BACKGROUND： Ventricular arrhythmia （VA） is one of the most common complications of myocardial infarction （MI）, and ventricular tachycardia and fibrillation are the main causes for sudden cardiac death. This study...BACKGROUND： Ventricular arrhythmia （VA） is one of the most common complications of myocardial infarction （MI）, and ventricular tachycardia and fibrillation are the main causes for sudden cardiac death. This study aimed to explore the effect of ramipril on the occurrence of VA and its mechanism after MI in rabbits. METHODS： Twenty-four New Zealand rabbits purchased from the Wuhan Laboratory Animal Research Center were divided into three groups： sham-operated （SHAM） group （n=8）, MI group （n=8） and MI with ramipril （RAM） group （n=8）. Rabbits in the SHAM group received a median sternotomy without ligation of the left ventricular coronary artery. Rabbits in the MI and RAM groups received a median sternotomy followed by ligation of the left coronary artery. The successful anterior MI was confirmed by elevation of the ST segment with more than 0.2 mV in lead II and II1. After MI, rabbits in the RAM group were fed with intragastric ramipril （1 mg/kg per day ） for 12 weeks. Before and 12 weeks after MI in the three groups, ventricular tachycardia or fibrillation （VT/VF） episodes and MAP in cadiocytes of the epicardium, mid-myocardium and endocardium were recorded by a multichannel physiograph. Student＇s t test and ANOVA were used for statistical analysis. RESULTS： VT/VF episodes were decreased more markedly in the RAM group than in the MI group after 12 weeks （2.6±0.8 vs. 12.±＋2.9, P〈0.05）. Twelve weeks after MI, the duration of repolarization for 90% （APD90） of three-tier ventricular myocytes in the MI group was longer than that before MI （258.2±21.1 vs. 230.1±23.2,278.0±23.8 vs. 245.8±25.4,242.6±22.7 vs. 227.0±21.7, P〈0.05）. However, the APD90 was not significantly different at 12 weeks before and after MI in the RAM group （P〉0.05）. Moreover, the transmural dispersion of repolarization （TDR） was increased more markedly 12 weeks after MI in the MI group than in the SHAM and RAM groups （36.2±10.2 vs. 18.7±6.2, 24.9±8.7, P〈0.05）. But the TDR was not significantly different between the RAM and SHAM groups （18.7±6.2 vs. 24.9±8.7, P〉0.05）. CONCLUSION： Ramipril may reduce the incidence of malignant ventricular arrhythmia via mprovement of transmembrance repolarization heterogeneity after MI.展开更多
Two experimental patterns of autogenous nerve replantation in situ and centrocentralnerve suture were performed on the rabbit median and ulnar nerves.The results of light andtransmission electron microscopy as well as...Two experimental patterns of autogenous nerve replantation in situ and centrocentralnerve suture were performed on the rabbit median and ulnar nerves.The results of light andtransmission electron microscopy as well as immunohistochemistry showed that autogenous nervereplantation in situ could inhibit the formation of neuroma.The mechanism might be that twoproximal stump axons could touch within the interpolated graft segment.Simple end-to-endnerve suture failed to inhibit neuroma development because of a lack of proper environment forthe touching between two proximal stump axons.展开更多
Changes in plasma atrial natriuretic peptide(ANP)and serum lipids were observed us-ing dietetic atherosclerosis(AS)models.The results showed that plasma ANP level of the ASgroup was significantly higher than that of t...Changes in plasma atrial natriuretic peptide(ANP)and serum lipids were observed us-ing dietetic atherosclerosis(AS)models.The results showed that plasma ANP level of the ASgroup was significantly higher than that of the control group(14.33±3.58μg/L vs 9.43±3.14μg/L).There was also a marked increase in serum Tch,TG,LDL-ch and VLDL-ch comparedwith the control group(P【0.01),suggesting that release of ANP increased with disturbance ofthe serum lipids and during AS formation,and that change in ANP was closely related to Tchand LDL-ch(P【0.05).Possible mechanisms causing these changes are also discussed.展开更多
Effects of WH-1 and WH-2 eye drops on experimental allergic uveitis(FAU)in rabbits induced by bovine serum albumin were clinically and pathologically observed in comparisonwith local drops of dexamethasone used as pos...Effects of WH-1 and WH-2 eye drops on experimental allergic uveitis(FAU)in rabbits induced by bovine serum albumin were clinically and pathologically observed in comparisonwith local drops of dexamethasone used as positive control.The results showed that WH-2 obvi-ously inhibited the inflammatory reactions while WH-1 did not.Protein concenwation in the aqueoushumor of WH-2-treated group of rabbits was 9.24±2.34mg/ml,which was notably lower(P【0.01)than both that of the untreated(14.33±3.14 mg/ml)and of the WH-1-treated(12.91±3.95mg/ml),but signifificantly higher than that of the dexame dexamethasone-treated goup(4.43±1.43mg/ml,P【0.01).The alleviation of the intraocular inflammatory reaction by therapy of WH-2eye drops was confimed pathologically.This study indicates that WH-2 has a positiveantiphlogistic effect on EAU in rabbits.展开更多
