European Rabbits as Reservoir for Coxiella burnetii

We studied the role of European rabbits (Oryctolagus cuniculus) as a reservoir for Coxiella burnetii in the Iberian region. High individual and population seroprevalences observed in wild and farmed rabbits, evidence of systemic infections, and vaginal shedding support the reservoir role of the European rabbit for C. burnetii.     

Study of the Dextran-DTPA-Gd at rabbit popliteal fossa lymph node metastasis from thigh transplanted tumor with interstitial magnetic resonance lymDhoqraDhv

Objective： The aim of the study was to investigate the developing situation of the interstitial magnetic resonance （MR） lymphoid contrast agent Dextran-DTPA-Gd through the rabbit popliteal fossa lymph node metastasis from thigh VX2 transplanted tumor injection to show targeting enhanced metastatic lymph nodes and lymphatics. Methods： VX2 tumor was transplanted to the right hind limb quadriceps of 12 healthy New Zealand rabbits and the left side as a contrast. Eight rabbits had homonymy popliteal lymph node metastasis after 1 month through 3.0 GE MRI and they were later injected with lym phatic targeting contrast agent Dextran-DTPA-Gd 0.4 mL （3.96 x 10^-3 tool/L） through bilateral hindlimb toe web respectively. Enhanced MR images were obtained with interval 10 min, 15 min, 20 rain, 25 min, 30 rain, 35 min, 40 rain, 45 rain, 50 min, 55 min, 60 min, 2 h, 4 h, and 24 h. The signal intensities before and after enhancing were measured to calculate the enhanc- ing rates （E%） of popliteal lymph node and the popliteal lymph node signal intensity-time curves were drawn to observe the development of cancer metastasis lymph nodes and lymphatics and to compare the differences of interval sides. Results： Ten minutes after injected into the rabbit＇s bilateral hindlimb toe web, we could see hind lymphatic and popliteal lymph nodes were strengthened significantly and evenly without blood vessels developing. The signal reached a peak after 35 rain with E% to 315%, which decreased to 205% after 4 h and would be undifferentiated with the surrounding tissues after 24 h. Sta- tistical analysis was made to popliteal lymph node enhancement rate. It was considered statistically significant as long as P 〈 0.05. The tumor-side popliteal lymph node manifested as coarse and irregular shape, lymphatic vessels tortuous dilated and lymphatic chain incomplete as a result of tumor infection. Conclusion： Dextran-DTPA-Gd is specific to lymphoid tissue development. It can targeting display regional lymphatic drainage concretion and the morphology of normal and cancer cells metastasis lymph nodes rapidly.     

缺血预处理对兔脊髓缺血损伤后的保护作用及其机制

目的:探讨缺血预处理对兔脊髓缺血损伤的保护作用及机制。方法:24只雄性新西兰大白兔随机数字表法分3组(每组8只):即缺血组(IC组)、缺血预处理组(IPC组)及假手术组(S组)。IC组夹闭兔腹主动脉肾下段20min,制作兔脊髓缺血模型;IPC组预先使脊髓缺血6min,再灌注30min后再次阻闭兔腹主动脉肾下段20min;S组除不夹闭腹主动脉外,其余处理同IC组。再灌注后8,12,24和48h分别对动物神经功能评分;再灌注后48h,测定血浆血栓素B2(TXB2,TXA2的稳定代谢产物)的含量及6-酮前列素(6-keto-PGF1α,PGI2的稳定代谢产物)的含量,然后处死动物取脊髓,测定脊髓组织中TXB2及6-keto-PGF1α的含量。结果:IPC组神经功能评分各时间点均明显高于IC组。与IC组相比,IPC组血浆和脊髓中TXB2含量明显减少,分别为(108±20)mg/L,(733±64)ng/g(P<0.05,F=27.93,132.887),而IPC组血浆和脊髓中6-keto-PGF1α含量明显增多,分别为(75±14)mg/L,(502±37)ng/g(P<0.05,F=13.185,64.141)。IPC组血浆和脊髓中TXB2/6-keto-PGF1α分别为(1.45±0.17),(1.47±0.19),明显低于IC组(P<0.05,F=20.83,29.447)。结论:缺血预处理对脊髓缺血损伤有显著的保护作用,保护机制与缺血预处理改善脊髓缺血损伤后TXA2-PGI2平衡失调有关。     

