Name: utilizing an orally dissolving strip for pharmacological and toxicological studies: a simple and humane alternative to oral gavage for animals
Uploaded: 2016-03-23T15:00:00
Description: Watch this Scientific Journal Video about Utilizing an Orally Dissolving Strip for Pharmacological and Toxicological Studies: A Simple and Humane Alternative to Oral Gavage for Animals at JoVE.com

The authors would like to acknowledge Jamie Thuy for technical work. This work was supported, in part, by Research grants SC CTSI NIH/NCRR/NCATS -- UL1TR000130 (D.L.D.), AA022448 (D.L.D.), and the USC School of Pharmacy. Additionally, fast dissolving oral films containing IVM were kindly provided by Cure Pharmaceutical (Oxnard, CA).

All procedure described have been approved by the Institutional Animal Care and Use Committee (IACUC) of the University of Southern California.
1. Animal Handling and Habituation
<ol>
	<li>Introduction
	<ol>
		<li>Allow mice to acclimate to the husbandry conditions and handling technique of the experiment to decrease stress during the ensuing drug administration procedures. During this time, record the body weight and food intake of each mouse; if desired, they can later be used as a non-invasive point of compar...

<ol>
	<li>Brown, A. P., Dinger, N., Levine, B. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stress+produced+by+gavage+administration+in+the+rat.">Stress produced by gavage administration in the rat.</a> Contemp Top Lab Anim Sci. 39 (1), 17-21 (2000).</li><li>Gonzales, 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=Alternative+method+of+oral+administration+by+peanut+butter+pellet+formulation+results+in+target+engagement+of+BACE1+and+attenuation+of+gavage-induced+stress+responses+in+mice.">Alternative method of oral administration by peanut butter pellet formulation results in target engagement of BACE1 and attenuation of gavage-induced stress responses in mice.</a> Pharmacol Biochem Behav. 126, 28-35 (2014).</li><li>Walker, M. 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=A+less+stressful+alternative+to+oral+gavage+for+pharmacological+and+toxicological+studies+in+mice.">A less stressful alternative to oral gavage for pharmacological and toxicological studies in mice.</a> Toxicol Appl Pharmacol. 260 (1), 65-69 (2012).</li><li>Zhang, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Voluntary+oral+administration+of+drugs+in+mice.">Voluntary oral administration of drugs in mice.</a> Protocol Exchange: Nature Publishing Group. , (2011).</li><li>Froehlich, J. C., Hausauer, B. J., Federoff, D. L., Fischer, S. M., Rasmussen, D. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Prazosin+reduces+alcohol+drinking+throughout+prolonged+treatment+and+blocks+the+initiation+of+drinking+in+rats+selectively+bred+for+high+alcohol+intake.">Prazosin reduces alcohol drinking throughout prolonged treatment and blocks the initiation of drinking in rats selectively bred for high alcohol intake.</a> Alcohol Clin Exp Res. 37 (9), 1552-1560 (2013).</li><li>Goldkuhl, R., Carlsson, H. E., Hau, J., Abelson, K. S. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effect+of+subcutaneous+injection+and+oral+voluntary+ingestion+of+buprenorphine+on+post-operative+serum+corticosterone+levels+in+male+rats.">Effect of subcutaneous injection and oral voluntary ingestion of buprenorphine on post-operative serum corticosterone levels in male rats.</a> Eur Surg Res. 41 (3), 272-278 (2008).</li><li>Marx, J. O., Vudathala, D., Murphy, L., Rankin, S., Hankenson, F. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Antibiotic+administration+in+the+drinking+water+of+mice.">Antibiotic administration in the drinking water of mice.</a> J Am Assoc Lab Anim Sci. 53 (3), 301-306 (2014).</li><li>Ferguson, S. A., Boctor, S. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Use+of+food+wafers+for+multiple+daily+oral+treatments+in+young+rats.">Use of food wafers for multiple daily oral treatments in young rats.</a> J Am Assoc Lab Anim Sci. 48 (3), 292-295 (2009).</li><li>Turner, P. V., Brabb, T., Pekow, C., Vasbinder, M. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Administration+of+substances+to+laboratory+animals:+routes+of+administration+and+factors+to+consider.">Administration of substances to laboratory animals: routes of administration and factors to consider.</a> J Am Assoc Lab Anim Sci. 50 (5), 600-613 (2011).</li><li>Bala, R., Pawar, P., Khanna, S., Arora, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Orally+dissolving+strips:+A+new+approach+to+oral+drug+delivery+system.">Orally dissolving strips: A new approach to oral drug delivery system.</a> Int J Pharm Investig. 3 (2), 67-76 (2013).</li><li>Potashkin, J. A., Blume, S. R., Runkle, N. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Limitations+of+animal+models+of+Parkinson's+disease.">Limitations of animal models of Parkinson's disease.</a> Parkinsons Dis. 2011, (2010).</li><li>Machholz, E., Mulder, G., Ruiz, C., Corning, B. F., Pritchett-Corning, K. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Manual+restraint+and+common+compound+administration+routes+in+mice+and+rats.">Manual restraint and common compound administration routes in mice and rats.</a> Journal of Visualized Experiments JoVE. (67), e2771 (2012).</li><li>Yardley, M. 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Oral gavage is associated with numerous complications that result in potentially compromised data collection and high rates of animal attrition1. Here a simple method of oral drug delivery is introduced through which mice (and potentially other animals) can easily and reliably consume the drug of choice through an orally dissolving strip (ODS). Notably, the use of this method represents a safe, convenient, and humane alternative to oral gavage.
Other current alternatives to oral gav...