Modification was made on the reversed-phase high performance liquid chromatography(RP-HPLC)with Yue et al's method as a base.The modified RP-HPLC was used to detect leukotriene B_4(LTB_4)and 5-hydroxyeicosatetraen...Modification was made on the reversed-phase high performance liquid chromatography(RP-HPLC)with Yue et al's method as a base.The modified RP-HPLC was used to detect leukotriene B_4(LTB_4)and 5-hydroxyeicosatetraenoic acid(5-HETE).It was found that the modified method has the merits of simpler procedures,shorter testing time and more satisfactory efficacy.展开更多
The dynamic changes of tumor necrosis factor (TNF) in the circulating blood and its effects on the severity of Pseudomonas aeruginosa induced septic shock were observed in rabbits. 7×109 and 2×109 P. aerugin...The dynamic changes of tumor necrosis factor (TNF) in the circulating blood and its effects on the severity of Pseudomonas aeruginosa induced septic shock were observed in rabbits. 7×109 and 2×109 P. aeruginosa per ki1ogram body weight were intravenously infused to the rabbits to induce mild and severe septic shock.Particular dynamic characterictics of the changes of the circulating TNF were found during P. aeruginosa septic shock. The increase of TNF level in the circulating blood was closely correlated to the initiation and development of P. aeruginosa shock. It is concluded that TNF plays an important role in the mediation of the pathological manifestations of P. aeruginosa shock.展开更多
Simple stretching was applied to the median nerve of rabbits in vivo to study the relationship of different tension with the change of intraneural blood vessels. It was found that when the tension on the nerve was 42 ...Simple stretching was applied to the median nerve of rabbits in vivo to study the relationship of different tension with the change of intraneural blood vessels. It was found that when the tension on the nerve was 42 g, the intraneural blood backflow was blocked, while the arterioles entering the nerve trunk remained open; when the tension was increased to 93 g, the intraneural blood volume was decreased along with the increase of vascular permeability; and when the tension was further increased to 137 g, the intraneural blood supply was completely interrupted.The main injurious factors resulting in acute stretching injury of the peripheral nerves and the clinical significance of the changes of intraneural blood circulation were discussed.展开更多
Objective： To establish an experimental model of urethral stricture in rabbits. Methods： A total of 21 adult male New Zealand rabbits were included into group. After intravenous anesthesia, urethroscopy was performe...Objective： To establish an experimental model of urethral stricture in rabbits. Methods： A total of 21 adult male New Zealand rabbits were included into group. After intravenous anesthesia, urethroscopy was performed with a pediatric resectoscope （F13）. Fifteen animals were randomly selected as the study group. A lcm-long circumferential electrocoagulation of the bulbar urethra was performed to these animals until ulceration of the mucosa. The remaining 6 animals underwent video urethroscopy without electrocoagulation, serving as controls. On the 30th day, retrograde urethrogram and urethroscopy were performed to evaluate urethral stricture formation, histological examinations （HE and Sirius Red staining） were done to assess urethral pathological change. Results： Two rabbits in study group died and no death occurred in controls. Based on urethrogram and urethroscopy, no rabbits in control group developed urethral stricture, while significant stricture formation was observed in every case of the study group. Histological examination showed a normal urethra in control cases, while at stricture site of the study group extensive fibrosis of muscle and submucous tis High collagen expression in fibrosis tissue was assayed sue by was observed with a large number of fibroblasts infiltration Sirius Red staining. Conclusion： A lcm-long endoscopic electrocoagulation can successfully induce urethral stricture formation in rabbit models. This method offers an ideal animal model for the fundamental and clinical study of urethral stricture展开更多
Objective: To observe the subclinical damage and natural repairing process of the tibial nerve during and after limb lengthening with slow stretching in 10 rabbits. Methods: The tibia of Japanese rabbits was lengthene...Objective: To observe the subclinical damage and natural repairing process of the tibial nerve during and after limb lengthening with slow stretching in 10 rabbits. Methods: The tibia of Japanese rabbits was lengthened by 4O%. Before, during and in the following 8 weeks after the limb elongation, the compound sensory evoked potential (CSEP) of posterior tibial nerves in both hind limbs was recorded with electrophysiological instrument. The histological changes were observed under light and electron microscope . Results: During limb lengthening, significant changes in the latent period, peak value and area of the CSEP were fond. The latent period recovered by 50% ac 65% respectively in 2th and 4th week after the tibia being lengthened by 40%. An the 3 parameters of the CSEP, were restored up to 95% as the control in 8th week after elongation and the histological damages also recovered at the same time. Conclusion: The subclinical damage of the peripheral nerve during limb lengthening is temporary and convertible with Ilizarov’s [1] gradual limb lengthening method .展开更多
