.5cc Insulin Syringe, 29G x 1/2&#34;</td>
			<td style="width:128px;">BD</td>
			<td style="width:119px;">7629</td>
			<td>Syringe for intraperitoneal injection</td>
		</tr>
	</tbody>
</table>

murine salivary functional assessment via pilocarpine stimulation following fractionated radiation

Hyposalivation is commonly observed in the autoimmune reaction of Sj&#246;gren's syndrome or following radiation injury to the major salivary glands. In these cases, questions remain regarding disease pathogenesis and effective interventions. An optimized technique that allows functional assessment of the salivary glands is invaluable for investigating exocrine gland biology, dysfunction, and therapeutics. Here, we present a step by step approach to performing pilocarpine stimulated saliva secretion, including tracheostomy and the dissection of the three major murine salivary glands. We also detail the appropriate murine head and neck anatomy accessed during these techniques. This approach is scalable, allowing for multiple mice to be processed simultaneously, thus improving the efficiency of the work flow. We aim to improve the reproducibility of these methods, each of which has further applications within the field. In addition to saliva collection, we discuss metrics for quantifying and normalizing functional capacity of these tissues. Representative data are included from submandibular glands with depressed salivary gland function 2 weeks following fractionated radiation (4 doses of 6.85 Gy).

When performing high dose pilocarpine stimulated saliva collection, it is important to maintain the airway to prevent aspiration or choking from secretions in the oral cavity. A schematic of the tracheostomy is provided (Figure 1). Following tracheal incision, the stoma must remain clear of tissue and fluids.
To enhance capillary action during saliva collection, mice should be positioned with their ...

Watch this Scientific Journal Video about Murine Salivary Functional Assessment via Pilocarpine Stimulation Following Fractionated Radiation at JoVE.com

Murine Salivary Functional Assessment via Pilocarpine Stimulation Following Fractionated Radiation

We present a detailed approach to performing saliva collection, including murine tracheostomy and the isolation of three major salivary glands.

Hyposalivation is commonly observed in the autoimmune reaction of Sj&#246;gren's syndrome or following radiation injury to the major salivary glands. In ...

