Background:Paraplegia after spinal cord ischemia is a devastating condition in the clinic.Here,we develop an awake rabbit model of spinal cord ischemia with delayed paraplegia and explore the influence of ambient temp...Background:Paraplegia after spinal cord ischemia is a devastating condition in the clinic.Here,we develop an awake rabbit model of spinal cord ischemia with delayed paraplegia and explore the influence of ambient temperature on the outcomes after injury.Methods:A total of 47 male rabbits were involved in the present study.Transient spinal cord ischemia was induced by occluding the infrarenal abdominal aorta of awake rabbits at different ambient temperatures.To find the optimal conditions for developing delayed paraplegia,hindlimb motor function after ischemia was evaluated between experiments.Results:The onset and magnitude of ischemic injury varied with the ambient temperature maintained during the peri-i schemia period.More serious spinal cord injury occurred when ischemia was induced at higher temperatures.At 18°C,25-minute ischemia resulted in 74%of rabbits developing delayed paraplegia.At a temperature of 28°C or higher,most of the animals developed acute paraplegia immediately.While at 13°C,rabbits usually regained normal motor function without paraplegia.Conclusion:This awake rabbit model is highly reproducible and will be helpful in future studies of delayed paraplegia after spinal cord ischemia.The ambient temperature must be considered while using this model during investigation of therapeutic interventions.展开更多
Objective: To explore an intervention method to reduce the mortality of alloxan diabetes model, and to preliminarily analyze the mechanism of alloxan induced animal death. Methods: Healthy New Zealand rabbits were ran...Objective: To explore an intervention method to reduce the mortality of alloxan diabetes model, and to preliminarily analyze the mechanism of alloxan induced animal death. Methods: Healthy New Zealand rabbits were randomly divided into injection group, control group, experimental group and blank group. The single injection group was injected with 100 mg/kg alloxan once. The control group was given 5% glucose solution and 100 mg/kg alloxan was injected in two times. The experimental group was given 5% glucose solution orally, 100 mg/kg alloxan, 7 mL 0.9% NaCl intravenously and 5 mL 5% glucose intraperitoneally immediately, and blood glucose was continuously monitored, 10 mL 5% glucose intravenously and 10 mL 5% glucose intraperitoneally every 4 h in the hypoglycemic stage. The blank group does nothing. Liver and kidney tissues at different time periods were stained with HE and organ index was evaluated. Results: 1) A single injection of 100 mg/kg alloxan without any intervention resulted in 100% mortality. Before modeling, oral administration of 5% glucose solution, divided into two injections of 100 mg/kg alloxan, mortality reached 100%;A single injection of 100 mg/kg alloxan and continuous intervention of normal saline and glucose for 20 h can significantly reduce the mortality of alloxan induced diabetic rabbit model. 2) Liver and kidney tissues were damaged in different degrees at different time periods, and liver and kidney indexes were significantly increased after alloxan injection compared with the normal group, with statistical significance (P > 0.05). Conclusion: 1) Every 4 hours of hypoglycemia, 10 ml 5% glucose was injected intravenously 10 ml 5% glucose intraperitoneally. It can reduce the death rate of alloxan diabetic rabbit model and shorten the time of blood glucose measurement. 2) After the injection of alloxan, acute lesions of liver and kidney may occur in different degrees, or one of the causes of acute death of experimental animals.展开更多
The prophylactic effects of Chinese propolis against cypermethrin toxicity were evaluated by performing ovary and uterus histopathology, as well as by characterizing ovarian function, embryos, and litters. Cypermethri...The prophylactic effects of Chinese propolis against cypermethrin toxicity were evaluated by performing ovary and uterus histopathology, as well as by characterizing ovarian function, embryos, and litters. Cypermethrin induced atypia in the ovary and uterus, and decreased the ovulation sites and the number of embryos. Cypermethrin-induced oxidative stress during pregnancy, decreased the parturition rate as well as the number and weight of offspring and increased the incidence of morphological malformations in the offspring. Administration of propolis to cypermethrin-treated animals mitigated cypermethrin-induced reproductive toxicity.展开更多
Microarc oxidation（MAO） has become a promising technique for the surface modification of implants. Therefore, the aims of this study were to further quantitatively and qualitatively evaluate the osteointegration abi...Microarc oxidation（MAO） has become a promising technique for the surface modification of implants. Therefore, the aims of this study were to further quantitatively and qualitatively evaluate the osteointegration abilities of MAO-treated and smooth surface（SF） implants in vivo and to investigate the areas in which the superiority of MAO-treated implants are displayed. In a rabbit model,a comprehensive histomorphological, osteogenic, mineralizational, and integrative assessment was performed using light microscopy, fluorescence microscopy, confocal laser scanning microscopy, and radiographic analyses. Compared with the SF groups, the MAO-treated groups exhibited more active contact osteogenesis, as well as distant osteogenesis, under fluorescence examination, the mineral apposition rate was found to be greater for all of the MAO-treated implants, and the osteointegration index（OI） value was greater in the MAO-treated groups at different times. In conclusion, the calcium-rich amorphous layer created by MAO provided a better environment for osteointegration, with more active contact osteogenesis, a more rapid mineral apposition rate and greater OI values.展开更多
Acute hemorrhagic anemia can decrease blood flow and oxygen supply to brain, and affect its physiological function. While detecting changes in brain function in patients with acute hemorrhagic anemia is helpful for pr...Acute hemorrhagic anemia can decrease blood flow and oxygen supply to brain, and affect its physiological function. While detecting changes in brain function in patients with acute hemorrhagic anemia is helpful for preventing neurological complications and evaluating therapeutic effects, clinical changes in the nervous systems of these patients have not received much attention. In part, this is because current techniques can only indirectly detect changes in brain function following onset of anemia, which leads to lags between real changes in brain function and their detection.展开更多
Objective:To explore the feasibility of establishing an animal model of chronic radiationinduced lung injury.Methods:Twenty-eight New Zealand white rabbits were randomly divided into 3 groups(the right lung irradiatio...Objective:To explore the feasibility of establishing an animal model of chronic radiationinduced lung injury.Methods:Twenty-eight New Zealand white rabbits were randomly divided into 3 groups(the right lung irradiation group,the whole lung irradiation group and the control group).Animal model of radiation-induced lung injury was established b) highdoes radiotherapy in the irradiation groups,then all rabbits underwent CT and pathological examinations at 1.2.4.8.12.16 weeks,respectively after radiation.Results:Within 4 weeks of irradiation,some rabbits in the right lung irradiation group and whole lung irradiation group died. CT and pathological examinations all showed acute radiation pneumonitis.At 8-12 weeks after irradiation,CT scanning showed ground glass samples signs,patchy shadows and fibrotic stripes. Pathological examination showed the fibrosis pulmonary alveolar wall thickened obviously. Conclusions:The clinical animal model of chronic radiation-induced lung injury which corresponds to practical conditions in clinic can be successfully established.展开更多