The regulatory effects of phospholipase A2(PLA2) inhibitors, chloroquine and dexamethasone, on the activity of blood PLA2 and its related lipid mediators during endotoxic shock were observed in rabbits. The rabbits we...The regulatory effects of phospholipase A2(PLA2) inhibitors, chloroquine and dexamethasone, on the activity of blood PLA2 and its related lipid mediators during endotoxic shock were observed in rabbits. The rabbits were randomized into 4 groups as follows : The normal control (NC) group consisted of 12 rabbits with sham injection . the endotoxic shork (ES) group of 31 rabbits, the chloquine pretreated (CQ) group of 16 rabbits receiving 3 mg/kg of chlorqouine and the dexamethasone-pretreated (DM) group of 10 rabbits receiving 5 mg/kg of dexamethasone. Blood was sampled before and 5 and 30 min, 1 ,3, 5 and 8 h after the administration of endotoxin for the determination of PLA2, platelet activating factor (PAF) , TXB2 and 6-keto-PGF1α. In addrtion, changes of mean arterial pressure (MAP) and respiratory rate (RR) were also carefully recorded. It was found that the activities of PLA2 and PAF and the levels of TXB2 and 6-keto-PGF1α. were significantly increased after the infusion of endotoxin. CQ and DM markedly suppressed the activities of PLA2 and PAF. The inhibition of CQ on TXB2 and 6-keto-PGF1α was greater than that of DM. Besides, CQ and DM could increase the survival rate of the animals from 48% to 75% (CQ group) and 70% (DM group). These findings suggest that PLA2 inhibitors such as CQ and DM can significantly attenuate the formation of shock mediators such as PLA2, PAF, TXB2 and 6-keto-PGF1α, and so improve the prognosis of the victims of endotoxic shock.展开更多
The aim of this study was to identify the long noncoding RNAs(IncRNAs)specifically expressed in partially injured anterior cruciate ligament(ACL)and medial collateral ligament(MCL)of rabbits.Partial damage models of A...The aim of this study was to identify the long noncoding RNAs(IncRNAs)specifically expressed in partially injured anterior cruciate ligament(ACL)and medial collateral ligament(MCL)of rabbits.Partial damage models of ACL and MCL were established in 3-month-old healthy male New Zealand white rabbits.Expression of IncRNA and mRNA in the injured tissue was detected by high-throughput sequencing technology,and biological functions of the resulted differentially expressed RNAs were evaluated by Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses.展开更多
In order to clarify whether gentamicin （GM） could damage the renal glomeruli,theultrastructural changes of the renal cortex were observed in rabbits after they received a singleinjection of 100 mg/kg GM or 100 mg...In order to clarify whether gentamicin （GM） could damage the renal glomeruli,theultrastructural changes of the renal cortex were observed in rabbits after they received a singleinjection of 100 mg/kg GM or 100 mg·kg<sup>-10</sup>·d<sup>-1</sup> GM for 3 consecutive days.The animals ofthe control group received equal amount of normal saline.It was found that some myelin figuresappeared in the epithelial cells of the proximal tubules as early as 1 h after a single GM injec-tion;severe swelling,degeneration,and obvious changes of the organelles were seen in the en-dothelial cells of the glomerular capillaries,the podocytes and the epithelial cells of the proxi-mal tubules 24 h after an injection of GM;and fusion of the processes of podocytes,thickeningof the glomerular membrane and necrosis of the epithelial cells of a part of the’proximal tubuleswere encountered 24h after the 3rd GM injection.These findings demonstrate that GM can in-jure not only the proximal tubules but also the glomeruli in rabbits.展开更多
Objective To study the relaxant effect mechanism of an estrone derivate EA303 on isolate colonic smooth muscle of rabbits.Methods Preparations of the isolated colonic smooth muscle of rabbits were prepared.The effect ...Objective To study the relaxant effect mechanism of an estrone derivate EA303 on isolate colonic smooth muscle of rabbits.Methods Preparations of the isolated colonic smooth muscle of rabbits were prepared.The effect of EA303 on potassium channel,β receptor and prostaglandin were studied by observing the difference of relaxant dose-effect curves of EA303 on preparations pre-contracted with BaCl2,High K+ solution and Acetylcholine chloride(ACh)in the absence or presence incubation with glibenclamide(10 μM),propranolol(0.1 μM)and Indometacin(10 μM).Results The relaxant effect of EA303 on contraction caused by BaCl2 and High K+ solution were weakened by glibenclamide inhibiting the opening of K+ channel while the relaxant effect of that on contraction caused by ACh was strengthened,after adding propranolol inhabiting β receptor,EA303 attenuated the relaxant action on contraction caused by BaCl2.EA303 had some relaxant impact on contraction induced by High K+ solution after adding indometacin inhabiting the synthesis the prostaglandin(PG).Conclusions The relaxant effect of EA303 on isolated colonic smooth muscle of rabbits may be related with PG synthesis enzyme,potassium channel and β receptor.展开更多