The overall goal of this procedure is to evaluate murine salivary function by pilocarpine stimulation. This method can be applied to both understand the natural history of salivary gland disfunction, and to test the efficacy of any potential interventions. Our protocol provides a modular platform of techniques, including murine tracheotomy, saliva collection, and gland dissection.Clinically, this technique has implications for studies assessing either dry mouth, or over-production of saliva. And it can also be applied to other intra-oral procedures requiring airway management. Those first learning this protocol may find the tracheostomy and gland dissection challenging.We hope this video will help you to learn proper gland isolation technique, as well as the relevant anatomy. Using an analytical balance, weigh out 20 milligrams of pilocarpine, then dissolve it in 2 milliliters of sterile saline. Pilocarpine solutions must be made fresh on their day of use.Next, weigh all of the collection vessels for the procedure, and weigh the mouse to accurately dose it. Use the C57 black 6 strain. After anesthetizing the mouse, and confirming anesthesia with the toe pinch, apply ophthalmic ointment using a cotton-tipped applicator, and position the mouse supine.Then, secure its limbs, nose, and tail with surgical tape. Next, clean and wet the neck using an alcohol wipe. Now, use forceps to pinch the ventral midline neck, and with scissors, make a small, superficial cut.Then, guide the scissors into the opening and slowly open the blades subcutaneously to separate the tissue planes. While keeping the skin raised, carefully make another cut one centimeter below the mouth. Then, make two lateral incisions, inferior and superior to the first cut.Now, using forceps, gently pull apart the skin to access head and neck anatomy. Proceed using a dissecting microscope at eight times magnification. Using fine forceps, gently lift the submandibular gland to expose the four infrahyoid muscles overlying the trachea.Avoid tearing or disrupting the surrounding vasculature or excretory ducts. If collecting saliva from more than one mouse, prepare all the mice to this point before proceeding. One person can handle up to five mice concurrently.Now, to continue the surgery, use small dissecting scissors to remove the medial portion of the strap muscles while staying close to the midline. Remove just enough muscle to visualize the trachea and prevent the muscles from interfering with the procedure. When dissecting the strap muscles, it is especially important to avoid nicking nearby vessels.A nick can lead to volume depletion secondary to hemorrhage, and thus make pilocarpine ineffective for induction of salivary secretion. To proceed, reflect the strap muscles away from the trachea to visualize the larynx, trachea, and thyroid gland. Ensure that the trachea is clear of overlying tissue.Finally, make a horizontal incision in the trachea, inferior to the thyroid, using small dissecting scissors, not a scalpel. Make certain that this airway is patent, and clear of fluid. For the saliva collection, first remove the tape near the mouth, and then tilt the dissection stage at 45 degrees to direct the saliva flow cranially.Next, use a 0.5 milliliter syringe with a 29-gauge half-inch needle to administer an intraperitoneal pilocarpine injection. Then, start a timer. If multiple mice are being injected, work quickly with an assistant's help.Next, use standard forceps to open the mouth and bring a capillary tube into position. A bead of saliva should form within a few minutes. Place one end of the capillary tube into the saliva, and put the other end into a collecting tube positioned below the dissecting stage.As needed, reposition the tube to draw up the saliva. Avoid making contact with mucosal tissues, as mucus could obstruct the inlet. Collect saliva for 12 minutes from time of injection.The stoma should remain clear throughout. If the mouse has depressed saliva function, transfer fluid from its mouth to the collection tube using a P200 micropipette. Always use a different tube or tip for each mouse.After completing all of the collections, reweigh the collection vessels. After euthanizing the mouse by carbon dioxide asphyxiation, make a careful thoracotomy, and place the mouse supine on the dissection microscope stage. Then, reposition the glands at the original surgical site.Under eight times magnification, visualize the major glands, the PG, SMG and SLG. The PG is diffuse, and is positioned lateral to the SMG and the SLG. Dissect the PG first.Grasp the tail of the PG with forceps, pulling it away from the underlying structures. Build to a gentle tension, and then cut the head of the PG with dissecting scissors. Next, breach the capsule surrounding the SMGs with forceps.Then, gently separate the left and right SMG. Next, free the dorsal aspect of the SMG from the surrounding non-glandular tissue. To remove the SMG, tighten the Wharton's duct with forceps, and cut the duct with dissecting scissors.The SLG is in the superolateral aspect of the SMG. To separate the two glands, grasp each with separate forceps, and position one tine in the tissue plane between the glands. Then, slowly build tension, and the two glands will gradually come apart.After isolating the glandular tissue, immediately reweigh the collection vessels. As a positive control for the analysis, mouse SMGs were irradiated and compared to controls. Two weeks after four fractions of radiation at 6.85 gray, saliva function significantly decreased.Both total saliva secretion, and the secretion normalized to the gland wet weight showed salivary functional capacity was reduced, demonstrating the sensitivity of the assay. Next, SMGs were dissected. They could be fixed, sectioned, and stained.Hematoxylin and eosin staining was used to compare the gross architecture with or without pilocarpine stimulation. Additionally, the tissues were immunostained for a membrane sodium-potassium chloride transporter, NKCC1. In either stain, the tissues showed similar cell morphology, irrespective of pilocarpine stimulation.After watching this video, you should have a good understanding of how to evaluate murine salivary function by pilocarpine stimulation. Once mastered, this full technique can be done in under an hour. This method allows salivary researchers to collect whole saliva to quantify gland function, and to cleanly and reproducibly isolate the three major salivary glands.While attempting this procedure, especially with more than one mouse, it's important to move quickly, and to terminate saliva collection at the correct time point. Following this procedure, composition and enzyme activity can be determined from whole saliva, while glandular tissues can be processed for histology or immunostaining.