Reliability of the rabbit postero‐lateral spinal fusion model: A meta‐analysis

The rabbit model of spinal fusion with the autogenous iliac crest bone graft (ICBG) control is widely used to evaluate bone graft substitutes and enhancers. This study examined the reliability of this model using meta‐analysis. A systematic literature search from January 1995 to May 2011 identified 56 studies, involving 733 animals. The primary outcome was fusion success calculated as logit event rate. Study design, surgical technique, rabbit characteristics (gender, species, age, weight), and institution were analyzed. Overall fusion success was 52.4%. Important positive variables were time‐point >4 weeks, ICBG dose >1 cm³, initial weight of animals ≥3 kg, level at L4‐5 or L5‐6, and age ≥6 months. Inter‐ and intra‐institutional reliability was excellent. The rabbit model ICBG control group is reliable, although several factors can affect results. Fusion under normal handling occurs reliably in 5 weeks. The volume of bone graft should be >1 cm³ but no benefits are present with >2 cm³. The animals should weigh a minimum of 3 kg and be at least 6 months old. © 2013 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 31:1261–1269, 2013     

体素内不相干运动和扩散张量成像评价不同剂量非离子型单聚体碘对比剂致兔急性肾损伤

目的 探讨体素内不相干运动（IVIM）和扩散张量成像（DTI）评价不同剂量非离子型单聚体碘对比剂对兔造成的急性肾损伤（AKI）的价值。方法 选择新西兰大白兔36只，随机分为A、B、C、D 4组。分别对4组注射不同剂量的碘海醇，A组：等量生理盐水；B组：半倍剂量碘海醇；C组：常规剂量碘海醇；D组：2倍剂量碘海醇。于注射碘海醇1、24、72 h对兔进行肾脏IVIM、DTI扫描，扫描后每组随机处死3只兔，取右肾进行病理分析。比较4组间D值、D^*值、f值、FA值及缺氧诱导因子1α（HIF-1α）表达量的差异。结果 注射碘海醇1 h，各组D值、D^*值、f值均有所降低，其中D组皮质的D^*值、f值较A组降低最为显著（P均<0.05），髓质D值、D^*值、f值较A组明显下降（P均<0.05）。注射碘海醇24 h，各组指标明显降低，C、D组皮质及髓质D值、D^*值、f值较A组显著降低（P均<0.05）。注射碘海醇72 h，各组皮质及髓质D值、D^*值、f值均逐渐回升，但D组皮质D值、f值较A组仍降低（P均<0.05），C、D组髓质的D值、f值较A组仍降低（P均<0.05）。碘海醇对肾脏髓质损伤明显，可导致肾小球和肾小管细胞出现不同程度的病理损伤，以D组肾小球和肾小管细胞病理改变最显著，HIF-1α表达水平随碘海醇剂量的增加而逐渐升高。结论 应用IVIM、DTI可评估不同剂量碘海醇导致兔AKI，半倍剂量碘海醇对兔肾脏损伤程度最轻，2倍剂量碘海醇对兔肾脏损伤明显增强，注射碘海醇24 h肾损伤最严重，72 h可见不同程度恢复。     

液氮冷冻治疗仪辅助建立兔股骨头缺血性坏死模型

目的:为股骨头缺血性坏死(avascular necrosis of the femoral head,ANFH)的治疗研究建立动物模型。方法:40只健康大白兔建立双侧股骨头骨缺损模型,并用液氮冷冻治疗仪将股骨头冷冻坏死,术后2、4、6、8周处死兔子各4只,对兔子股骨头进行大体标本观察及取股骨头摄X线片。结果:(1)大体标本观察显示,术后2周时可见头部规整、光滑,未见明显塌陷;术后4~6周可见软骨面剥离;术后8周可见骨修复与骨吸收同时存在,股骨头有变小,有轻度塌陷改变,软骨呈苍白色,骨质脆。(2)X线检查示,术后2周可见骨密度有所增加,骨小梁结构完整;术后4~6周可见骨密度增加,骨小梁结构出现紊乱;术后8周可见骨小梁结构紊乱,软骨下囊性变。结论:液氮冷冻建立的兔ANFH模型适合模拟临床治疗的研究。     