In order for the successful translation of a drug from preclinical (animal testing) to clinical development, a series of well-defined, acute and chronic pharmacological and toxicological studies need to be performed in animal models using the intended clinical route of administration (which is normally the oral route). To accomplish this goal, most pre-clinical studies currently utilize an oral gavage procedure given that this method results in a consistent and precise delivery of the test compound to the animal. However, in many instances, oral gavage is not well tolerated by the animal and accumulating evidence suggests that the method is associated with a significant amount of stress induction1.
This is especially true in the development of treatments for chronic life-long conditions that require longer-term preclinical studies, such as is the case with, but not limited to, nearly every neuropsychiatric disorder. For instance, in a transgenic mouse model of Alzheimer&#39;s disease, it was recently suggested that the gavage method itself could confound experimental results due to dosing induced stress2. Similarly, in a mouse model of alcohol consumption, unpublished findings from our own laboratory have found that the repetitive insertion of the gavage tube - in and of itself - can significantly reduce the level of alcohol intake to the point of jeopardizing the integrity of the experimental paradigm (see Figure 1).
Given the aforementioned limitations associated with the oral gavage procedure, considerable effort has been put towards developing novel methods of preclinical oral drug delivery. Current alternative approaches include incorporating the test compound into peanut butter mixtures3, gelatinous molds4-5, chocolate pellets6, drinking water7, and wafer crackers8, all of which are associated with varying degrees of issues including the inability to be used reliably in the animal model, lack of adoption of test compound uptake by the test subject or individual preference for flavor that makes the drug less readily consumed9.
The procedure introduced herein describes a method in which the desired drug is incorporated into a flavored, orally dissolving strip (ODS) that can be easily and readily be used to orally administer the test compound to the test animal. This paper focuses on demonstrating the effectiveness of the ODS method using mice. However, there is no reason to expect that the same method would not also be useful in other rodent as well as larger mammalian subjects. Clinically, the use of ODS is starting to be adopted in pediatric and geriatric patients, as a way to overcome swallowing difficulties10. We propose that ODS can also be used successfully in preclinical drug discovery programs as a safe, convenient, and humane alternative to oral gavage.

<table border="0" cellpadding="0" cellspacing="0" width="948">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:203px;">Orally Dissolving Strip&#160;</td>
			<td style="width:185px;">Cure Pharmaceutical</td>
			<td style="width:89px;"></td>
			<td style="width:471px;">Available upon special request. Alternatively, ODS may also be prepared in-house.</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:203px;">Gavage Feeding Needle</td>
			<td style="width:185px;">VWR</td>
			<td align="right" style="width:89px;">7912</td>
			<td>Our rodent studies utilized a 18-gauge feeding needle. This size may need to be adjusted for use in other mammilian species.</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:203px;">Sucrose</td>
			<td style="width:185px;">Sigma Aldrich</td>
			<td style="width:89px;">S0389-500G</td>
			<td></td>
		</tr>
	</tbody>
</table>

utilizing an orally dissolving strip for pharmacological and toxicological studies: a simple and humane alternative to oral gavage for animals

