Objective To investigate the feasibility of establishing an anterior cruciate ligament (ACL) reconstruction model using hamstring tendon autograft in cynomolgus monkeys. Methods Twelve healthy adult male cynomolgus monkeys, weighing 8-13 kg, were randomly divided into two groups (n=6). In the experimental group, the ACL reconstruction model of the right lower limb was prepared by using a single bundle of hamstring tendon, and the ACL of the right lower limb was only cut off in the control group. The survival of animals in the two groups was observed after operation. Before operation and at 3, 6, and 12 months after operation, the knee range of motion, thigh circumference, and calf circumference of the two groups were measured; the anterior tibial translation D-value (ATTD) was measured by Ligs joint ligament digital body examination instrument under the loads of 13-20 N, respectively. At the same time, the experimental group underwent MRI examination to observe the graft morphology and the signal/ noise quotient (SNQ) was caculated. Results All animals survived to the end of the experiment. In the experimental group, the knee range of motion, thigh circumference, and calf circumference decreased first and then gradually increased after operation; the above indexes were significantly lower at 3 and 6 months after operation than before operation (P<0.05), and no significant difference was found between pre-operation and 12 months after operation (P>0.05). In the control group, there was no significant change in knee range of motion after operation, showing no significant difference between pre- and post-operation (P>0.05), but the thigh circumference and calf circumference gradually significantly decreased with time (P<0.05), and the difference was significant when compared with those before operation (P<0.05). At 6 and 12 months after operation, the thigh circumference and calf circumference were significantly larger in the experimental group than in the control group (P<0.05). At 3 and 6 months after operation, the knee range of motion was significantly smaller in the experimental group than in the control group (P<0.05). Under the loading condition of 13-20 N, the ATTD in the experimental group increased first and then decreased after operation; and the ATTD significantly increased at 3, 6 months after operation when compared with the value before operation (P<0.05). But there was no significant difference between the pre-operation and 12 months after operation (P>0.05). There was no significant change in ATTD in the control group at 3, 6, and 12 months after operation (P>0.05), and which were significantly higher than those before operation (P<0.05). At each time point after operation, the ATTD was significantly smaller in the experimental group than in the control group under the same load (P<0.05). The MRI examination of the experimental group showed that the ACL boundary gradually became clear after reconstruction and was covered by the synovial membrane. The SNQ at each time point after operation was significantly higher than that before operation, but gradually decreased with time, and the differences between time points were significant (P<0.05). Conclusion The ACL reconstruction model in cynomolgus monkey with autogenous hamstring tendon transplantation was successfully established.
ObjectiveTo introduce a new bone defect model based on the anatomical measurement of radius and ulna in rabbits for offering a standard model for further tissue engineering research. MethodsFifteen healthy 4-month-old New Zealand rabbits were selected for anatomic measurement and radiological measurement of the radius and ulna. Another 30 healthy 4-month-old New Zealand rabbits were randomly divided into groups A, B, and C (n=10). The radius bone defect was created bilaterally in 3 groups. In group A, the periosteum and interosseous membranes were fully removed with jig-saw by approach between extensor carpi radialis muscle and musculus extensor digitorum. The periosteum and interosseous membranes were fully removed in group B, and only periosteum was removed in group C with electric-saw by approach between extensor carpi radialis muscle and flexor digitorum profundus based on anatomical analysis results of ulnar and radial measurement. The gross observation, X-ray, micro-CT three-dimensional reconstruction, bone mineral density (BMD), and bone mineral content (BMC) were observed and recorded at immediate and 15 weeks after operation. HE staining and Masson staining were performed to observe bone formation in the defect areas. ResultsBlood vessel injury (1 rabbit), tendon injury (2 rabbits), postoperative hematoma (1 rabbit), and infection (1 rabbit) occurred in group A, postoperative infection (1 rabbit) in group C, and no postoperative complications in group B; the complication rate of group A (50%) was significantly higher than that of groups B (0%) and C (10%) (P<0.05). The radiological examination showed bone defects were fully repaired in groups A and B at 15 weeks, but bridging callus formation was observed in group C. There was no significant difference in BMC and BMD among 3 groups (P>0.05). HE staining and Masson staining results showed bone formation in group A, with structure disturbance and sclerosis. New bone formed in groups B and C, cartilage cells were observed in the center of bone cells. ConclusionThe radius bone defect model established by approach between extensor carpi radialis muscle and flexor digitorum profundus is an ideal model because of better exposures, less intra-operative blood loss, less complications. Interosseous membranes play a role in bone tissue repair process, and the mechanism needs further study.