murine-salivary-functional-assessment-via-pilocarpine-stimulation

Research

JoVE Journal

Medicine

Cannulation of the Mouse Submandibular Salivary Gland via the Wharton's Duct

Severe salivary gland hypofunction is frequently found in patients with Sj&ouml;gren's syndrome and those who receiving therapeutic 
irradiation in their head and neck regions for cancer treatment. Both groups of patients experience symptoms such as xerostomia (dry mouth), dysphagia 
(impaired chewing and swallowing), severe dental caries, altered taste, oro-pharyngeal infections (candidiasis), mucositis, pain and discomfort.
One innovative approach of regenerative medicine for the treatment of salivary gland hypo-function is speculated in RS Redman, E Mezey 
et al. 2009: stem cells can be directly deposited by cannulation into the gland as a potent method in reviving the functions of the impaired organ. Presumably, 
the migrated foreign stem cells will differentiate into glandular cells to function as part of the host salivary gland. Also, this cannulation technique is an 
expedient and effective delivery method for clinical gene transfer application.
Here we illustrate the steps involved in performing the cannulation procedure on the mouse submandibular salivary gland via the Wharton's duct 
(Fig 1). C3H mice (Charles River, Montreal, QC, Canada) are used for this experiment, which have been kept under clean conventional conditions at 
the McGill University animal resource center. All experiments have been approved by the University Animal Care Committee and were in accordance with the 
guidelines of the Canadian Council on Animal Care.
For this experiment, a trypan blue solution is infused into the gland through the opening of the Wharton's duct using a 
insulin syringe with a 29-gauge needle encased inside a polyethylene tube. Subsequently, the mouse is dissected to show that the infusions migrated 
into the gland successfully.

A protocol for the cannulation of the mouse submandibular salivary gland via the Wharton's duct is described. For this experiment, the trypan blue solution is used as a dyer to demonstrate how this technique effectively delivers infusions into the targeted gland, and to suggest the reliability of this new approach as a potential clinical drug/cell therapy for the regeneration of salivary glands.

Severe salivary gland hypofunction is frequently found in patients with Sj&ouml;gren's syndrome and those who receiving therapeutic 
irradiation in their ...

A Murine Model of Muscle Training by Neuromuscular Electrical Stimulation

Neuromuscular electrical stimulation (NMES) is a common clinical modality that is widely used to restore1, maintain2 or enhance3-5 muscle functional capacity. Transcutaneous surface stimulation of skeletal muscle involves a current flow between a cathode and an anode, thereby inducing excitement of the motor unit and the surrounding muscle fibers. 
NMES is an attractive modality to evaluate skeletal muscle adaptive responses for several reasons. First, it provides a reproducible experimental model in which physiological adaptations, such as myofiber hypertophy and muscle strengthening6, angiogenesis7-9, growth factor secretion9-11, and muscle precursor cell activation12 are well documented. Such physiological responses may be carefully titrated using different parameters of stimulation (for Cochrane review, see 13). In addition, NMES recruits motor units non-selectively, and in a spatially fixed and temporally synchronous manner14, offering the advantage of exerting a treatment effect on all fibers, regardless of fiber type. Although there are specified contraindications to NMES in clinical populations, including peripheral venous disorders or malignancy, for example, NMES is safe and feasible, even for those who are ill and/or bedridden and for populations in which rigorous exercise may be challenging. 
Here, we demonstrate the protocol for adapting commercially available electrodes and performing a NMES protocol using a murine model. This animal model has the advantage of utilizing a clinically available device and providing instant feedback regarding positioning of the electrode to elicit the desired muscle contractile effect. For the purpose of this manuscript, we will describe the protocol for muscle stimulation of the anterior compartment muscles of a mouse hindlimb.

A murine model of neuromuscular electrical stimulation (NMES), a safe and inexpensive clinical modality, to the anterior compartment muscles is described. This model has the advantage of modifying a readily available clinical device for the purpose of eliciting targeted and specific muscle contractions in mice.

Neuromuscular electrical stimulation (NMES) is a common clinical modality that is widely used to restore1, maintain2 or enhance3-5 muscle functional ...

Collecting Saliva and Measuring Salivary Cortisol and Alpha-amylase in Frail Community Residing Older Adults via Family Caregivers

Salivary measures have emerged in bio-behavioral research that are easy-to-collect, minimally invasive, and relatively inexpensive biologic markers of stress. This article we present the steps for collection and analysis of two salivary assays in research with frail, community residing older adults-salivary cortisol and salivary alpha amylase. The field of salivary bioscience is rapidly advancing and the purpose of this presentation is to provide an update on the developments for investigators interested in integrating these measures into research on aging. Strategies are presented for instructing family caregivers in collecting saliva in the home, and for conducting laboratory analyses of salivary analytes that have demonstrated feasibility, high compliance, and yield quality specimens. The protocol for sample collection includes: (1) consistent use of collection materials; (2) standardized methods that promote adherence and minimize subject burden; and (3) procedures for controlling certain confounding agents. We also provide strategies for laboratory analyses include: (1) saliva handling and processing; (2) salivary cortisol and salivary alpha amylase assay procedures; and (3) analytic considerations.