Prior to testing novel therapeutics in humans, short and long term preclinical (i.e., animal), repetitive pharmacological and toxicological testing is required. In most cases, the preferred route of administration is via oral delivery. At the present time, oral delivery is mostly accomplished using an oral gavage procedure, in part, because it can achieve consistent and precise dosing in the animal model. Although this method is well established it does have complications that can result in a high rate of animal attrition. To this end, the procedure introduced here describes an alternative to the oral gavage method in which the desired drug is incorporated into a tastant, orally dissolving strip (ODS) that can simply be presented to the test animal where it is then rapidly taken up with minimal manipulation of the test subject. Herein, we demonstrate that preclinical, oral drug delivery using the ODS method represents a safe, convenient, and humane alternative to oral gavage.

In the following representative investigations, social drinking was modeled using a 24 hr two-bottle choice (TBC) paradigm as previously described15. Briefly, mice had access to two bottles of solution, one of which contained water, and the other a 10% (v/v) ethanol solution. Subjects were subsequently assigned to drug treatment groups so that the average 10E (10% ethanol/90% water v/v)&#160;intake was similar across groups.
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Watch this Scientific Journal Video about Utilizing an Orally Dissolving Strip for Pharmacological and Toxicological Studies: A Simple and Humane Alternative to Oral Gavage for Animals at JoVE.com

Utilizing an Orally Dissolving Strip for Pharmacological and Toxicological Studies: A Simple and Humane Alternative to Oral Gavage for Animals

The following protocol describes a novel method for chronic oral drug administration using an orally dissolving strip (ODS) in lieu of the more commonly used oral gavage method. We demonstrate that preclinical, oral drug delivery using the ODS method represents a safe, convenient, and humane alternative to oral gavage.

Prior to testing novel therapeutics in humans, short and long term preclinical (i.e., animal), repetitive pharmacological and toxicological testing is ...

The overall goal of this procedure is to utilize an orally dissolvable bioadhesive polymer as a safe and human means of preclinical oral drug delivery. Using this procedure, a drug of interest can be incorporated into a flavored, orally dissolving strip for the oral administration of a test compound to an experimental animal. The main advantage of this technique is that it can be utilized instances when oral gavage isn't well tolerated.To decrease stress during the ensuing drug administration procedures, allow the mice to acclimate to the husbandry conditions and handling technique of the experiment. For each mouse, determine the pre-experimental weight by grasping the mouse first by the middle of the tail, and gently lifting the animal out of the cage. Immediately place the animal into a weigh boat on an animal scale, keeping a firm grasp on the medial aspect of the tail to avoid a degloving injury and record the weight of the animal.Record the weight of the food for a recommended two consecutive days to establish the baseline food consumption of each animal during the habituation period as well. After the animals have become acclimated to their environment transfer the animals to the room in which the subsequent experiments will occur. Before beginning the experiment, autoclave sterilize two stainless steel gavage needles per group, and one additional needle for back up.Next, use a commercially available single quarter inch hole puncher to cut 0.5 centimeter diameter orally dissolving strips, or ODS, for each animal from a standard rectangular test strip. On the day of the experiment, record the weight of the animals as just demonstrated and then place the first mouse onto a metal grid cage top. Pull back on the tail with the dominant thumb, index, and third finger.The mouse will grip the cage top and stretch out its back. Grasp the scruff of the neck with the non-dominant thumb, index finger, and third finger, to comfortably restrain the animal with a secure grip, and turn the animal to an upright position. Note the color of the mucosal membranes.A pink red appearance indicates the mouse is comfortably restrained. Now submerge the bulb tip of one of the gavage needles in freshly prepared 4.25%sucrose solution to serve as a tastant adhesive to the ODS. Then press down on an ODS with the bulb tip to attach the ODS to the needle tip, and place the strip near the nostrils and mouth to allow the animal to consume the film.Alternatively, the strip can be placed directly onto the tongue for the mouse to swallow. Replace the needle mid-group during the drug dosing session to prevent the spread of infection. Here, the effects of gavage administered ivermectrine on preference drinking are shown.As observed, ivermectine significantly reduces the 10%ethanol intake across the study compared to the placebo group. Compared to the control group however, the ethanol intake values of the placebo group are much too low, and thus may not accurately model social drinking behavior. When the same experiment is performed utilizing the ODS delivery system, there is no significant difference in the ethanol intake between the control and placebo treated mice, indicating that the ODS placebo group represents a valid control with which a comparison to the ivermectine group can be made.Indeed, by these controls, ivermectine significantly and consistently reduces the 10%ethanol intake of the animals. After watching this video, you should have a good understanding of how to utilize an orally dissolving strip as a safe and humane means of oral drug delivery.

