ObjectiveTo establish pig abdomen bullet wound model in seawater immersion condition and to analyze injury characteristics.
MethodsTwenty Xishuangbanna pigs were randomly divided into seawater immersion group and control group,with 10 in each group.The left lower quadrant anti McBurney point of the pig semi-floating in the seawater was shot by using domestic 81-1 assault rifle at the distance of 10 meters,which were salvaged out of seawater at 60 minutes after injury in the seawater immersion group.The pigs in the control group were treated same as the seawater immersion group except seawater immersion.The mean arterial pressure (MAP),rectal temperature (RT),heart rate (HR),respiratory (R),white blood cell count (WBC),and C-reactive protein (CRP) were tested at 1 h,4 h,8 h after injury.The death of pig was observed.
ResultsThe pig abdomen bullet wound models in the seawater immersion condition were successfully established.① Compared with the control group,the MAP and RT were significantly decreased at 1 h,4 h,8 h after injury,the HR or the R was significantly decreased at 4 h or 8 h after injury respectively in the seawater immersion group.② Compared with the normal value,the WBC obviously rose at 4 h and 8 h after injury,the CRP obviously rose at 1 h,4 h,and 8 h after injury in both two groups.Compared with the control group,the WBCs were significantly increased at 4 h and 8 h after injury (P<0.05),the CRPs were significantly increased at 1 h,4 h,and 8 h after injury (P<0.05) in the seawater immersion group.③ The mortality in the seawater immersion group (50%) was significantly higher than that in the control group (20%,P<0.05).
ConclusionThe injury is more serious,the infection time is earlier,and the infection degree is aggravated,the mortality rate is higher for pig abdomen bullet wound model in seawater immersion condition.
Objective To establish the model of pancreatoduodenal allotransplantation in pigs with enteric drainage (ED) and portal venous drainage (PVD). Methods Forty-six hybrid landraces were divided into two groups (donor and recipient groups) randomly, for pancreatoduodenal allotransplantation. Donors were perfused via abdomial aorta without clamping the portal venous outflow with UW solution after heparinization. Whole pancreatoduodenal graft was arvested with segments of abdomial aorta and portal vein and shaped under cold UW solution. Then, the end-to-end nastomosis was performed with the donor iliac artery bifurcation “Y” graft to the recipient superior mesenteric arteries and celiac artery. Furthermore, type Ⅰdiabete model was made by removal of the recipient pancreas. The venous anastomosis was reconstructed between the donor portal vein and the recipient superior mesenteric vein. Meanwhile, the end-to-side anastomosis was performed with the donor common iliac artery bifurcation “Y” graft to the recipient abdomial aorta and the side-to-side intestinal anastomosis was performed between the donor duodenum and the recipient jejunum. External jugular vein was intubated for transfusion. The levels of blood glucose， insulin and glucagon in blood were measured before and during the operation and 1， 3， 5， 7 d after operation. Results Twenty-three cases of pancreatoduodenal allotranplantations were performed on pigs. One died from complication of anesthesia. Success rate of operation was 95.7％.Complications of operation happened in 2 cases in which one was phlebothrombosis, incidence 4.5％and the other was duodenojejunal anastomotic leak, incidence 4.5％. The level of blood glucose increased within 30 min and recovered on the 2nd day after removal of pancreas. The levels of insulin and glucagon decreased within 30 min and recovered on the 2nd day after removal of pancreas. Rejection curred at the 1st day and reached the worst level on the 9th day after transplantation without the change of insulin and glucagon in blood and clinical symptoms of rejection. Conclusion Pancreatoduodenal transplantation in pigs can treat type Ⅰ diabete. ED and PVD can keep the function of endocrine in normal. The technique of duodenal transplantation with ED and PVD may pave the way for the further development of pancreas transplantation in clinic.
ObjectiveTo observe the pathological changes in heart and lung tissues in rats with pulmonary hypertension induced by monocrotaline.
MethodsTwenty-four male Sprague-Dawley rats were randomly and equally divided into an experimental group and a control group. The rats in the experimental group were intraperitoneally injected with monocrotaline to induce pulmonary hypertension, and the rats in the control group were treated with saline. All rats were fed for 3 weeks, and the general situation were observed. Then the rats were sacrificed for measurement of mean pulmonary artery pressure (mPAP), right ventricular hypertrophy index [RV/(LV+S)], changes of myocardial cells and lung vascular, calculated density of middle membrane smooth muscle cells (SMC) in medium/small pulmonary arteries accompanied with bronchi and alveoli, media thickness of pulmonary artery (PAMT), the percentage of wall thickness with outer diameter (WT%), the percentage of wall area with total area (WA%), the average diameter of myocardial cells (AD), and myocardial nuclei density (MND).