We demonstrate: (1) procedures for collection of salivary samples in cognitive impaired older adults by family caregivers in the home setting, (2) procedures for measuring stress activity via salivary cortisol and alpha amylase, and (3) representative profiles. Protocols that allow researchers to study stress-linked processes advance our understanding of biological sensitivity and susceptibility.

Salivary measures have emerged in bio-behavioral research  that are easy-to-collect, minimally invasive, and relatively inexpensive  biologic markers of ...

Myocardial Infarction and Functional Outcome Assessment in Pigs

Introduction of newly discovered cardiovascular therapeutics into first-in-man trials depends on a strictly regulated ethical and legal roadmap. One important prerequisite is a good understanding of all safety and efficacy aspects obtained in a large animal model that validly reflect the human scenario of myocardial infarction (MI). Pigs are widely used in this regard since their cardiac size, hemodynamics, and coronary anatomy are close to that of humans. Here, we present an effective protocol for using the porcine MI model using a closed-chest coronary balloon occlusion of the left anterior descending artery (LAD), followed by reperfusion. This approach is based on 90 min of myocardial ischemia, inducing large left ventricle infarction of the anterior, septal and inferoseptal walls. Furthermore, we present protocols for various measures of outcome that provide a wide range of information on the heart, such as cardiac systolic and diastolic function, hemodynamics, coronary flow velocity, microvascular resistance, and infarct size. This protocol can be easily tailored to meet study specific requirements for the validation of novel cardioregenerative biologics at different stages (i.e. directly after the acute ischemic insult, in the subacute setting or even in the chronic MI once scar formation has been completed). This model therefore provides a useful translational tool to study MI, subsequent adverse remodeling, and the potential of novel cardioregenerative agents.

This protocol describes the porcine myocardial infarction (MI) model using a 90 min closed-chest coronary balloon occlusion of the left anterior descending artery (LAD), followed by reperfusion. Furthermore, the protocol for several outcome parameters, such as cardiac function, hemodynamics, microvascular resistance, and infarct size, are also presented.

Introduction of newly discovered cardiovascular therapeutics into first-in-man trials depends on a strictly regulated ethical and legal roadmap. One ...

Controlling Parkinson's Disease With Adaptive Deep Brain Stimulation

Adaptive deep brain stimulation (aDBS) has the potential to improve the treatment of Parkinson&#39;s disease by optimizing stimulation in real time according to fluctuating disease and medication state. In the present realization of adaptive DBS we record and stimulate from the DBS electrodes implanted in the subthalamic nucleus of patients with Parkinson&#39;s disease in the early post-operative period. Local field potentials are analogue filtered between 3 and 47 Hz before being passed to a data acquisition unit where they are digitally filtered again around the patient specific beta peak, rectified and smoothed to give an online reading of the beta amplitude. A threshold for beta amplitude is set heuristically, which, if crossed, passes a trigger signal to the stimulator. The stimulator then ramps up stimulation to a pre-determined clinically effective voltage over 250 msec and continues to stimulate until the beta amplitude again falls down below threshold. Stimulation continues in this manner with brief episodes of ramped DBS during periods of heightened beta power.
Clinical efficacy is assessed after a minimum period of stabilization (5 min) through the unblinded and blinded video assessment of motor function using a selection of scores from the Unified Parkinson&#39;s Rating Scale (UPDRS). Recent work has demonstrated a reduction in power consumption with aDBS as well as an improvement in clinical scores compared to conventional DBS. Chronic aDBS could now be trialed in Parkinsonism.

Adaptive deep brain stimulation (aDBS) is effective for Parkinson&#8217;s disease, improving symptoms and reducing power consumption compared to conventional deep brain stimulation (cDBS). In aDBS we track a local field potential biomarker (beta oscillatory amplitude) in real time and use this to control the timing of stimulation.

Adaptive deep brain stimulation (aDBS) has the potential to improve the treatment of Parkinson&#39;s disease by optimizing stimulation in real time ...