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Medicine

Multi-photon Imaging of Tumor Cell Invasion in an Orthotopic Mouse Model of Oral Squamous Cell Carcinoma

Loco-regional invasion of head and neck cancer is linked to metastatic risk and presents a difficult challenge in designing and implementing patient management strategies. Orthotopic mouse models of oral cancer have been developed to facilitate the study of factors that impact invasion and serve as model system for evaluating anti-tumor therapeutics. In these systems, visualization of disseminated tumor cells within oral cavity tissues has typically been conducted by either conventional histology or with in vivo bioluminescent methods. A primary drawback of these techniques is the inherent inability to accurately visualize and quantify early tumor cell invasion arising from the primary site in three dimensions. Here we describe a protocol that combines an established model for squamous cell carcinoma of the tongue (SCOT) with two-photon imaging to allow multi-vectorial visualization of lingual tumor spread. The OSC-19 head and neck tumor cell line was stably engineered to express the F-actin binding peptide LifeAct fused to the mCherry fluorescent protein (LifeAct-mCherry). Fox1nu/nu mice injected with these cells reliably form tumors that allow the tongue to be visualized by ex-vivo application of two-photon microscopy. This technique allows for the orthotopic visualization of the tumor mass and locally invading cells in excised tongues without disruption of the regional tumor microenvironment. In addition, this system allows for the quantification of tumor cell invasion by calculating distances that invaded cells move from the primary tumor site. Overall this procedure provides an enhanced model system for analyzing factors that contribute to SCOT invasion and therapeutic treatments tailored to prevent local invasion and distant metastatic spread. This method also has the potential to be ultimately combined with other imaging modalities in an in vivo setting.

A comprehensive overview of the techniques involved in generating a mouse model of oral cancer and quantitative monitoring of tumor invasion within the tongue through multi-photon microscopy of labeled cells is presented. This system can serve as a useful platform for the molecular assessment and drug efficacy of anti-invasive compounds.

Loco-regional invasion of head and neck cancer is linked to metastatic risk and presents a difficult challenge in designing and implementing patient ...

A Simple Guide Screw Method for Intracranial Xenograft Studies in Mice

The grafting of human tumor cells into the brain of immunosuppressed mice is an established method for the study of brain cancers including glioblastoma (glioma) and medulloblastoma. The widely used stereotactic approach only allows for the injection of a single animal at a time, is labor intensive and requires highly specialized equipment. The guide screw method, initially developed by Lal et al.,1 was developed to eliminate cumbersome stereotactic procedures. We now describe a modified guide screw approach that is rapid and exceptionally safe; both of which are critical ethical considerations. Notably, our procedure now incorporates an infusion pump that allows up to 10 animals to be simultaneously injected with tumor cells.
To demonstrate the utility of this procedure, we established human U87MG glioma cells as intracranial xenografts in mice, which were then treated with AMG102; a fully human antibody directed to HGF/scatter factor currently undergoing clinical evaluation2-5. Systemic injection of AMG102 significantly prolonged the survival of all mice with intracranial U87MG xenografts and resulted in a number of complete cures. 
This study demonstrates that the guide screw method is an inexpensive, highly reproducible approach for establishing intracranial xenografts. Furthermore, it provides a relevant physiological model for validating novel therapeutic strategies for the treatment of brain cancers.

In order to evaluate novel therapeutic paradigms for the treatment of glioma, physiological relevant models are essential. We utilize an implantable guide screw procedure for establishment of intracranial xenograft models that is more rapid and safer than stereotactic approaches.

The grafting of human tumor cells into the brain of immunosuppressed mice is an established method for the study of brain cancers including glioblastoma ...

