We are grateful for the support from the following grants: a Translational Research Grant of NCRCH [2020WSA01], a KJXW Scientific Grant from Suzhou Commission of Health for Young Scholars [KJXW2020002], a Science and Technology Plan of Suzhou City (SKY2021038 and SKJY2021050), a grant from the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD), and a Primary Research &#38; Social Development Plan of Jiangsu Province (BE2018659).

All experiments involving animals were approved by the Animal Ethics Committee of Soochow University. All surgical procedures were performed under full anesthesia. Analgesics were not used to avoid interference with the natural course of the disease according to previous literatures28,29. Approval for the lack of analgesia was also granted by the Animal Ethics Committee of Soochow University.
1. Preparation
<ol>
	<li>Fast a C57BL/6 wild-type mouse 8-12 h before the surgery.</li>
	<li>Prepare 5% (w/v) TC solution (93 mM) diluted into 0.9% sodium chloride. Filter the solution through a 0.22 &#181;m filter.</li>
	<li>Autoclave the surgical instruments and materials, including forceps, scissors, blade holder, needle holder, hemostatic clip, vascular clamps, and sterile drapes, using a pressure sterilizer at a temperature of 121 &#176;C for 30 min.</li>
	<li>Prepare a homemade microsyringe. To do this, manually install a disposable insulin tip and a prolonged plastic pipette tip onto a 25 &#181;L flat tip Microliter syringe. Sterilize through irradiation.</li>
</ol>
2. Anesthesia and preoperative preparation
<ol>
	<li>Weigh 6- to 8-week-old male C57BL/6 wild-type mice (approximately 21-23 g). Induce general anesthesia with an intraperitoneal injection of 1% pentobarbital sodium solution at a dose of 50 mg/kg.</li>
	<li>Fix the mouse in the supine position on anirradiatedfoam flat plate with the tape.</li>
	<li>Prepare the operation region of each animal by removing its fur with a depilation cream from the xiphoid process level down to the connecting line of the bilateral anterior superior iliac spine, with the left and right sides parallel to the front axillary line.</li>
	<li>Prepare a sterile surgical field with particular focus on the surgical area, consisting of the area prepared on the animal and the front of the surgeon.
	<ol>
		<li>Disinfect the benchtop.</li>
		<li>Clean the incision site with multiple applications of surgical scrub solution. Wipe the skin two to three times with 0.5% iodophor and allow it dry for 1-2 min each time.</li>
		<li>Cover the mouse with sterile drapes.</li>
	</ol>
	</li>
</ol>
3. Surgical procedure
NOTE: Figure 1 depicts the anatomy and morphology of the mouse pancreas before and after retrograde injection of TC into the biliopancreatic duct by microinjection.
<ol>
	<li>Make an approximate 2 to 3 cm long median abdominal incision.</li>
	<li>Locate the duodenum from left to right along the stomach. Gently pull the duodenum out and to the left side using surgical forceps and a disinfectant-soaked cotton swab to expose the pancreas, the biliopancreatic duct, and the duodenal papilla. Take care not to injure the intestinal wall or related vessels.</li>
	<li>Use 8-0 sutures to pass through the connection between the duodenum and pancreas around the papilla, and pull them to the left side of the mouse body to fix the duodenum.</li>
	<li>Gently pull the skin and the lower edge of the liver aside. Clamp the common hepatic duct, making sure not to clamp the portal vein or pancreas. Clamp the proximal biliopancreatic duct.</li>
	<li>Pierce the microinjector into the distal biliopancreatic duct retrogradely. Fix the needle tip near the duodenal papilla with a clamp. Infuse 10 &#181;L of 5% TC into the pancreatic duct at a rate of 5 &#181;L/min.</li>
	<li>Keep the biliopancreatic duct closed for 5 min to achieve a stable pressure. Then, pull out the microinjector and remove the clamps.</li>
	<li>Restore the duodenum to the original anatomical position and check the bleeding.</li>
	<li>Close the wound with 6-0 sutures and disinfect with 0.5% iodophor.</li>
</ol>
4. Recovery and postoperative management
<ol>
	<li>Recover the animals from anesthesia on a 37 &#176;C thermal pad. Do not send the operated animals to the temporal postoperative room until all the animals have woken up.</li>
	<li>Administer 0.8 mL of 0.9% saline subcutaneously and slowly for fluid supplementation.</li>
	<li>Monitor the animals postoperatively for their general condition and signs of infections or illness.</li>
</ol>
5. Serological testing and histology evaluation
<ol>
	<li>At 24 h post-operation, anesthetize the mice with pentobarbital sodium using the same dose and injection route.</li>
	<li>Collect all the blood from the abdominal aorta (about 0.8 mL per mouse) and spin at 1,500 x g for 15 min to isolate the serum for further testing.</li>
	<li>Collect the pancreas tissues.</li>
	<li>Open the thoracic cavity to collect the lung tissues.</li>
	<li>Measure the biochemistry function indexes from the serum, including amylase, lipase, liver function (alanine transaminase (ALT) and aspartate transaminase (AST)), and kidney function (urea and creatine), using commercial kits according to the manufacturers&#39; instructions.</li>
	<li>Homogenize the lung and pancreas tissues and measure the myeloperoxidase (MPO) level using a commercial kit according to the manufacturer&#39;s instructions.</li>
	<li>Open the thoracic cavity and perfuse with 20 mL of phosphate-buffered saline (PBS) twice, then collect the pancreas. Immerse into 4% paraformaldehyde solution for 24 h. Dehydrate in a series of alcohol concentrations and embed in paraffin.</li>
	<li>Use a microtome to prepare 5 &#181;m thick pancreas tissue sections.</li>
	<li>Perform H&#38;E staining for histological evaluation of the pancreas.</li>
	<li>Evaluate the pathological scores according to the criteria proposed by Schmidt et al.30.</li>
</ol>