一站式CT能谱灌注成像预测兔腋窝淋巴结性质

目的 探讨一站式CT能谱灌注成像定量参数预测兔腋窝淋巴结性质的应用价值。方法 将60只新西兰纯种雌性大白兔随机分为2组,分别建立兔乳腺癌腋窝转移性淋巴结（转移组）与炎性淋巴结动物模型（炎症组）。于建模后第4周末对实验兔行一站式CT能谱灌注成像扫描,扫描完成后摘取腋窝淋巴结行病理检查,并与CT图像逐一对照。采用两独立样本t检验比较2组能谱参数和灌注参数的差异,以Logistic回归和ROC曲线分析单一参数和联合参数诊断实验兔腋窝淋巴结性质的效能。结果 转移组淋巴结的血流量（BF）、血容量（BV）、动静脉期碘浓度（IC）、标准化碘基值（NIC）和40~70 keV间的能谱曲线斜率（λ）均高于炎症组（P均<0.05）,平均通过时间（MTT）和表面通透性（PS）差异无统计学意义（P均>0.05）。最佳联合参数（BF+动脉期λ+静脉期λ）的AUC为0.942,以0.65为临界值,其诊断实验兔腋窝乳腺癌转移性淋巴结的敏感度、特异度、阳性预测值和阴性预测值分别为79.68%、95.92%、92.91%和82.70%。结论 一站式CT能谱灌注成像定量参数鉴别兔腋窝乳腺癌转移性淋巴结与炎性淋巴结的诊断效能较好,联合参数（BF+动脉期λ+静脉期λ）具有较高诊断价值。     

一种新西兰兔颈椎椎间融合模型的建立及评价

目的 利用兔颈椎骨性结构测量数据建立兔颈椎椎间植骨融合内固定动物模型,观察不同时间点椎间融合情况。 方法 选取雄性健康新西兰大白兔36只（2.0~2.5 kg）,随机分为A、B、C、D 4组,每组9只。A组用于解剖测量兔颈椎椎体结构;B、C、D组造模行颈椎椎间植骨融合内固定,植骨材料选用兔自体髂骨。术后4、8、12周对实验动物或标本分别进行大体观察、X线检查、手触检查及微型计算机断层扫描（micro computed tomography,Micro-CT）。 结果 自颈2（C2）~颈6（C6）椎体长度、椎体下端矢状径、椎体下端斜径差异有统计学意义（P＜0.01）。X线检查显示B、C、D组植骨充分,钢板螺钉置入情况良好,仅1例术后发生螺钉松动退钉。B、C、D组手触检查颈椎融合率分别为22.2%（2/9）、55.6%（5/9）、88.9%（8/9）。C组新生骨体积与植入材料总体积比值和X线评分高于B组,D组BV/TV和X线评分高于B组和C组,差异有统计学意义（P＜0.01）。 结论 颈椎椎间植骨融合内固定模型建立方法简便,为颈椎椎间融合的基础研究提供了一种可靠的动物模型。     

椎体间纤维性融合重建兔脊柱稳定性的初步探索

目的:研究椎体间纤维性融合后脊柱节段的稳定性,探讨椎体间纤维性融合在治疗脊柱节段失稳中的可行性。方法:将18只6月龄新西兰白兔随机分为两组,均摘除L4/5椎间盘髓核,A组在椎间植入环状聚乳酸-聚羟基乙酸(poly L-lactic-co-glycolic-acid,PLGA)可吸收支架;B组单纯髓核摘除。于术前、术后4周、12周行X线检查,运用Image J软件测量椎间盘高度指数(DHI)并计算其百分数(%DHI),分别于术后4周、8周、12周处死3只动物,行组织病理及免疫组化观察。结果:1只动物死亡,17只实验动物术后存活至预期时间,未补充实验动物。12周时,侧位X线片示两组椎间高度较术前均有下降,两组椎间高度的差异有统计学意义(P<0.05),A、B两组屈伸活动度与术前相比差异均无统计学意义(P>0.05)。X线片显示A组手术节段椎体无明显移位及反向成角,B组1只兔子出现前屈位腰椎后凸曲度增加,手术节段椎间隙变窄并邻近软骨终板钙化。细胞组织学观察:术后4周时A组见新生血管及纤维组织生成,有少量类软骨细胞出现,未观察到PLGA支架结构;B组见较多纤维细胞生成。术后8周时,A组出现软骨细胞,纤维组织排列不规则,并见少量的胶原纤维及成纤维细胞;B组纤维组织进一步增生,形成瘢痕样组织。术后12周时,A组大量的胶原纤维、软骨组织交互长入,排列杂乱无序,此时的胶原纤维较8周时增多;B组仍为纤维细胞和瘢痕组织,且Ⅰ型胶原表达高于Ⅱ型胶原。结论:椎体间植入PLGA并利用其与椎体骨髓血的诱导成骨作用短期内可以形成椎间纤维融合;短期内观察椎间纤维融合能够维持一定的脊柱节段稳定性并保留部分生理活动功能,但中远期效果有待进一步观察。