ResultsCompared with the control group, the condition of rats in the experimental group were getting worse obviously.mPAP and RV/(LV+S) were both increased (both P < 0.05). The observation by light microscope revealed that obvious myocardial hypertrophy and structure disturbances, severe luminal stenosis of medium/small pulmonary arteries, medial thickening, infiltration of inflammatory cell in tissue space, proliferation of unorganized collagen fibers in the experimental group. The observation by electronic microscope showed proliferation of endothelial cell with irregular nuclei, increased organelles and vacuoles in the experimental group. The differences in SMC, PAMT, WT%, WA%, AD, and MND were significant between two groups (all P < 0.05).
ConclusionsThe monocrotaline can induced pulmonary hypertension and right ventricular hypertrophy. The mechanism may be related to severe stenosis or occlusion of the vessel lumen caused by plexiform proliferation of endothelial cells, proliferation of smooth muscle cells and collagen fibers, compensatory hypertrophy and hyperplasia of myocardial cells.
ObjectiveTo establish a stable laboratory model of temporary hypoparathyroidism following thyroid operation in rabbits.
MethodsTwenty New Zealand white rabbits were randomized into 2 groups (the four parathyroid glands injured group and the two inferior parathyroid glands injured group, n=10 for each group). In the two inferior parathyroid glands injured group, blood supply vessels of the two inferior parathyroid glands were injured with ligation. In the four parathyroid glands injured group, total thyroidectomy (including two superior parathyroid glands) were performed and blood supply vessels of the two inferior parathyroid glands were injured with ligation. The number of the identified parathyroid glands were counted during operation. Serum calcium and parathyroid hormone (PTH) were evaluated preoperatively and postoperatively on 1 d, 2 d, 3 d, 5 d and in 1 week, 2 weeks, 3 weeks, and 4 weeks. Model achievement rate were calculated.
ResultsFour parathyroid glands were identified in rabbits. The two superior parathyroid glands were in thyroid tissue which were identified with histology, and the two inferior parathyroid glands located in the fascia plane between the sternohyoid, sternothyroid muscles and the carotid artery which can easily be identified with naked eye. There were no significant difference in preoperative calcium and PTH between the two groups (P > 0.05). In the two inferior parathyroid glands injured group, significantly decreased in serum calcium were observed on 1 d, 2 d and 3 d after operation (P < 0.05). In the four parathyroid glands injured group, significantly decreased in blood calcium were observed on 1 d, 2 d, 3 d and 5 d after operation (P < 0.05). The lowest level of serum calcium was observed on 1 d in two groups. Postoperative serum PTH were significantly declined in two groups on 1 d, 2 d, 3 d, 5 d, and in 1 week, 2 weeks and 3 weeks (P < 0.05). The lowest serum PTH was also observed on 1 d in two groups. Significantly lower serum PTH were found in the four parathyroid glands injured group on 1 d, 2 d and 3 d than in the two inferior parathyroid glands injured group (P < 0.05). Lower PTH level were found in the four parathyroid glands injured group on 5 d, and in 1 week, 2 weeks, 3 weeks and 4 weeks, but no significance (P > 0.05). Positive correlation between serum calcium and PTH were noticed (r=0.771, P=0.000). Model achievement rate were higher on 3 d and 5 d in the four parathyroid glands injured group than that of the two inferior parathyroid glands injured group (P < 0.05).
ConclusionsStable animal model of temporary hypoparathyroidism following thyroidectomy can be established by total-thyroidectomy plus ligation the blood vessels of the two inferior parathyroid glands. This model can be used for further study.
Objective To study the effects of malondialdehyde (MDA), superoxide dismutase (SOD) and tumor necrosis factor-α (TNF-α) on brain tissue in rats with pancreatic encephalopathy (PE). Methods Thirty-six Wistar rats were randomly divided into control group (n=6) and PE model group (n=30). In control group, rats were injected with normal saline by internal carotid artery (0.1 ml/100 g) and were killed on the first day after the injection. In PE model group, rats were injected with phospholipases A2 (0.1 ml/100 g, 1 000 U/0.1 ml) by internal carotid artery, to establish animal model of PE in rat and 10 rats were killed on day 1, 3, 7 respectively after the injection. The changes of water content in the brain were measured. Leucocytes aggregation and margination in the microvessels, and the changes of cerebral cells and nerve fibers were observed. The levels of MDA, TNF-α and the activity of SOD were tested in the brain homogenate in rats. Results In PE model group, water contents of brain increased; The phenomena of leucocytes accumulation and margination, cellular edema of neurons and demyelination of nerve fibers became more obvious; The levels of MDA and TNF-α increased significantly than those in the control group, while the activity of SOD reduced (P＜0．05， P＜0.01)． Conclusion Inthe rat model of PE, MDA, SOD, and TNF-α play important roles on the occurrence and development of brain injury.