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The TC-induced SAP model is an excellent research tool. As shown in this study, this model is very easily realized in general labs without employing specific devices. When used in combination with histology and biochemical analysis, it provides a cost- (inexpensive reagents) and time-saving (24 h time window) approach for inducing and evaluating AP. Adjusting the concentration of TC also offers the possibility of producing mild and moderate AP. Perides et al. also employed TC to induce SAP in mice20</su...

Acute pancreatitis (AP) is an acute inflammation of the pancreas characterized by obstruction of the main pancreatic duct with subsequent ductal distension and pancreas autodigestion by its abnormally activated enzymes. Its clinical manifestations include local or systemic inflammation, abdominal pain, and elevation of serum amylase1,2. According to the severity classification3, AP can present in mild, moderate, and severe forms, and among them, severe acute pancreatitis (SAP) is the most concerning condition due to its high mortality rate of more than 30%4. In the United States, AP is one of the most common reasons for hospitalization, affecting over 200,000 patients5. Moreover, AP, especially SAP, is increasing annually and affecting younger age groups6. However, there is a lack of effective treatment options in current clinical practice6,7. Therefore, it is necessary to explore the molecular mechanisms involved in AP, thereby facilitating treatment improvement.
Well-established experimental animal models are required for studying the mechanisms involved in AP and evaluating the effectiveness of different treatment modalities. With the easy accessibility of transgenic and knockout strains and their small size, which minimizes the doses of drugs required for in vivo evaluation, mice are preferred for AP research. Therefore, several models of AP have been developed in mice8,9.
Working from a mild pancreatitis rat model induced through the intravenous administration of caerulein10, Niederau et al. developed a SAP mouse model presented with acinar cell necrosis induced using the same drug and injection route11. Although this model possesses several advantages, including noninvasiveness, rapid induction, wide reproducibility, and applicability, the major disadvantage is that only a mild form of AP is developed in most cases, thereby limiting its clinical relevance. Alcohol is considered one of the major etiologic factors of AP; however, Foitzik et al. reported that it causes pancreatic injury only when combined with other factors, such as exocrine hyperstimulation12. Moreover, although alcohol-induced AP models developed via different administration routes, and drug doses have been reported13,14,15, their major disadvantage is the difficulty in reproducing them. Intraperitoneal administration of L-arginine can also induce AP in mice16; however, its low clinical relevance hinders its application. Taurocholate, a bile salt, was first proposed by Creutzfeld et al. in 1965 for inducing a condition resembling human AP via pancreatic duct infusion17. Although controversies exist regarding its clinical relevance in pathophysiology18,19, taurocholate-induced pancreatitis remains an indispensable model for SAP.
As this model is simple to realize and is also effective in mice, it is now one of the most used AP models for small animal in vivo studies. Perides et al. employed sodium taurocholate (TC) to induce SAP in mice20, providing insights to understand its pathology. Combined with genetic modification techniques, this model has allowed us to confirm several specific genes involved in AP. For example, Bicozo et al. showed that a knockout of the CD38 gene protected against a model of TC-infusion pancreatitis and attributed the mechanisms to alterations in intracellular Ca2+ signaling21. Fanczal et al. investigated the physiological implication of TRPM2 expression in the plasma membrane of mouse pancreatic acinar and ductal cells, and demonstrated reduced severity of TC-induced SAP in TRPM2 knockout mice22. Furthermore, this model also provides a simple and effective way to test many novel drugs in vivo. For instance, this method enabled validation of the therapeutic effects of caffeine23, dehydrocholic acid24, and various antioxidants and anticoagulants25,26. This evidence demonstrates the versatility of the TC-induced SAP model. Although Wittel et al. described a similar mouse model27, a lack of details on the implementation procedures could result in an inability to reproduce the findings. In this article, we focus on methods using a simple homemade microsyringe and study TC-induced SAP, thereby providing possible guidance not only for further study of the pathogenesis and treatment of AP, but also for a perfectly adaptable experimental method for many other substances.