Objective To explore the influence of styptic fiber on clotting time in rabbits so as to provide experiment data for its development.Methods Onto 0.1 mL aliquots of citrated anti-coagulant rabbit blood placed in a sur...Objective To explore the influence of styptic fiber on clotting time in rabbits so as to provide experiment data for its development.Methods Onto 0.1 mL aliquots of citrated anti-coagulant rabbit blood placed in a surfacial plate 25 ul of 0.2 mol·L-1 CaCl2 solution was dropped,and mixed well with glass stirrer;the resulting mixture was immediately capped with a piece of styptic fiber(test product group)or absorptive gelatin sponge(positive control group)of 2 cm diameter.Then,the surficial plate was rinsed with 30ml of purified water at 5,10,20,30,40 and 50 min after capping;the rinsings were allowed to stand for 1 h and were subjected to OD determination at a wavelength of 541 nm.The above procedure was repeated twice,the average value of the twice experiments was taken for evaluation of the hemostatic effect of test product.For negative control group,all procedures except for capping were same as the test product group.The haemostatic effect was judged by percent OD relative to OD at 0 min in negative control group(OD 0 min)(OD 0 min was considered as 100%);if OD value at a time was less than 80% of OD 0 min,it should be designated as primary clotting time(PCT),less than 20% as complete clotting time(CCT).Results The measured PCT was 20min for both negative and positive control groups;CCT was 50,30 and 5 min for negative control,positive control and test product groups,respectively,showing the test styptic fiber had a CCT 8 times shorter than untreated blood,10 times shorter than negative control and 6 times shorter than positive control.Conclusions The test styptic fiber has powerful hemostatic effect.展开更多
Objective: To establish a rabbit atrial fibrillation model with rapid atrial pacing (RAP) and investigate its ultrastructural changes and expressions of L-type calcium channel subunits and potassium channel Kv4. 3. Me...Objective: To establish a rabbit atrial fibrillation model with rapid atrial pacing (RAP) and investigate its ultrastructural changes and expressions of L-type calcium channel subunits and potassium channel Kv4. 3. Methods: Thirty-six rabbits were performed electrical stimulation through bipolar endo-cardial led by surgical technique. 600 beat per min from 0 to 48 h. Atrial ultrastructure was observed by transmission electron microscope (TEM) after different pacing times. mRNA were measured by reverse transcription-polymera.se chain reaction (RT-PCR). Results: Atrial ultrastructure had alteration after 3 hours' pacing, such as mitochondria vacuolization, myofilament lysis and glucogen aggregation. The mRNA of the Ca2+ channel β1 and α1 subunits began to decrease after pacing of 6 h. which were paralleled with the change of Kv4. 3 mRNA. But the auxiliary subunit α2 were not affected. Conclusion: Ultrastructural changes and mRNA levels of L-type calcium channel subunits and potassium channel Kv4. 3 are decreased after RAP. with a mechanism of transcriptional down-regulation of underlying ion channels due to calcium overloading after RAP.展开更多
This study aimed to characterize and identify calcium-chelating peptides from rabbit bone collagen and explore the underlying chelating mechanism.Collagen peptides and calcium were extracted from rabbit bone by instan...This study aimed to characterize and identify calcium-chelating peptides from rabbit bone collagen and explore the underlying chelating mechanism.Collagen peptides and calcium were extracted from rabbit bone by instant ejection steam explosion(ICSE)combined with enzymatic hydrolysis,followed by chelation reaction to prepare rabbit bone peptide-calcium chelate(RBCP-Ca).The chelating sites were further analyzed by liquid chromatography-tandem mass(LC-MS/MS)spectrometry while the chelating mechanism and binding modes were investigated.The structural characterization revealed that RBCP successfully chelated with calcium ions.Furthermore,LC-MS/MS analysis indicated that the binding sites included both acidic amino acids(Asp and Glu)and basic amino acids(Lys and Arg),Interestingly,three binding modes,namely Inter-Linking,Loop-Linking and Mono-Linking were for the first time found,while Inter-Linking mode accounted for the highest proportion(75.1%),suggesting that chelation of calcium ions frequently occurred between two peptides.Overall,this study provides a theoretical basis for the elucidation of chelation mechanism of calcium-chelating peptides.展开更多
The high-intensity heavy-ion accelerator facility(HIAF)is a scientific research facility complex composed of multiple cas-cade accelerators of different types,which pose a scheduling problem for devices distributed ov...The high-intensity heavy-ion accelerator facility(HIAF)is a scientific research facility complex composed of multiple cas-cade accelerators of different types,which pose a scheduling problem for devices distributed over a certain range of 2 km,involving over a hundred devices.The white rabbit,a technology-enhancing Gigabit Ethernet,has shown the capability of scheduling distributed timing devices but still faces the challenge of obtaining real-time synchronization calibration param-eters with high precision.This study presents a calibration system based on a time-to-digital converter implemented on an ARM-based System-on-Chip(SoC).The system consists of four multi-sample delay lines,a bubble-proof encoder,an edge controller for managing data from different channels,and a highly effective calibration module that benefits from the SoC architecture.The performance was evaluated with an average RMS precision of 5.51 ps by measuring the time intervals from 0 to 24,000 ps with 120,000 data for every test.The design presented in this study refines the calibration precision of the HIAF timing system.This eliminates the errors caused by manual calibration without efficiency loss and provides data support for fault diagnosis.It can also be easily tailored or ported to other devices for specific applications and provides more space for developing timing systems for particle accelerators,such as white rabbits on HIAF.展开更多
