ObjectiveTo explore the feasibility of establishment of a artificial joint aseptic loosening mouse model by cobalt-chromium particles stimulation.MethodsTwenty-four 8-week-old male severe combined immunodeficient (SCID) mice were divided into experimental group (n=12) and control group (n=12). The titanium nail was inserted into the tibial medullary cavity of mouse in the two groups to simulate artificial joint prosthesis replacement. And the cobalt-chromium particles were injected into the tibial medullary cavity of mouse in experimental group. The survival of the mouse was observed after operation; the position of the titanium nail and the bone mineral density of proximal femur were observed by X-ray film, CT, and Micro-CT bone scanning; and the degree of dissolution of the bone tissue around the tibia was detected by biomechanical test and histological staining.ResultsTwo mice in experimental group died, and the rest of the mice survived until the experiment was completed. Postoperative imaging examination showed that there was no obvious displacement of titanium nails in control group, and there were new callus around the titanium nails. In experimental group, there was obvious osteolysis around the titanium nails. The bone mineral density of the proximal tibia was 91.25%±0.67%, and the maximum shear force at the tibial nail-bone interface was (5.93±0.85) N in experimental group, which were significantly lower than those in control group [102.07%±1.87% and (16.76±3.09) N] (t=5.462, P=0.041; t=3.760, P=0.046). Histological observation showed that a large number of inflammatory cells could be seen around the titanium nails in experimental group, while there was no inflammatory cells, and obvious bone tissue formation was observed in control group.ConclusionThe artificial joint aseptic loosening mouse model can be successfully established by cobalt-chromium particles stimulation.
ObjectiveTo observe the effect of using tungsten drills to prepare mouse knee osteochondral injury model by comparing with the needle modeling method, in order to provide an appropriate animal modeling method for osteochondral injury research.MethodsA total of 75 two-month-old male C57BL/6 mice were randomly divided into 3 groups (n=25). Mice in groups A and B were used to prepare the right knee osteochondral injury models by using needles and tungsten drills, respectively; group C was sham-operation group. The general condition of the mice was observed after operation. The samples were taken at 1 day and 1, 2, 4, and 8 weeks after modeling, and HE staining was performed. The depth, width, and cross-sectional area of the injury site at 1 day in groups A and B were measured, and the percentage of the injury depth to the thickness of the articular cartilage (depth/thickness) was calculated. Toluidine blue staining and immunohistochemical staining for collagen type Ⅱ were performed at 8 weeks, and the International Cartilage Research Society (ICRS) score was used to evaluate the osteochondral healing in groups A and B.ResultsAll mice survived to the completion of the experiment. HE staining showed that group C had normal cartilage morphology. At 1 day after modeling, the injury in group A only broke through the cartilage layer and reached the subchondral bone without entering the bone marrow cavity; the injury in group B reached the bone marrow cavity. The depth, width, cross-sectional area, and depth/thickness of the injury in group A were significantly lower than those in group B (P<0.05). At 1, 2, 4, and 8 weeks after modeling, there was no obvious tissue filling in the injured part of group A, and no toluidine blue staining and expression of collagen type Ⅱ were observed at 8 weeks; while the injured part of group B was gradually filled with tissue, the toluidine blue staining and the expression of collagen type Ⅱ were seen at 8 weeks. At 8 weeks, the ICRS score of group A was 8.2±1.3, which was lower than that of group B (13.6±0.9), showing significant difference (t=−7.637, P=0.000).ConclusionThe tungsten drills can break through the subchondral bone layer and enter the bone marrow cavity, and the injury can heal spontaneously. Compared with the needle modeling method, it is a better method for modeling knee osteochondral injury in mice.
Objective To investigate how to establish stable mice cervical heart transplantation model. Methods Totally, 40 male C57 mice with the age of 6-8 weeks and weight of 19-24 g were randomly divided into recipients and donors (n=20 in each group). Mice cervical heart transplantation model was established by connecting the ascending aorta of donors to the right cervical common artery of recipients through end to side anastmosis and the pulmonary artery of donors to the right external jugular vein of recipients through end to end anastmosis. Results More than 95% recipients survived after surgery. Cold ischemia time was 15±5 min, warm ischemia time 23±6 min, and the whole operation took about 55±15 min. The recipients survived more than 30 d with functional heart grafts. Histologically, there was no difference between the heart graft one month after the transplantion and the normal heart. Conclusion Cervical heart transplantation of mice model is reliable and feasible, which is easy to monitor the survival condition of heart graft by visual examination and palpation, which will benefit the basic research in transplantation field.