An experimental model of rhegmatogenous retinal detachment in rabbits was established to simulate the pathophysiologic condition of human RRD. 24 rabbits were randomly divided into 3 groups and underwent vitrectomy ...An experimental model of rhegmatogenous retinal detachment in rabbits was established to simulate the pathophysiologic condition of human RRD. 24 rabbits were randomly divided into 3 groups and underwent vitrectomy with a vitrector and/or retinotomy with a Charles flute needle, with 12 in group Ⅰ (vitrectomy and retinotomy), 7 in group Ⅱ (retinotomy) and 5 in group Ⅲ (vitrectomy). All animals underwent follow-up examinations with direct and indirect ophthalmoscopy and fundus photography 12 h and day 1, 3, 5, 7, 10, 14, 21, and 28 after the procedure(s). Retinal changes were recorded. As a result, 10 RRDs were successfully established in group Ⅰ. Direct and indirect ophthalmoscopy and fundus photography demonstrated typical features of RRD. No RRD developed in group Ⅱ and Ⅲ. It was concluded that the experimental rhegmatogenous retinal detachment produced in a rabbit model after vitrectomy with retinotomy in this study was a convenient and reliable one. This RRD model mimicked the typical pathophysiological changes in humans.展开更多
AIM: To determine if rabbit models can be used to quantify the mechanical behaviour involved in tibial stress fracture(TSF) development.METHODS: Fresh rabbit tibiae were loaded under compression using a specifically-d...AIM: To determine if rabbit models can be used to quantify the mechanical behaviour involved in tibial stress fracture(TSF) development.METHODS: Fresh rabbit tibiae were loaded under compression using a specifically-designed test apparatus. Weights were incrementally added up to a load of 30 kg and the mechanical behaviour of the tibia was analysed using tests for buckling, bone strain and hysteresis. Structural mechanics equations were subsequently employed to verify that the results were within the range of values predicted by theory. A finite element(FE) model was developed using cross-sectional computer tomography(CT) images scanned from one of the rabbit bones, and a static load of 6 kg(1.5 times the rabbit's body weight) was applied to represent running. The model was validated using the experimental strain gauge data, then geometric and elemental convergence tests were performed in order to find the minimum number of cross-sectional scans and elements respectively required for convergence. The analysis was then performed using both the model and the experimental results to investigate the mechanical behaviour of the rabbit tibia under compressive load and to examine crack initiation.RESULTS: The experimental tests showed that un der a compressive load of up to 12 kg, the rabbit tibia demonstrates linear behaviour with little hysteresis Up to 30 kg, the bone does not fail by elastic buckling however, there are low levels of tensile stress which predominately occur at and adjacent to the anterio border of the tibial midshaft: this suggests that fatigue failure occurs in these regions, since bone under cycli loading initially fails in tension. The FE model predic tions were consistent with both mechanics theory and the strain gauge results. The model was highly sensi tive to small changes in the position of the applied load due to the high slenderness ratio of the rabbit s tibia. The modelling technique used in the curren study could have applications in the development o human FE models of bone, where, unlike rabbit tibia the model would be relatively insensitive to very sma changes in load position. However, the rabbit mode itself is less beneficial as a tool to understand the me chanical behaviour of TSFs in humans due to the sma size of the rabbit bone and the limitations of human scale CT scanning equipment.CONCLUSION: The current modelling technique could be used to develop human FE models. However, the rabbit model itself has significant limitations in under standing human TSF mechanics.展开更多
AIM:To evaluate whether a novel tyrosine kinase inhibitor nintedanib could inhibit basic fibroblast growth factor(bFGF)and vascular endothelial growth factor(VEGF)simultaneously for retinal vascular disease in vivo.ME...AIM:To evaluate whether a novel tyrosine kinase inhibitor nintedanib could inhibit basic fibroblast growth factor(bFGF)and vascular endothelial growth factor(VEGF)simultaneously for retinal vascular disease in vivo.METHODS:After a laser induced rabbit retinal vein occlusion(RVO)model was made,0.5 mg of nintedanib was injected intravitreally in the left eye on the third day while the right eye was as a control.Intracameral samples were taken on the day before laser treatment and days 1,3,7,14,21,and 28 after treatment.Enzyme-linked immunosorbent assay(ELISA)was used to test the bFGF and VEGF-A concentrations in the aqueous humor.RESULTS:Both bFGF and VEGF-A rose significantly on the third day after laser treatment in both eyes.In the control eye the bFGF concentration peaked on the 14th day while the VEGF-A concentration dropped rapidly soon after the third day.After nintadanib injection in the study eye,both bFGF and VEGF-A showed a significant reduction on the 4th day(7th day after laser treatment)when compared to the control eye,and kept on low level in the following several weeks.CONCLUSION:Intravitreal injection of nintedanib can inhibit the expression of bFGF and VEGF in the process of RVO model to a certain extent,which is expected to become a new method for the treatment of retinal vascular diseases or fibrotic diseases.展开更多
Background： Chronic stress contributes to increased risks ofatherosclerotic diseases including heart disease, stroke, and transient ischemic attack. However, its underline mechanisms are poorly understood. This study...Background： Chronic stress contributes to increased risks ofatherosclerotic diseases including heart disease, stroke, and transient ischemic attack. However, its underline mechanisms are poorly understood. This study aimed to elucidate the mechanism via which chronic stress exerts its effect on atherosclerosis （AS）. Methods： Fifty male New Zealand white rabbits were used. Aortic balloon-injury model was applied. Both social stress and physical stress methods were adopted to establish chronic stress models. The lumen stenotic degree, intimal and medial areas, maximum fibrous cap thickness, and plaque contents were measured with histological sections. Proteomic methods were applied to detect protein changes in abdominal aortas to identify the specialized mediators. Real-time reverse transcription-polymerase chain reaction was used for further verification and investigation. Results： The stress rabbits exhibited lower body weight, worse fur state, more inactivity behavior, and higher serum cortisol level. Chronic stress was significantly associated with the decreased medial area and increased plaque instability, which was manifested by thinner fibrous caps, larger lipid cores, more macrophages, and new vessels but fewer smooth muscle cells and elastic fibers. After chronic stress, the apoptosis-related genes UBE2K, BAX, b）~S, Ca.v^ase 3, Caspase 9, and P53 were upregulated, and B^Z-2/BAX was down-regulated; the angiogenesis-related genes ANG and VEGF-A were also highly expressed in atherosclerotic arteries. Conclusions： Rabbit models of chronic stress were successfully established by applying both social stress and physical stress for 8 weeks. Chronic stress can reduce AS tunica media and accelerate plaque instability by promoting apoptosis and neovascularization.展开更多