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>0.5% iodophor</td>
			<td>Shanghai Likang Disinfectant</td>
			<td>310102</td>
			<td>4 mL/mouse</td>
		</tr>
		<tr>
			<td>0.9% sodium chloride</td>
			<td>Sinopharm Group Co., Ltd.</td>
			<td>10019318</td>
			<td>0.8 mL/mouse</td>
		</tr>
		<tr>
			<td>1% Pentobarbital sodium</td>
			<td>Sigma</td>
			<td>P3761</td>
			<td>0.2 -0.25 mL/mouse</td>
		</tr>
		<tr>
			<td>25 &#956;L flat tip Microliter syringe</td>
			<td>Gaoge, Shanghai</td>
			<td>A124019</td>
			<td></td>
		</tr>
		<tr>
			<td>4% Paraformaldehyde</td>
			<td>Beyotime, Nantong, China</td>
			<td>P0099-500ml</td>
			<td></td>
		</tr>
		<tr>
			<td>5% sodium taurocholate (TC)</td>
			<td>Aladdin</td>
			<td>S100834-5g</td>
			<td>10 &#956;L/SAP mouse</td>
		</tr>
		<tr>
			<td>6-0 Sterile nylon microsuture with threaded needle (1/2 circle)</td>
			<td>Cheng-He</td>
			<td>20093</td>
			<td></td>
		</tr>
		<tr>
			<td>75% alcohol</td>
			<td>Sinopharm Group Co., Ltd.</td>
			<td>10009218</td>
			<td>4 mL/mouse</td>
		</tr>
		<tr>
			<td>8-0 Sterile nylon microsuture with threaded needle (3/8 circle)</td>
			<td>Cheng-He</td>
			<td>19064</td>
			<td></td>
		</tr>
		<tr>
			<td>ALT Activity Assay Kit</td>
			<td>EPNK, Anhui, China</td>
			<td>ALT0012</td>
			<td></td>
		</tr>
		<tr>
			<td>Amylase Assay Kit</td>
			<td>EPNK, Anhui, China</td>
			<td>AMY0012</td>
			<td></td>
		</tr>
		<tr>
			<td>Angled small bulldog clamp with 12 mm jaw (3 cm)</td>
			<td>Cheng-He</td>
			<td>HC-X022</td>
			<td></td>
		</tr>
		<tr>
			<td>aspen shavings or shreds for mouse bedding</td>
			<td>Beijing Vital River Laboratory Animal Technology</td>
			<td>VR03015</td>
			<td></td>
		</tr>
		<tr>
			<td>AST Activity Assay Kit</td>
			<td>EPNK, Anhui, China</td>
			<td>AST0012</td>
			<td></td>
		</tr>
		<tr>
			<td>Blood Urea Nitrogen (BUN) Assay Kit</td>
			<td>EPNK, Anhui, China</td>
			<td>BUN0011</td>
			<td></td>
		</tr>
		<tr>
			<td>C57BL/6 mouse</td>
			<td>Beijing Vital River Laboratory Animal Technology</td>
			<td>213</td>
			<td></td>
		</tr>
		<tr>
			<td>Creatine Assay Kit</td>
			<td>EPNK, Anhui, China</td>
			<td>CRE0012</td>
			<td></td>
		</tr>
		<tr>
			<td>Feature microtome blade</td>
			<td>Beyotime, Nantong, China</td>
			<td>E0994</td>
			<td></td>
		</tr>
		<tr>
			<td>Hemostatic Forceps (9.5 cm, Curved)</td>
			<td>JZ, Shanghai Medical Instruments Co. Ltd.</td>
			<td>JC3901</td>
			<td></td>
		</tr>
		<tr>
			<td>Lipase Assay Kit</td>
			<td>Jiancheng, Nanjing, China</td>
			<td>A054-2-1</td>
			<td></td>
		</tr>
		<tr>
			<td>Microtome</td>
			<td>Leica biosystem, Germany</td>
			<td>RM2245</td>
			<td></td>
		</tr>
		<tr>
			<td>Mindray biochemistry analyzer</td>
			<td>Mindray, Shenzhen, China</td>
			<td>BS-420</td>
			<td></td>
		</tr>
		<tr>
			<td>MPO Assay Kit</td>
			<td>Jiancheng, Nanjing, China</td>
			<td>A044-1-1</td>
			<td></td>
		</tr>
		<tr>
			<td>Normal mouse chow</td>
			<td>Trophic, Nantong, China</td>
			<td>LAD 1000</td>
			<td></td>
		</tr>
		<tr>
			<td>Phosphate buffered saline</td>
			<td>Beyotime, Nantong, China</td>
			<td>C0221A</td>
			<td></td>
		</tr>
		<tr>
			<td>Straight micro-bulldog clamp with 5 mm jaw (1.5 cm)</td>
			<td>JZ, Shanghai Medical Instruments Co. Ltd.</td>
			<td>W40130</td>
			<td></td>
		</tr>
		<tr>
			<td>Straight or curved forceps (11.0 cm)</td>
			<td>Cheng-He</td>
			<td>HC-X091A or HC-X090A</td>
			<td></td>
		</tr>
		<tr>
			<td>Straight Scissors (10.0 cm)</td>
			<td>Cheng-He, Ningbo, China</td>
			<td>HC-J039102</td>
			<td></td>
		</tr>
		<tr>
			<td>Thermo Scientific Centrifuge</td>
			<td>Thermo Scientific, USA</td>
			<td>Multifuge X1R</td>
			<td></td>
		</tr>
	</tbody>
</table>