《义务教育英语课程标准(2022年版)》指出,教师应组织开展生动多样的活动,如对话交流、短剧展示、歌曲演唱、故事创编、海报设计等,引导学生做到“想表达”“能表达”和“会表达”,体验英语学习的乐趣与意义,获得成就感和自信心。文章...《义务教育英语课程标准(2022年版)》指出,教师应组织开展生动多样的活动,如对话交流、短剧展示、歌曲演唱、故事创编、海报设计等,引导学生做到“想表达”“能表达”和“会表达”,体验英语学习的乐趣与意义,获得成就感和自信心。文章以绘本Clever Rabbit and the Lion的戏剧教学为例,阐述在戏剧教学中培养学生积极心理品质的策略。展开更多
Objective:To investigate the morphological changes of the neuronal neurites in diabetic rabbit brain. Methods: Twenty- four New Zealand White rabbits were divided into 2 groups: control group and type Ⅱ diabetic grou...Objective:To investigate the morphological changes of the neuronal neurites in diabetic rabbit brain. Methods: Twenty- four New Zealand White rabbits were divided into 2 groups: control group and type Ⅱ diabetic group induced by high - carbohydrate and high- fat diet. The levels of blood sugar and insulin were detected at week 0(w0), w4, w8, w13, w18, w23 and w28. Brain tissue was stained by Nissl staining and immunolistochemistry with a specific antibody to neurofilament proteins. Result: In diabetic rabbits, the amount of large pyramidal neuron was significantly reduced, and neuronal neurites became swollen, whorled, disrupted and changed in caliber. In hippocampus CA1 region neurofilament staining was very weak. Conclusion: Neurotoxicity of chronic hyperglycemia might be relevant to vascular chronic complications, which affected the expression of NF and led to neurophysiological and structural changes in the brain of rabbits with type Ⅱ diabetes.展开更多
基金supported by a grant from the Natural Science Foundation of Hubei(2007ABA288)
文摘BACKGROUND： Ventricular arrhythmia （VA） is one of the most common complications of myocardial infarction （MI）, and ventricular tachycardia and fibrillation are the main causes for sudden cardiac death. This study aimed to explore the effect of ramipril on the occurrence of VA and its mechanism after MI in rabbits. METHODS： Twenty-four New Zealand rabbits purchased from the Wuhan Laboratory Animal Research Center were divided into three groups： sham-operated （SHAM） group （n=8）, MI group （n=8） and MI with ramipril （RAM） group （n=8）. Rabbits in the SHAM group received a median sternotomy without ligation of the left ventricular coronary artery. Rabbits in the MI and RAM groups received a median sternotomy followed by ligation of the left coronary artery. The successful anterior MI was confirmed by elevation of the ST segment with more than 0.2 mV in lead II and II1. After MI, rabbits in the RAM group were fed with intragastric ramipril （1 mg/kg per day ） for 12 weeks. Before and 12 weeks after MI in the three groups, ventricular tachycardia or fibrillation （VT/VF） episodes and MAP in cadiocytes of the epicardium, mid-myocardium and endocardium were recorded by a multichannel physiograph. Student＇s t test and ANOVA were used for statistical analysis. RESULTS： VT/VF episodes were decreased more markedly in the RAM group than in the MI group after 12 weeks （2.6±0.8 vs. 12.±＋2.9, P〈0.05）. Twelve weeks after MI, the duration of repolarization for 90% （APD90） of three-tier ventricular myocytes in the MI group was longer than that before MI （258.2±21.1 vs. 230.1±23.2,278.0±23.8 vs. 245.8±25.4,242.6±22.7 vs. 227.0±21.7, P〈0.05）. However, the APD90 was not significantly different at 12 weeks before and after MI in the RAM group （P〉0.05）. Moreover, the transmural dispersion of repolarization （TDR） was increased more markedly 12 weeks after MI in the MI group than in the SHAM and RAM groups （36.2±10.2 vs. 18.7±6.2, 24.9±8.7, P〈0.05）. But the TDR was not significantly different between the RAM and SHAM groups （18.7±6.2 vs. 24.9±8.7, P〉0.05）. CONCLUSION： Ramipril may reduce the incidence of malignant ventricular arrhythmia via mprovement of transmembrance repolarization heterogeneity after MI.
文摘Two experimental patterns of autogenous nerve replantation in situ and centrocentralnerve suture were performed on the rabbit median and ulnar nerves.The results of light andtransmission electron microscopy as well as immunohistochemistry showed that autogenous nervereplantation in situ could inhibit the formation of neuroma.The mechanism might be that twoproximal stump axons could touch within the interpolated graft segment.Simple end-to-endnerve suture failed to inhibit neuroma development because of a lack of proper environment forthe touching between two proximal stump axons.
文摘Changes in plasma atrial natriuretic peptide(ANP)and serum lipids were observed us-ing dietetic atherosclerosis(AS)models.The results showed that plasma ANP level of the ASgroup was significantly higher than that of the control group(14.33±3.58μg/L vs 9.43±3.14μg/L).There was also a marked increase in serum Tch,TG,LDL-ch and VLDL-ch comparedwith the control group(P【0.01),suggesting that release of ANP increased with disturbance ofthe serum lipids and during AS formation,and that change in ANP was closely related to Tchand LDL-ch(P【0.05).Possible mechanisms causing these changes are also discussed.