The pathogenesis and therapeutic treatment of intrauterine adhesions （IUAs） remain unsolved, highlighting the need for stable and effective experimental animal models. In this study, uterine electrocoagulaUon of twe...The pathogenesis and therapeutic treatment of intrauterine adhesions （IUAs） remain unsolved, highlighting the need for stable and effective experimental animal models. In this study, uterine electrocoagulaUon of twenty-one female New Zealand White rabbits was carried out to establish an IUA model. As rabbits have two completely separate uterine horns, each rabbit had its own internal control： one uterine horn was given an electrothermal injury （Group A, n=21）, and the contralateral uterine horn received no treatment and served as the control （Group B, n=21）. The en- dometrial morphology, number of endometrial glands, area of endometrial fibrosis, and number of implanted fetuses were compared between the two groups. In Group A, the numbers of endometrial glands on Days 7 and 14 and the number of implanted fetuses were significantly lower than those in Group B（P〈0.05, P〈0.05, and P〈0.01, respectively）, while the ratio of the area with endometrial stromal fibrosis to the total endometrial area was significantly increased （P〈0.01）. These results suggest that this method of electrothermal injury is effective for the establishment of a rabbit lUA model between 7 and 14 d after surgery.展开更多
Background : The objective of this study was to validate an animal model for dry eye during and after the administration of 1% ophthalmic atropine sulfate(OAS) in New Zealand white(NZW) rabbits.Methods : OAS(1%) was a...Background : The objective of this study was to validate an animal model for dry eye during and after the administration of 1% ophthalmic atropine sulfate(OAS) in New Zealand white(NZW) rabbits.Methods : OAS(1%) was applied three times per day to 30 eyes of 15 healthy NZW rabbits. Sacrifice, enucleation, and lacrimal gland removal took place on days 15, 21,and 30(OAS group). A second group(n = 5) was used as control. Clinical evaluations took place on days 3, 10, 15, 18, 21, 24 and 30. The primary endpoints were:Schirmer I test, tear break-up time(TBUT), and corneal fluorescein staining. As secondary endpoints, clinical changes including intraocular pressure, and histopathology were evaluated.Results : While OAS was administered, the Schirmer I test showed a statistically significant reduction for OAS group versus control( p < 0.001), and versus basal production( p < 0.001). TBUT showed statistically significant differences between groups(days 3 and 10;p = 0.001) and versus basal values(day 3;p < 0.001). Fluorescein staining showed a statistically significant difference(day 3;p = 0.001). The most frequent clinical finding was conjunctival hyperemia(76.9% OAS vs. 20% control). For histopathology, all OAS subjects presented some degree of inflammation(86.7% minimal;13.3% mild) whereas the control presented only 30% minimal inflammation. Goblet cell density showed no difference.Conclusions : The effectiveness of the OAS dry eye model in NZW rabbits as reported in previous studies was confirmed, provided that the application of the drug is maintained throughout the intervention;it is not a viable model after OAS administration is suspended.展开更多
Background: Research on the etiology and pathophysiology of fusiform aneurysm has been impeded due to the inability to collect fusiform aneurysm specimens. We aim to resolve this through the development of a novel fus...Background: Research on the etiology and pathophysiology of fusiform aneurysm has been impeded due to the inability to collect fusiform aneurysm specimens. We aim to resolve this through the development of a novel fusiform aneurysm model in rabbits.Methods: Sixty New Zealand White rabbits were divided into ten groups (n = 6 per group): groups A, B, C, D, E and groups a, b, c, d, e. Elastase, at a concentration of 0, 0.5, 1, 2.5 and 5 U/μL respectively was administered to each rabbit to incubate their carotid arteries. Three weeks later, angiography, histomorphometry,immunohistochemistry and immunofluorescent were performed.Results: Heparin administration is indispensable. No thrombosis was observed in groups A, B, C, D and E, whereas,increased thromboembolism occurred in groups a, b, c, d and e. Based on the size and wall thickness of aneurysms specimens, 5 U/μL was the optimal concentration of elastase to induce fusiform aneurysms. At 5 U/μL, the intraluminal carotid diameter increased significantly from 2.50 ± 0.32 mm to 3.11 ± 0.55 mm (p < 0.01). The wall thickness significantly reduced from 176.0 ± 39.8 μm to 39.7 ± 14.6 μm (p < 0.01) post aneurysm induction. The histolopathological evaluation revealed the elastic lamina and the smooth muscle cell''''s lamina were markedly attenuated and the intimal endothelial lamina became thin or even absent.Conclusions: Our research demonstrates that intracranial fusiform aneurysm could be modeled in rabbit carotid artery adventitia incubation by porcine pancreatic elastase.展开更多
This study aimed to establish a new propofol target-controlled infusion（TCI） model in animals so as to study the general anesthetic mechanism at multi-levels in vivo. Twenty Japanese white rabbits were enrolled and ...This study aimed to establish a new propofol target-controlled infusion（TCI） model in animals so as to study the general anesthetic mechanism at multi-levels in vivo. Twenty Japanese white rabbits were enrolled and propofol（10 mg/kg） was administrated intravenously. Artery blood samples were collected at various time points after injection, and plasma concentrations of propofol were measured. Pharmacokinetic modeling was performed using Win Nonlin software. Propofol TCI within the acquired parameters integrated was conducted to achieve different anesthetic depths in rabbits, monitored by narcotrend. The pharmacodynamics was analyzed using a sigmoidal inhibitory maximal effect model for narcotrend index（NI） versus effect-site concentration. The results showed the pharmacokinetics of propofol in Japanese white rabbits was best described by a two-compartment model. The target plasma concentrations of propofol required at light anesthetic depth was 9.77±0.23 μg/m L, while 12.52±0.69 μg/m L at deep anesthetic depth. NI was 76.17±4.25 at light anesthetic depth, while 27.41±5.77 at deep anesthetic depth. The effect-site elimination rate constant（ke0） was 0.263/min, and the propofol dose required to achieve a 50% decrease in the NI value from baseline was 11.19 μg/m L（95% CI, 10.25–13.67）. Our results established a new propofol TCI animal model and proved the model controlled the anesthetic depth accurately and stably in rabbits. The study provides a powerful method for exploring general anesthetic mechanisms at different anesthetic depths in vivo.展开更多
This study is to establish a rabbit model for human prosthetic joint infection and biofiim formation. Thirty-two healthy adult rabbits were randomly divided into four groups and implanted with stainless steel screws a...This study is to establish a rabbit model for human prosthetic joint infection and biofiim formation. Thirty-two healthy adult rabbits were randomly divided into four groups and implanted with stainless steel screws and ultra-high molecular weight polyethylene （UHMWPE） washers in the non-articular surface of the femoral lateral condyle of the right hind knees. The rabbit knee joints were inoculated with 1 mL saline containing 0, 102, 103, 104 CFU of Staphylococcus epidermidis （S. epidermidis） isolated from the patient with total knee arthroplasty （TKA） infection, respectively. On the 14th postoperative day, the UHMWPE washers from the optimal 103 CFU group were further examined. The SEM examination showed a typical biofilm construction that circular S. epidermidis were embedded in a mucous-like matrix. In addition, the LCSM examination showed that the biofilm consisted of the polysaccharide stained bright green fluorescence and S. epidermidis radiating red fluorescence. Thus, we successfully create a rabbit model for prosthetic joint infection and biofilm formation, which should be valuable for biofilm studies.展开更多