ObjectiveTo understand research progress of animal model of esophageal achalasia and discuss its pathogenesis briefly.Method Literatures about research progress of animal model of esophageal achalasia were reviewed. ResultsThe models of esophageal achalasia could been made in several ways, such as the obstruction model, the classic denervation model, and the increasingly popular gene model. These models were all based on the theory of the corresponding causes, with the processing of different factors, then completed the preparation of animal model. Conclusionsanimal model of esophageal achalasia goes through three stages: obstruction model, denervation model, and gene model. gene model of esophageal achalasia based on congenital theory could help us understand this disease better and make an ideal animal model, which could provide a reliable evidence for etiology study.
This study aims to evaluate the ability of C-arm cone-beam CT to detect intracranial hematomas in canine models. Twenty one healthy canines were divided into seven groups and each group had three animals. Autologous blood and contrast agent (3 mL) were slowly injected into the left/right frontal lobes of each animal. Canines in the first group, the control group, were only injected with autologous blood without contrast agent. Each animal in all the 7 groups was scanned with C-arm cone-beam CT and multislice computed tomography (MSCT) after 5 minutes. The attenuation values and their standard deviations of the hematoma and uniformed brain tissues were measured to calculate the image noise, signal to noise ratio (SNR) and contrast to noise ratio (CNR). A scale with scores 1-3 was used to rate the quality of the reconstructed image of different hematoma as a subjective evaluation, and all the experimental data were processed with statistical treatment. The results revealed that when the density of hematoma was less than 65 HU, hematomata were not very clear on C-arm CT images, and when the density of hematoma was more than 65 HU, hematomata showed clearly on both C-arm CT and MSCT images and the scores of them were close. The coherence between the two physicians was very reliable. The same results were obtained with C-arm cone-beam CT and MSCT grades in measuring SD value, SNR, and CNR. The reasonable choice of density detection range of intracranial hematoma with C-arm cone-beam CT could be effectively applied to monitoring the intracranial hemorrhage during interventional diagnosis and treatment.
ObjectiveTo explore the method and feasibility of establishing patent ductus arteriosus (PDA) model in Bama miniature pig by using autologous jugular vein, and to provide a large animal model for the development of PDA occluder and the study of pulmonary hypertension associated with congenital heart disease. MethodsFive male Bama miniature pigs weighing about 45 kg were selected to gain the PDA model of the autogenous jugular vein, which was fixed by glutaraldehyde and anastomosed between the ascending aorta and the main pulmonary artery. The patency of PDA was confirmed by echocardiography and angiocardiography immediately and one week after the operation. Two animals were selected to undergo transcatheter closure of PDA via femoral vein 1 week after the operation, and the rest were euthanized to obtain PDA and lung tissue for pathological examination. ResultsThe PDA model was successfully established in all five animals with a success rate of 100.0%. Immediately and 1 week after the operation, echocardiography and angiography showed that PDA blood flow was unobstructed, and hematoxylin-eosin staining showed that PDA endothelialization was good. One week after the operation, two animals were successfully treated with transcatheter femoral vein occlusion. The pathological examination of lung tissue showed thickening of the intima and muscular layer of pulmonary arterioles, thickening of pulmonary interstitium and infiltration of neutrophils. ConclusionIt is safe and feasible to establish a large animal model of PDA by using autogenous jugular vein anastomosis between the ascending aorta and the main pulmonary artery. The model can be used for the development of PDA interventional occlusive devices and the pathophysiological study of congenital heart disease-related pulmonary hypertension.
ObjectiveTo research the procedure for creating an animal model of mitral regurgitation by implanting a device through the apical artificial chordae tendineae, and to assess the stability and dependability of the device. MethodsTwelve large white swines were employed in the experiments. Through a tiny hole in the apex of the heart, the artificial chordae tendineae of the mitral valve was inserted under the guidance of transcardiac ultrasonography. Before, immediately after, and one and three months after surgery, cardiac ultrasonography signs were noted. Results All models were successfully established. During the operation and the follow-up, no swines died. Immediately after surgery, the mitral valve experienced moderate regurgitation. Compared with preoperation, there was a variable increase in the amount of regurgitation and the values of heart diameters at a 3-month follow-up (P<0.05). ConclusionIn off-pump, the technique of pulling the mitral valve leaflets with chordae tendineae implanted transapically under ultrasound guidance can stably and consistently create an animal model of mitral regurgitation.