establishment of a mouse severe acute pancreatitis model using retrograde injection of sodium taurocholate into the biliopancreatic duct

The prevalence of acute pancreatitis (AP), especially severe acute pancreatitis (SAP), is increasing in younger age groups annually. However, there is a lack of effective treatments in the current clinical practice. With the easy accessibility of transgenic and knockout strains and their small size, which allows minimal doses of drugs required for in vivo evaluation, a well-established experimental model in mice is preferred for AP research. Moreover, SAP induced through sodium taurocholate (TC) is currently one of the most widely used and best characterized models. This model has been investigated for novel therapies and possible molecular events during the process of AP. Here, we present the generation of an AP mouse model using sodium taurocholate and a simple homemade microsyringe. Moreover, we also provide the methodology for the subsequent histology and serological testing.

By carefully following the instructions above, we obtained a mean surgery duration of approximately 40 min. The mice were slightly inactive and had lost approximately 0.5-1.75 g, 0.85-1.85 g and 0.5-4.73 g of weight at 24 h, 48 h and 72 h post-operation, respectively (Figure 2).
From the time of surgery completion to 24 h post-operation, as the disease developed, the mice became inactive and showed slow responses and actions.
The surviv...

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Establishment of a Mouse Severe Acute Pancreatitis Model using Retrograde Injection of Sodium Taurocholate into the Biliopancreatic Duct

A mouse model of severe acute pancreatitis is described herein. The procedure presented here is very rapid, simple, and accessible, thereby potentially allowing the study of the molecular mechanisms and different therapeutic interventions in acute pancreatitis in a convenient way.

The prevalence of acute pancreatitis (AP), especially severe acute pancreatitis (SAP), is increasing in younger age groups annually. However, there is a ...

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4.0K Views.  the First Affiliated Hospital of Soochow University. A mouse model of severe acute pancreatitis is described herein. The procedure presented here is very rapid, simple, and accessible, thereby potentially allowing the study of the molecular mechanisms and different therapeutic interventions in acute pancreatitis in a convenient way.