AIM:To compare two different laparotomy methods for modeling rabbit VX2 hepatocarcinoma.METHODS:Thirty New Zealand rabbits were randomly divided into two groups:A and B.Group A was assigned a traditional laparotomy me...AIM:To compare two different laparotomy methods for modeling rabbit VX2 hepatocarcinoma.METHODS:Thirty New Zealand rabbits were randomly divided into two groups:A and B.Group A was assigned a traditional laparotomy method(embedding tumor fragments directly into the liver with tweezers).Group B was subjected to an improved laparotomy method(injection of tumor fragments into the liver through a 15 G syringe needle).The operation time, incision length, incision infection rate, and mortality rate were compared between the two groups after laparotomy.Magnetic resonance imaging(MRI) was performed to evaluate tumor formation rates and the characteristics of the tumors 2 wk after laparotomy.RESULTS:The mean operation times for the two groups(Group A vs Group B) were 23.2 ± 3.4 min vs 17.5 ± 2.9 min(P < 0.05); the incision length was 3.3 ± 0.5 cm vs 2.4 ± 0.6 cm(P < 0.05); and the mortality rate after 2 wk was 26.7% vs 0%(P < 0.05); all of these outcomes were significantly different between the two groups.The incision infection rates in the two groups were 6.7% vs 0%(P > 0.05), whichwere not significantly different.MRI performed after 2weeks showed that the tumor formation rates in the two groups were 90.9%vs 93.3%(P>0.05).These rates were not significantly different between the two groups.The celiac implantation rate and abdominal wall metastasis rate in the two groups were 36.4%vs 13.3%(P<0.05)and 27.2%vs 6.7%(P<0.05),respectively,which were significantly different between the two groups.CONCLUSION:The tumor formation rates were not significantly different between the two methods for modeling rabbit VX2 hepatocarcinoma.However,the improved method is recommended because it has certain advantages.展开更多
Background： Although obstructive sleep apnea （OSA） has been recognized as a major risk factor for cardiovascular complications and its clinical features are well characterized, it is difficult to replicate the OSA ...Background： Although obstructive sleep apnea （OSA） has been recognized as a major risk factor for cardiovascular complications and its clinical features are well characterized, it is difficult to replicate the OSA hypoxic model in humans. We aimed to establish an experimental rabbit model for chronic OSA and to explore its application to measure blood pressure （BP）, myocardial systolic function, and oxidative stress. Methods： The rabbit model for OSA was established by repeatedly closing the airway and then reopening it. A tube specially designed with a bag that could be alternately inflated and deflated according to a predetermined time schedule, resulting in recurrent airway occlusions and chronic intermittent hypoxia （CIH） imitating OSA patterns in humans, was used. Twenty-four rabbits were randomly divided into obstruction, sham, and control groups, and their upper airways were alternately closed for 15 s and then reopened for 105 s in a 120-s-long cycle, for 8 h each day over 12 consecutive weeks. Before and after the experiment, the BP of each rabbit was monitored. Levels of interleukin-6 （IL-6） and tumor necrosis factor-α （TNF-α） in the serum, superoxide dismutase （SOD） activity, malondialdehyde （MDA） and reactive oxygen species （ROS） contents, as well as Na＋-K＋-ATPase/Ca2＋-ATPase activities in cardiac muscle were examined. In addition, cardiac functional parameters were measured using echocardiography. Results： After 3 months, all rabbits in the obstruction group manifested sleepiness performance similar to that observed in OSA patients. Traces of airflow and SpO2 showed that this model mimicked the respiratory events involved in OSA, including increased respiratory effort and decreased oxygen saturation. Gradually, the BP rose each month. CIH led to obvious oxidative stress and injured myocardial systolic performance. The serum levels of IL-6 and TNF-α increased significantly （64.75 ± 9.05 pg/ml vs. 147.00 ± 19.24 pg/ml and 59.38 ± 8.21 pg/ml vs. 264.75 ± 25.54 pg/ml, respectively, both P 〈 0.001）. Compared with the sham and the control groups, myocardial activities of Na＋-K＋-ATPase/Ca-2＋-ATPase and SOD in the obstruction group decreased markedly, while ROS and MDA content increased. Conclusions： These results show that the rabbit model for OSA simulates the pathophysiological characteristics of OSA in humans, which implies that this animal model is feasible and useful to study the mechanisms involved in the cardiovascular consequences of OSA.展开更多
To develop an easy, reproducible experimental model of cerebral infarction(CI)without craniotomy in New Zealand white rabbits,a silicone rubber cylinder embedded in a nylon suture was delivered to the middle cerebral ...To develop an easy, reproducible experimental model of cerebral infarction(CI)without craniotomy in New Zealand white rabbits,a silicone rubber cylinder embedded in a nylon suture was delivered to the middle cerebral arteries through the internal carotid artery in anesthetized animals.Rabbits were sacrificed 0.5-5 h after embolization.CI size and location were ascertained by the tripheny1-2H-tetrazoliuni chloride(TTC)staining method;cerebral blood flow(CBF)was measured prior to and after embolization.Pco2,temperature and blood pressure were monitored and kept constant.CI occurred in all rabbits after 4 h of ischemia,in 50% after 3 h and only in 33% after 2.5 h.CI did not occur within less than 2.5 h of ischemia.No correlation was found between size and location of CI and occlusion time.CBF was maximally reduced in the right MCA territory but was also reduced in both anterior cerebral arteries and left MCA territories.This model is technically easy and the retrievable embolus allows the study of reperfusion by pulling on the nylon suture.It is suitable for studying chemical and molecular changes of the ischemic cells and/or for studying neuroimage changes after ischemic stroke.展开更多
Objective To investigate the effects of low dosage of β-elemene on the radiosensitivity of rabbit VX2 renal transplant carcinoma model. Methods We took the rabbit VX2 renal transplant carcinoma as the model. Experime...Objective To investigate the effects of low dosage of β-elemene on the radiosensitivity of rabbit VX2 renal transplant carcinoma model. Methods We took the rabbit VX2 renal transplant carcinoma as the model. Experimental rabbits were divided into three groups: the control group, the radiation group, and the radiation +β-elemene (radiosensitivity) group. The change of tumor was observed by Spiral CT and B ultrasound to compare its regrowth period. The tumor was measured by light microscopy and electron microscopy. Results The tumor in radiosensitivity group was restrained obviously and the sensitization enhancement ratio (SER) of β-elemene was 1.89. Different apoptosis was observed under transmission electron microscopy. Conclusion Low dosage β-elemene can enhance the radiosensitivity of rabbit VX2 renal transplant carcinoma model and induce the apoptosis of tumor cells, but the mechanism needs further study. It promotes apoptosis in mechanisms in vitro.展开更多