Objective To observe the growth of orthotopic transplanted tumor in nude mice after stomatin-like protein 2 (SLP-2) expression decreased, and to further study the role of SLP-2 in the development and progression of esophageal squamous cell carcinoma. Methods Using RNA interference technique, esophageal squamous cell carcinoma cell lines with specific expression of SLP-2 and stable expression of luciferase were established. The healthy female nude mice with weight ranging from 19 to 22 g were randomly divided into 3 groups (n=12), 6 mice were used to establish subcutaneous xenografts, and the other 6 mice were used to establish the orthotopic transplanted tumor model (Group 1: cell infected with SLP-2-1 plasmid; group 2: cell infected with SLP-2-2 plasmid; group 3: cell infected with SHGFP plasmid). Index of the experiment end was weight loss and poor general situation in any mouse. Before the nude mice were sacrificed, the luciferase value of the tumor was detected by using in vivo imaging technique. After the nude mice were sacrificed, the primary tumor was removed for pathology examination. Results There was no significant difference in region of interest (ROI) value between the group 1 and group 2 (P=0.943). The ROI value for both groups 1 and 2 was significantly lower than that in the group 3 (P=0.002, P=0.000). The primary tumor infiltrated into the muscularis propria of esophageal was observed in all groups. Conclusion SLP-2 is involved in the development and progression of esophageal squamous cell carcinoma, and the decrease of SLP-2 expression can inhibit the growth of esophageal squamous cell carcinoma.
Objective To explore the feasibility of establishing a rabbit model of flail chest. Methods Flail chest model was eatablished in 12 New Zealand white rabbits after anesthesia and sterile surgery. The paradoxical movement of chest wall was recorded by the biological signal acquisition system, arterial blood was collected for blood gas analysis, the vital signs were recorded by electrocardiogram (ECG) and the lung tissue was taken for the pathological analysis at the end of the experiment. The effect of flail chest on the respiratory function of experimental animals was analyzed to evaluate the feasibility of establishing flail chest model. Results All surgeries were successful without mortality. The operation time was 41.42±7.08 min. Duration of endotracheal intubation was 79.33±12.21 min. Statistical results showed that the pH, partial pressure of arterial carbon dioxide (PaCO2) and base excess (BE) increased; while partial pressure of oxygen (PaO2) and oxygen saturation (SaO2) reduced. Pathological results showed that flail chest not intervented for a long period would lead to organic lesions. Conclusion The rabbit model of flail chest is feasible, safe, repeatable, easy and simple to handle. The animal is easy to access which is the foundation to study the disease process, recovery procedure and the efficacy after intervention.
ObjectiveTo explore the feasibility of goat tricuspid regurgitation (TR) model by one chordae tendineae cutter via right anterior-lateral minimal incision.MethodsTR model was established in 6 goats with a self-made tricuspid valve chordae tendineae cutter. The goats were placed in a left lateral position and procedure was performed via a right anterior-lateral minimal thoracotomy in the fourth intercostal. Under the guidance of transesophageal ultrasound and digital subtraction angiography, the chordae tendineae of anterior leaflet was cut until moderate to severe regurgitation was confirmed. Echocardiography and laboratory examinations were performed preoperatively, immediately and 3 months after surgery. Additionally, all goats were sacrificed to clarify pathological evaluation.ResultsTR was successfully established in 6 goats. The right atrium pressure increased significantly immediately after surgery (P<0.05). During a follow-up of 3 months, the progression of TR was aggravated (P<0.05), and the annular diameter increased from 2.15±0.23 cm to 2.65±0.20 cm. Overall, there was no statistically significant change in transvalvular gradient and velocity between preoperation and postoperation. Laboratory test results showed no abnormalities between preoperation and postoperation. Autopsy evaluation demonstrated obvioue chordae tendineae transection of the anterior leaflet.ConclusionIt is feasible to establish TR model via a right minimal anterior lateral thoracotomy in the fourth intercostal space. This novel TR goats model will allow investigation of transcatheter interventional device and serve as a chronic model in the future.