Video: Establishment of a Mouse Severe Acute Pancreatitis Model using Retrograde Injection of Sodium Taurocholate into the Biliopancreatic Duct

Retinal Detachment Model in Rodents by Subretinal Injection of Sodium Hyaluronate

Subretinal injection of sodium hyaluronate is a widely accepted method of inducing retinal detachment (RD). However, the height and duration of RD or the occurrence of subretinal hemorrhage can affect photoreceptor cell death in the detached retina. Hence, it is advantageous to create reproducible RDs without subretinal hemorrhage for evaluating photoreceptor cell death. We modified a previously reported method to create bullous and persistent RDs in a reproducible location with rare occurrence of subretinal hemorrhage. The critical step of this modified method is the creation of a self-sealing scleral incision, which can prevent leakage of sodium hyaluronate after injection into the subretinal space. To make the self-sealing scleral incision, a scleral tunnel is created, followed by scleral penetration into the choroid with a 30 G needle. Although choroidal hemorrhage may occur during this step, astriction with a surgical spear reduces the rate of choroidal hemorrhage. This method allows a more reproducible and reliable model of photoreceptor death in diseases that involve RD such as rhegmatogenous RD, retinopathy of prematurity, diabetic retinopathy, central serous chorioretinopathy, and age-related macular degeneration (AMD).

Creating experimental retinal detachments with a reproducible and sustained height of detachment, and without subretinal hemorrhage, is important for studying the pathophysiology of photoreceptor cell loss in retinal disease and evaluating potential therapeutic interventions. Here, we report such a method in detail.

Subretinal injection of sodium hyaluronate is a widely accepted method of inducing retinal detachment (RD). However, the height and duration of RD or the ...

Establishment and Characterization of UTI and CAUTI in a Mouse Model

Urinary tract infections (UTI) are highly prevalent, a significant cause of morbidity and are increasingly resistant to treatment with antibiotics. Females are disproportionately afflicted by UTI: 50% of all women will have a UTI in their lifetime. Additionally, 20-40% of these women who have an initial UTI will suffer a recurrence with some suffering frequent recurrences with serious deterioration in the quality of life, pain and discomfort, disruption of daily activities, increased healthcare costs, and few treatment options other than long-term antibiotic prophylaxis. Uropathogenic Escherichia coli (UPEC) is the primary causative agent of community acquired UTI. Catheter-associated UTI (CAUTI) is the most common hospital acquired infection accounting for a million occurrences in the US annually and dramatic healthcare costs. While UPEC is also the primary cause of CAUTI, other causative agents are of increased significance including Enterococcus faecalis. Here we utilize two well-established mouse models that recapitulate many of the clinical characteristics of these human diseases. For UTI, a C3H/HeN model recapitulates many of the features of UPEC virulence observed in humans including host responses, IBC formation and filamentation. For CAUTI, a model using C57BL/6 mice, which retain catheter bladder implants, has been shown to be susceptible to E. faecalis bladder infection. These representative models are being used to gain striking new insights into the pathogenesis of UTI disease, which is leading to the development of novel therapeutics and management or prevention strategies.

The ability to model urinary tract infections (UTI) is crucial in order to be able to understand bacterial pathogenesis and spawn the development of novel therapeutics. This work&#8217;s goal is to demonstrate mouse models of experimental UTI and catheter associated UTI that recapitulate and predict findings seen in humans.

Urinary tract infections (UTI) are highly prevalent, a significant cause of morbidity and are increasingly resistant to treatment with antibiotics. ...

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 ...

Oleic Acid-Injection in Pigs As a Model for Acute Respiratory Distress Syndrome

The acute respiratory distress syndrome is a relevant intensive care disease with an incidence ranging between 2.2% and 19% of intensive care unit patients. Despite treatment advances over the last decades, ARDS patients still suffer mortality rates between 35 and 40%. There is still a need for further research to improve the outcome of patients suffering from ARDS. One problem is that no single animal model can mimic the complex pathomechanism of the acute respiratory distress syndrome, but several models exist to study different parts of it. Oleic acid injection (OAI)-induced lung injury is a well-established model for studying ventilation strategies, lung mechanics and ventilation/perfusion distribution in animals. OAI leads to severely impaired gas exchange, deterioration of lung mechanics and disruption of the alveolo-capillary barrier. The disadvantage of this model is the controversial mechanistic relevance of this model and the necessity for central venous access, which is challenging especially in smaller animal models. In summary, OAI-induced lung injury leads to reproducible results in small and large animals and hence represents a well-suited model for studying ARDS. Nevertheless, further research is necessary to find a model that mimics all parts of ARDS and lacks the problems associated with the different models existing today.

