ObjectiveTo understand the initiation, maturing, and resolution of thrombus by comparing the length and weight of thrombus at different time in the rat inferior vena cava (IVC) stenosis model. MethodsForty-eight female Sprague Dawley rats, weighing 180-230 g, were selected to prepare the IVC stenosis model by blocking the most of the IVC blood flow. The length and weight of IVC thrombus were measured at different time points, the histological features were observed via HE staining. ResultsBlood clots formed after 2 hours of modeling, the thrombus length and weight showed no significant difference between at 2 hours and 4 hours after modeling (P>0.05). The thrombus length and weight increased significantly at 6 hours, showing significant differences between at 2 and 4 hours and at 6, 8, 12, 24, and 48 hours (P<0.05); and from 6 to 48 hours, there was no significant difference in the thrombus length and weight (P>0.05), indicating that thrombus was stable, or maturing. Blood clots began to become smaller after 3 days when compared with ones at 48 hours (P<0.05), indicating the start of resolution at 3 days. At 7 days, the thrombus length and weight became further smaller when compared with ones at 3 days (P<0.05). The thrombus completely subsided at 21 days, the IVC recanalized. HE staining showed that thrombus formed after 2 hours of modeling; from 6 to 48 hours, the lumen became hyperemia, and the inflammatory cells, especially neutrophils, could be found. The organization of thrombus could be observed at 3 days and 7 days; thrombus gradually vanished at 21 days. ConclusionThe time of thrombus initiation, maturing stage, and resolution stage is 6 hours, 6 to 48 hours, and 3 to 21 days after modeling, respectively.
Abstract: Objective To study the pathophysiological mechanism of the morphological change of immature pulmonary vessels in the piglet model of congenital heart defect with decreased pulmonary blood flow established with balloon atrial septostomy and pulmonary artery banding. Methods Twenty piglets at an age of one to two months were divided into three groups with random number table. For the control group (group C,n=6), small incisions were carried out on the right chest to produce a transient reduction in the pulmonary blood; for the lowmedium pulmonary artery stenosis group (group T1, n=7), the balloon dilator was delivered through the surface of the right atrium and septostomy and pulmonary artery banding were performed, and the systolic transpulmonary artery banding pressure (Trans-PABP) was controlled to be 20.30 mm Hg; For the severe pulmonary artery stenosis group (group T2, n=7), the same surgical procedures with group T1 were performed while TransPABP was controlled to be more [CM(159mm]than 3050 mm Hg.At 2 months after surgery respectively,a lung tissue of 1.0 cm×0.8 cm×0.8 cm from the lateral segment of the right middle lobe was taken out to be observed under optic microscope. The morphological change of the distal arterioles was detected. Furthermore, the content of vascular endothelial growth factor (VEGF) and matrix metalloproteinase2( MMP2) were also examined by the method of enzymelinked immunosorbent assay (ELISA). Results The model was successfully established in all the survival piglets of the group T1 and group T2. Two months after operation, the inner diameter of the pulmonary arterioles in group T1 was significantly higher than that in group C (82.89±10.72 μm vs.74.12±9.28 μm;t=－5.892, Plt;0.05), so as group T2 (85.47±5.25 μm vs.74.12±9.28 μm;t=-6.325, Plt;0.05); the number of arterioles per square centimeter (NAPSC) of group T1 was significantly lower than that of the group C (229.70±88.00 entries/cm 2 vs. 431.50±40.60 entries/cm2; t=39.526, Plt;0.05), so as group T2 (210.00±40.30 entries/cm2 vs. 431.50±40.60 entries/cm2; t=67.858, Plt;0.05). Two months after operation, the lung expression of MMP -2 and VEGF in group T1 was significantly lower than that in group C (58.30±19.60 ng/ml vs. 81.20±16.70 ng/ml, t=14.261, Plt;0.05; 17.80±3.00 pg/ml vs. 21.40±3.80 pg/ml, t=8.482, P＜0.05), so does group T2 (42.10±15.20 ng/ml vs. 81.20±16.70 ng/ml, t=27.318, P＜0.05; 12.30±3.20 pg/ml vs. 21.40±3.80 pg/ml, t=15.139, P＜0.05). Conclusion Structural remodeling of pulmonary extracellular matrix is an important feature of the piglet model of congenital heart defect with decreased pulmonary blood flow. The arterioles show significant hypoplasia or degradation. Change in the structural proteins and cytokines during the reduction of blood in the lung is the key to structural remodeling.
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.
Objective To provide a reliable experimental model for gastroesophageal reflux (GER) study. Methods Twenty Japan 5-month-old male rabbits wererandomly divided into two groups: group cardiomyotomy(n=10), group partial cardiomyectomy(n=10). The operations of cardiomyotomy and parital cardiomyectomy were performed in 2 groups respectively. All the animals underwent intraesophagealpH detection 1 week before operation and 4 weeks after operation. The mean changes of reflux ratios were compared between before operation and after operation.Results In gastroesophageal reflux ratio between before operation and after operation, there was no significant difference in group cardiomyotomy (1.98%±1.52% and 4.32%±2.39%, Pgt;0.05) and there was significant difference in group partialcardiomyectomy（1.56%±1.57% and 13.56%±3.27%, Plt;0.05）. Conclusion The reliable experimental model of GER can be made with procedure of partial cardiomyectomy. It can be used in estimating the operative procedure of antireflux and is conducive to dynamic observation and study of esophagitis.
