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.
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.
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.
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.
Objective To summarize the research progress on rodent models of cervical spinal cord injury (SCI). Methods The relevant domestic and foreign literature in recent years was reviewed, the methods of establishing the rodent models of cervical SCI and the evaluation methods of behavior, imaging, neuroelectrophysiology, and histology were summarized. Results Cervical SCI involves primary and secondary injuries. Primary cervical SCI can be simulated with contusion, contusion compression, fracture dislocation, spinal cord traction, and spinal cord transection; scondary cervical SCI can be simulated with photochemical model and excitotoxicity model. Certain evaluation methods such as behavior, imaging, neuroelectrophysiology, and histology are used to evaluation during model building and research. Conclusion Different rodent models of cervical SCI have different advantages and application directions, and it is critical importance for the study of cervical SCI to establish effective animal models.
ObjectiveTo investigate the appropriate concentration of methicillin-resistant Staphylococcus aureus (MRSA) in establishing chronic femoral osteomyelitis model in rabbits.MethodsForty-eight adult New Zealand white rabbits were randomly divided into 6 groups with 8 rabbits in each group. Animals in groups B, C, D, E, and F were injected 1×109, 1×108, 1×107, 1×106, 1×105 CFU/mL MRSA on the location of 2 cm of the femoral supracondyle, respectively, and group A was injected with aseptic saline as a control. The general observation were performed at 4 weeks after operation, and the wound secretions were taken for bacteriological examination. The serum C-reactive protein content was detected at preoperation and 2 weeks and 4 weeks after operation. The X-ray, CT scan, and Norden imaging scoring were performed at 4 weeks after operation. At 4 weeks after operation, the animals were sacrificed, and the specimens were observed and evaluated by general scores; and the HE staining and histological score were also performed.ResultsFive rabbits died of severe infection in group B, 2 died in group C, and no rabbit died in groups D, E, and F. General observation showed that the incision healed without soft tissue swelling in group A; most animals had visible incision swelling and sinus formation, femoral thickening, bone destruction, and damage decreased with the decreasing of the concentration of liquid bacterial in groups B-D; the infection signs were seen in groups E and F, and the degree of infection were less than that of group D. Bacteriological examination showed that fistula formation animal in groups B, C, D, and E were cultured with positive results, and with the decrease of concentration, the number of animal fistula formation decreased gradually; and bacteriological culture did not be performed in group F because of no sinus formation. There was no significant difference in the content of C-reactive protein between groups before operation (P>0.05). The contents of C-reactive protein in groups B-F were significantly higher than those in group A at 2 and 4 weeks after operation (P<0.05). At 4 weeks after operation, the content of C-reactive protein was in the order of groups B, C, D, E, F, and A in turn from high to low, showing significant differences between groups (P<0.05). Imaging examination showed that there was no soft tissue swelling and bone destruction in group A; bone destruction, massive sequestrum formation, and soft tissue swelling were found in groups B and C; bone destruction was observed in groups D and E, and the degree of sequestrum formation was not as good as that in group C; and there was a small amount of bone infection in group F. The Norden scores in groups B-F were significantly higher than that in group A, and in groups B and C than those in groups D, E, and F, and in groups D and E than that in group F (P<0.05); there was no significant difference between groups B and C, and between groups D and E (P>0.05). The specimens general observation scores in groups B-F were significantly higher than that in group A, while in groups B and C than those in groups D, E, and F (P<0.05); there was no significant difference between groups D, E, and F (P>0.05). HE staining showed that the structure of bone trabecula in group A was clear and the structure was arranged neatly; in groups B-F, trabecular bone destruction and inflammatory cell infiltration were seen and the degree gradually decreased. The histological scores in groups B-F were significantly higher than that in group A, and in group B than those in groups C-F, in groups C and D than that in group F (P<0.05); there was no significant difference between groups C, D, and E, and between groups E and F (P>0.05).ConclusionThe optimal MRSA concentration of rabbit model of chronic osteomyelitis of femur is between 1×106 and 1×107 CFU/mL.