文摘Effects of WH-1 and WH-2 eye drops on experimental allergic uveitis(FAU)in rabbits induced by bovine serum albumin were clinically and pathologically observed in comparisonwith local drops of dexamethasone used as positive control.The results showed that WH-2 obvi-ously inhibited the inflammatory reactions while WH-1 did not.Protein concenwation in the aqueoushumor of WH-2-treated group of rabbits was 9.24±2.34mg/ml,which was notably lower(P【0.01)than both that of the untreated(14.33±3.14 mg/ml)and of the WH-1-treated(12.91±3.95mg/ml),but signifificantly higher than that of the dexame dexamethasone-treated goup(4.43±1.43mg/ml,P【0.01).The alleviation of the intraocular inflammatory reaction by therapy of WH-2eye drops was confimed pathologically.This study indicates that WH-2 has a positiveantiphlogistic effect on EAU in rabbits.
文摘Modification was made on the reversed-phase high performance liquid chromatography(RP-HPLC)with Yue et al's method as a base.The modified RP-HPLC was used to detect leukotriene B_4(LTB_4)and 5-hydroxyeicosatetraenoic acid(5-HETE).It was found that the modified method has the merits of simpler procedures,shorter testing time and more satisfactory efficacy.
文摘The dynamic changes of tumor necrosis factor (TNF) in the circulating blood and its effects on the severity of Pseudomonas aeruginosa induced septic shock were observed in rabbits. 7×109 and 2×109 P. aeruginosa per ki1ogram body weight were intravenously infused to the rabbits to induce mild and severe septic shock.Particular dynamic characterictics of the changes of the circulating TNF were found during P. aeruginosa septic shock. The increase of TNF level in the circulating blood was closely correlated to the initiation and development of P. aeruginosa shock. It is concluded that TNF plays an important role in the mediation of the pathological manifestations of P. aeruginosa shock.
文摘Simple stretching was applied to the median nerve of rabbits in vivo to study the relationship of different tension with the change of intraneural blood vessels. It was found that when the tension on the nerve was 42 g, the intraneural blood backflow was blocked, while the arterioles entering the nerve trunk remained open; when the tension was increased to 93 g, the intraneural blood volume was decreased along with the increase of vascular permeability; and when the tension was further increased to 137 g, the intraneural blood supply was completely interrupted.The main injurious factors resulting in acute stretching injury of the peripheral nerves and the clinical significance of the changes of intraneural blood circulation were discussed.
基金Supported by the Key Sci-Tech Research Project of Shaanxi Province(2006K12-G3)
文摘Objective： To establish an experimental model of urethral stricture in rabbits. Methods： A total of 21 adult male New Zealand rabbits were included into group. After intravenous anesthesia, urethroscopy was performed with a pediatric resectoscope （F13）. Fifteen animals were randomly selected as the study group. A lcm-long circumferential electrocoagulation of the bulbar urethra was performed to these animals until ulceration of the mucosa. The remaining 6 animals underwent video urethroscopy without electrocoagulation, serving as controls. On the 30th day, retrograde urethrogram and urethroscopy were performed to evaluate urethral stricture formation, histological examinations （HE and Sirius Red staining） were done to assess urethral pathological change. Results： Two rabbits in study group died and no death occurred in controls. Based on urethrogram and urethroscopy, no rabbits in control group developed urethral stricture, while significant stricture formation was observed in every case of the study group. Histological examination showed a normal urethra in control cases, while at stricture site of the study group extensive fibrosis of muscle and submucous tis High collagen expression in fibrosis tissue was assayed sue by was observed with a large number of fibroblasts infiltration Sirius Red staining. Conclusion： A lcm-long endoscopic electrocoagulation can successfully induce urethral stricture formation in rabbit models. This method offers an ideal animal model for the fundamental and clinical study of urethral stricture
文摘Objective: To observe the subclinical damage and natural repairing process of the tibial nerve during and after limb lengthening with slow stretching in 10 rabbits. Methods: The tibia of Japanese rabbits was lengthened by 4O%. Before, during and in the following 8 weeks after the limb elongation, the compound sensory evoked potential (CSEP) of posterior tibial nerves in both hind limbs was recorded with electrophysiological instrument. The histological changes were observed under light and electron microscope . Results: During limb lengthening, significant changes in the latent period, peak value and area of the CSEP were fond. The latent period recovered by 50% ac 65% respectively in 2th and 4th week after the tibia being lengthened by 40%. An the 3 parameters of the CSEP, were restored up to 95% as the control in 8th week after elongation and the histological damages also recovered at the same time. Conclusion: The subclinical damage of the peripheral nerve during limb lengthening is temporary and convertible with Ilizarov’s [1] gradual limb lengthening method .