Sublingual Immunotherapy as an Alternative to Induce Protection Against Acute Respiratory Infections

Sublingual route has been widely used to deliver small molecules into the bloodstream and to modulate the immune response at different sites. It has been shown to effectively induce humoral and cellular responses at systemic and mucosal sites, namely the lungs and urogenital tract. Sublingual vaccination can promote protection against infections at the lower and upper respiratory tract; it can also promote tolerance to allergens and ameliorate asthma symptoms. Modulation of lung&#8217;s immune response by sublingual immunotherapy (SLIT) is safer than direct administration of formulations by intranasal route because it does not require delivery of potentially harmful molecules directly into the airways. In contrast to intranasal delivery, side effects involving brain toxicity or facial paralysis are not promoted by SLIT. The immune mechanisms underlying SLIT remain elusive and its use for the treatment of acute lung infections has not yet been explored. Thus, development of appropriate animal models of SLIT is needed to further explore its potential advantages. 
This work shows how to perform sublingual administration of therapeutic agents in mice to evaluate their ability to protect against acute pneumococcal pneumonia. Technical aspects of mouse handling during sublingual inoculation, precise identification of sublingual mucosa, draining lymph nodes and isolation of tissues, bronchoalveolar lavage and lungs are illustrated. Protocols for single cell suspension preparation for FACS analysis are described in detail. Other downstream applications for the analysis of the immune response are discussed. Technical aspects of the preparation of Streptococcus pneumoniae inoculum and intranasal challenge of mice are also explained.
SLIT is a simple technique that allows screening of candidate molecules to modulate lungs&#8217; immune response. Parameters affecting the success of SLIT are related to molecular size, susceptibility to degradation and stability of highly concentrated formulations.

The present work illustrates the convenience of using sublingual immunotherapy to boost the innate immune response in the lungs and confer protection against acute pneumococcal pneumonia in mouse.

Sublingual route has been widely used to deliver small molecules into the bloodstream and to modulate the immune response at different sites. It has been ...

Utilizing Murine Inducible Telomerase Alleles in the Studies of Tissue Degeneration/Regeneration and Cancer

Telomere dysfunction-induced loss of genome integrity and its associated DNA damage signaling and checkpoint responses are well-established drivers that cause tissue degeneration during ageing. Cancer, with incidence rates greatly increasing with age, is characterized by short telomere lengths and high telomerase activity. To study the roles of telomere dysfunction and telomerase reactivation in ageing and cancer, the protocol shows how to generate two murine inducible telomerase knock-in alleles 4-Hydroxytamoxifen (4-OHT)-inducible TERT-Estrogen Receptor (mTERT-ER) and Lox-Stopper-LoxTERT (LSL-mTERT). The protocol describes the procedures to induce telomere dysfunction and reactivate telomerase activity in mTERT-ER and LSL-mTERT mice in vivo. The representative data show that reactivation of telomerase activity can ameliorate the tissue degenerative phenotypes induced by telomere dysfunction. In order to determine the impact of telomerase reactivation on tumorigenesis, we generated prostate tumor model G4 PB-Cre4 PtenL/L p53L/L LSL-mTERTL/L and thymic T-cell lymphoma model G4 Atm-/- mTERTER/ER. The representative data show that telomerase reactivation in the backdrop of genomic instability induced by telomere dysfunction can greatly enhance tumorigenesis. The protocol also describes the procedures used to isolate neural stem cells (NSCs) from mTERT-ER and LSL-mTERT mice and reactivate telomerase activity in NSCs in vitro. The representative data show that reactivation of telomerase can enhance the self-renewal capability and neurogenesis in vitro. Finally, the protocol describes the procedures for performing telomere FISH (Fluorescence In Situ Hybridization) on both mouse FFPE (Formalin Fixed and Paraffin Embedded) brain tissues and metaphase chromosomes of cultured cells.

Telomere and telomerase play essential roles in ageing and tumorigenesis. The goal of this protocol is to show how to generate two murine inducible telomerase knock-in alleles and how to utilize them in the studies of tissue degeneration/regeneration and cancer.

Telomere dysfunction-induced loss of genome integrity and its associated DNA damage signaling and checkpoint responses are well-established drivers that ...