Objective To study the mid-facial development characteristics of the goats with cleft palate after in-utero surgical repair at different stages. Methods Twenty-four Boer hybrid female goats were selected, aged from 8 to 12 months and weighing from 35 to 55 kg. The mating day was designated for 0 day. At 30 days, pregnant was confirmed by B-ultrasound test, and the goats were divided into 5 groups (experimental groups 1, 2, 3, 4, and normal control group). Twenty pregnant goats of 4 experimental groups (n=5) were injected DL-anabasine (15 mg/day) from 31 to 42 days to establish cleft palate model of fetal lamb, 4 pregnant goats of normal control group used as controls without injection. At pregnant 65, 90, and 120 days, cleft palate was repaired in the uterus in experimental groups 1, 2, and 3, while cleft palate was not repaired in experimental group 4. After 1 month of birth, the maxillary bone width (posterior premolar morphological measurement, PPMM) and the maxillary bone length (anterior premolar morphological measurement, APMM) were measured with CT scanning. The dry skull of goats were harvested for gross observation. Results There was no significant difference in PPMM and APMM between experimental group 1 and the normal control group (P gt; 0.05), but there were significant differences between experimental groups 1 and 4 (P lt; 0.05) at 1 month after birth. Significant differences were oberved in PPMM and APMM between experimental group 2 and normal control group, experimental group 4 (P lt; 0.05). There were significant differences in PPMM between experimental group 3 and normal control group, experimental group 4 (P lt; 0.05), in APMM between experimental group 3 and normal control group (P lt; 0.05). Five goats with cleft palate in experimental group 4 died at 1-2 months after birth. Conclusion At pregnant 65 days, in-utero surgical repair of cleft palate has less influences on mid-facial development. The earlier repair is performed, the higher risk of miscarriage was.
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.
Objective To study value of severe acute pancreatitis (SAP) rat model induced by retrograde pancreaticobiliary duct infusion of methylene blue in combination with sodium taurocholate. Methods The SPF 90 SD rats, 45 male rats and 45 female rats of them, were randomly divided into control group (C group), sodium taurocholate group (ST group) and methylene blue in combination with sodium taurocholate group (MBST group), which were retrogradely infused with the 0.9% normal saline, sodium taurocholate plus DAPI, and methylene blue plus sodium taurocholate plus DAPI respectively into the pancreaticobiliary duct. The success rate of puncture, degree necrosis of pancreas tissue, range of pancreatic lesions, and the incidence of bile or intestinal leakage were compared among the three groups. Results ① The success rate of puncture in the MBST group was significantly higher than that in the ST group (P=0.003) and the C group (P=0.006), which had no significant difference between the ST group and the C group (P=0.782). ② The necrosis degree of pancreas tissues in the MBST group and ST group became more and more severe with the extension of time (P<0.050), which in the MBST group was more serious than that in the ST group (P<0.050). ③ The point of pancreatic lesions range in the MBST group was significantly higher than that in the ST group (P=0.003). ④ The incidence of bile or intestinal leakage in the MBST group was significantly lower than that in the C group (P=0.008) and the ST group (P=0.004). Conclusions Retrograde pancreaticobiliary duct infusion of methylene blue in combination with sodium taurocholate can improve success rate of puncture, aggravate necrosis degree of pancreatic tissue, increase lesion scope of pancreatic tissue, and reduce rate of bile or intestinal leakage, which can provide a stable animal model for basic research of SAP.
This study was to build a canine portal hypertension model by intra-portal administration of high polymer material polyurethane and organic solvent tetrahydrofuran mixed solutions in order to evaluate the effectiveness of the model. Twelve local crossbreed dogs were selected randomly, with intra-portal administration of 8% (weight/volume) polyurethane-tetrahydrofuran solutions through an incision in the upper abdomen to build the portal hypertension model. We measured the portal vein pressure before modeling, during modeling, and four-, eight-, and twelve-weeks after modeling, respectively. Then we evaluated the effectiveness of the model comparing values of data with those data obtained before modeling started, which were regarded as the normal values. The results showed that the portal vein pressure rose by 2.5 times after the solution administrated instantly as much as that before modeling, and maintained at 1.5 times after 4 weeks. This method presents an easy operation, low animal mortality and reliable model of portal hypertension. Its less abdominal adhesions and its ability in keeping normal anatomic structure specially make it suit for surgical research of portal hypertension.