RESUMO
Objective To discuss the feasibility of biodegradable covered magnesium alloys stent for a rabbit model of lateral aneurysm in the common carotid artery (CCA). Methods The left CCA was ligated in 20 conventional New Zealand rabbits. MRA of the neck was performed 1 month after ligation. The rabbits with thickening of the right CCA and non-or slight thickening of the bilateral vertebral arteries were selected for lateral aneurysm model making. The venous pouch and the right CCA wall by discontinuous extroversion sutures, to form a lateral aneurysm model. The biodegradable covered magnesium alloys stents or Willis covered stents were inserted two weeks after model making. Angiography was performed prior to the procedure, 3, 6 and 12 months after stent implantation to evaluate the disappearance of the aneurysms and patency of the right CCA. The degradation behaviour is invastagated with molybdenum target 2 weeks, 1, 2, 4, 6,9 and 12 months after stent placement. Results The left CCAs were successful ligated in all rabbits. MRA 1 month after ligation showed thickening of the right CCA and non-thickening of the bilateral vertebral arteries in 17 of 20 rabbits. In these animals, the CCA lateral aneurysm model was deemed successful, and biodegradable covered magnesium alloys stents and Willis covered stents were implanted in 9 and 8 aneurysms, respectively. DSA after biodegradable covered magnesium alloys stent placement displayed disappearance of the aneurysms and patency of the CCA in all 9 rabbits during follow-ups. DSA 3 months after Willis stent placement displayed patency of the CCA in 7 rabbits and occlusion of the artery in one. No occlusion of the right CCA was observed on angiography at 6 and 12 months. The degradation of the biodegradable covered magnesium alloys stent was investigated with molybdenum target during follow-ups, and no changes was observed in Willis covered stent. Conclusion Biodegradable covered magnesium alloys stent is a feasible approach for the treatment of a lateral aneurysm in the right CCA.
RESUMO
Objective To explore effects of shuanghuanglian combined with levofloxacin on antibiotic resistance of Staphylococcus Aureus ATCC29213 to levofloxacin. Methods Tissue cage infection model with Staphylococcus aureus was established in rabbits, and the infected animals were given with levofloxacin alone ( group A ) or in combination with shuanghuanglian ( group B) for 5 days respectively. Steady-state concentration of levofloxacin in tissue cage, bacteria recovery and bacterial resistance in tissue cage infection model were studied. Results Steady-state concentration of levofloxacin in tissue cage was not significantly different between group A and group B. The recovery rate of bacteria was significantly lower in group B than in group A (20. 0% vs. 100. 0%). The minimum inhibitory concentration (MIC) was lower in group B than in group A. Conclusion Shuanghuanglian combined with levofloxacin is helpful to reduce antibiotic resistance of Staphylococcus aureus to levofloxacin, indicating that some Chinese traditional medicine combined with antibiotics can reduce antibiotic resistance.
RESUMO
ObjectiveTo dynamically assess the regular pattern of both bone quantity and bone quality by means of MR spectroscopey and Micro-CT scanning in an osteoporosis rabbit model induced by ovariectomy and glucocorticoid, so as to explore the advantage of combining MRS with Micro-CT. MethodsSixty 8-month-old,mature female New Zealand white rabbits were allocated into three groups. Group B ( n =20 ) underwent bilateral ovariectomy (OVX)and Group C (n =20 )underwent OVX combining with daily i. m.injections of methylprednisolone sodium succinate (MPS). Group A ( n =20 ) were used as sham controls. Bone marrow fat fraction (FF) and bone microstructure parameters were detected by MR spectroscopy and Micro-CT scanning at 2,4,8, and 10 weeks ( 5 rabbits at each time point every group) after operation in three groups. ResultsLumber spine bone marrow FF in Group C was significantly increased over the time course of osteoporosis development with significant difference between Group C and Group A at 4,8,and 10 weeks after operation( all P＜0. 01 ). Bone mineral density(BMD) in Group C at 8 and 10 weeks after OVX was significantly decreased compared with Group A ( P＜0. 0l ). A moderately significant negative correlation between marrow fat content and bone microstructure parameters such as BMD, bone volume fraction, trabecular thickness, connectivity density, and trabecular plate number was found, while FF was positively correlated with structure model index and trabecular spacing( all P＜0. 01 ). ConclusionsMRS and MicroCT scanning noninvasively evaluate the bone marrow changes of osteoporosis in the field of pathophysiology and microstructure. Combination of both modalities seems to be valuable in the early, comprehensive assessment of bone quality and bone mass in osteoporosis.