[ Objective] This study was conducted to explore the method of establishing Lipopolysaccharide （LPS） -induced mastitis pathological models and reveal dynamic pathological changes of mammary tissue before and after L...[ Objective] This study was conducted to explore the method of establishing Lipopolysaccharide （LPS） -induced mastitis pathological models and reveal dynamic pathological changes of mammary tissue before and after LPS perfusion, finally providing convenient animal models for establishing LPS- induced acute clinical mastitis researches. [ Method] Twelve lactating rabbits （the 7th day after parturition） were perfused with LPS into the fourth mammary gland via the teat duct. Exactly at 2h before perfusion, 6 h, 12 h, 24 h, 48 h, 72 h, 5 d and 7 d after, the indexes such as rectal temperature, total white blood calls and neutrophils, C -response protein （CPR） content and lactate dehydrogenase （LDH） activity were determined, respectively. Then the rabbits were euthanatized and the mammary glands were removed and fixed for histopathologic evalua- tions. [Result] The results showed that inflammatory cells were observed in mammary tissue 6 h after LPS perfusion, structure of mammary tissue disorderly at 24 h, self - regeneration after 48 h and back to normal at 7 d. LDH activity was increasing significantly （ P 〈 0.05） at 12 h （ P 〈 0.05）, peaking at 24 h, decreasing at 5 d （ P 〈 0.05） and returning to health at 7 d. CRP content was increasing significantly （ P 〈 0.05） at 6 to 72 h, pea- king at 12 h, decreasing at 48 h, back to normal at 5 d. [ Conclusion] The results suggested that the rabbit experimental mastitis model was suc- cassfullv constructed bv LPS Derfusion via teat duct.展开更多
基金supported by the Science and Technology Research Project(KJQN202212805)of the Chongqing Education Commissionthe Special Funding Project(2021XJS08)of Army Medical University。
文摘Background:Paraplegia after spinal cord ischemia is a devastating condition in the clinic.Here,we develop an awake rabbit model of spinal cord ischemia with delayed paraplegia and explore the influence of ambient temperature on the outcomes after injury.Methods:A total of 47 male rabbits were involved in the present study.Transient spinal cord ischemia was induced by occluding the infrarenal abdominal aorta of awake rabbits at different ambient temperatures.To find the optimal conditions for developing delayed paraplegia,hindlimb motor function after ischemia was evaluated between experiments.Results:The onset and magnitude of ischemic injury varied with the ambient temperature maintained during the peri-i schemia period.More serious spinal cord injury occurred when ischemia was induced at higher temperatures.At 18°C,25-minute ischemia resulted in 74%of rabbits developing delayed paraplegia.At a temperature of 28°C or higher,most of the animals developed acute paraplegia immediately.While at 13°C,rabbits usually regained normal motor function without paraplegia.Conclusion:This awake rabbit model is highly reproducible and will be helpful in future studies of delayed paraplegia after spinal cord ischemia.The ambient temperature must be considered while using this model during investigation of therapeutic interventions.
文摘Objective: To explore an intervention method to reduce the mortality of alloxan diabetes model, and to preliminarily analyze the mechanism of alloxan induced animal death. Methods: Healthy New Zealand rabbits were randomly divided into injection group, control group, experimental group and blank group. The single injection group was injected with 100 mg/kg alloxan once. The control group was given 5% glucose solution and 100 mg/kg alloxan was injected in two times. The experimental group was given 5% glucose solution orally, 100 mg/kg alloxan, 7 mL 0.9% NaCl intravenously and 5 mL 5% glucose intraperitoneally immediately, and blood glucose was continuously monitored, 10 mL 5% glucose intravenously and 10 mL 5% glucose intraperitoneally every 4 h in the hypoglycemic stage. The blank group does nothing. Liver and kidney tissues at different time periods were stained with HE and organ index was evaluated. Results: 1) A single injection of 100 mg/kg alloxan without any intervention resulted in 100% mortality. Before modeling, oral administration of 5% glucose solution, divided into two injections of 100 mg/kg alloxan, mortality reached 100%;A single injection of 100 mg/kg alloxan and continuous intervention of normal saline and glucose for 20 h can significantly reduce the mortality of alloxan induced diabetic rabbit model. 2) Liver and kidney tissues were damaged in different degrees at different time periods, and liver and kidney indexes were significantly increased after alloxan injection compared with the normal group, with statistical significance (P > 0.05). Conclusion: 1) Every 4 hours of hypoglycemia, 10 ml 5% glucose was injected intravenously 10 ml 5% glucose intraperitoneally. It can reduce the death rate of alloxan diabetic rabbit model and shorten the time of blood glucose measurement. 2) After the injection of alloxan, acute lesions of liver and kidney may occur in different degrees, or one of the causes of acute death of experimental animals.
文摘The prophylactic effects of Chinese propolis against cypermethrin toxicity were evaluated by performing ovary and uterus histopathology, as well as by characterizing ovarian function, embryos, and litters. Cypermethrin induced atypia in the ovary and uterus, and decreased the ovulation sites and the number of embryos. Cypermethrin-induced oxidative stress during pregnancy, decreased the parturition rate as well as the number and weight of offspring and increased the incidence of morphological malformations in the offspring. Administration of propolis to cypermethrin-treated animals mitigated cypermethrin-induced reproductive toxicity.
文摘Microarc oxidation（MAO） has become a promising technique for the surface modification of implants. Therefore, the aims of this study were to further quantitatively and qualitatively evaluate the osteointegration abilities of MAO-treated and smooth surface（SF） implants in vivo and to investigate the areas in which the superiority of MAO-treated implants are displayed. In a rabbit model,a comprehensive histomorphological, osteogenic, mineralizational, and integrative assessment was performed using light microscopy, fluorescence microscopy, confocal laser scanning microscopy, and radiographic analyses. Compared with the SF groups, the MAO-treated groups exhibited more active contact osteogenesis, as well as distant osteogenesis, under fluorescence examination, the mineral apposition rate was found to be greater for all of the MAO-treated implants, and the osteointegration index（OI） value was greater in the MAO-treated groups at different times. In conclusion, the calcium-rich amorphous layer created by MAO provided a better environment for osteointegration, with more active contact osteogenesis, a more rapid mineral apposition rate and greater OI values.
基金supported by the Science and Technology Project of Shenzhen,No.JCY20120613170958482the First Affiliated Hospital of Shenzhen University Breeding Program,No.2012015
文摘Acute hemorrhagic anemia can decrease blood flow and oxygen supply to brain, and affect its physiological function. While detecting changes in brain function in patients with acute hemorrhagic anemia is helpful for preventing neurological complications and evaluating therapeutic effects, clinical changes in the nervous systems of these patients have not received much attention. In part, this is because current techniques can only indirectly detect changes in brain function following onset of anemia, which leads to lags between real changes in brain function and their detection.
文摘Objective:To explore the feasibility of establishing an animal model of chronic radiationinduced lung injury.Methods:Twenty-eight New Zealand white rabbits were randomly divided into 3 groups(the right lung irradiation group,the whole lung irradiation group and the control group).Animal model of radiation-induced lung injury was established b) highdoes radiotherapy in the irradiation groups,then all rabbits underwent CT and pathological examinations at 1.2.4.8.12.16 weeks,respectively after radiation.Results:Within 4 weeks of irradiation,some rabbits in the right lung irradiation group and whole lung irradiation group died. CT and pathological examinations all showed acute radiation pneumonitis.At 8-12 weeks after irradiation,CT scanning showed ground glass samples signs,patchy shadows and fibrotic stripes. Pathological examination showed the fibrosis pulmonary alveolar wall thickened obviously. Conclusions:The clinical animal model of chronic radiation-induced lung injury which corresponds to practical conditions in clinic can be successfully established.