A Simple Device to Rapidly Prepare Whole Mounts of the Mouse Intestine

Preparing whole mounts of the mouse small intestine and colon for subsequent analysis or quantification can be time consuming and difficult. We describe the use of a simple device to cut and &#8216;roll&#8217; mouse intestines to rapidly prepare whole mount preparations of superior and uniform quality to that which can be achieved by hand. The device comprises a base that holds 4 stainless steel rods and a top, which acts a cutting guide. The rods are inserted into the lumen of the small intestine [divided into thirds] and the colon. The rods and samples are then placed over a piece of filter paper or card into the holding slots in the base of the device. The top of the device is then positioned and serves as a cutting guide. The two angled sections in the center of the top piece are used to guide a knife or scalpel and cut the intestines longitudinally on the top of the rods. Once the intestinal sections have been cut, the top is removed and the card,&#160;tissue and rods gently removed from the device and placed on the bench. The rods are then gently rolled sideways to flatten and stick the intestinal segments onto the underlying piece of filter paper or card. The final preparation can then be examined or fixed and stored for later analysis. The preparations are invaluable for the study of intestinal changes in normal or genetically modified mouse models. The preparations have been used for the study and quantification of the effects of inflammation (colitis), damage, pre-cancerous lesions (aberrant crypt foci (ACFs) and mucin depleted foci (MDFs)) and polyps or tumors.

The use of a simple device to cut and &#8216;roll&#8217; mouse intestines to rapidly prepare whole mount preparations is described.

Preparing whole mounts of the mouse small intestine and colon for subsequent analysis or quantification can be time consuming and difficult. We describe ...

Development of an Alpha-synuclein Based Rat Model for Parkinson's Disease via Stereotactic Injection of a Recombinant Adeno-associated Viral Vector

In order to study the molecular pathways of Parkinson&#39;s disease (PD) and to develop novel therapeutic strategies, scientific investigators rely on animal models. The identification of PD-associated genes has led to the development of genetic PD models. Most transgenic &#945;-SYN mouse models develop gradual &#945;-SYN pathology but fail to display clear dopaminergic cell loss and dopamine-dependent behavioral deficits. This hurdle was overcome by direct targeting of the substantia nigra with viral vectors overexpressing PD-associated genes. Local gene delivery using viral vectors provides an attractive way to express transgenes in the central nervous system. Specific brain regions can be targeted (e.g. the substantia nigra), expression can be induced in the adult setting and high expression levels can be achieved. Further, different vector systems based on various viruses can be used. The protocol outlines all crucial steps to perform a viral vector injection in the substantia nigra of the rat to develop a viral vector-based alpha-synuclein animal model for Parkinson&#39;s disease.

Development of an Alpha-synuclein Based Rat Model for Parkinson&#039;s Disease via Stereotactic Injection of a Recombinant Adeno-associated Viral Vector

This manuscript describes how viral vector-mediated local gene delivery provides an attractive way to express transgenes in the central nervous system. The protocol outlines all crucial steps to perform a viral vector injection in the substantia nigra of the rat to develop a viral vector-based animal model for Parkinson's disease.

In order to study the molecular pathways of Parkinson&#39;s disease (PD) and to develop novel therapeutic strategies, scientific investigators rely on ...

A Standardized Approach to Extra-Oral and Intra-Oral Digital Photography

Contemporary dentistry mandates a more comprehensive and personalized analysis of each patient. Technological advances in digital photography have played vital roles in diagnostic accuracy, treatment planning, execution of therapies, and outcome evaluations, including esthetic enhancement. Digital photography also provides an excellent platform for patient education, communication, and co-management of cases with other healthcare providers. However, intra-oral photography often faces challenges such as inaccessibility of areas to be captured, different moveable vs. fixed tissues involved, contamination with saliva or blood, and differing illumination needs on various locations. Thus, a more standardized and systematic approach is proposed for intra- and extra-oral documentation via digital photography to overcome the existing technical challenges. The current work will outline the appropriate equipment specifications (camera bodies, macro lens, and flashes), positions and postures of the operator and patients, proper techniques of tissue retraction, the use of appropriate intra-oral mirrors, and the essential elements such as aperture settings (F-stop), ISO, shutter speed, and white balance. This article aims to provide all dental professionals with an approachable linear array of guidelines to produce simplified and standardized visual tools for more efficient and effective documentation.

The present protocol describes a method to capture intra- and extra-oral photographs for digital documentation in the clinical practice of dentistry. The protocol highlights all the critical components involved and the commonly utilized settings to capture dental photographs for clinical documentation.

Contemporary dentistry mandates a more comprehensive and personalized analysis of each patient. Technological advances in digital photography have played ...