In this article, we present a protocol to induce acute lung injury in pigs by central-venous injection of oleic acid. This is an established animal model for studying the acute respiratory distress syndrome (ARDS).

The acute respiratory distress syndrome is a relevant intensive care disease with an incidence ranging between 2.2% and 19% of intensive care unit ...

Isometric Contractility Measurement of the Mouse Mesenteric Artery Using Wire Myography

The wire myograph technique is used to assess the contractility of vascular smooth muscles in response to depolarization, GPCR agonists/inhibitors and drugs. It is widely used in many studies on the physiological functions of vascular smooth muscle, the pathogenesis of vascular diseases such as hypertension, and the development of smooth muscle relaxant drugs. The mouse is a widely used model animal with a large pool of disease models and genetically modified strains. We introduced this method to measure the isometric contraction of mouse mesenteric artery in detail. A 1.4-mm segment of mouse mesenteric resistance artery was isolated and mounted on a myograph chamber by passing two steel wires through its lumen. After equilibration and normalization steps, the vessel segment was potentiated by a high-K+ solution twice prior to the contraction assay. As an example of the application of this method in drug development, we measured the relaxant effect of a novel natural substance, neoliensinine, isolated from a Chinese herb, embryos of the lotus seed (Nelumbo nucifera Gaertn.) on mouse mesenteric arteries. The vessel segments mounted on the myograph chamber were stimulated with a high-K+ solution. When the force tension reached a stable sustained phase, cumulative doses of neoliensinine were added to the chamber. We found that neoliensinine had a dose-dependent relaxant effect on smooth muscle contraction, thus suggesting that it bears potential activity against hypertension. In addition, as the vessel segment can survive at least 4 hours after mounting and maintain contractility induced by the high-K+ solution for many times, we suggest that the wire myograph system may be used for the time-consuming process of drug screening.

The wire myograph technique is used to investigate vascular smooth muscle functions and screen new drugs. We report a detailed protocol for measuring the isometric contractility of the mouse mesenteric artery and for screening new relaxants of vascular smooth muscle.

The wire myograph technique is used to assess the contractility of vascular smooth muscles in response to depolarization, GPCR agonists/inhibitors and ...

Establishment of a Severe Dry Eye Model Using Complete Dacryoadenectomy in Rabbits

Dry eye disease (DED) is a complex disease with multiple etiologies and variable symptoms, having ocular surface inflammation as its key pathophysiologic step. Despite advances in our understanding of DED, significant knowledge gaps remain. Advances are limited in part due to the lack of informative animal models. The authors recently reported on a method of DED induced by injecting all orbital lacrimal gland (LG) tissues with the lectin concanavalin A. Here, we report a novel model of aqueous-deficient DED based on the surgical resection of all orbital LG (dacryoadenectomy) tissues. Both methods use rabbits because of their similarity to human eyes in terms of the size and structure of the ocular surface. One week after removal of the nictitating membrane, the orbital superior LG was surgically removed under anesthesia, followed by removal of the palpebral superior LG, and finally removal of the inferior LG. Dacryoadenectomy induced severe DED, evidenced by a marked reduction in the tear break up time test and the Schirmer&#39;s tear test, and significantly increased tear osmolarity and rose bengal staining. Dacryoadenectomy-induced DED lasted at least eight weeks. There were no complications and animals tolerated the procedure well. The technique can be mastered relatively easily by those with adequate surgical experience and appreciation of the relevant rabbit anatomy. Since this model recapitulates the features of human aqueous-deficient DED, it is suitable for studies of ocular surface homeostasis, DED, and candidate therapeutics.

A novel approach is presented to induce chronic dry eye disease in rabbits by surgically removing all orbital lacrimal glands. This method, distinct from those previously reported, produces a stable, reproducible model of aqueous deficient dry eye well suited to study tear physiology and pathophysiology and ocular therapeutics.

Dry eye disease (DED) is a complex disease with multiple etiologies and variable symptoms, having ocular surface inflammation as its key pathophysiologic ...