文摘An experimental model of rhegmatogenous retinal detachment in rabbits was established to simulate the pathophysiologic condition of human RRD. 24 rabbits were randomly divided into 3 groups and underwent vitrectomy with a vitrector and/or retinotomy with a Charles flute needle, with 12 in group Ⅰ (vitrectomy and retinotomy), 7 in group Ⅱ (retinotomy) and 5 in group Ⅲ (vitrectomy). All animals underwent follow-up examinations with direct and indirect ophthalmoscopy and fundus photography 12 h and day 1, 3, 5, 7, 10, 14, 21, and 28 after the procedure(s). Retinal changes were recorded. As a result, 10 RRDs were successfully established in group Ⅰ. Direct and indirect ophthalmoscopy and fundus photography demonstrated typical features of RRD. No RRD developed in group Ⅱ and Ⅲ. It was concluded that the experimental rhegmatogenous retinal detachment produced in a rabbit model after vitrectomy with retinotomy in this study was a convenient and reliable one. This RRD model mimicked the typical pathophysiological changes in humans.
文摘AIM: To determine if rabbit models can be used to quantify the mechanical behaviour involved in tibial stress fracture(TSF) development.METHODS: Fresh rabbit tibiae were loaded under compression using a specifically-designed test apparatus. Weights were incrementally added up to a load of 30 kg and the mechanical behaviour of the tibia was analysed using tests for buckling, bone strain and hysteresis. Structural mechanics equations were subsequently employed to verify that the results were within the range of values predicted by theory. A finite element(FE) model was developed using cross-sectional computer tomography(CT) images scanned from one of the rabbit bones, and a static load of 6 kg(1.5 times the rabbit's body weight) was applied to represent running. The model was validated using the experimental strain gauge data, then geometric and elemental convergence tests were performed in order to find the minimum number of cross-sectional scans and elements respectively required for convergence. The analysis was then performed using both the model and the experimental results to investigate the mechanical behaviour of the rabbit tibia under compressive load and to examine crack initiation.RESULTS: The experimental tests showed that un der a compressive load of up to 12 kg, the rabbit tibia demonstrates linear behaviour with little hysteresis Up to 30 kg, the bone does not fail by elastic buckling however, there are low levels of tensile stress which predominately occur at and adjacent to the anterio border of the tibial midshaft: this suggests that fatigue failure occurs in these regions, since bone under cycli loading initially fails in tension. The FE model predic tions were consistent with both mechanics theory and the strain gauge results. The model was highly sensi tive to small changes in the position of the applied load due to the high slenderness ratio of the rabbit s tibia. The modelling technique used in the curren study could have applications in the development o human FE models of bone, where, unlike rabbit tibia the model would be relatively insensitive to very sma changes in load position. However, the rabbit mode itself is less beneficial as a tool to understand the me chanical behaviour of TSFs in humans due to the sma size of the rabbit bone and the limitations of human scale CT scanning equipment.CONCLUSION: The current modelling technique could be used to develop human FE models. However, the rabbit model itself has significant limitations in under standing human TSF mechanics.
基金Supported by Medical Health Science and Technology Project of Zhejiang Province(No.2020KY654).
文摘AIM:To evaluate whether a novel tyrosine kinase inhibitor nintedanib could inhibit basic fibroblast growth factor(bFGF)and vascular endothelial growth factor(VEGF)simultaneously for retinal vascular disease in vivo.METHODS:After a laser induced rabbit retinal vein occlusion(RVO)model was made,0.5 mg of nintedanib was injected intravitreally in the left eye on the third day while the right eye was as a control.Intracameral samples were taken on the day before laser treatment and days 1,3,7,14,21,and 28 after treatment.Enzyme-linked immunosorbent assay(ELISA)was used to test the bFGF and VEGF-A concentrations in the aqueous humor.RESULTS:Both bFGF and VEGF-A rose significantly on the third day after laser treatment in both eyes.In the control eye the bFGF concentration peaked on the 14th day while the VEGF-A concentration dropped rapidly soon after the third day.After nintadanib injection in the study eye,both bFGF and VEGF-A showed a significant reduction on the 4th day(7th day after laser treatment)when compared to the control eye,and kept on low level in the following several weeks.CONCLUSION:Intravitreal injection of nintedanib can inhibit the expression of bFGF and VEGF in the process of RVO model to a certain extent,which is expected to become a new method for the treatment of retinal vascular diseases or fibrotic diseases.
文摘Background： Chronic stress contributes to increased risks ofatherosclerotic diseases including heart disease, stroke, and transient ischemic attack. However, its underline mechanisms are poorly understood. This study aimed to elucidate the mechanism via which chronic stress exerts its effect on atherosclerosis （AS）. Methods： Fifty male New Zealand white rabbits were used. Aortic balloon-injury model was applied. Both social stress and physical stress methods were adopted to establish chronic stress models. The lumen stenotic degree, intimal and medial areas, maximum fibrous cap thickness, and plaque contents were measured with histological sections. Proteomic methods were applied to detect protein changes in abdominal aortas to identify the specialized mediators. Real-time reverse transcription-polymerase chain reaction was used for further verification and investigation. Results： The stress rabbits exhibited lower body weight, worse fur state, more inactivity behavior, and higher serum cortisol level. Chronic stress was significantly associated with the decreased medial area and increased plaque instability, which was manifested by thinner fibrous caps, larger lipid cores, more macrophages, and new vessels but fewer smooth muscle cells and elastic fibers. After chronic stress, the apoptosis-related genes UBE2K, BAX, b）~S, Ca.v^ase 3, Caspase 9, and P53 were upregulated, and B^Z-2/BAX was down-regulated; the angiogenesis-related genes ANG and VEGF-A were also highly expressed in atherosclerotic arteries. Conclusions： Rabbit models of chronic stress were successfully established by applying both social stress and physical stress for 8 weeks. Chronic stress can reduce AS tunica media and accelerate plaque instability by promoting apoptosis and neovascularization.
基金Project supported by the Key Research and Development Program of Shandong Province(No.2015GSF118124)the Projects of Medical and Health Technology Development Program in Shandong Province(No.2016WS0369)the National Research and Development Plan(No.2016YFC1000600),China
文摘The pathogenesis and therapeutic treatment of intrauterine adhesions （IUAs） remain unsolved, highlighting the need for stable and effective experimental animal models. In this study, uterine electrocoagulaUon of twenty-one female New Zealand White rabbits was carried out to establish an IUA model. As rabbits have two completely separate uterine horns, each rabbit had its own internal control： one uterine horn was given an electrothermal injury （Group A, n=21）, and the contralateral uterine horn received no treatment and served as the control （Group B, n=21）. The en- dometrial morphology, number of endometrial glands, area of endometrial fibrosis, and number of implanted fetuses were compared between the two groups. In Group A, the numbers of endometrial glands on Days 7 and 14 and the number of implanted fetuses were significantly lower than those in Group B（P〈0.05, P〈0.05, and P〈0.01, respectively）, while the ratio of the area with endometrial stromal fibrosis to the total endometrial area was significantly increased （P〈0.01）. These results suggest that this method of electrothermal injury is effective for the establishment of a rabbit lUA model between 7 and 14 d after surgery.