Diffuse Optical Spectroscopy for the Quantitative Assessment of Acute Ionizing Radiation Induced Skin Toxicity Using a Mouse Model

Acute skin toxicities from ionizing radiation (IR) are a common side effect from therapeutic courses of external beam radiation therapy (RT) and negatively impact patient quality of life and long term survival. Advances in the understanding of the biological pathways associated with normal tissue toxicities have allowed for the development of interventional drugs, however, current response studies are limited by a lack of quantitative metrics for assessing the severity of skin reactions. Here we present a diffuse optical spectroscopic (DOS) approach that provides quantitative optical biomarkers of skin response to radiation. We describe the instrumentation design of the DOS system as well as the inversion algorithm for extracting the optical parameters. Finally, to demonstrate clinical utility, we present representative data from a pre-clinical mouse model of radiation induced erythema and compare the results with a commonly employed visual scoring. The described DOS method offers an objective, high through-put evaluation of skin toxicity via functional response that is translatable to the clinical setting.

We present a diffuse optical spectroscopic (DOS) approach that provides quantitative optical biomarkers of skin response to radiation. We describe DOS instrumentation design, optical parameters extraction algorithms and the animal handling procedures required to yield representative data from a pre-clinical mouse model of radiation induced erythema.

Acute skin toxicities from ionizing radiation (IR) are a common side effect from therapeutic courses of external beam radiation therapy (RT) and ...

Retroductal Submandibular Gland Instillation and Localized Fractionated Irradiation in a Rat Model of Salivary Hypofunction

Normal tissues that lie within the portals of radiation are inadvertently damaged. Salivary glands are often injured during head and neck radiotherapy. Irreparable cell damage results in a chronic loss of salivary function that impairs basic oral activities, and increases the risk of oral infections and dental caries. Salivary hypofunction and its complications gravely impact a patient's comfort. Current symptomatic management of the condition is ineffective, and newer therapies to assuage the condition are needed. 
Salivary glands are exocrine glands, which expel their secretions into the mouth via excretory ducts. Cannulation of these ducts provides direct access to the glands. Retroductal delivery of a contrast agent to major salivary glands is a routine out-patient procedure for diagnostic imaging. Using a similar procedure, localized treatment of the glands is feasible. However, performing this technique in preclinical studies with small animals poses unique challenges. In this study we describe the technique of retroductal administration in rat submandibular glands, a procedure that was refined in Dr. Bruce Baum's laboratory (NIH)1, and lay out a procedure for local gland irradiation.

Salivary gland hypofunction, a major adverse effect of head and neck radiotherapy diminishes a patient's quality of life. The demonstration of efficacy of new therapies in animal models is a prerequisite before clinical transition. This protocol describes retroductal administration and local irradiation of rat submandibular glands.

Normal tissues that lie within the portals of radiation are inadvertently damaged. Salivary glands are often injured during head and neck radiotherapy. ...

Electrophysiological Assessment of Murine Atria with High-Resolution Optical Mapping

Recent genome-wide association studies targeting atrial fibrillation (AF) have indicated a strong association between the genotype and electrophysiological phenotype in the atria. That encourages us to utilize a genetically-engineered mouse model to elucidate the mechanism of AF. However, it is difficult to evaluate the electrophysiological properties in murine atria due to their small size. This protocol describes the electrophysiological evaluation of atria using an optical mapping system with a high temporal and spatial resolution in Langendorff perfused murine hearts. The optical mapping system is assembled with dual high-speed complementary metal oxide semiconductor cameras and high magnification objective lenses, to detect the fluorescence of a voltage-sensitive dye and Ca2+ indicator. To focus on the assessment of murine atria, optical mapping is performed with an area of 2 mm &#215; 2 mm or 10 mm x 10 mm, with a 100 &#215; 100 resolution (20 &#181;m/pixel or 100 &#181;m/pixel) and sampling rate of up to 10 kHz (0.1 ms) at maximum. A 1-French size quadripolar electrode pacing catheter is placed into the right atrium through the superior vena cava avoiding any mechanical damage to the atrium, and pacing stimulation is delivered through the catheter. An electrophysiological study is performed with programmed stimulation including constant pacing, burst pacing, and up to triple extrastimuli pacing. Under a spontaneous or pacing rhythm, the optical mapping recorded the action potential duration, activation map, conduction velocity, and Ca2+ transient individually in the right and left atria. In addition, the programmed stimulation also determines the inducibility of atrial tachyarrhythmias. Precise activation mapping is performed to identify the propagation of the excitation in the atrium during an induced atrial tachyarrhythmia. Optical mapping with a specialized setting enables a thorough electrophysiological evaluation of the atrium in murine pathological models.