Establishment and Evaluation of a Porcine Vein Graft Disease Model

Venous graft disease (VGD) is the leading cause of coronary artery bypass graft (CABG) failure. Large animal models of CABG-VGD are needed for the investigation of disease mechanisms and the development of therapeutic strategies. 
To perform the surgery, we enter the cardiac chamber through the third intercostal space and carefully dissect the internal mammary vein and immerse it in normal saline. The right main coronary artery is then treated for ischemia. The target vessel is incised, a shunt plug is placed, and the distal end of the graft vein is anastomosed. The ascending aorta is partially blocked, and the proximal end of the graft vein is anastomosed after perforation. The graft vein is checked for patency, and the proximal right coronary artery is ligated. 
CABG surgery is performed in minipigs to harvest the left internal mammary vein for its use as a vascular graft. Serum biochemical tests are used to evaluate the physiological status of the animals after surgery. Ultrasound examination shows that the proximal, middle, and distal end of the graft vessel are unobstructed. In the surgical model, turbulent blood flow in the graft is observed upon histological examination after the CABG surgery, and venous graft stenosis associated with intimal hyperplasia is observed in the graft. The study here provides detailed surgical procedures for the establishment of a repeatable CABG-induced VGD model.

In this protocol, novel pig vein bypass grafting was performed through a small incision in the left chest wall without cardiopulmonary bypass. A postoperative pathology study was done, which showed intimal thickening.

Venous graft disease (VGD) is the leading cause of coronary artery bypass graft (CABG) failure. Large animal models of CABG-VGD are needed for the ...

A Simple Pit Assay Protocol to Visualize and Quantify Osteoclastic Resorption In Vitro

Mature osteoclasts are multinucleated cells that can degrade bone through the secretion of acids and enzymes. They play a crucial role in various diseases (e.g., osteoporosis and bone cancer) and are therefore important objects of research. In vitro, their activity can be analyzed by the formation of resorption pits. In this protocol, we describe a simple pit assay method using calcium phosphate (CaP) coated cell culture plates, which can be easily visualized and quantified. Osteoclast precursors derived from human peripheral blood mononuclear cells (PBMCs) were cultured on the coated plates in the presence of osteoclastogenic stimuli. After 9 days of incubation, osteoclasts were fixed and stained for fluorescence imaging while the CaP coating was counterstained by calcein. To quantify the resorbed area, the CaP coating on plates was stained with 5% AgNO3 and visualized by brightfield imaging. The resorption pit area was quantified using ImageJ.

A Simple Pit Assay Protocol to Visualize and Quantify Osteoclastic Resorption In Vitro

Here, we present a simple and effective assay procedure for resorption pit assays using calcium phosphate coated cell culture plates.

Mature osteoclasts are multinucleated cells that can degrade bone through the secretion of acids and enzymes. They play a crucial role in various diseases ...

High-Resolution Cardiac Positron Emission Tomography/Computed Tomography for Small Animals

Positron emission tomography (PET) and computed tomography (CT) are among the most employed diagnostic imaging techniques, and both serve in understanding cardiac function and metabolism. In preclinical research, dedicated scanners with high sensitivity and high spatio-temporal resolution are employed, designed to cope with the demanding technological requirements posed by the small heart size and very high heart rates of mice and rats. In this paper, a bimodal cardiac PET/CT imaging protocol for experimental mouse and/or rat models of cardiac diseases is described, from animal preparation and image acquisition and reconstruction to image processing and visualization.
In particular, the 18F-labeled fluorodeoxyglucose ([18F]FDG)-PET scan allows for the measurement and visualization of glucose metabolism in the different segments of the left ventricle (LV). Polar maps are convenient tools to display this information. The CT part consists of a time-resolved 3D reconstruction of the entire heart (4D-CT) using retrospective gating without electrocardiography (ECG) leads, allowing the morphofunctional evaluation of the LV and the subsequent quantification of the most important cardiac function parameters, such as ejection fraction (EF) and stroke volume (SV). Using an integrated PET/CT scanner, this protocol can be executed within the same anesthesia induction without the need to reposition the animal between different scanners. Hence, PET/CT can be seen as a comprehensive tool for the morphofunctional and metabolic evaluation of the heart in several small animal models of cardiac diseases.

Here, we present an experimental imaging protocol for the quantification of cardiac function and morphology using high-resolution positron emission tomography/computed tomography for small animals. Both mice and rats are considered, discussing the different requirements of computed tomography contrast agents for the two species.

Positron emission tomography (PET) and computed tomography (CT) are among the most employed diagnostic imaging techniques, and both serve in understanding ...