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 investigate the transporting function of subretinal fluid in retinal pigment epithelium(RPE) of experimental retinal detachment (RD).
METHODS: Twenty-seven pigmented rabbits with one eye as retinal detachment model and the other eye as control were divided into 4 groups ,ic. 7 rabbits in each group at random. The Na十-K+-ATPase activity in RPE-choroidal tissue at the detached region in both experimental and control eyes was determined at the lst,2nd,3rd and 4th week after retinal detachment,and also the ultrastructure of the RPE-choroidal tissues observed. RESULTS:The
activity of Na十-K+-ATPase of experimental eyesE[(2.16士1.26)/mu;mol(mgmiddot;h)]was significantly lower than that of the controis[(4.84plusmn;1.59)mu;mol/(mgmiddot;h)]. The degree of decreasing activity was relieving along with increasing of the course of RD. The inward pinocytosis in RPE cells under electron-microscope was found from the 2nd week samples afterwards and becoming obvious along with increasing of the disease course.
CONCLUSIONS:The outward transporting function of RPE was increased after RD,it became decreased along with increasing of the course df RD and the inward transporting function then developed.
Objective To review the research advances in animal models of human disc degeneration. Methods The relative articles in recent years were extensively reviewed. Studies both at home and abroad were analyzed and classified. The advantages and disadvantages of each method were compared. Results Studies were classified as either experimentally induced models or spontaneous models. The induced models were subdivided as mechanical (alteration of forces on the normal disc), structural (injury or chemical alteration) and genetically induced models. Spontaneous models included those animals that naturally developed degenerative disc disease. Conclusion Animal model of intervertebral disc degeneration is an important path for revealing the pathogenesis of human disc degeneration, and play an important role in testing novel interventions. With recent advances in the relevance of animal models and humans, it has a great prospect in study of human disc degeneration.
Objective To establish a rabbit model of ventilator-induced lung injury. Methods Fourty healthy New Zealand rabbits were randomly divided into 3 groups: ie. a routine 8 mL/kg tidal volume group( VT8 group) , 25 mL/kg large tidal volume group( VT25 group) , and 40 mL/kg large tidal volume group( VT40 group) . VT25 and VT40 group were further divided into 2 hours and 4 hours ventilation subgroups. Arterial blood gas, lung mechanical force and hemodynamic parameters were monitored. Lungtissue was sampled for evaluate lung wet/dry ratio and lung injury by HE stain. Bronchoalveolar lavage fluid ( BALF) was collected for measurement of protein concentration, total and differential cell counts. Results Compared with VT8 group, lung injury score in both VT40 and VT25 groups were elevated significantly, ofwhich 4 hour VT40 subgroup was the highest. Lung pathology examination of VT40 group revealed apparent alveolar deformation, interstitial and alveolar space exudation, inflammatory cells infiltration, pulmonary consolidation and alveolar hemorrhage. Lung pathology examination of VT25 group showed pulmonary intervalthickening, inflammatory cells infiltration, while alveolar intravasation was mild. Blood gas analysis showed that PaO2 /FiO2 was deteriorated with time in VT25 and VT40 groups, and PaO2 /FiO2 at the 3 hours in VT40 group( lt; 300 mm Hg) had met the acute lung injury standard, while which in VVT25 group was above 300 mmHg. Lung wet/dry ratio, BALF protein concentration, total nucleated cell and neutrophilic leukocyte were elevated in both VT25 and VT40 groups, of which 4 hours VT40 group was the highest. Conclusion Using 4 hours ventilation at a tidal volume of 40 mL/kg can successfully establish the rabbit model of ventilator-induced lung injury.
Objective To investigate the rat model of cardiac allograft vasculopathy after heart transplantation in rat abdominal cavity. Methods Forty Wistar rats and 40SDrats were divided into control group and experiment group randomly pair-matching. Rat model ofheterotopic heart transplantation was developed. Low doseCyclosporine A were injected into the abdominal cavity in experiment group, while the control group had not received the Cyclosporine A. Transplant hearts were harvested at two weeks and four weeks post-operatively and changes of coronary artery were observed by light microscope. Results There were no alteration of tunica intima of coronary artery in control group at two weeks and four weeks post-transplantation. Tunica intima of coronary artery increased in thickness at two weeks post-transplantation in experiment group and concentric circular change occurred at four weeks post-transplantation. Lumen of coronary artery constricted transparent and cardiac allograft vasculopathy occurred. Conclusion This animal model is reliable of cardiac allograft vasculopathy.