This protocol describes the electrophysiological evaluation of murine atria utilizing an optical mapping system with a high temporal and spatial resolution, including dual recordings of the membrane voltage and Ca2+ transient under programmed stimulation through a specialized electrode catheter.

Recent genome-wide association studies targeting atrial fibrillation (AF) have indicated a strong association between the genotype and ...

Development and Functional Characterization of Murine Tolerogenic Dendritic Cells

The immune system operates by maintaining a tight balance between coordinating responses against foreign antigens and maintaining an unresponsive state against self-antigens as well as antigens derived from commensal organisms. The disruption of this immune homeostasis can lead to chronic inflammation and to the development of autoimmunity. Dendritic cells (DCs) are the professional antigen-presenting cells of the innate immune system involved in activating na&#239;ve T cells to initiate immune responses against foreign antigens. However, DCs can also be differentiated into TolDCs that act to maintain and promote T cell tolerance and to suppress effector cells contributing to the development of either autoimmune or chronic inflammation conditions. The recent advancement in our understanding of TolDCs suggests that DC tolerance can be achieved by modulating their differentiation conditions. This phenomenon has led to tremendous growth in developing TolDC therapies for numerous immune disorders caused due to break in immune tolerance. Successful studies in preclinical autoimmunity murine models have further validated the immunotherapeutic utility of TolDCs in the treatment of autoimmune disorders. Today, TolDCs have become a promising immunotherapeutic tool in the clinic for reinstating immune tolerance in various immune disorders by targeting pathogenic autoimmune responses while leaving protective immunity intact. Although an array of strategies has been proposed by multiple labs to induce TolDCs, there is no consistency in characterizing the cellular and functional phenotype of these cells. This protocol provides a step-by-step guide for the development of bone marrow-derived DCs in large numbers, a unique method used to differentiate them into TolDCs with a synthetic triterpenoid 2-cyano-3,12-dioxooleana-1,9-dien-28-oic acid-difluoro-propyl-amide (CDDO-DFPA), and the techniques used to confirm their phenotype, including analyses of essential molecular signatures of TolDCs. Finally, we show a method to assess TolDC function by testing their immunosuppressive response in vitro and in vivo in a preclinical model of multiple sclerosis.

Here, we present a protocol to develop and characterize tolerogenic dendritic cells (TolDCs) and evaluate their immunotherapeutic utility.

The immune system operates by maintaining a tight balance between coordinating responses against foreign antigens and maintaining an unresponsive state ...

Radiation Treatment of Organotypic Cultures from Submandibular and Parotid Salivary Glands Models Key In Vivo Characteristics

Hyposalivation and xerostomia create chronic oral complications that decrease the quality of life in head and neck cancer patients who are treated with radiotherapy. Experimental approaches to understanding mechanisms of salivary gland dysfunction and restoration have focused on in vivo models, which are handicapped by an inability to systematically screen therapeutic candidates and efficiencies in transfection capability to manipulate specific genes. The purpose of this salivary gland organotypic culture protocol is to evaluate maximal time of culture viability and characterize cellular changes following ex vivo radiation treatment. We utilized immunofluorescent staining and confocal microscopy to determine when specific cell populations and markers are present during a 30-day culture period. In addition, cellular markers previously reported in in vivo radiation models are evaluated in cultures that are irradiated ex vivo. Moving forward, this method is an attractive platform for rapid ex vivo assessment of murine and human salivary gland tissue responses to therapeutic agents that improve salivary function.

Using three-dimensional organotypic cultures to visualize morphology and functional markers of salivary glands may provide novel insights into the mechanisms of tissue damage following radiation. Described here is a protocol to section, culture, irradiate, stain, and image 50&#8211;90 &#956;m thick salivary gland sections prior to and following exposure to ionizing radiation.

Hyposalivation and xerostomia create chronic oral complications that decrease the quality of life in head and neck cancer patients who are treated with ...