Objective To study the method to prepare the animal model of goat cleft palate by injection of anabasine and the effect of the malformation on the development of the facial mid-part. Methods A total of 40 female boer hybrid goats were selected, aging 8-12 months and weighing 35-55 kg. The mating day was 0 day, and at 30 days the goats assured pregnant byB type ultrasonic test were divided into 4 groups (n=10) according to intramuscular injection of 10 (experimental group 1), 15 (experimental group 2), 20 (experimental group 3) mg/ d, and no injection (control group), respectively, from the 31st to 42nd day. At pregnant 120 days and 1 month after birth, 5 fetal goats of each group were used for three dimensional reconstruction ofskull with CT scan. The maxillary bone width named as PPMM and the maxillary bone length named as APMM were measured then the hard palate general observation was performed and dry skull of goats was harvested to observe the development of maxillary. Results After injection, all pregnant lambs aborted in experimental group 3; 2 pregnant lambs aborted and 8lambs maintained pregnancy in experimental group 2. At 120 days of pregnant, no cleft palate was observed in 5 fetal lambs of experimental group 1 and control group, respectively; cleft palate and maxillary dysplasia occurred in 3 fetal lambs of experimental group 2. Among 11 newborn lambs of experimental group 1 and 8 newborn lambs of control group, no cleft palate was observed;among 7 newborn lambs of experimental group 2, cleft palate occurred in 5 with obvious maxillary dysplasia and eating difficultly. General observation of hard palate and dry skull showed obvious hypoplasia of maxillary in experimental group 2. There were significant differences in PPMM and APMM between the experimental group 2 and the control group at pregnant 120 days and 1 month after birth (P lt; 0.05). Five lambs with cleft palates of experimental group 2 survived for 1-2 months. Conclusion The animal models of goat cleft palate can established by intramuscular injection of anabasine at a dose of 15 mg/d from the 31st to 42nd day of pregnant. The facial character of the induced cleft palate goat is similar to that of human cleft palate.
Objective To introduce the research progress in the immune of composite tissue allotransplantation. Methods The related articles were reviewed to summarize the immune characteristics, experimental developments, and cl inical experiences of composite tissue allotransplantation. Results Composite allogeneic tissue is on the body surface, including the composition of the complex with high antigenicity. There are a lot of differences in the immune responsesbetween composite tissue allotransplantation and organ transplantation, such as immunosuppressant protocol, rejectiondiagnosis, and chronic rejection. Conclusion In the next study, it is urgently needed to learn these experiences and toestabl ish the special standard of composite tissue allotransplantation in induction of immune tolerance, local medication, and rejection diagnosis.
Objective To build animal models of keloid by method of tissue engineering and to discuss the feasibility of using it in clinical and lab researches. Methods Fibroblasts(FB) were isolated from keloids and cultured. The seventh and eighth generation of the cultured FBs were inoculated into the copolymers of polylactic acid and polyglycolic PLGA. After being cultured in rotatory cell culture system （RCCS）for 1 week,the FB was transplanted into athymic mice. The specimens were obtained 4 weeks and 8 weeks and examined histologically. Results All mice survived.The collagen patterns of all keloids were pressed in every specimen obtained 8 weeks. Fibrocytes andFB were observed in specimens by electronic microscope. There were abundent rough endoplasmic reticulum (RER) in FB， which indicated that FB’s capability of synthesizing and secreting collagen was preserved and the cellular characteristicwas remained. Conclusion There is a good affinity between PLGAand FB. The composition of PLGA and FB can form keloids in athymic mice,so that it deserves further researching and developing.
ObjectiveTo explore the construction of heart preservation model of empty beating donor based on extracorporeal membrane oxygenation (ECMO). MethodsFrom January 2022 to August 2023, 20 Guangxi Bama miniature pigs weighing 25-30 kg were selected, half male and half female. Under general anesthesia and heparinization, a midline thoracotomy was performed. The pericardium was cut after freeing the anterior and posterior vena cavae, and a perfusion needle was inserted near the brachiocephalic artery in the ascending aorta, connected to a blood collection bag to collect 500-600 mL of blood. The anterior and posterior vena cavae were ligated, the aorta was blocked and perfused with HTK solution to stop the heart beating. The superior and inferior vena cavae were cut off, the right pulmonary vein was decompressed, the aorta and left and right pulmonary arteries and veins were cut off, and the whole heart was removed. An ECMO device was used to continuously perfuse a cardioprotective solution mainly composed of oxygenated warm blood, maintaining the isolated pig heart beating for 8 hours, monitoring (once/hour) ECMO perfusion parameters, blood gas indicators, perfusate electrolytes, detecting inflammatory factors, myocardial enzymes, myoglobin, and troponin levels. Myocardial tissue was taken for hematoxylin-eosin (HE) staining to observe myocardial cell damage and evaluate the quality of heart preservation. ResultsAmong the 20 isolated beating preservation pig hearts, 17 successfully resumed beating, 3 experienced ventricular fibrillation, resuscitated after intracardiac electrical defibrillation, and all 20 pig hearts successfully beat for 8 hours. There was no statistical difference in ECMO perfusion parameters, blood gas indicators, perfusate electrolytes, and inflammatory factors at each time point (P>0.05). There were statistical increases in myocardial enzymes, myoglobin, and troponin levels (P<0.05). HE staining results suggested that there was no severe myocardial damage. ConclusionECMO technology can be used for pig heart preservation with good results, and this study provides experimental evidence for improving heart preservation research in clinical heart transplantation.
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.