RESUMO
Objective To study the possibility of establishment of an animal model of hydronephrosis by ureteropelvic junction obstruction,and to evaluate the value of CT perfusion imaging in assessment of the renal function in the animal models. Method Fifty 10-week-old male New Zealand rabbits were randomly assigned to two groups:sham-operated group with separation of the left ureter (20 rabbits),and model group (30 rabbits) with the left ureter embedded at the ureteropelvic junction under the psoas major muscle. The left kidney function in the two groups was confirmed to be normal by SPECT before operation. CT perfusion and SPECT imagings were performed to assess the left kidney function in the two groups at three months after surgery,and the results were compared with that of pathological examination. Statistical analysis was performed on the parameters of SPECT and CT perfusion imaging and glomerular filtration rate (GFR). Results The success rate of model establishment was 70%,showing pathological changes of chronic hydronephrosis. CT perfusion demonstrated that BF,BV,PS of the left renal cortex and medulla were decreased,and had a good positive correlation with the changes of GFR. Conclusions It is feasible to establish a rabbit model of chronic hydronephrosis by embedding the left ureter at ureteropelvic junction under the psoas major muscle,and CT perfusion imaging parameters can be used to evaluate the renal function in the animal models.
RESUMO
@#Objective To establish an animal model of heart failure with preserved ejection fraction(EF)resulting from hypertension.Methods35 male New-Zealand rabbits were randomly assigned to 2 groups:constriction was performed at the abdominal aorta 1 cm just above right renal artery in operated group(n=25),and the sham-operated animals were taken as control group(n=10).The clinical manifestations of heart failure were followed up carefully.Systolic and diastolic function,and systemic hemodynamics were investigated with echocardiography and left ventricle catheter.ResultsIn operated group,marked ventricular hypertrophy was observed 2 weeks after operation.4 weeks after operation,the clinical manifestations of heart failure presented,and IVRT and LVEDP increased,and-dp/dt max decreased.Tissue doppler image indicated that e/a ratio of annulus of mitral valve decreased(P<0.05).However,EF and +dp/dt max were preserved.ConclusionThe operated animals presented the clinical manifestation of heart failure,and diastolic function of left ventricle injured,however,ejection fraction was preserved,which corresponded with the character of heart failure with preserved ejection fraction resulting from hypertension.
RESUMO
@#ObjectiveTo establish a method to induce heterotopic ossification (HO) after spinal cord injury. Methods10 New Zealand White rabbits underwent a complete transection of the thoracic (T10) spinal cord. Just after transection, the right hind limb of every rabbit was immobilized with a plaster support to keep the knee in extension and the hip unrestricted. The plaster was temporarily removed once a day (six times per week) to allow the knees passively mobilized at the maximum range for 5 min. Local swelling, local skin temperature and grade of ossification of the paraplegic limbs were observed. After 5 weeks, the rabbits were sacrificed, and the quadriceps muscles of the right hind limbs were removed for the histological examination. ResultsAfter 5-week immobilization and temporary passive mobilization, HO was successfully induced in all 10 rabbits. There was local skin temperature increase and local swelling in the right hind limbs. The histological changes were similar to those observed in clinical HO. Conclusion5-week immobilization and temporary passive mobilization approach may successfully induce HO, and it may be used to study the pathogenesis of HO after spinal cord injury.
RESUMO
Objective The effect of oral L-Dopa on healing of the experimental mandibular defect of rabbits was studied.Method 52 rabbits were assigned randomly to experimental group and control group.After bone defect being made on mandible,rabbits had been given with L-Dopa in experimental group.Healing bone samples were adopted at 14,21,30,42,49 days after operation,observed x-ray and histological changes and calculated out the bone histomorphometric parameters.Results X-ray inspection indicated that bone defect of the experimental group had completed callus union from 30th day.But,a part of the defect of control group did not appear callus union radiologically.Histological examination had the same result.Bone histormorphometry examination exhibited that there was a significant difference between TBV of the experimental and the control group(P