基金sponsored by Laboratorios Sophia,SA de CV(Zapopan,Jalisco,Mexico)。
文摘Background : The objective of this study was to validate an animal model for dry eye during and after the administration of 1% ophthalmic atropine sulfate(OAS) in New Zealand white(NZW) rabbits.Methods : OAS(1%) was applied three times per day to 30 eyes of 15 healthy NZW rabbits. Sacrifice, enucleation, and lacrimal gland removal took place on days 15, 21,and 30(OAS group). A second group(n = 5) was used as control. Clinical evaluations took place on days 3, 10, 15, 18, 21, 24 and 30. The primary endpoints were:Schirmer I test, tear break-up time(TBUT), and corneal fluorescein staining. As secondary endpoints, clinical changes including intraocular pressure, and histopathology were evaluated.Results : While OAS was administered, the Schirmer I test showed a statistically significant reduction for OAS group versus control( p < 0.001), and versus basal production( p < 0.001). TBUT showed statistically significant differences between groups(days 3 and 10;p = 0.001) and versus basal values(day 3;p < 0.001). Fluorescein staining showed a statistically significant difference(day 3;p = 0.001). The most frequent clinical finding was conjunctival hyperemia(76.9% OAS vs. 20% control). For histopathology, all OAS subjects presented some degree of inflammation(86.7% minimal;13.3% mild) whereas the control presented only 30% minimal inflammation. Goblet cell density showed no difference.Conclusions : The effectiveness of the OAS dry eye model in NZW rabbits as reported in previous studies was confirmed, provided that the application of the drug is maintained throughout the intervention;it is not a viable model after OAS administration is suspended.
文摘Background: Research on the etiology and pathophysiology of fusiform aneurysm has been impeded due to the inability to collect fusiform aneurysm specimens. We aim to resolve this through the development of a novel fusiform aneurysm model in rabbits.Methods: Sixty New Zealand White rabbits were divided into ten groups (n = 6 per group): groups A, B, C, D, E and groups a, b, c, d, e. Elastase, at a concentration of 0, 0.5, 1, 2.5 and 5 U/μL respectively was administered to each rabbit to incubate their carotid arteries. Three weeks later, angiography, histomorphometry,immunohistochemistry and immunofluorescent were performed.Results: Heparin administration is indispensable. No thrombosis was observed in groups A, B, C, D and E, whereas,increased thromboembolism occurred in groups a, b, c, d and e. Based on the size and wall thickness of aneurysms specimens, 5 U/μL was the optimal concentration of elastase to induce fusiform aneurysms. At 5 U/μL, the intraluminal carotid diameter increased significantly from 2.50 ± 0.32 mm to 3.11 ± 0.55 mm (p < 0.01). The wall thickness significantly reduced from 176.0 ± 39.8 μm to 39.7 ± 14.6 μm (p < 0.01) post aneurysm induction. The histolopathological evaluation revealed the elastic lamina and the smooth muscle cell''''s lamina were markedly attenuated and the intimal endothelial lamina became thin or even absent.Conclusions: Our research demonstrates that intracranial fusiform aneurysm could be modeled in rabbit carotid artery adventitia incubation by porcine pancreatic elastase.
基金supported by a grant from Shenzhen Baoan Hospital Affiliated to Southern Medical University
文摘This study aimed to establish a new propofol target-controlled infusion（TCI） model in animals so as to study the general anesthetic mechanism at multi-levels in vivo. Twenty Japanese white rabbits were enrolled and propofol（10 mg/kg） was administrated intravenously. Artery blood samples were collected at various time points after injection, and plasma concentrations of propofol were measured. Pharmacokinetic modeling was performed using Win Nonlin software. Propofol TCI within the acquired parameters integrated was conducted to achieve different anesthetic depths in rabbits, monitored by narcotrend. The pharmacodynamics was analyzed using a sigmoidal inhibitory maximal effect model for narcotrend index（NI） versus effect-site concentration. The results showed the pharmacokinetics of propofol in Japanese white rabbits was best described by a two-compartment model. The target plasma concentrations of propofol required at light anesthetic depth was 9.77±0.23 μg/m L, while 12.52±0.69 μg/m L at deep anesthetic depth. NI was 76.17±4.25 at light anesthetic depth, while 27.41±5.77 at deep anesthetic depth. The effect-site elimination rate constant（ke0） was 0.263/min, and the propofol dose required to achieve a 50% decrease in the NI value from baseline was 11.19 μg/m L（95% CI, 10.25–13.67）. Our results established a new propofol TCI animal model and proved the model controlled the anesthetic depth accurately and stably in rabbits. The study provides a powerful method for exploring general anesthetic mechanisms at different anesthetic depths in vivo.
基金Acknowledgements We thank the National Natural Science Foundation of China （Grant No. 21371106） and the Major State Basic Research Development Program of China （973 Program, 2011CB606205） for the financial support. The authors would like to thank the Department of Microbiology of Chinese PLA General Hospital for bacterial culture experiments. Animal experiments were done at Laboratory Animal Center of Chinese PLA General Hospital. SEM and LCSM were performed at Tsinghna University.
文摘This study is to establish a rabbit model for human prosthetic joint infection and biofiim formation. Thirty-two healthy adult rabbits were randomly divided into four groups and implanted with stainless steel screws and ultra-high molecular weight polyethylene （UHMWPE） washers in the non-articular surface of the femoral lateral condyle of the right hind knees. The rabbit knee joints were inoculated with 1 mL saline containing 0, 102, 103, 104 CFU of Staphylococcus epidermidis （S. epidermidis） isolated from the patient with total knee arthroplasty （TKA） infection, respectively. On the 14th postoperative day, the UHMWPE washers from the optimal 103 CFU group were further examined. The SEM examination showed a typical biofilm construction that circular S. epidermidis were embedded in a mucous-like matrix. In addition, the LCSM examination showed that the biofilm consisted of the polysaccharide stained bright green fluorescence and S. epidermidis radiating red fluorescence. Thus, we successfully create a rabbit model for prosthetic joint infection and biofilm formation, which should be valuable for biofilm studies.