文摘The regulatory effects of phospholipase A2(PLA2) inhibitors, chloroquine and dexamethasone, on the activity of blood PLA2 and its related lipid mediators during endotoxic shock were observed in rabbits. The rabbits were randomized into 4 groups as follows : The normal control (NC) group consisted of 12 rabbits with sham injection . the endotoxic shork (ES) group of 31 rabbits, the chloquine pretreated (CQ) group of 16 rabbits receiving 3 mg/kg of chlorqouine and the dexamethasone-pretreated (DM) group of 10 rabbits receiving 5 mg/kg of dexamethasone. Blood was sampled before and 5 and 30 min, 1 ,3, 5 and 8 h after the administration of endotoxin for the determination of PLA2, platelet activating factor (PAF) , TXB2 and 6-keto-PGF1α. In addrtion, changes of mean arterial pressure (MAP) and respiratory rate (RR) were also carefully recorded. It was found that the activities of PLA2 and PAF and the levels of TXB2 and 6-keto-PGF1α. were significantly increased after the infusion of endotoxin. CQ and DM markedly suppressed the activities of PLA2 and PAF. The inhibition of CQ on TXB2 and 6-keto-PGF1α was greater than that of DM. Besides, CQ and DM could increase the survival rate of the animals from 48% to 75% (CQ group) and 70% (DM group). These findings suggest that PLA2 inhibitors such as CQ and DM can significantly attenuate the formation of shock mediators such as PLA2, PAF, TXB2 and 6-keto-PGF1α, and so improve the prognosis of the victims of endotoxic shock.
文摘The aim of this study was to identify the long noncoding RNAs(IncRNAs)specifically expressed in partially injured anterior cruciate ligament(ACL)and medial collateral ligament(MCL)of rabbits.Partial damage models of ACL and MCL were established in 3-month-old healthy male New Zealand white rabbits.Expression of IncRNA and mRNA in the injured tissue was detected by high-throughput sequencing technology,and biological functions of the resulted differentially expressed RNAs were evaluated by Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses.
文摘In order to clarify whether gentamicin （GM） could damage the renal glomeruli,theultrastructural changes of the renal cortex were observed in rabbits after they received a singleinjection of 100 mg/kg GM or 100 mg·kg<sup>-10</sup>·d<sup>-1</sup> GM for 3 consecutive days.The animals ofthe control group received equal amount of normal saline.It was found that some myelin figuresappeared in the epithelial cells of the proximal tubules as early as 1 h after a single GM injec-tion;severe swelling,degeneration,and obvious changes of the organelles were seen in the en-dothelial cells of the glomerular capillaries,the podocytes and the epithelial cells of the proxi-mal tubules 24 h after an injection of GM;and fusion of the processes of podocytes,thickeningof the glomerular membrane and necrosis of the epithelial cells of a part of the’proximal tubuleswere encountered 24h after the 3rd GM injection.These findings demonstrate that GM can in-jure not only the proximal tubules but also the glomeruli in rabbits.
文摘Objective To study the relaxant effect mechanism of an estrone derivate EA303 on isolate colonic smooth muscle of rabbits.Methods Preparations of the isolated colonic smooth muscle of rabbits were prepared.The effect of EA303 on potassium channel,β receptor and prostaglandin were studied by observing the difference of relaxant dose-effect curves of EA303 on preparations pre-contracted with BaCl2,High K+ solution and Acetylcholine chloride(ACh)in the absence or presence incubation with glibenclamide(10 μM),propranolol(0.1 μM)and Indometacin(10 μM).Results The relaxant effect of EA303 on contraction caused by BaCl2 and High K+ solution were weakened by glibenclamide inhibiting the opening of K+ channel while the relaxant effect of that on contraction caused by ACh was strengthened,after adding propranolol inhabiting β receptor,EA303 attenuated the relaxant action on contraction caused by BaCl2.EA303 had some relaxant impact on contraction induced by High K+ solution after adding indometacin inhabiting the synthesis the prostaglandin(PG).Conclusions The relaxant effect of EA303 on isolated colonic smooth muscle of rabbits may be related with PG synthesis enzyme,potassium channel and β receptor.
文摘Objective To explore the influence of styptic fiber on clotting time in rabbits so as to provide experiment data for its development.Methods Onto 0.1 mL aliquots of citrated anti-coagulant rabbit blood placed in a surfacial plate 25 ul of 0.2 mol·L-1 CaCl2 solution was dropped,and mixed well with glass stirrer;the resulting mixture was immediately capped with a piece of styptic fiber(test product group)or absorptive gelatin sponge(positive control group)of 2 cm diameter.Then,the surficial plate was rinsed with 30ml of purified water at 5,10,20,30,40 and 50 min after capping;the rinsings were allowed to stand for 1 h and were subjected to OD determination at a wavelength of 541 nm.The above procedure was repeated twice,the average value of the twice experiments was taken for evaluation of the hemostatic effect of test product.For negative control group,all procedures except for capping were same as the test product group.The haemostatic effect was judged by percent OD relative to OD at 0 min in negative control group(OD 0 min)(OD 0 min was considered as 100%);if OD value at a time was less than 80% of OD 0 min,it should be designated as primary clotting time(PCT),less than 20% as complete clotting time(CCT).Results The measured PCT was 20min for both negative and positive control groups;CCT was 50,30 and 5 min for negative control,positive control and test product groups,respectively,showing the test styptic fiber had a CCT 8 times shorter than untreated blood,10 times shorter than negative control and 6 times shorter than positive control.Conclusions The test styptic fiber has powerful hemostatic effect.