ObjectiveTo improve and assess the method of establishing myocardial infarction model in New Zealand rabbits. MethodsA total of 60 New Zealand rabbits were randomly divided into two groups:the left anterior descending coronary artery was ligated in a LAD group (n=30); the left circumflex coronary artery was ligated in a LC group (n=30). Electrocardiogram (ECG), ultrasound cardiogram (UCG), hemodynamics and histology procedures were performed to detect the changes of cardiac structure and function after myocardial infarction induced by LAD and LC ligation. ResultsSuccess rate of the LC group was significantly higher than that in the LAD group (P < 0.01), but the survival rate in the LC group was slightly lower than the LAD group (P < 0.05); ECG within 24 h and 1 week after surgery showed that the average values of ST segment elevation in the LC group were significantly higher than that in the LAD group (P < 0.05); UCG and hemodynamics results showed cardiac function in the LAD group did not decrease significantly (P > 0.05). In contrast, cardiac function in the LC group were significantly decreased (P < 0.05). Histopathologic analysis showed that the area of myocardial infarction in the LC group was significantly larger than that in the LAD group (P < 0.01). ConclusionThe myocardial infarction induced by the left circumflex coronary artery ligation is more consistent than that induced by the left anterior descending coronary artery ligation, suggesting that the former is a more appropriate experimental model for evaluations.
Objective To probe the effects of lumbricus on wound healing after hemorroidectomy.Methods After the solution made from artificial grown lumbricus was sprung to the wound of animal and patient after hemorroidectomy, the wound inflammation, wound healing and changes of laboratory determinations were observed and compared to those of the control group. Results In animal study, lumbricus could inhibit the growth of staphylococci, bacillus coli and bacillus aeruginosus. The time of wound healing in experimental group was 4 days shorter than that in control group. At 4d and 7 day the numbers of the capillary, blood vessel endodermis and desmohemoblast desmocyte and splitting epithelium of trial group were much more than those of control group. At 4d the trial group′s numbers of splitting mesenchymal cell were much more than that of control group. From 3d on the wound healing and granulation filling of experimental group were much quicker than those of control group. In clinical study, the time of wound healing of trial group ( a mean of 16.5 days) was shorter than that of control group (21.2 days). From 3d on, the epidermis′ growth speed of the trial patients was much quicker than that of control group and was without wound infection and granulation overproliferation. Conclusion Lumbricus can inhibit wound inflammation response and accelerate wound healing. Lumbricus is inexpensive and easily preserved, and could be used on the wound after hemorroidectomy to accelerate wound healing.
Objective To refine the technique of portal inflow occlusion and parenchymal transection for laparoscopic hepatectomy in the porcine model. Methods Ten pigs were used. The portal inflow complete or selective occlusion was carried out with portal triad clamping or dissection and division of the left portal pedicle. The sequential laparoscopic local hepatectomy, left lateral lobectomy, and left medial lobectomy were performed without portal inflow occlusion. Parenchymal transection was performed with harmonic scalpel, LigaSure, microwave dissector, bipolar electrocautery, surgical clips, and endoscopic stapler. The efficacy and safety of different techniques in laparoscopic parenchymal transection of the liver were compared. Results The ischemic liver was darken with complete or selective portal triad clamping. The ischemic demarcation line between left and right lobe was obvious with the dissection and division of the left portal pedicle. There was an applicable scope of each hepatic parenchymal transection apparatus. The optimal combination of different techniques could increase efficacy and reduce hemorrhage in laparoscopic parenchymal transection of the liver. Conclusion Technical refinements of portal inflow occlusion and parenchymal transection in porcine models could provide evidences to clinical appliance of laparoscopic anatomic major hepatectomy.
Objective To investigate the effect of the traditional Chinese medicine “Tetrandrine”(TET) and its significance on epidermal growth factor(EGF) and its receptor(EGFR) in the lung of nitrofen-induced congenital diaphragmatic hernia(CDH) rat model. Methods Twenty female rats were given maternal administration of a single oral dose (115 mg/rat) of nitrofen to induce CDH at 9.5 days after pregnancy and were dividedinto normal solution group(NS, n=5), dexamethasone group (Dex, n=5),tetrandrine group (TET, n=5) and Dex+TET group(n=5) at 18.5 days; 4 rats were given edible oil as controls. All fetuses were delivered by cesarean section at 21.5 days. Lung histologic evaluations and EGF, EGFR immunohistochemical staining and image analysis were performed. Results CDH was observed in 64 of the 137 rat fetuses (46.7%) in the experimental groups; no CHD was observed in 36 rat fetuses of control group. The lungs of CDH fetuses showed marked hypoplasia in NS group, in contrast to improved mesenchymal differentiationin that of Dex, TET, Dex+TET groups. The expression of EGF was weaker and weaker and that of EGFR was ber and ber as following order: NS, TET, DEX, T+D and control groups; showing significant differences between them (Plt;0.05). Conclusion Prenatal TET administration shows marked improvement in pulmonary hypoplasia through preregulating crest-time of EGF expression and upregulating EGFR expression in the lungs of nitrofen-induced CDH rat model. A combination of TET and Dex would generate evident synergistic effect.