Sodium Taurocholate Induced Severe Acute Pancreatitis in C57BL/6 Mice

Biliary acute pancreatitis induction by sodium taurocholate infusion has been widely used by the scientific community due to the representation of the human clinical condition and reproduction of inflammatory events corresponding to the onset of clinical biliary pancreatitis. The severity of pancreatic damage can be assessed by measuring the concentration, speed, and volume of the infused bile acid. This study provides an updated checklist of the materials and methods used in the protocol reproduction and shows the main results from this acute pancreatitis (AP) model. Most of the previous publications have limited themselves to reproducing this model in rats. We have applied this method in mice, which provides additional advantages (i.e., the availability of an arsenal of reagents and antibodies for these animals along with the possibility of working with genetically modified strains of mice) that may be relevant to the study. For acute pancreatitis induction in mice, we present a systematic protocol, with a defined dose of 2.5% sodium taurocholate at an infusion speed 10 &#181;L/min for 3 min in C57BL/6 mice that reaches its maximal level of severity within 12 h of induction and highlight results with outcomes that validate the method. With practice and technique, the total estimated time, from the induction of anesthesia to the completion of the infusion, is 25 min per animal.

Animal models for severe acute pancreatitis enable the study of pathophysiological changes at the initial stage, facilitating observation of the evolution of inflammatory events. Here we provide a protocol for the induction of severe acute biliary pancreatitis by retrograde infusion of sodium taurocholate into the pancreatic duct of anesthetized C57BL/6 mice.

Biliary acute pancreatitis induction by sodium taurocholate infusion has been widely used by the scientific community due to the representation of the ...

A Mouse Model for Chronic Pancreatitis via Bile Duct TNBS Infusion

Chronic pancreatitis (CP) is a complex disease involving pancreatic inflammation and fibrosis, glandular atrophy, abdominal pain and other symptoms. Several rodent models have been developed to study CP, of which the bile duct 2,4,6 -trinitrobenzene sulfonic acid (TNBS) infusion model replicates the features of neuropathic pain seen in CP. However, bile duct drug infusion in mice is technically challenging. This protocol demonstrates the procedure of bile duct TNBS infusion for generation of a CP mouse model. TNBS was infused into the pancreas through the ampulla of Vater in the duodenum. This protocol optimized drug volume, surgical techniques, and drug handling during the procedure. TNBS-treated mice showed features of CP as reflected by bodyweight and pancreas weight reductions, changes in pain-associated behaviors, and abnormal pancreatic morphology. With these improvements, mortality associated with TNBS injection was minimal. This procedure is not only critical in generating pancreatic disease models but is also useful in local pancreatic drug delivery.

Chronic pancreatitis (CP) is a disease characterized by inflammation and fibrosis of the pancreas, often associated with intractable abdominal pain. This article focuses on refining the technique to generate a mouse model of CP via bile duct infusion with 2,4,6 -trinitrobenzene sulfonic acid (TNBS).

Chronic pancreatitis (CP) is a complex disease involving pancreatic inflammation and fibrosis, glandular atrophy, abdominal pain and other symptoms. ...

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 ...

Enema of Traditional Chinese Medicine for Patients with Severe Acute Pancreatitis

Severe acute pancreatitis (SAP) is characterized by high mortality rates, numerous complications, and extreme difficulties in treatment. A traditional Chinese medicine (TCM) enema has been widely utilized in clinical and experimental studies of SAP. It has been demonstrated to have beneficial effects in protecting pancreatic function and delaying disease progression. The procedure of TCM enema is to perfuse the Chinese medicinal liquid of raw rhubarb (Rheum officinale Baill. DaHuang) from the anus into the rectum and colon. Basic steps of the procedure include boiling the herbal solution in advance, using a disposable enema kit to assist patients in taking a left lying position, raising the patient's hip 10 cm, and carefully inserting the enema 30-35 cm into the anus, with a drip speed of 60-80 drops/min. The medicine liquid temperature should be equivalent to the patient's body temperature, typically between 37-39 &#176;C. The end of the enema operation should be slow, and Tui na (massage therapy) should be administered before extubation. The medication liquid should be kept in the rectum for more than 1 h. After issuing an enema, it is essential to observe the patient's feces and abdomen, and to evaluate the remission of abdominal signs and symptoms.

An enema is a type of traditional Chinese medicine (TCM) therapy used to treat severe acute pancreatitis (SAP). The therapy involves instilling a TCM liquid into the rectum and colon through the anus to keep the liquid in the intestine, absorbing through the intestinal mucosa. This study aims to standardize the enema procedure for SAP patients.

Severe acute pancreatitis (SAP) is characterized by high mortality rates, numerous complications, and extreme difficulties in treatment. A traditional ...