基金Supported by National Natural Science Foundation of China (No.30370583)
文摘Objective: To establish a rabbit atrial fibrillation model with rapid atrial pacing (RAP) and investigate its ultrastructural changes and expressions of L-type calcium channel subunits and potassium channel Kv4. 3. Methods: Thirty-six rabbits were performed electrical stimulation through bipolar endo-cardial led by surgical technique. 600 beat per min from 0 to 48 h. Atrial ultrastructure was observed by transmission electron microscope (TEM) after different pacing times. mRNA were measured by reverse transcription-polymera.se chain reaction (RT-PCR). Results: Atrial ultrastructure had alteration after 3 hours' pacing, such as mitochondria vacuolization, myofilament lysis and glucogen aggregation. The mRNA of the Ca2+ channel β1 and α1 subunits began to decrease after pacing of 6 h. which were paralleled with the change of Kv4. 3 mRNA. But the auxiliary subunit α2 were not affected. Conclusion: Ultrastructural changes and mRNA levels of L-type calcium channel subunits and potassium channel Kv4. 3 are decreased after RAP. with a mechanism of transcriptional down-regulation of underlying ion channels due to calcium overloading after RAP.
基金granted by the National Key R&D Program of China (2021YFD21001005)National Natural Science Foundation of China (31972102,32101980)+1 种基金Special key project of Chongqing technology innovation and application development (cstc2021jscx-cylhX0014)Chongqing Technology Innovation and Application Development Special Project (cstc2021jscx-tpyzxX0014)。
文摘This study aimed to characterize and identify calcium-chelating peptides from rabbit bone collagen and explore the underlying chelating mechanism.Collagen peptides and calcium were extracted from rabbit bone by instant ejection steam explosion(ICSE)combined with enzymatic hydrolysis,followed by chelation reaction to prepare rabbit bone peptide-calcium chelate(RBCP-Ca).The chelating sites were further analyzed by liquid chromatography-tandem mass(LC-MS/MS)spectrometry while the chelating mechanism and binding modes were investigated.The structural characterization revealed that RBCP successfully chelated with calcium ions.Furthermore,LC-MS/MS analysis indicated that the binding sites included both acidic amino acids(Asp and Glu)and basic amino acids(Lys and Arg),Interestingly,three binding modes,namely Inter-Linking,Loop-Linking and Mono-Linking were for the first time found,while Inter-Linking mode accounted for the highest proportion(75.1%),suggesting that chelation of calcium ions frequently occurred between two peptides.Overall,this study provides a theoretical basis for the elucidation of chelation mechanism of calcium-chelating peptides.
基金supported by high-intensity heavy-ion accelerator facility(HIAF)approved by the National Development and Reform Commission of China(2017-000052-73-01-002107)。
文摘The high-intensity heavy-ion accelerator facility(HIAF)is a scientific research facility complex composed of multiple cas-cade accelerators of different types,which pose a scheduling problem for devices distributed over a certain range of 2 km,involving over a hundred devices.The white rabbit,a technology-enhancing Gigabit Ethernet,has shown the capability of scheduling distributed timing devices but still faces the challenge of obtaining real-time synchronization calibration param-eters with high precision.This study presents a calibration system based on a time-to-digital converter implemented on an ARM-based System-on-Chip(SoC).The system consists of four multi-sample delay lines,a bubble-proof encoder,an edge controller for managing data from different channels,and a highly effective calibration module that benefits from the SoC architecture.The performance was evaluated with an average RMS precision of 5.51 ps by measuring the time intervals from 0 to 24,000 ps with 120,000 data for every test.The design presented in this study refines the calibration precision of the HIAF timing system.This eliminates the errors caused by manual calibration without efficiency loss and provides data support for fault diagnosis.It can also be easily tailored or ported to other devices for specific applications and provides more space for developing timing systems for particle accelerators,such as white rabbits on HIAF.
文摘《义务教育英语课程标准(2022年版)》指出,教师应组织开展生动多样的活动,如对话交流、短剧展示、歌曲演唱、故事创编、海报设计等,引导学生做到“想表达”“能表达”和“会表达”,体验英语学习的乐趣与意义,获得成就感和自信心。文章以绘本Clever Rabbit and the Lion的戏剧教学为例,阐述在戏剧教学中培养学生积极心理品质的策略。
基金These authors contribute equally to this work.Supported by the Hunan science fourndation(JJY2069)
文摘Objective:To investigate the morphological changes of the neuronal neurites in diabetic rabbit brain. Methods: Twenty- four New Zealand White rabbits were divided into 2 groups: control group and type Ⅱ diabetic group induced by high - carbohydrate and high- fat diet. The levels of blood sugar and insulin were detected at week 0(w0), w4, w8, w13, w18, w23 and w28. Brain tissue was stained by Nissl staining and immunolistochemistry with a specific antibody to neurofilament proteins. Result: In diabetic rabbits, the amount of large pyramidal neuron was significantly reduced, and neuronal neurites became swollen, whorled, disrupted and changed in caliber. In hippocampus CA1 region neurofilament staining was very weak. Conclusion: Neurotoxicity of chronic hyperglycemia might be relevant to vascular chronic complications, which affected the expression of NF and led to neurophysiological and structural changes in the brain of rabbits with type Ⅱ diabetes.