ObjectiveTo provide the reliable model in the rat for the study of liver transplantation.MethodsA surgical experience with one hundred and fifty orthotopic liver transplants in rats was reviewed,meanwhile a simple method with biliary extradrainage as well as bile collection was introduced.Results The operative successful rate was 93.8%（91/97）,the survival rate after one week was 85.9%(55/64),the recipient underwent an anhepatic period of 19 min,the operative time of donor and recipient were 37 min and 56 min,respectively.ConclusionThe result indicates that the model is reliable in the study of liver transplantation.The hard work and meticulous surgical performance are the key to successful operation.
In order to investigater the effect of nutritional support on nutrients metabolism after liver resection,we researched into the hepatectomy and total parenteral nutrition model in rats.The features of the model were no fasting before surgery,10% glucose subcutaneous injection prior to operation avoiding of blood loss and shortening of the surgical process.The 7-day mortality was markedly decreased.Anesthetized with phenobarbital(25mg/kg) injection in combination of ether inhalation,the rats recovered quickly from anesthesia and developed almost no infection of the respiratory tract after hepatectomy.The rats were supplied parenterally energy of 573kJ/kg and a marked improvement in survival was achieved after liver resection.By applying dual preventive rotation equipment of protective spring and IN-Stopper,nutrient solution could be safely infused.
Ojective To establish a rat model of hyperoxia induced acute lung injury. Methods Eighty healthy male SD rats were randomly divided into an air group and a hyperoxia group ( ≥95% O2 ) .Each group was further divided into 12 h, 24 h, 36 h, 48 h, 60 h subgroups. Arterial blood gas was monitored. Lung tissue was sampled for evaluation of lung wet to dry ratio, lung index, and pulmonary permeation index. Bronchoalveolar lavage fluid ( BALF) was collected for measurement of lactatedehydrogenase ( LDH) activity and white blood cell count ( WBC) . Results After hyperoxia exposure for 48 ～60 h, lung pathology showed alveolar structure disruption, lung parenchyma wrath bleeding and edema.Lung wet to dry ratio, lung index, pulmonary permeation index, LDH and WBC in BALF all increased significantly, peaked at 48 h and remained at high level at 60 h while PaO2 dropped progressively.Conclusion Exposure to ≥ 95% O2 for 48 ～60 h can successfully establish the rat model of hyperoxia induced acute lung injury.
Objective To compare the effect of different defect diameters on healing in the middle 1/3 tibia monolayer cortical bone defect mouse model so as to establish an animal model for bone tissue engineering study, mechanism study on bone defect repair, and gene therapy research. Methods Ten 8-week-old C57BL/6J mice, weighing (20 ± 2) g, were randomly divided into 2 groups, 5 mice in each group. The middle 1/3 tibiae monolayer cortical bone defect model of 0.8 mm (group A) or 1.0 mm (group B) in diameter was established with burr drill. At 7, 21, and 28 days after modeling, the molybdenum target X-ray radiography was used to observe the defect repair; at 28 days, Micro CT and three-dimensional imaging were used to evaluate bone defect repair, and tibia specimens were harvested for HE staining. Results At 7 days after modeling, tibia fracture occurred in 5 mice in group B, no fracture in group A. X-ray films, Micro CT scan, and HE staining showed bony union in group A at 28 days. The quantitative analysis of trabecular bone by Micro CT showed that trabecular number, connectivity density, and bone volume in group A were significantly greater than those in group B (P lt; 0.05), mean of segmented region—mean 2 was significantly less than that in group B (P lt; 0.05), but no significant difference was found in trabecular separation and trabecular thickness between 2 groups (P gt; 0.05). Conclusion The middle 1/3 tibia monolayer cortical bone defect mouse model of 0.8 mm in diameter is the ideal animal model for study repair mechanism of tibia defect or bone tissue engineering.