基金Supported by Natural Science Foundation of Hunan Province,China,No.14JJ2034Project of the Development and Reform Commission of Hunan Province,China,No.2013-1199Project of the Science and Technology Department of Hunan Province,China,No.2014TT2017
文摘AIM:To compare two different laparotomy methods for modeling rabbit VX2 hepatocarcinoma.METHODS:Thirty New Zealand rabbits were randomly divided into two groups:A and B.Group A was assigned a traditional laparotomy method(embedding tumor fragments directly into the liver with tweezers).Group B was subjected to an improved laparotomy method(injection of tumor fragments into the liver through a 15 G syringe needle).The operation time, incision length, incision infection rate, and mortality rate were compared between the two groups after laparotomy.Magnetic resonance imaging(MRI) was performed to evaluate tumor formation rates and the characteristics of the tumors 2 wk after laparotomy.RESULTS:The mean operation times for the two groups(Group A vs Group B) were 23.2 ± 3.4 min vs 17.5 ± 2.9 min(P < 0.05); the incision length was 3.3 ± 0.5 cm vs 2.4 ± 0.6 cm(P < 0.05); and the mortality rate after 2 wk was 26.7% vs 0%(P < 0.05); all of these outcomes were significantly different between the two groups.The incision infection rates in the two groups were 6.7% vs 0%(P > 0.05), whichwere not significantly different.MRI performed after 2weeks showed that the tumor formation rates in the two groups were 90.9%vs 93.3%(P>0.05).These rates were not significantly different between the two groups.The celiac implantation rate and abdominal wall metastasis rate in the two groups were 36.4%vs 13.3%(P<0.05)and 27.2%vs 6.7%(P<0.05),respectively,which were significantly different between the two groups.CONCLUSION:The tumor formation rates were not significantly different between the two methods for modeling rabbit VX2 hepatocarcinoma.However,the improved method is recommended because it has certain advantages.
文摘Background： Although obstructive sleep apnea （OSA） has been recognized as a major risk factor for cardiovascular complications and its clinical features are well characterized, it is difficult to replicate the OSA hypoxic model in humans. We aimed to establish an experimental rabbit model for chronic OSA and to explore its application to measure blood pressure （BP）, myocardial systolic function, and oxidative stress. Methods： The rabbit model for OSA was established by repeatedly closing the airway and then reopening it. A tube specially designed with a bag that could be alternately inflated and deflated according to a predetermined time schedule, resulting in recurrent airway occlusions and chronic intermittent hypoxia （CIH） imitating OSA patterns in humans, was used. Twenty-four rabbits were randomly divided into obstruction, sham, and control groups, and their upper airways were alternately closed for 15 s and then reopened for 105 s in a 120-s-long cycle, for 8 h each day over 12 consecutive weeks. Before and after the experiment, the BP of each rabbit was monitored. Levels of interleukin-6 （IL-6） and tumor necrosis factor-α （TNF-α） in the serum, superoxide dismutase （SOD） activity, malondialdehyde （MDA） and reactive oxygen species （ROS） contents, as well as Na＋-K＋-ATPase/Ca2＋-ATPase activities in cardiac muscle were examined. In addition, cardiac functional parameters were measured using echocardiography. Results： After 3 months, all rabbits in the obstruction group manifested sleepiness performance similar to that observed in OSA patients. Traces of airflow and SpO2 showed that this model mimicked the respiratory events involved in OSA, including increased respiratory effort and decreased oxygen saturation. Gradually, the BP rose each month. CIH led to obvious oxidative stress and injured myocardial systolic performance. The serum levels of IL-6 and TNF-α increased significantly （64.75 ± 9.05 pg/ml vs. 147.00 ± 19.24 pg/ml and 59.38 ± 8.21 pg/ml vs. 264.75 ± 25.54 pg/ml, respectively, both P 〈 0.001）. Compared with the sham and the control groups, myocardial activities of Na＋-K＋-ATPase/Ca-2＋-ATPase and SOD in the obstruction group decreased markedly, while ROS and MDA content increased. Conclusions： These results show that the rabbit model for OSA simulates the pathophysiological characteristics of OSA in humans, which implies that this animal model is feasible and useful to study the mechanisms involved in the cardiovascular consequences of OSA.
文摘To develop an easy, reproducible experimental model of cerebral infarction(CI)without craniotomy in New Zealand white rabbits,a silicone rubber cylinder embedded in a nylon suture was delivered to the middle cerebral arteries through the internal carotid artery in anesthetized animals.Rabbits were sacrificed 0.5-5 h after embolization.CI size and location were ascertained by the tripheny1-2H-tetrazoliuni chloride(TTC)staining method;cerebral blood flow(CBF)was measured prior to and after embolization.Pco2,temperature and blood pressure were monitored and kept constant.CI occurred in all rabbits after 4 h of ischemia,in 50% after 3 h and only in 33% after 2.5 h.CI did not occur within less than 2.5 h of ischemia.No correlation was found between size and location of CI and occlusion time.CBF was maximally reduced in the right MCA territory but was also reduced in both anterior cerebral arteries and left MCA territories.This model is technically easy and the retrievable embolus allows the study of reperfusion by pulling on the nylon suture.It is suitable for studying chemical and molecular changes of the ischemic cells and/or for studying neuroimage changes after ischemic stroke.
基金This work was supported by the National Natural Science Foundation of China (No30371831)
文摘Objective To investigate the effects of low dosage of β-elemene on the radiosensitivity of rabbit VX2 renal transplant carcinoma model. Methods We took the rabbit VX2 renal transplant carcinoma as the model. Experimental rabbits were divided into three groups: the control group, the radiation group, and the radiation +β-elemene (radiosensitivity) group. The change of tumor was observed by Spiral CT and B ultrasound to compare its regrowth period. The tumor was measured by light microscopy and electron microscopy. Results The tumor in radiosensitivity group was restrained obviously and the sensitization enhancement ratio (SER) of β-elemene was 1.89. Different apoptosis was observed under transmission electron microscopy. Conclusion Low dosage β-elemene can enhance the radiosensitivity of rabbit VX2 renal transplant carcinoma model and induce the apoptosis of tumor cells, but the mechanism needs further study. It promotes apoptosis in mechanisms in vitro.
基金supported by China Postdoctoral Science Foundation(20090451250)the Program for Changjiang Scholars and Innovative Research Team in Ministry of Education of China(IRT0848)the Project of Youth Fund of Education of Department of Sichuan Province(09ZB054)
文摘[ Objective] This study was conducted to explore the method of establishing Lipopolysaccharide （LPS） -induced mastitis pathological models and reveal dynamic pathological changes of mammary tissue before and after LPS perfusion, finally providing convenient animal models for establishing LPS- induced acute clinical mastitis researches. [ Method] Twelve lactating rabbits （the 7th day after parturition） were perfused with LPS into the fourth mammary gland via the teat duct. Exactly at 2h before perfusion, 6 h, 12 h, 24 h, 48 h, 72 h, 5 d and 7 d after, the indexes such as rectal temperature, total white blood calls and neutrophils, C -response protein （CPR） content and lactate dehydrogenase （LDH） activity were determined, respectively. Then the rabbits were euthanatized and the mammary glands were removed and fixed for histopathologic evalua- tions. [Result] The results showed that inflammatory cells were observed in mammary tissue 6 h after LPS perfusion, structure of mammary tissue disorderly at 24 h, self - regeneration after 48 h and back to normal at 7 d. LDH activity was increasing significantly （ P 〈 0.05） at 12 h （ P 〈 0.05）, peaking at 24 h, decreasing at 5 d （ P 〈 0.05） and returning to health at 7 d. CRP content was increasing significantly （ P 〈 0.05） at 6 to 72 h, pea- king at 12 h, decreasing at 48 h, back to normal at 5 d. [ Conclusion] The results suggested that the rabbit experimental mastitis model was suc- cassfullv constructed bv LPS Derfusion via teat duct.
